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Khogali R, Bastos A, Bargul JL, Getange D, Kabii J, Masiga D, Villinger J. Tissue-specific localization of tick-borne pathogens in ticks collected from camels in Kenya: insights into vector competence. Front Cell Infect Microbiol 2024; 14:1382228. [PMID: 38698904 PMCID: PMC11063324 DOI: 10.3389/fcimb.2024.1382228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 03/15/2024] [Indexed: 05/05/2024] Open
Abstract
Background Tick-borne pathogen (TBP) surveillance studies often use whole-tick homogenates when inferring tick-pathogen associations. However, localized TBP infections within tick tissues (saliva, hemolymph, salivary glands, and midgut) can inform pathogen transmission mechanisms and are key to disentangling pathogen detection from vector competence. Methods We screened 278 camel blood samples and 504 tick tissue samples derived from 126 camel ticks sampled in two Kenyan counties (Laikipia and Marsabit) for Anaplasma, Ehrlichia, Coxiella, Rickettsia, Theileria, and Babesia by PCR-HRM analysis. Results Candidatus Anaplasma camelii infections were common in camels (91%), but absent in all samples from Rhipicephalus pulchellus, Amblyomma gemma, Hyalomma dromedarii, and Hyalomma rufipes ticks. We detected Ehrlichia ruminantium in all tissues of the four tick species, but Rickettsia aeschlimannii was only found in Hy. rufipes (all tissues). Rickettsia africae was highest in Am. gemma (62.5%), mainly in the hemolymph (45%) and less frequently in the midgut (27.5%) and lowest in Rh. pulchellus (29.4%), where midgut and hemolymph detection rates were 17.6% and 11.8%, respectively. Similarly, in Hy. dromedarii, R. africae was mainly detected in the midgut (41.7%) but was absent in the hemolymph. Rickettsia africae was not detected in Hy. rufipes. No Coxiella, Theileria, or Babesia spp. were detected in this study. Conclusions The tissue-specific localization of R. africae, found mainly in the hemolymph of Am. gemma, is congruent with the role of this tick species as its transmission vector. Thus, occurrence of TBPs in the hemolymph could serve as a predictor of vector competence of TBP transmission, especially in comparison to detection rates in the midgut, from which they must cross tissue barriers to effectively replicate and disseminate across tick tissues. Further studies should focus on exploring the distribution of TBPs within tick tissues to enhance knowledge of TBP epidemiology and to distinguish competent vectors from dead-end hosts.
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Affiliation(s)
- Rua Khogali
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
- Department of Parasitology, Faculty of Veterinary Medicine, University of Khartoum, Khartoum North, Sudan
| | - Armanda Bastos
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
- Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa
| | - Joel L. Bargul
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Dennis Getange
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- School of Life Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - James Kabii
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Daniel Masiga
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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Kiplagat S, Villinger J, Kigen CK, Kidambasi KO, Muema JM, Mwangi SM, Wangari M, Matoke-Muhia D, Masiga DK, Bargul JL. Discovery of the vector of visceral leishmaniasis, Phlebotomus ( Artemievus) alexandri Sinton, 1928, in Kenya suggests complex transmission dynamics. Curr Res Parasitol Vector Borne Dis 2023; 4:100134. [PMID: 37593661 PMCID: PMC10428034 DOI: 10.1016/j.crpvbd.2023.100134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/12/2023] [Accepted: 07/21/2023] [Indexed: 08/19/2023]
Abstract
Visceral and cutaneous leishmaniasis are endemic to specific regions due to the ecological preferences of phlebotomine sand flies and Leishmania spp. transmission. Sand fly entomological data in northern Kenya are scarce due to limited studies and neglect of leishmaniasis. The aim of this study was to investigate: (i) sand fly diversity and distribution; (ii) occurrence of Leishmania DNA within sand flies; and (iii) blood-meal sources of sand flies in Laisamis, northern Kenya. We conducted an entomological survey during February and March of 2021 in five areas of Laisamis sub-county using standard CDC light traps. A total of 1009 sand flies (394 male and 615 female) were morphologically identified, and representative samples verified by PCR amplification and sequencing of the cytochrome c oxidase subunit 1 (cox1) gene. Similarly, we identified blood-meal sources and Leishmania DNA in female sand flies by PCR amplicon sequencing of the vertebrate cytochrome b (cyt b) gene and internal transcribed spacer 1 (ITS1) of the 28S rRNA gene, respectively. Sergentomyia clydei (59.8%) was the most abundant sand fly species. Though collected mainly from one locality (Tirgamo), 14.8% of samples belonged to Phlebotomus (Artemievus) alexandri Sinton, 1928. We detected DNA of Leishmania major in 5.19% of Ph. alexandri, whereas Leishmania adleri DNA was detected in S. clydei (7.51%), Sergentomyia squamipleuris (8.00%), and Sergentomyia africanus (8.33%). Nine of 13 blood-fed sand flies had obtained blood from humans, of which 33.3% had L. major DNA. Both Ph. alexandri and S. clydei primarily fed on humans and could potentially be involved in the transmission of cutaneous leishmaniasis. The findings of this study contribute to the understanding of sand fly vector populations and their potential to transmit leishmaniasis in the area.
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Affiliation(s)
- Steve Kiplagat
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
| | - Collins K. Kigen
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
| | - Kevin O. Kidambasi
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, P.O. Box 62000-00200, Kenya
- Institute for Immunology and Infection Research, School of Biological Science, University of Edinburgh, Edinburgh, UK
| | - Jackson M. Muema
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, P.O. Box 62000-00200, Kenya
| | - Stephie M. Mwangi
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
| | - Maureen Wangari
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
| | - Damaris Matoke-Muhia
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
- Centre for Biotechnology Research and Development, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
| | - Daniel K. Masiga
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
| | - Joel L. Bargul
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, P.O. Box 62000-00200, Kenya
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Gashururu RS, Maingi N, Githigia SM, Getange DO, Ntivuguruzwa JB, Habimana R, Cecchi G, Gashumba J, Bargul JL, Masiga DK. Trypanosomes infection, endosymbionts, and host preferences in tsetse flies ( Glossina spp.) collected from Akagera park region, Rwanda: A correlational xenomonitoring study. One Health 2023; 16:100550. [PMID: 37363264 PMCID: PMC10288097 DOI: 10.1016/j.onehlt.2023.100550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 04/10/2023] [Accepted: 04/21/2023] [Indexed: 06/28/2023] Open
Abstract
Akagera National Park and its surroundings are home to tsetse flies and a number of their mammalian hosts in Rwanda. A One-health approach is being used in the control and surveillance of both animal and human trypanosomosis in Rwanda. Determination of the infection level in tsetse flies, species of trypanosomes circulating in vectors, the source of tsetse blood meal and endosymbionts is crucial in understanding the epidemiology of the disease in animals and humans in the region. Tsetse flies (n = 1101), comprising Glossina pallidipes (n = 771) and Glossina morsitans centralis (n = 330) were collected from Akagera park and surrounding areas between May 2018 and June 2019. The flies were screened for trypanosomes, vertebrate host DNA to identify sources of blood meal, and endosymbionts by PCR - High Resolution Melting analysis and amplicon sequencing. The feeding frequency and the feeding indices (selection index - W) were calculated to identify the preferred hosts. An overall trypanosome infection rate of 13.9% in the fly's Head and Proboscis (HP) and 24.3% in the Thorax and Abdomen (TA) were found. Eight trypanosome species were identified in the tsetse fly HP and TA, namely: Trypanosoma (T.) brucei brucei, T. congolense Kilifi, T. congolense savannah, T. vivax, T. simiae, T. evansi, T. godfreyi, T. grayi and T. theileri. We found no evidence of human-infective T. brucei rhodesiense. We also identified eighteen species of vertebrate hosts that tsetse flies fed on, and the most frequent one was the buffalo (Syncerus caffer) (36.5%). The frequently detected host by selection index was the rhinoceros (Diceros bicornis) (W = 16.2). Most trypanosome infections in tsetse flies were associated with the buffalo blood meal. The prevalence of tsetse endosymbionts Sodalis and Wolbachia was 2.8% and 4.8%, respectively. No Spiroplasma and Salivary Gland Hypertrophy Virus were detected. These findings implicate the buffaloes as the important reservoirs of tsetse-transmitted trypanosomes in the area. This contributes to predicting the main cryptic reservoirs and therefore guiding the effective control of the disease. The study findings provide the key scientific information that supports the current One Health collaboration in the control and surveillance of tsetse-transmitted trypanosomosis in Rwanda.
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Affiliation(s)
- Richard S Gashururu
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
- School of Veterinary Medicine, University of Rwanda, P.O. Box 57, Nyagatare, Rwanda
| | - Ndichu Maingi
- Faculty of Veterinary Medicine, University of Nairobi, P.O. Box 29053, Nairobi, Kenya
| | - Samuel M Githigia
- Faculty of Veterinary Medicine, University of Nairobi, P.O. Box 29053, Nairobi, Kenya
| | - Dennis O Getange
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
| | - Jean B Ntivuguruzwa
- School of Veterinary Medicine, University of Rwanda, P.O. Box 57, Nyagatare, Rwanda
| | - Richard Habimana
- Food and Drugs Assessment and Registration Department, Rwanda Food and Drugs Authority (FDA), P.O Box 1948, Kigali, Rwanda
| | - Giuliano Cecchi
- Food and Agriculture Organization of the United Nations (FAO), Animal Production and Health Division, Rome, Italy
| | | | - Joel L Bargul
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya
| | - Daniel K Masiga
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
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Muema JM, Mutunga JM, Obonyo MA, Getahun MN, Mwakubambanya RS, Akala HM, Cheruiyot AC, Yeda RA, Juma DW, Andagalu B, Johnson JL, Roth AL, Bargul JL. Isoliensinine from Cissampelos pariera rhizomes exhibits potential gametocytocidal and anti-malarial activities against Plasmodium falciparum clinical isolates. Malar J 2023; 22:161. [PMID: 37208735 DOI: 10.1186/s12936-023-04590-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 05/15/2023] [Indexed: 05/21/2023] Open
Abstract
BACKGROUND The unmet demand for effective malaria transmission-blocking agents targeting the transmissible stages of Plasmodium necessitates intensive discovery efforts. In this study, a bioactive bisbenzylisoquinoline (BBIQ), isoliensinine, from Cissampelos pariera (Menispermaceae) rhizomes was identified and characterized for its anti-malarial activity. METHODS Malaria SYBR Green I fluorescence assay was performed to evaluate the in vitro antimalarial activity against D6, Dd2, and F32-ART5 clones, and immediate ex vivo (IEV) susceptibility for 10 freshly collected P. falciparum isolates. To determine the speed- and stage-of-action of isoliensinine, an IC50 speed assay and morphological analyses were performed using synchronized Dd2 asexuals. Gametocytocidal activity against two culture-adapted gametocyte-producing clinical isolates was determined using microscopy readouts, with possible molecular targets and their binding affinities deduced in silico. RESULTS Isoliensinine displayed a potent in vitro gametocytocidal activity at mean IC50gam values ranging between 0.41 and 0.69 µM for Plasmodium falciparum clinical isolates. The BBIQ compound also inhibited asexual replication at mean IC50Asexual of 2.17 µM, 2.22 µM, and 2.39 µM for D6, Dd2 and F32-ART5 respectively, targeting the late-trophozoite to schizont transition. Further characterization demonstrated a considerable immediate ex vivo potency against human clinical isolates at a geometric mean IC50IEV = 1.433 µM (95% CI 0.917-2.242). In silico analyses postulated a probable anti-malarial mechanism of action by high binding affinities for four mitotic division protein kinases; Pfnek1, Pfmap2, Pfclk1, and Pfclk4. Additionally, isoliensinine was predicted to possess an optimal pharmacokinetics profile and drug-likeness properties. CONCLUSION These findings highlight considerable grounds for further exploration of isoliensinine as an amenable scaffold for malaria transmission-blocking chemistry and target validation.
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Affiliation(s)
- Jackson M Muema
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya.
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya.
| | - James M Mutunga
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
- Department of Biological Sciences, School of Pure and Applied Sciences, Mount Kenya University, Thika, Kenya
- School of Engineering Design, Technology and Professional Programs, Pennsylvania State University, University Park, PA, 16802, USA
| | - Meshack A Obonyo
- Department of Biochemistry and Molecular Biology, Egerton University, Egerton, Kenya
| | - Merid N Getahun
- International Centre of Insect Physiology and Ecology (Icipe), Nairobi, Kenya
| | | | - Hoseah M Akala
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Agnes C Cheruiyot
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Redemptah A Yeda
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Dennis W Juma
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Ben Andagalu
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Jaree L Johnson
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Amanda L Roth
- U.S. Army Medical Research Directorate-Africa (USAMRD-A), Centre for Global Health Research (CGHR), Kenya Medical Research Institute (KEMRI), Kisumu, Kenya
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya.
- International Centre of Insect Physiology and Ecology (Icipe), Nairobi, Kenya.
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Nakakaawa L, Gbala ID, Cheseto X, Bargul JL, Wesonga JM. Oral acute, sub-acute toxicity and phytochemical profile of Brassica carinata A. Braun microgreens ethanolic extract in Wistar rats. J Ethnopharmacol 2023; 305:116121. [PMID: 36599374 DOI: 10.1016/j.jep.2022.116121] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/24/2022] [Accepted: 12/27/2022] [Indexed: 06/17/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Currently, there is a remarkable increase in the consumption of microgreens, (young edible vegetables or herbs), as potential nutraceuticals for the management of diseases. Brassica carinata A. Braun is one of the traditional leafy vegetables cultivated in various parts of Sub- Saharan Africa. The plant is revered for its efficacy in the treatment of wounds and gastrointestinal disorders among other medicinal benefits. It is therefore crucial to characterize Brassica carinata microgreens for their phytoconstituents and ascertain their safety for use. AIM OF THE STUDY The study evaluated the oral acute and subacute toxicity of Brassica carinata microgreens ethanol extract (BMEE) in Wistar rats and identification of its chemical composition and profile. MATERIALS AND METHODS For acute toxicity (14 days), rats were grouped into four and received a single oral dose, the control group received distilled water, while others received 500 mg/kg, 1000 mg/kg, and 2000 mg/kg of BMEE. For the subacute toxicity (28 days), rats in four groups received daily doses of 250 mg/kg, 500 mg/kg or 1000 mg/kg and distilled water. Daily clinical observations like lethargy and mortality were conducted. Hematological, biochemical, and histopathological evaluations were performed at the end of each experiment. Phytochemical profile was determined using a UV-VIS spectrophotometer and Gas Chromatography coupled to Mass Spectrometry (GC-MS) analysis determined the potential bioactive components in the microgreens extract. RESULTS In both acute and sub-acute toxicity studies, no mortalities, indications of abnormality, or any treatment related adverse effects were observed at doses of 2000 mg/kg, 1000 mg/kg, 500 mg/kg, and 250 mg/kg. The LD50 of BMEE was above 2000 mg/kg. No significant (p > 0.05) changes in the hematological and biochemical parameters of the treated groups compared to the control groups in both studies. Histopathological examination of the liver, kidney, lungs, and heart revealed a normal architecture of the tissues in all the treated animals. Phytochemical analyses revealed the presence of flavonoids (most abundant), phenols and alkaloids. Phytol, linoleic acid, and 9,12,15-octadecatrienoic acid, among other compounds, were identified by GC-MS analysis. CONCLUSION The results showed that B. carinata microgreens ethanol extract is nontoxic and found to have several compounds with reported pharmacological significance suggesting safety for use.
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Affiliation(s)
- Lilian Nakakaawa
- Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic, Sciences Technology, and Innovation (PAUSTI), Juja, Kenya.
| | - Ifeoluwa D Gbala
- Department of Molecular Biology and Biotechnology, Pan African University Institute for Basic, Sciences Technology, and Innovation (PAUSTI), Juja, Kenya.
| | - Xavier Cheseto
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya.
| | - Joel L Bargul
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya; Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Juja, Kenya.
| | - John M Wesonga
- Department of Horticulture and Food Security, JKUAT, Juja, Kenya.
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Makori TO, Bargul JL, Lambisia AW, Mwanga MJ, Murunga N, de Laurent ZR, Lewa CS, Mutunga M, Kellam P, Cotten M, Nokes DJ, Phan M, Agoti CN. Genomic epidemiology of the rotavirus G2P[4] strains in coastal Kenya pre- and post-rotavirus vaccine introduction, 2012-8. Virus Evol 2023; 9:vead025. [PMID: 37207000 PMCID: PMC10190042 DOI: 10.1093/ve/vead025] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 03/07/2023] [Accepted: 04/14/2023] [Indexed: 05/21/2023] Open
Abstract
The introduction of rotavirus vaccines into the national immunization programme in many countries has led to a decline in childhood diarrhoea disease burden. Coincidentally, the incidence of some rotavirus group A (RVA) genotypes has increased, which may result from non-vaccine-type replacement. Here, we investigate the evolutionary genomics of rotavirus G2P[4] which has shown an increase in countries that introduced the monovalent Rotarix® vaccine. We examined sixty-three RVA G2P[4] strains sampled from children (aged below 13 years) admitted to Kilifi County Hospital, coastal Kenya, pre- (2012 to June 2014) and post-(July 2014 to 2018) rotavirus vaccine introduction. All the sixty-three genome sequences showed a typical DS-1-like genome constellation (G2-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2). Pre-vaccine G2 sequences predominantly classified as sub-lineage IVa-3 and co-circulated with low numbers of sub-lineage IVa-1 strains, whereas post-vaccine G2 sequences mainly classified into sub-lineage IVa-3. In addition, in the pre-vaccine period, P[4] sub-lineage IVa strains co-circulated with low numbers of P[4] lineage II strains, but P[4] sub-lineage IVa strains predominated in the post-vaccine period. On the global phylogeny, the Kenyan pre- and post-vaccine G2P[4] strains clustered separately, suggesting that different virus populations circulated in the two periods. However, the strains from both periods exhibited conserved amino acid changes in the known antigenic epitopes, suggesting that replacement of the predominant G2P[4] cluster was unlikely a result of immune escape. Our findings demonstrate that the pre- and post-vaccine G2P[4] strains circulating in Kilifi, coastal Kenya, differed genetically but likely were antigenically similar. This information informs the discussion on the consequences of rotavirus vaccination on rotavirus diversity.
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Affiliation(s)
| | | | | | - Mike J Mwanga
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
| | - Nickson Murunga
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
| | - Zaydah R de Laurent
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
| | - Clement S Lewa
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
| | - Martin Mutunga
- Epidemiology and Demography Department Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Off Hospital Road, P.O BOX 230-80108, Kilifi, Kenya
| | - Paul Kellam
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, Exhibition Road, London SW7 2AZ, UK
- Kymab Ltd, The Bennet Building (B930), Babraham Research Campus, Cambridge CB22 3AT, UK
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Ndotono EW, Khamis FM, Bargul JL, Tanga CM. Gut microbiota shift in layer pullets fed on black soldier fly larvae-based feeds towards enhancing healthy gut microbial community. Sci Rep 2022; 12:16714. [PMID: 36202892 PMCID: PMC9537291 DOI: 10.1038/s41598-022-20736-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 09/19/2022] [Indexed: 12/03/2022] Open
Abstract
Globally, most gut microbiota-related studies have focused on broilers due to their diverse microbial communities compared to that of layer chicken. However, in Africa few studies have been undertaken despite the increasing benefits to the poultry industry. The utilization of Insect-Based diets to improve the gastrointestinal function and gut health in poultry is increasingly gaining global attention. Here, we evaluated the potential roles of commercial black soldier fly larvae-based feeds (BSFLF) in reshaping the abundance, composition and diversity of the gut microbiota of layer chickens using high throughput Oxford nanopore Minion sequencing of the full length bacterial 16S rRNA gene. Two hundred and fifty ISA Brown layer chicks were reared in pens for a period of 20 weeks. The layer pullets were allotted 5 dietary treatments that were formulated as follows: control diet (T1): 100% FM + 0% BSFL, T2: 25% BSFL + 75% FM; T3: 50% BSFL + 50% FM; T4: 75% BSFL + 25% FM, and T5: 100% BSFL + 0% FM. Sampling was done from the eight major regions including oesophagus, crop, proventriculus, gizzard, duodenum, ileum, large intestines and ceca. Out of the 400,064 classified reads analyzed, the most dominant phyla identified across the feed treatments were Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria. The diet treatment with 100% inclusion levels of BSFL showed the highest intra-species alpha diversity and richness according to Chao1 and Shannon index. Intra-species beta diversity assessment revealed that the diet types significantly influenced the abundance of the microbiota, but differences between most abundant taxa were similar. There was increase in abundance of potentially beneficial bacteria (Lactobacillus, Bacteroides and Enterococcus) with increased inclusion levels of BSFLF in layer pullets diets. Across the different gut segments, Lactobacillus dominated all the eight regions and the ceca was the most diverse segment. Our findings unravel complex gut microbial shift in laying hen fed BSFLF and therefore underpins the potential roles of beneficial bacteria as promising prebiotics and probiotics in reshaping of the gut microbiota to maintain good gut health.
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Affiliation(s)
- Evalyne W Ndotono
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya.,Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Fathiya M Khamis
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya.
| | - Joel L Bargul
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya.,Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Chrysantus M Tanga
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya
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Muema JM, Bargul JL, Obonyo MA, Njeru SN, Matoke-Muhia D, Mutunga JM. Contemporary exploitation of natural products for arthropod-borne pathogen transmission-blocking interventions. Parasit Vectors 2022; 15:298. [PMID: 36002857 PMCID: PMC9404607 DOI: 10.1186/s13071-022-05367-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 06/16/2022] [Indexed: 11/26/2022] Open
Abstract
An integrated approach to innovatively counter the transmission of various arthropod-borne diseases to humans would benefit from strategies that sustainably limit onward passage of infective life cycle stages of pathogens and parasites to the insect vectors and vice versa. Aiming to accelerate the impetus towards a disease-free world amid the challenges posed by climate change, discovery, mindful exploitation and integration of active natural products in design of pathogen transmission-blocking interventions is of high priority. Herein, we provide a review of natural compounds endowed with blockade potential against transmissible forms of human pathogens reported in the last 2 decades from 2000 to 2021. Finally, we propose various translational strategies that can exploit these pathogen transmission-blocking natural products into design of novel and sustainable disease control interventions. In summary, tapping these compounds will potentially aid in integrated combat mission to reduce disease transmission trends.
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Affiliation(s)
- Jackson M Muema
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), P.O. Box 62000, Nairobi, 00200, Kenya.
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), P.O. Box 62000, Nairobi, 00200, Kenya.,International Centre of Insect Physiology and Ecology (Icipe), P.O. Box 30772, Nairobi, 00100, Kenya
| | - Meshack A Obonyo
- Department of Biochemistry and Molecular Biology, Egerton University, P.O. Box 536, Egerton, 20115, Kenya
| | - Sospeter N Njeru
- Centre for Traditional Medicine and Drug Research (CTMDR), Kenya Medical Research Institute (KEMRI), P.O. Box 54840, Nairobi, 00200, Kenya
| | - Damaris Matoke-Muhia
- Centre for Biotechnology Research Development (CBRD), Kenya Medical Research Institute (KEMRI), P.O. Box 54840, Nairobi, 00200, Kenya
| | - James M Mutunga
- Department of Biological Sciences, Mount Kenya University (MKU), P.O. Box 54, Thika, 01000, Kenya.,School of Engineering Design, Technology and Professional Programs, Pennsylvania State University, University Park, PA, 16802, USA
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9
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Gbala ID, Macharia RW, Bargul JL, Magoma G. Membrane Permeabilization and Antimicrobial Activity of Recombinant Defensin-d2 and Actifensin against Multidrug-Resistant Pseudomonas aeruginosa and Candida albicans. Molecules 2022; 27:molecules27144325. [PMID: 35889198 PMCID: PMC9317813 DOI: 10.3390/molecules27144325] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 06/18/2022] [Accepted: 06/22/2022] [Indexed: 12/10/2022] Open
Abstract
Antimicrobial resistance requires urgent efforts towards the discovery of active antimicrobials, and the development of strategies to sustainably produce them. Defensin and defensin-like antimicrobial peptides (AMPs) are increasingly gaining pharmacological interest because of their potency against pathogens. In this study, we expressed two AMPs: defensin-d2 derived from spinach, and defensin-like actifensin from Actinomyces ruminicola. Recombinant pTXB1 plasmids carrying the target genes encoding defensin-d2 and actifensin were generated by the MEGAWHOP cloning strategy. Each AMP was first expressed as a fusion protein in Escherichia coli, purified by affinity chromatography, and was thereafter assayed for antimicrobial activity against multidrug-resistant (MDR) pathogens. Approximately 985 µg/mL and 2895 µg/mL of recombinant defensin-d2 and actifensin, respectively, were recovered with high purity. An analysis by MALDI-TOF MS showed distinct peaks corresponding to molecular weights of approximately 4.1 kDa for actifensin and 5.8 kDa for defensin-d2. An in vitro antimicrobial assay showed that MDR Pseudomonas aeruginosa and Candida albicans were inhibited at minimum concentrations of 7.5 µg/mL and 23 µg/mL for recombinant defensin-d2 and actifensin, respectively. The inhibitory kinetics of the peptides revealed cidal activity within 4 h of the contact time. Furthermore, both peptides exhibited an antagonistic interaction, which could be attributed to their affinities for similar ligands, as deduced by peptide–ligand profiling. Moreover, both peptides inhibited biofilm formation, and they exhibited no resistance potential and low hemolytic activity. The peptides also possess the ability to permeate and disrupt the cell membranes of MDR P. aeruginosa and C. albicans. Therefore, recombinant actifensin and defensin-d2 exhibit broad-spectrum antimicrobial activity and have the potential to be used as therapy against MDR pathogens.
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Affiliation(s)
- Ifeoluwa D. Gbala
- Molecular Biology and Biotechnology, Institute for Basic Sciences, Technology and Innovation, Pan African University, Nairobi P.O. Box 62000-00200, Kenya;
- Correspondence:
| | - Rosaline W. Macharia
- Centre for Biotechnology and Bioinformatics, University of Nairobi, Nairobi P.O. Box 30197-00100, Kenya;
| | - Joel L. Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi P.O. Box 62000-00200, Kenya;
- International Centre of Insect Physiology and Ecology, Nairobi P.O. Box 30772-00100, Kenya
| | - Gabriel Magoma
- Molecular Biology and Biotechnology, Institute for Basic Sciences, Technology and Innovation, Pan African University, Nairobi P.O. Box 62000-00200, Kenya;
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi P.O. Box 62000-00200, Kenya;
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10
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Ndotono EW, Khamis FM, Bargul JL, Tanga CM. Insights into the Gut Microbial Communities of Broiler Chicken Fed Black Soldier Fly Larvae-Desmodium-Based Meal as a Dietary Protein Source. Microorganisms 2022; 10:microorganisms10071351. [PMID: 35889070 PMCID: PMC9319420 DOI: 10.3390/microorganisms10071351] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 06/30/2022] [Accepted: 07/01/2022] [Indexed: 11/16/2022] Open
Abstract
The utilization of insect-based diets to improve gastrointestinal function and gut health in poultry is gaining global attention as a promising feed additive. The objective of this study was to determine the optimal inclusion level of the full-fat black soldier fly larvae (BSFL) and Desmodium intortum (DI) in broiler chicken diets and to evaluate their impact on the microbial community in the gut. The bacterial communities were characterized using Oxford nanopore sequencing of the full-length bacterial 16S rRNA gene. Four dietary treatments, T1 (25% DI + 75% BSFL), T2 (50% DI + 50% BSFL), T3 (75% DI + 25% BSFL) and T4 (100% fishmeal + 0% DI + BSFL), were fed to the broiler chickens for a period of 42 days. Out of the 395,034 classified reads analyzed, the most predominant phyla identified across all the four dietary treatments were Firmicutes (94%), Bacteroidetes (3%), and Proteobacteria (2%). The T1 diet showed the highest alpha diversity and richness according to the Chao1 and Shannon indices. Beta diversity assessment revealed a significant influence of diet on the abundance of the microbiome. There was an increase in beneficial lactic acid bacteria with increasing inclusion of BSFL in the diets. Our findings strongly support the inclusion of BSFL into poultry diet as a promising protein source to reshape the gut microbiota for improved gut health, immune response, and food safety.
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Affiliation(s)
- Evalyne W. Ndotono
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi P.O. Box 30772-00100, Kenya; (E.W.N.); (J.L.B.); (C.M.T.)
| | - Fathiya M. Khamis
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi P.O. Box 30772-00100, Kenya; (E.W.N.); (J.L.B.); (C.M.T.)
- Correspondence: ; Tel.: +254-7-1372-6325
| | - Joel L. Bargul
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi P.O. Box 30772-00100, Kenya; (E.W.N.); (J.L.B.); (C.M.T.)
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Kiambu P.O. Box 62000-00200, Kenya
| | - Chrysantus M. Tanga
- International Centre of Insect Physiology and Ecology (ICIPE), Nairobi P.O. Box 30772-00100, Kenya; (E.W.N.); (J.L.B.); (C.M.T.)
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11
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Kegode TM, Bargul JL, Mokaya HO, Lattorff HMG. Phytochemical composition and bio-functional properties of Apis mellifera propolis from Kenya. R Soc Open Sci 2022; 9:211214. [PMID: 35911197 DOI: 10.6084/m9.figshare.c.6080792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 06/13/2022] [Indexed: 05/25/2023]
Abstract
There is an increased demand for natural products like propolis, yet little information is available about the chemical composition of African propolis and its bio-functional properties. Therefore, in this study, we aimed to quantify the phytochemicals and determine the antioxidant and antimicrobial properties of Apis mellifera propolis (n = 59) sourced from various regions in Kenya. Principal component analysis (PCA) showed that the sampling region had a remarkable impact on the propolis's composition and bio-functional properties. Generally, the propolis contained high amounts of phytochemicals, particularly alkaloids (5.76 g CE/100 g) and phenols (2.24 g GAE/100 g). Furthermore, analysis of propolis by gas chromatography-mass spectrometry (GC-MS) revealed various compounds with varying bio-functional activities. These compounds included triterpenoids alpha- and beta-amyrin, oleanen-3-yl-acetate, urs-12-en-24-oic acid, lanosta-8,24-dien-3-one, and hydrocarbons tricosane and nondecane, which have been reported to have either antimicrobial or antioxidant activities. The propolis samples collected from hotter climatic conditions contained a higher composition of phytochemicals, and additionally, they displayed higher antioxidant and antimicrobial activities than those obtained from cooler climatic conditions. Key findings of this study demonstrate the occurrence of relatively high phytochemical content in Kenya's propolis, which has antioxidant and antimicrobial properties; hence this potential could be harnessed for disease control.
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Affiliation(s)
- Timothy M Kegode
- International Centre of Insect Physiology and Ecology (icipe), PO Box 30772-00100, Nairobi, Kenya
- Biochemistry Department, Jomo Kenyatta University of Agriculture and Technology, PO Box 62000-00200, Nairobi, Kenya
| | - Joel L Bargul
- International Centre of Insect Physiology and Ecology (icipe), PO Box 30772-00100, Nairobi, Kenya
- Biochemistry Department, Jomo Kenyatta University of Agriculture and Technology, PO Box 62000-00200, Nairobi, Kenya
| | - Hosea O Mokaya
- International Centre of Insect Physiology and Ecology (icipe), PO Box 30772-00100, Nairobi, Kenya
| | - H Michael G Lattorff
- International Centre of Insect Physiology and Ecology (icipe), PO Box 30772-00100, Nairobi, Kenya
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12
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Kegode TM, Bargul JL, Mokaya HO, Lattorff HMG. Phytochemical composition and bio-functional properties of Apis mellifera propolis from Kenya. R Soc Open Sci 2022; 9:211214. [PMID: 35911197 PMCID: PMC9326266 DOI: 10.1098/rsos.211214] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 06/13/2022] [Indexed: 05/10/2023]
Abstract
There is an increased demand for natural products like propolis, yet little information is available about the chemical composition of African propolis and its bio-functional properties. Therefore, in this study, we aimed to quantify the phytochemicals and determine the antioxidant and antimicrobial properties of Apis mellifera propolis (n = 59) sourced from various regions in Kenya. Principal component analysis (PCA) showed that the sampling region had a remarkable impact on the propolis's composition and bio-functional properties. Generally, the propolis contained high amounts of phytochemicals, particularly alkaloids (5.76 g CE/100 g) and phenols (2.24 g GAE/100 g). Furthermore, analysis of propolis by gas chromatography-mass spectrometry (GC-MS) revealed various compounds with varying bio-functional activities. These compounds included triterpenoids alpha- and beta-amyrin, oleanen-3-yl-acetate, urs-12-en-24-oic acid, lanosta-8,24-dien-3-one, and hydrocarbons tricosane and nondecane, which have been reported to have either antimicrobial or antioxidant activities. The propolis samples collected from hotter climatic conditions contained a higher composition of phytochemicals, and additionally, they displayed higher antioxidant and antimicrobial activities than those obtained from cooler climatic conditions. Key findings of this study demonstrate the occurrence of relatively high phytochemical content in Kenya's propolis, which has antioxidant and antimicrobial properties; hence this potential could be harnessed for disease control.
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Affiliation(s)
- Timothy M. Kegode
- International Centre of Insect Physiology and Ecology (icipe), PO Box 30772-00100, Nairobi, Kenya
- Biochemistry Department, Jomo Kenyatta University of Agriculture and Technology, PO Box 62000-00200, Nairobi, Kenya
| | - Joel L. Bargul
- International Centre of Insect Physiology and Ecology (icipe), PO Box 30772-00100, Nairobi, Kenya
- Biochemistry Department, Jomo Kenyatta University of Agriculture and Technology, PO Box 62000-00200, Nairobi, Kenya
| | - Hosea O. Mokaya
- International Centre of Insect Physiology and Ecology (icipe), PO Box 30772-00100, Nairobi, Kenya
| | - H. Michael G. Lattorff
- International Centre of Insect Physiology and Ecology (icipe), PO Box 30772-00100, Nairobi, Kenya
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13
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Bargul JL, Mkwashapi DM, Namagembe I, Nakityo I, Nakimuli A, Byamugisha J, Semakula D, Seeley J, Sewankambo NK. Case studies from the experience of early career researchers in East Africa in building community engagement in research. AAS Open Res 2022; 5:13. [PMID: 38323169 PMCID: PMC10541536 DOI: 10.12688/aasopenres.13349.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2022] [Indexed: 02/08/2024] Open
Abstract
Background: In this paper, we explain how three early career researchers actively engaged community members in their health research projects in Kenya, Tanzania and Uganda, and what was learnt from the experience. The research project in Kenya was on camel trypanosomiasis and the role of camel biting keds (or louse flies) in disease transmission. The project in Tanzania looked at the effect of human immunodeficiency virus and antiretroviral therapy on fertility and ascertained the trends in the use of family planning services amongst women of reproductive age. The focus of the project in Uganda was the implementation of maternal death surveillance and the response policy to determine the cause of maternal deaths and how they might be prevented. Methods: In the three different settings, efforts to ensure local community engagement provided a focus for the researchers to hone their skills in explaining research concepts and working in partnership with community members to co-develop ideas, their research methods and outputs. Results: Involvement of communities in scientific research, which entailed a two-way mutual engagement process, led to (i) generation of new research ideas that shaped the work, (ii) strengthened mutual trust, and (iii) promoted uptake of research findings. Conclusion: Our key findings strongly support the need for considering community engagement as one of the key components in research studies.
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Affiliation(s)
- Joel L. Bargul
- Animal Health Theme, International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. Box 30772-00100, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, P.O. Box 62000-00200, Kenya
- THRiVE, c/o School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
| | - Denna M. Mkwashapi
- THRiVE, c/o School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
- National Institutes for Medical Research, Mwanza, P.O. Box 1462, Tanzania
| | - Imelda Namagembe
- THRiVE, c/o School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
- School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
- Mulago Specialized Women and Neonatal Hospital (MSWNH), Kampala, P.O Box 7272, Uganda
| | - Immaculate Nakityo
- THRiVE, c/o School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
- School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
| | - Annettee Nakimuli
- School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
| | - Josaphat Byamugisha
- School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
| | - Daniel Semakula
- THRiVE, c/o School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
- School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
| | - Janet Seeley
- THRiVE, c/o School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
- Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, WC1H 9SH, UK
| | - Nelson K. Sewankambo
- THRiVE, c/o School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
- School of Medicine, Makerere University College of Health Sciences, Kampala, P.O. Box 7072, Uganda
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Serem EK, Bargul JL, Ngari MM, Abdullahi OA, Mburu DM. Farmers' knowledge, perceptions, and practices on animal trypanosomosis and the tsetse fly vector: A cross-sectional study around Kenya's Arabuko-Sokoke Forest Reserve at the livestock-wildlife interface. Open Res Afr 2022; 5:22. [PMID: 37600566 PMCID: PMC10439355 DOI: 10.12688/openresafrica.13397.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/13/2022] [Indexed: 08/22/2023]
Abstract
Background: Animal African trypanosomosis (AAT) is a veterinary disease caused by trypanosomes transmitted cyclically by tsetse flies. AAT causes huge agricultural losses in sub-Saharan Africa. Both tsetse flies and trypanosomosis (T&T) are endemic in the study area inhabited by smallholder livestock farmers at the livestock-wildlife interface around Arabuko-Sokoke Forest Reserve (ASFR) in Kilifi County on the Kenyan coast. We assessed farmers' knowledge, perceptions and control practices towards T&T. Methods: A cross-sectional study was conducted during November and December 2017 to collect data from 404 randomly selected cattle-rearing households using a structured questionnaire. Descriptive statistics were used to determine farmers' knowledge, perceptions, and control practices towards T&T. Demographic factors associated with knowledge of T&T were assessed using a logistic regression model. Results: Participants consisted of 53% female, 77% married, 30% elderly (>55 years), and the majority (81%) had attained primary education or below. Most small-scale farmers (98%) knew the tsetse fly by its local name, and 76% could describe the morphology of the adult tsetse fly by size in comparison to the housefly's ( Musca domestica). Only 16% of the farmers knew tsetse flies as vectors of livestock diseases. Higher chances of adequate knowledge on T&T were associated with the participants' (i) age of 15-24 years (aOR 2.88 (95% CI 1.10-7.52), (ii) level of education including secondary (aOR 2.46 (95% CI 1.43-4.24)) and tertiary (aOR 3.80 (95% CI 1.54-9.37)), and (iii) employment status: self-employed farmers (aOR 6.54 (95% CI 4.36-9.80)). Conclusions: Our findings suggest that small-scale farmers around ASFR have limited knowledge of T&T. It is envisaged that efforts geared towards training of the farmers would bridge this knowledge gap and sharpen the perceptions and disease control tactics to contribute to the prevention and control of T&T.
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Affiliation(s)
- Erick K Serem
- Department of Public Health, School of Health and Human Sciences, Pwani University, Kilifi, P.O Box 195-80108 Kilifi, Kenya
- Pwani University Bioscience Research Centre (PUBReC), Pwani University, Kilifi, P.O Box 195-80108, Kenya
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, P.O Box 62000-00200, Kenya
- Animal Health Theme, International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O Box 30772-00100, Kenya
| | - Moses M Ngari
- Department of Public Health, School of Health and Human Sciences, Pwani University, Kilifi, P.O Box 195-80108 Kilifi, Kenya
- KEMRI/Wellcome Trust Research Programme, Clinical Trials Facility, Kilifi, P.O Box 230-80108, Kenya
| | - Osman A Abdullahi
- Department of Public Health, School of Health and Human Sciences, Pwani University, Kilifi, P.O Box 195-80108 Kilifi, Kenya
- Pwani University Bioscience Research Centre (PUBReC), Pwani University, Kilifi, P.O Box 195-80108, Kenya
| | - David M Mburu
- Pwani University Bioscience Research Centre (PUBReC), Pwani University, Kilifi, P.O Box 195-80108, Kenya
- Department of Biological Sciences, Pwani University, Kilifi, P.O Box 195-80108, Kenya
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15
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Mwaki DM, Kidambasi KO, Kinyua J, Ogila K, Kigen C, Getange D, Villinger J, Masiga DK, Carrington M, Bargul JL. Molecular detection of novel Anaplasma sp . and zoonotic hemopathogens in livestock and their hematophagous biting keds (genus Hippobosca) from Laisamis, northern Kenya. Open Res Afr 2022; 5:23. [PMID: 37396343 PMCID: PMC10314185 DOI: 10.12688/openresafrica.13404.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 05/13/2022] [Indexed: 07/04/2023]
Abstract
Background: Livestock are key sources of livelihood among pastoral communities. Livestock productivity is chiefly constrained by pests and diseases. Due to inadequate disease surveillance in northern Kenya, little is known about pathogens circulating within livestock and the role of livestock-associated biting keds (genus Hippobosca) in disease transmission. We aimed to identify the prevalence of selected hemopathogens in livestock and their associated blood-feeding keds. Methods: We randomly collected 389 blood samples from goats (245), sheep (108), and donkeys (36), as well as 235 keds from both goats and sheep (116), donkeys (11), and dogs (108) in Laisamis, Marsabit County, northern Kenya. We screened all samples for selected hemopathogens by high-resolution melting (HRM) analysis and sequencing of PCR products amplified using primers specific to the genera: Anaplasma, Trypanosoma, Clostridium, Ehrlichia, Brucella, Theileria, and Babesia. Results: In goats, we detected Anaplasma ovis (84.5%), a novel Anaplasma sp. (11.8%), Trypanosoma vivax (7.3%), Ehrlichia canis (66.1%), and Theileria ovis (0.8%). We also detected A. ovis (93.5%), E. canis (22.2%), and T. ovis (38.9%) in sheep. In donkeys, we detected ' Candidatus Anaplasma camelii' (11.1%), T. vivax (22.2%), E. canis (25%), and Theileria equi (13.9%). In addition, keds carried the following pathogens; goat/sheep keds - T. vivax (29.3%) , Trypanosoma evansi (0.86%), Trypanosoma godfreyi (0.86%), and E. canis (51.7%); donkey keds - T. vivax (18.2%) and E. canis (63.6%); and dog keds - T. vivax (15.7%), T. evansi (0.9%), Trypanosoma simiae (0.9%) , E. canis (76%), Clostridium perfringens (46.3%), Bartonella schoenbuchensis (76%), and Brucella abortus (5.6%). Conclusions: We found that livestock and their associated ectoparasitic biting keds carry a number of infectious hemopathogens, including the zoonotic B. abortus. Dog keds harbored the most pathogens, suggesting dogs, which closely interact with livestock and humans, as key reservoirs of diseases in Laisamis. These findings can guide policy makers in disease control.
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Affiliation(s)
- Daniel M. Mwaki
- Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. BOX 30772-00100, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, P.O. BOX 62000-00200, Kenya
- Department of Zoology, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, P.O. Box 62000-00200, Kenya
| | - Kevin O. Kidambasi
- Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. BOX 30772-00100, Kenya
| | - Johnson Kinyua
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, P.O. BOX 62000-00200, Kenya
| | - Kenneth Ogila
- Department of Zoology, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, P.O. Box 62000-00200, Kenya
| | - Collins Kigen
- Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. BOX 30772-00100, Kenya
| | - Dennis Getange
- Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. BOX 30772-00100, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, P.O. BOX 62000-00200, Kenya
| | - Jandouwe Villinger
- Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. BOX 30772-00100, Kenya
| | - Daniel K. Masiga
- Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. BOX 30772-00100, Kenya
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Joel L. Bargul
- Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology (icipe), Nairobi, P.O. BOX 30772-00100, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, P.O. BOX 62000-00200, Kenya
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16
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Collins M, Ngetich C, Owido M, Getange D, Harris R, Bargul JL, Bodha B, Njoroge D, Muloi D, Martins DJ, Villinger J, Githaka N, Baylis M, Fèvre EM, Kanduma E, Younan M, Bell-Sakyi L. Detection of Antibodies to Ehrlichia spp. in Dromedary Camels and Co-Grazing Sheep in Northern Kenya Using an Ehrlichia ruminantium Polyclonal Competitive ELISA. Microorganisms 2022; 10:microorganisms10050916. [PMID: 35630361 PMCID: PMC9144424 DOI: 10.3390/microorganisms10050916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 04/22/2022] [Accepted: 04/26/2022] [Indexed: 12/13/2022] Open
Abstract
A disease with clinical and post-mortem presentation similar to those seen in heartwater, a tick-borne disease of domestic and wild ruminants caused by the intracellular bacterium Ehrlichia ruminantium, was first reported in dromedary camels in Kenya in 2016; investigations carried out at the time to determine the cause were inconclusive. In the present study, we screened sera from Kenyan camels collected before (2015) and after (2020) the 2016 disease outbreak for antibodies to Ehrlichia spp. using an E. ruminantium polyclonal competitive ELISA (PC-ELISA). Median antibody levels were significantly higher (p < 0.0001) amongst camels originating from areas where the heartwater-like disease was reported than from disease-free areas, for animals sampled in both 2015 and 2020. Overall median seropositivity was higher in camels sampled in 2015 than in 2020, which could have been due to higher mean age in the former group. Camels that were PCR-positive for Candidatus Ehrlichia regneryi had significantly lower (p = 0.03) median antibody levels than PCR-negative camels. Our results indicate that Kenyan camels are frequently exposed to E. ruminantium from an early age, E. ruminantium was unlikely to have been the sole cause of the outbreak of heartwater-like disease; and Ca. E. regneryi does not appreciably cross-react with E. ruminantium in the PC-ELISA.
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Affiliation(s)
- Marisol Collins
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (M.C.); (R.H.); (D.M.); (M.B.); (E.M.F.)
| | - Collins Ngetich
- International Livestock Research Institute, Nairobi P.O. Box 30709-00100, Kenya; (C.N.); (M.O.); (N.G.)
| | - Milton Owido
- International Livestock Research Institute, Nairobi P.O. Box 30709-00100, Kenya; (C.N.); (M.O.); (N.G.)
| | - Dennis Getange
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi P.O. Box 62000-00200, Kenya; (D.G.); (J.L.B.)
| | - Robert Harris
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (M.C.); (R.H.); (D.M.); (M.B.); (E.M.F.)
| | - Joel L. Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi P.O. Box 62000-00200, Kenya; (D.G.); (J.L.B.)
- International Centre of Insect Physiology and Ecology, Nairobi P.O. Box 30772-00100, Kenya;
| | - Boku Bodha
- Directorate of Veterinary Services, County Government of Marsabit, Marsabit P.O. Box 384-60500, Kenya;
| | - Daniel Njoroge
- Department of Biochemistry and Molecular Biology, Faculty of Science, Egerton University, Njoro P.O. Box 536-20115, Kenya;
| | - Dishon Muloi
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (M.C.); (R.H.); (D.M.); (M.B.); (E.M.F.)
- International Livestock Research Institute, Nairobi P.O. Box 30709-00100, Kenya; (C.N.); (M.O.); (N.G.)
| | | | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology, Nairobi P.O. Box 30772-00100, Kenya;
| | - Naftaly Githaka
- International Livestock Research Institute, Nairobi P.O. Box 30709-00100, Kenya; (C.N.); (M.O.); (N.G.)
| | - Matthew Baylis
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (M.C.); (R.H.); (D.M.); (M.B.); (E.M.F.)
| | - Eric M. Fèvre
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (M.C.); (R.H.); (D.M.); (M.B.); (E.M.F.)
- International Livestock Research Institute, Nairobi P.O. Box 30709-00100, Kenya; (C.N.); (M.O.); (N.G.)
| | - Esther Kanduma
- Department of Biochemistry, Faculty of Science and Technology, University of Nairobi, Nairobi P.O. Box 30197-00100, Kenya;
| | - Mario Younan
- Food and Agriculture Organisation of the United Nations (FAO), Programme and Operational Support to Syria Crisis, UN Cross-Border Hub, Gaziantep 27010, Turkey;
| | - Lesley Bell-Sakyi
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (M.C.); (R.H.); (D.M.); (M.B.); (E.M.F.)
- Correspondence:
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Bargul JL, Mkwashapi DM, Namagembe I, Nakityo I, Nakimuli A, Byamugisha J, Semakula D, Seeley J, Sewankambo NK. Building community and public engagement in research – the experience of early career researchers in East Africa. AAS Open Res 2022. [DOI: 10.12688/aasopenres.13349.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: In this paper, we explain how three early career researchers actively engaged community members in health research in Kenya, Tanzania and Uganda in their research projects, and what was learnt from the experience. The research project in Kenya was on camel trypanosomiasis and the role of camel biting keds (or louse flies) in disease transmission. The project in Tanzania looked at the effect of human immunodeficiency virus (HIV) and antiretroviral therapy on fertility and ascertained the trends in the use of family planning services amongst women of reproductive age. The focus of the project in Uganda was the implementation of maternal death surveillance and the response policy to determine the cause of maternal deaths and how they might be prevented. Methods: In the three different settings, efforts to ensure local community engagement provided a focus for the researchers to hone their skills in explaining research concepts and working in partnership with community members to co-develop ideas, their research methods and outputs. Results: Involvement of communities in scientific research, which entailed a two-way mutual engagement process, led to (i) generation of new research ideas that shaped the work, (ii) strengthened mutual trust, and (iii) promoted uptake of research findings. Conclusions: Our key findings strongly support the need for considering community engagement as one of the key components in research studies.
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18
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Naitore C, Villinger J, Kibet CK, Kalayou S, Bargul JL, Christoffels A, Masiga DK. The developmentally dynamic microRNA transcriptome of Glossina pallidipes tsetse flies, vectors of animal trypanosomiasis. Bioinform Adv 2021; 2:vbab047. [PMID: 36699416 PMCID: PMC9710702 DOI: 10.1093/bioadv/vbab047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 11/25/2021] [Accepted: 12/24/2021] [Indexed: 01/28/2023]
Abstract
Summary MicroRNAs (miRNAs) are single stranded gene regulators of 18-25 bp in length. They play a crucial role in regulating several biological processes in insects. However, the functions of miRNA in Glossina pallidipes, one of the biological vectors of African animal trypanosomosis in sub-Saharan Africa, remain poorly characterized. We used a combination of both molecular biology and bioinformatics techniques to identify miRNA genes at different developmental stages (larvae, pupae, teneral and reproductive unmated adults, gravid females) and sexes of G. pallidipes. We identified 157 mature miRNA genes, including 12 novel miRNAs unique to G. pallidipes. Moreover, we identified 93 miRNA genes that were differentially expressed by sex and/or in specific developmental stages. By combining both miRanda and RNAhybrid algorithms, we identified 5550 of their target genes. Further analyses with the Gene Ontology term and KEGG pathways for these predicted target genes suggested that the miRNAs may be involved in key developmental biological processes. Our results provide the first repository of G. pallidipes miRNAs across developmental stages, some of which appear to play crucial roles in tsetse fly development. Hence, our findings provide a better understanding of tsetse biology and a baseline for exploring miRNA genes in tsetse flies. Availability and implementation Raw sequence data are available from NCBI Sequence Read Archives (SRA) under Bioproject accession number PRJNA590626. Supplementary information Supplementary data are available at Bioinformatics Advances online.
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Affiliation(s)
- Careen Naitore
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772, Nairobi 00100, Kenya,Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), P.O. Box 62000, Nairobi 00200, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772, Nairobi 00100, Kenya,To whom correspondence should be addressed. or
| | - Caleb K Kibet
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772, Nairobi 00100, Kenya
| | - Shewit Kalayou
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772, Nairobi 00100, Kenya
| | - Joel L Bargul
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772, Nairobi 00100, Kenya,Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), P.O. Box 62000, Nairobi 00200, Kenya
| | - Alan Christoffels
- South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute (SANBI), University of the Western Cape, Bellville 7530, South Africa
| | - Daniel K Masiga
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772, Nairobi 00100, Kenya,To whom correspondence should be addressed. or
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Gashururu S. R, Maingi N, Githigia SM, Gasana MN, Odhiambo PO, Getange DO, Habimana R, Cecchi G, Zhao W, Gashumba J, Bargul JL, Masiga DK. Occurrence, diversity and distribution of Trypanosoma infections in cattle around the Akagera National Park, Rwanda. PLoS Negl Trop Dis 2021; 15:e0009929. [PMID: 34910728 PMCID: PMC8726506 DOI: 10.1371/journal.pntd.0009929] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 01/04/2022] [Accepted: 10/19/2021] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND African Trypanosomiases threaten the life of both humans and animals. Trypanosomes are transmitted by tsetse and other biting flies. In Rwanda, the African Animal Trypanosomiasis (AAT) endemic area is mainly around the tsetse-infested Akagera National Park (NP). The study aimed to identify Trypanosoma species circulating in cattle, their genetic diversity and distribution around the Akagera NP. METHODOLOGY A cross-sectional study was carried out in four districts, where 1,037 cattle blood samples were collected. The presence of trypanosomes was determined by microscopy, immunological rapid test VerY Diag and PCR coupled with High-Resolution Melt (HRM) analysis. A parametric test (ANOVA) was used to compare the mean Packed cell Volume (PCV) and trypanosomes occurrence. The Cohen Kappa test was used to compare the level of agreement between the diagnostic methods. FINDINGS The overall prevalence of trypanosome infections was 5.6%, 7.1% and 18.7% by thin smear, Buffy coat technique and PCR/HRM respectively. Microscopy showed a low sensitivity while a low specificity was shown by the rapid test (VerY Diag). Trypanosoma (T.) congolense was found at a prevalence of 10.7%, T. vivax 5.2%, T. brucei brucei 2% and T. evansi 0.7% by PCR/HRM. This is the first report of T.evansi in cattle in Rwanda. The non-pathogenic T. theileri was also detected. Lower trypanosome infections were observed in Ankole x Friesian breeds than indigenous Ankole. No human-infective T. brucei rhodesiense was detected. There was no significant difference between the mean PCV of infected and non-infected animals (p>0.162). CONCLUSIONS Our study sheds light on the species of animal infective trypanosomes around the Akagera NP, including both pathogenic and non-pathogenic trypanosomes. The PCV estimation is not always an indication of trypanosome infection and the mechanical transmission should not be overlooked. The study confirms that the area around the Akagera NP is affected by AAT, and should, therefore, be targeted by the control activities. AAT impact assessment on cattle production and information on the use of trypanocides are needed to help policymakers prioritise target areas and optimize intervention strategies. Ultimately, these studies will allow Rwanda to advance in the Progressive Control Pathway (PCP) to reduce or eliminate the burden of AAT.
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Affiliation(s)
- Richard Gashururu S.
- School of Veterinary Medicine, University of Rwanda, Nyagatare, Rwanda
- Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Ndichu Maingi
- Faculty of Veterinary Medicine, University of Nairobi, Nairobi, Kenya
| | | | | | - Peter O. Odhiambo
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Dennis O. Getange
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Richard Habimana
- School of Veterinary Medicine, University of Rwanda, Nyagatare, Rwanda
- Rwanda Food and Drugs Authority, Kigali, Rwanda
| | - Giuliano Cecchi
- Food and Agriculture Organization of the United Nations (FAO), Animal Production and Health Division, Rome, Italy
| | - Weining Zhao
- Food and Agriculture Organization of the United Nations (FAO), Animal Production and Health Division, Rome, Italy
| | | | - Joel L. Bargul
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Daniel K. Masiga
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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20
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Muema JM, Bargul JL, Mutunga JM, Obonyo MA, Asudi GO, Njeru SN. Neurotoxic Zanthoxylum chalybeum root constituents invoke mosquito larval growth retardation through ecdysteroidogenic CYP450s transcriptional perturbations. Pestic Biochem Physiol 2021; 178:104912. [PMID: 34446188 DOI: 10.1016/j.pestbp.2021.104912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 06/24/2021] [Accepted: 06/27/2021] [Indexed: 06/13/2023]
Abstract
Intracellular effects exerted by phytochemicals eliciting insect growth-retarding responses during vector control intervention remain largely underexplored. We studied the effects of Zanthoxylum chalybeum Engl. (Rutaceae) (ZCE) root derivatives against malaria (Anopheles gambiae) and arbovirus vector (Aedes aegypti) larvae to decipher possible molecular targets. We report dose-dependent biphasic effects on larval response, with transient exposure to ZCE and its bioactive fraction (ZCFr.5) inhibiting acetylcholinesterase (AChE) activity, inducing larval lethality and growth retardation at sublethal doses. Half-maximal lethal concentrations (LC50) for ZCE against An. gambiae and Ae. aegypti larvae after 24-h exposure were 9.00 ppm and 12.26 ppm, respectively. The active fraction ZCFr.5 exerted LC50 of 1.58 ppm and 3.21 ppm for An. gambiae and Ae. aegypti larvae, respectively. Inhibition of AChE was potentially linked to larval toxicity afforded by 2-tridecanone, palmitic acid (hexadecanoic acid), linoleic acid ((Z,Z)-9,12-octadecadienoic acid), sesamin, β-caryophyllene among other compounds identified in the bioactive fraction. In addition, the phenotypic larval retardation induced by ZCE root constituents was exerted through transcriptional modulation of ecdysteroidogenic CYP450 genes. Collectively, these findings provide an explorative avenue for developing potential mosquito control agents from Z. chalybeum root constituents.
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Affiliation(s)
- Jackson M Muema
- Department of Biochemistry, Jomo Kenyatta University of Agriculture & Technology (JKUAT), Nairobi, Kenya; Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology & Ecology (icipe), Nairobi, Kenya; Department of Entomology, U.S Army Medical Research Directorate-Africa, Kenya (USAMRD-A/K), Kisumu, Kenya.
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture & Technology (JKUAT), Nairobi, Kenya; Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology & Ecology (icipe), Nairobi, Kenya
| | - James M Mutunga
- Department of Entomology, U.S Army Medical Research Directorate-Africa, Kenya (USAMRD-A/K), Kisumu, Kenya
| | - Meshack A Obonyo
- Department of Biochemistry & Molecular Biology, Egerton University, Egerton, Kenya
| | - George O Asudi
- Department of Biochemistry, Microbiology & Biotechnology, Kenyatta University, Nairobi, Kenya
| | - Sospeter N Njeru
- Centre for Traditional Medicine and Drug Research (CTMDR), Kenya Medical Research Institute (KEMRI), Nairobi, Kenya.
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21
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Bargul JL, Kidambasi KO, Getahun MN, Villinger J, Copeland RS, Muema JM, Carrington M, Masiga DK. Transmission of 'Candidatus Anaplasma camelii' to mice and rabbits by camel-specific keds, Hippobosca camelina. PLoS Negl Trop Dis 2021; 15:e0009671. [PMID: 34398891 PMCID: PMC8389426 DOI: 10.1371/journal.pntd.0009671] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 08/26/2021] [Accepted: 07/20/2021] [Indexed: 11/17/2022] Open
Abstract
Anaplasmosis, caused by infection with bacteria of the genus Anaplasma, is an important veterinary and zoonotic disease. Transmission by ticks has been characterized but little is known about non-tick vectors of livestock anaplasmosis. This study investigated the presence of Anaplasma spp. in camels in northern Kenya and whether the hematophagous camel ked, Hippobosca camelina, acts as a vector. Camels (n = 976) and > 10,000 keds were sampled over a three-year study period and the presence of Anaplasma species was determined by PCR-based assays targeting the Anaplasmataceae 16S rRNA gene. Camels were infected by a single species of Anaplasma, 'Candidatus Anaplasma camelii', with infection rates ranging from 63-78% during the dry (September 2017), wet (June-July 2018), and late wet seasons (July-August 2019). 10-29% of camel keds harbored 'Ca. Anaplasma camelii' acquired from infected camels during blood feeding. We determined that Anaplasma-positive camel keds could transmit 'Ca. Anaplasma camelii' to mice and rabbits via blood-feeding. We show competence in pathogen transmission and subsequent infection in mice and rabbits by microscopic observation in blood smears and by PCR. Transmission of 'Ca. Anaplasma camelii' to mice (8-47%) and rabbits (25%) occurred readily after ked bites. Hence, we demonstrate, for the first time, the potential of H. camelina as a vector of anaplasmosis. This key finding provides the rationale for establishing ked control programmes for improvement of livestock and human health.
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Affiliation(s)
- Joel L. Bargul
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Kevin O. Kidambasi
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Merid N. Getahun
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Robert S. Copeland
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Jackson M. Muema
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, United Kingdom
| | - Daniel K. Masiga
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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22
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Nattoh G, Maina T, Makhulu EE, Mbaisi L, Mararo E, Otieno FG, Bukhari T, Onchuru TO, Teal E, Paredes J, Bargul JL, Mburu DM, Onyango EA, Magoma G, Sinkins SP, Herren JK. Horizontal Transmission of the Symbiont Microsporidia MB in Anopheles arabiensis. Front Microbiol 2021; 12:647183. [PMID: 34394019 PMCID: PMC8355901 DOI: 10.3389/fmicb.2021.647183] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 06/24/2021] [Indexed: 12/13/2022] Open
Abstract
The recently discovered Anopheles symbiont, Microsporidia MB, has a strong malaria transmission-blocking phenotype in Anopheles arabiensis, the predominant Anopheles gambiae species complex member in many active transmission areas in eastern Africa. The ability of Microsporidia MB to block Plasmodium transmission together with vertical transmission and avirulence makes it a candidate for the development of a symbiont-based malaria transmission blocking strategy. We investigate the characteristics and efficiencies of Microsporidia MB transmission between An. arabiensis mosquitoes. We show that Microsporidia MB is not transmitted between larvae but is effectively transmitted horizontally between adult mosquitoes. Notably, Microsporidia MB was only found to be transmitted between male and female An. arabiensis, suggesting sexual horizontal transmission. In addition, Microsporidia MB cells were observed infecting the An. arabiensis ejaculatory duct. Female An. arabiensis that acquire Microsporidia MB horizontally are able to transmit the symbiont vertically to their offspring. We also investigate the possibility that Microsporidia MB can infect alternate hosts that live in the same habitats as their An. arabiensis hosts, but find no other non-anopheline hosts. Notably, Microsporidia MB infections were found in another primary malaria African vector, Anopheles funestus s.s. The finding that Microsporidia MB can be transmitted horizontally is relevant for the development of dissemination strategies to control malaria that are based on the targeted release of Microsporidia MB infected Anopheles mosquitoes.
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Affiliation(s)
- Godfrey Nattoh
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Institute for Basic Sciences Technology and Innovation, Pan African University, Nairobi, Kenya
| | - Tracy Maina
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Edward E Makhulu
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Lilian Mbaisi
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
| | - Enock Mararo
- The Royal (Dick) School of Veterinary Studies, Roslin Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Fidel G Otieno
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Tullu Bukhari
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Thomas O Onchuru
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Physical and Biological Sciences, Bomet University College, Bomet, Kenya
| | - Evan Teal
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Juan Paredes
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Joel L Bargul
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Institute for Basic Sciences Technology and Innovation, Pan African University, Nairobi, Kenya
| | - David M Mburu
- Pwani University Biosciences Research Centre (PUBReC), Kilifi, Kenya
| | | | - Gabriel Magoma
- Institute for Basic Sciences Technology and Innovation, Pan African University, Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Steven P Sinkins
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Jeremy K Herren
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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23
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Getange D, Bargul JL, Kanduma E, Collins M, Bodha B, Denge D, Chiuya T, Githaka N, Younan M, Fèvre EM, Bell-Sakyi L, Villinger J. Ticks and Tick-Borne Pathogens Associated with Dromedary Camels ( Camelus dromedarius) in Northern Kenya. Microorganisms 2021; 9:1414. [PMID: 34209060 PMCID: PMC8306667 DOI: 10.3390/microorganisms9071414] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/17/2022] Open
Abstract
Ticks and tick-borne pathogens (TBPs) are major constraints to camel health and production, yet epidemiological data on their diversity and impact on dromedary camels remain limited. We surveyed the diversity of ticks and TBPs associated with camels and co-grazing sheep at 12 sites in Marsabit County, northern Kenya. We screened blood and ticks (858 pools) from 296 camels and 77 sheep for bacterial and protozoan TBPs by high-resolution melting analysis and sequencing of PCR products. Hyalomma (75.7%), Amblyomma (17.6%) and Rhipicephalus (6.7%) spp. ticks were morphologically identified and confirmed by molecular analyses. We detected TBP DNA in 80.1% of blood samples from 296 healthy camels. "Candidatus Anaplasma camelii", "Candidatus Ehrlichia regneryi" and Coxiella burnetii were detected in both camels and associated ticks, and Ehrlichia chaffeensis, Rickettsia africae, Rickettsia aeschlimannii and Coxiella endosymbionts were detected in camel ticks. We also detected Ehrlichia ruminantium, which is responsible for heartwater disease in ruminants, in Amblyomma ticks infesting camels and sheep and in sheep blood, indicating its endemicity in Marsabit. Our findings also suggest that camels and/or the ticks infesting them are disease reservoirs of zoonotic Q fever (C. burnetii), ehrlichiosis (E. chaffeensis) and rickettsiosis (R. africae), which pose public health threats to pastoralist communities.
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Affiliation(s)
- Dennis Getange
- International Centre of Insect Physiology and Ecology (icipe), Nairobi P.O. Box 30772-00100, Kenya; (D.G.); (T.C.)
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi P.O. Box 62000-00200, Kenya
| | - Joel L. Bargul
- International Centre of Insect Physiology and Ecology (icipe), Nairobi P.O. Box 30772-00100, Kenya; (D.G.); (T.C.)
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi P.O. Box 62000-00200, Kenya
| | - Esther Kanduma
- Department of Biochemistry, School of Medicine, University of Nairobi, Nairobi P.O. Box 30197-00100, Kenya;
| | - Marisol Collins
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (M.C.); (E.M.F.); (L.B.-S.)
| | - Boku Bodha
- Directorate of Veterinary Services, County Government of Marsabit, Marsabit P.O. Box 384-60500, Kenya; (B.B.); (D.D.)
| | - Diba Denge
- Directorate of Veterinary Services, County Government of Marsabit, Marsabit P.O. Box 384-60500, Kenya; (B.B.); (D.D.)
| | - Tatenda Chiuya
- International Centre of Insect Physiology and Ecology (icipe), Nairobi P.O. Box 30772-00100, Kenya; (D.G.); (T.C.)
| | - Naftaly Githaka
- International Livestock Research Institute, Nairobi P.O. Box 30709-00100, Kenya;
| | - Mario Younan
- Food and Agriculture Organization of the United Nations (FAO), Programme & Operational Support to Syria Crisis, UN cross-border hub, Gaziantep 27010, Turkey;
| | - Eric M. Fèvre
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (M.C.); (E.M.F.); (L.B.-S.)
- International Livestock Research Institute, Nairobi P.O. Box 30709-00100, Kenya;
| | - Lesley Bell-Sakyi
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK; (M.C.); (E.M.F.); (L.B.-S.)
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), Nairobi P.O. Box 30772-00100, Kenya; (D.G.); (T.C.)
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Isebe TI, Bargul JL, Gichuki BM, Njunge JM, Tuju J, Rono MK. Molecular characterization of Plasmodium falciparum PHISTb proteins as potential targets of naturally-acquired immunity against malaria. Wellcome Open Res 2021. [DOI: 10.12688/wellcomeopenres.15919.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Plasmodium falciparum causes the deadliest form of malaria in humans. Upon infection, the host’s infected red blood cells (iRBCs) are remodelled by exported parasite proteins to provide a niche for parasite development and maturation. Methods: Here we analysed the role of three PHISTb proteins Pf3D7_0532400, Pf3D7_1401600, and Pf3D7_1102500 by expressing recombinant proteins and evaluated antibody responses against these proteins using immune sera from malaria-exposed individuals from Kenya and The Gambia in Africa. Results: Children and adults from malaria-endemic regions recognized the three PHISTb proteins. Responses against PHISTb proteins varied with malaria transmission intensity in three different geographical sites in Kenya (Siaya and Takaungu) and The Gambia (Sukuta). Antibody responses against PHISTb antigens Pf3D7_1102500 and Pf3D7_1401600 were higher in Sukuta, a low transmission region in Gambia, compared to Siaya, a high transmission region in western Kenya, unlike Pf3D7_0532400. Anti-PHIST responses indicate negative correlation between antibody levels and malaria transmission intensity for Pf3D7_1102500 and Pf3D7_1401600. We report a correlation in antibody responses between schizont and gametocyte extract, but this is not statistically significant (cor=0.102, p=0.2851, CI=95%) and, Pf3D7_0532400 (cor=0.11, p=0.249, CI=95%) and Pf3D7_1401600 (cor=0.02, p=0.7968, CI=95%). We report a negative correlation in antibody responses between schizont and Pf3D7_1102500 (cor=-0.008, p=0.9348, CI=95%). There is a correlation between gametocyte extract and Pf3D7_1401600 (cor=-0.0402, p=0.6735, CI=95%), Pf3D7_1102500 (cor=0.0758, p=0.4271, CI=95%) and Pf3D7_0532400 (cor=0.155, p=0.1028, CI=95%). Acquisition of anti-PHIST antibodies correlates with exposure to malaria for Pf3D7_0532400 (p=0.009) but not Pf3D7_1102500 and Pf3D7_1401600 (p=0.507 and p=0.15, respectively, CI=95%). Children aged below 2 years had the lowest antibody levels which do not correlate with age differences. Conclusions: Collectively, these findings provide evidence of natural immunity against PHISTb antigens that varies with level of malaria exposure and underscore their potential as possible serological markers to P. falciparum infection aimed at contributing to malaria control through vaccine development.
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Mwangi SJ, Gwela A, Mwikali K, Bargul JL, Nduati EW, Ndungu FM, Bejon P, Rayner JC, Abdi AI. Impact of Plasmodium falciparum small-sized extracellular vesicles on host peripheral blood mononuclear cells. Wellcome Open Res 2021. [DOI: 10.12688/wellcomeopenres.16131.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Exagerated immune activation has a key role in the pathogenesis of malaria. During blood-stage infection, Plasmodium falciparum can interact directly with host immune cells through infected red blood cells (PfiRBCs), or indirectly by the release of extracellular vesicles (EVs). Here, we compared the impact of PfiRBCs and P. falciparum small-sized EVs (PfsEVs, also known as exosomes) from a Kenyan clinical isolate (PfKE12) adapted to short-term laboratory culture conditions on host peripheral blood mononuclear cells (PBMC). Methods: PfsEVs were isolated from cell-free culture-conditioned media by ultracentrifugation while mature trophozoite PfiRBCs were purified by magnetic column separation. The PfsEVs and the PfiRBCs were co-cultured for 18 hours with PBMC. Cellular responses were quantified by cell surface expression of activation markers (CD25, CD69) and cytokine/chemokine levels in the supernatant. Results: Relative to negative control conditions, PfsEVs induced CD25 expression on CD4+, CD19+ and CD14+ cells, while PfiRBCs induced on CD19+ and CD14+ cells. Both PfsEVs and PfiRBCs induced CD69 on CD4+, CD8+ and CD19+ cells. In addition, PfiRBCs induced higher expression of CD69 on CD14+ cells. CD69 induced by PfiRBCs on CD4+ and CD19+ cells was significantly higher than that induced by PfsEVs. Secretion of MIP1α, MIP1β, GM-CSF, IL-6, IL-8, and TNFα were significantly induced by both PfsEVs and PfiRBCs whereas MCP-1, IL-10, IL-17α were preferentially induced by PfsEVs and IP-10 and IFN-γ by PfiRBCs. Prior exposure to malaria (judged by antibodies to schizont extract) was associated with lower monocyte responses to PfsEVs. Conclusions: PfsEVs and PfiRBCs showed differential abilities to induce secretion of IL-17α and IFN-γ, suggesting that the former are better at inducing Th17, whilst the latter induce Th1 immune responses respectively. Prior exposure to malaria significantly reduces the ability of PfsEVs to activate monocytes, suggesting immune tolerance to PfsEVs may play a role in naturally acquired anti-disease immunity.
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Tawich SK, Bargul JL, Masiga D, Getahun MN. Supplementing Blood Diet With Plant Nectar Enhances Egg Fertility in Stomoxys calcitrans. Front Physiol 2021; 12:646367. [PMID: 33859570 PMCID: PMC8042263 DOI: 10.3389/fphys.2021.646367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/25/2021] [Indexed: 11/19/2022] Open
Abstract
Stomoxys calcitrans (stable fly) is a cosmopolitan biting fly of both medical and veterinary importance. Unlike blood-feeding-related behavior of stable fly, its plant feeding, the fitness value, and the S. calcitrans-plant interaction are less understood. Here we show based on two chloroplast DNA genes, ribulose bisphosphate carboxylase large chain (rbcL) and the intergenic spacer gene trnH-psbA, that field-collected male and female stable flies fed on various plant species. We investigated the fitness cost of plant feeding using Parthenium hysterophorus, one of the plant species identified to have been fed on by the field-collected flies. Supplementation of blood feeding with a flowering P. hysterophorus plant as nectar source enhanced egg hatchability significantly as compared to blood alone, showing the fitness value of nectar supplementation. However, nectar supplementation did not affect the number of eggs laid or longevity of S. calcitrans as compared to flies that fed on blood alone. S. calcitrans maintained on sugar alone failed to lay eggs. The various plants stable flies fed on demonstrated chemodiversity with their own signature scent. The behavioral response of S. calcitrans to these signature compounds varied from strong attraction (γ-terpinene) to neutral (linalool oxide and myrcene) to repellency (butanoic acid). Our study demonstrated that stable flies feed on nectar, and plant nectar supplementation of blood feeding enhanced larval emergence. Thus, our result has implication in stable fly reproduction, survival, disease transmission, boosting laboratory colony, and the possibility of using plant-derived odors for mass trapping of stable fly, for instance, using γ-terpinene.
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Affiliation(s)
- Simon K. Tawich
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Joel L. Bargul
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Daniel Masiga
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Merid N. Getahun
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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Abera D, Kibet CK, Degefa T, Amenga-Etego L, Bargul JL, Golassa L. Genomic analysis reveals independent evolution of Plasmodium falciparum populations in Ethiopia. Malar J 2021; 20:129. [PMID: 33663492 PMCID: PMC7934276 DOI: 10.1186/s12936-021-03660-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 02/20/2021] [Indexed: 11/12/2022] Open
Abstract
Background Plasmodium falciparum parasite populations in Ethiopia have been experiencing local selective pressures from drugs and immunity, leading to evolutionary adaptation. However, there was a paucity of data on genomic characterization and evolutionary adaptations of P. falciparum isolates from the central area of Ethiopia. Methods Whole-genome analysis of 25 P. falciparum isolates from central Ethiopia, specifically from West Arsi, were studied to determine their genetic diversity, population structures, and signatures of selection in known drug resistance alleles against global isolates from Cambodia, Thailand, DR Congo, and Malawi. Results A total of 18,517 high-quality single-nucleotide polymorphisms (SNPs) were identified in Ethiopian P. falciparum isolates. About 84% of the Ethiopian P. falciparum isolates had a FWS value > 0.95 showing a dominant single genotype infection in most isolates at the time of collection with little potential for out-crossing as expected in areas with low transmission intensity. Within-host diversity of Ethiopian infections was significantly different from East African (p < 0.001), but not Southeast Asian infections (P > 0.05). A significant population structure has been observed by PCA and population differentiation between Ethiopian parasites and East African (Fst ~ 10%) and Southeast Asian populations (Fst ~ 18%), suggesting limited gene flow and the independent evolution of the Ethiopian parasite population. Moreover, a total of 125 genes under balancing selection was found that include ama1, trap, eba175, and lsa3, previously identified as targets of human host immunity. Recent directional selection analysis using integrated standardized haplotype score (IHS) did not detect any selection signatures in the Pfcrt, Pfdhfr, Pfdhps, Pfmdr1, and PfK13 genes. However, known drug resistance-conferring mutations analysis showed that at least one SNP marker was fixed in these genes, but not in Pfdhps and PfK13. Conclusion Plasmodium falciparum populations in the central region of Ethiopia was structurally diverged from both Southeast Asian and other East African populations. Malaria infections in Ethiopia had low within-host diversity, and parasites carry fixed chloroquine resistance markers despite the withdrawal of this drug for the treatment of P. falciparum. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-021-03660-y.
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Affiliation(s)
- Deriba Abera
- Department of Biochemistry, College of Health Sciences, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya.,School of Medical Laboratory Sciences, Faculty of Health Sciences, Jimma University, Jimma, Ethiopia
| | - Caleb K Kibet
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Teshome Degefa
- School of Medical Laboratory Sciences, Faculty of Health Sciences, Jimma University, Jimma, Ethiopia
| | - Lucas Amenga-Etego
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana
| | - Joel L Bargul
- Department of Biochemistry, College of Health Sciences, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya.,International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia.
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Nattoh G, Bargul JL, Magoma G, Mbaisi L, Butungi H, Mararo E, Teal E, Herren JK. The fungus Leptosphaerulina persists in Anopheles gambiae and induces melanization. PLoS One 2021; 16:e0246452. [PMID: 33617536 PMCID: PMC7899377 DOI: 10.1371/journal.pone.0246452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 01/20/2021] [Indexed: 12/13/2022] Open
Abstract
Anopheles mosquitoes are colonized by diverse microorganisms that may impact on host biology and vectorial capacity. Eukaryotic symbionts such as fungi have been isolated from Anopheles, but whether they are stably associated with mosquitoes and transmitted transstadially across mosquito life stages or to subsequent generations remains largely unexplored. Here, we show that a Leptosphaerulina sp. fungus isolated from the midgut of An. gambiae can be stably associated with An. gambiae host and that it imposes low fitness cost when re-introduced through co-feeding. This fungus is transstadially transmitted across An. gambiae developmental stages and to their progeny. It is present in field-caught larvae and adult mosquitoes at moderate levels across geographical regions. We observed that Leptosphaerulina sp. induces a distinctive melanotic phenotype across the developmental stages of mosquito. As a eukaryotic symbiont that is stably associated with An. gambiae Leptosphaerulina sp. can be explored for paratransgenesis.
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Affiliation(s)
- Godfrey Nattoh
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Pan African University Institute for Basic Sciences Technology and Innovation, Nairobi, Kenya
- * E-mail:
| | - Joel L. Bargul
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Science and Technology, Nairobi, Kenya
| | - Gabriel Magoma
- Pan African University Institute for Basic Sciences Technology and Innovation, Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Science and Technology, Nairobi, Kenya
| | - Lilian Mbaisi
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Hellen Butungi
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Wits Research Institute for Malaria, University of the Witwatersrand, Johannesburg, South Africa
| | - Enock Mararo
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Evan Teal
- International Centre of Insect Physiology and Ecology, Nairobi, Kenya
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Mwangi KW, Macharia RW, Bargul JL. Gene co-expression network analysis of Trypanosoma brucei in tsetse fly vector. Parasit Vectors 2021; 14:74. [PMID: 33482903 PMCID: PMC7821691 DOI: 10.1186/s13071-021-04597-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/13/2021] [Indexed: 01/14/2023] Open
Abstract
Background Trypanosoma brucei species are motile protozoan parasites that are cyclically transmitted by tsetse fly (genus Glossina) causing human sleeping sickness and nagana in livestock in sub-Saharan Africa. African trypanosomes display digenetic life cycle stages in the tsetse fly vector and in their mammalian host. Experimental work on insect-stage trypanosomes is challenging because of the difficulty in setting up successful in vitro cultures. Therefore, there is limited knowledge on the trypanosome biology during its development in the tsetse fly. Consequently, this limits the development of new strategies for blocking parasite transmission in the tsetse fly. Methods In this study, RNA-Seq data of insect-stage trypanosomes were used to construct a T. brucei gene co-expression network using the weighted gene co-expression analysis (WGCNA) method. The study identified significant enriched modules for genes that play key roles during the parasite’s development in tsetse fly. Furthermore, potential 3′ untranslated region (UTR) regulatory elements for genes that clustered in the same module were identified using the Finding Informative Regulatory Elements (FIRE) tool. Results A fraction of gene modules (12 out of 27 modules) in the constructed network were found to be enriched in functional roles associated with the cell division, protein biosynthesis, mitochondrion, and cell surface. Additionally, 12 hub genes encoding proteins such as RNA-binding protein 6 (RBP6), arginine kinase 1 (AK1), brucei alanine-rich protein (BARP), among others, were identified for the 12 significantly enriched gene modules. In addition, the potential regulatory elements located in the 3′ untranslated regions of genes within the same module were predicted. Conclusions The constructed gene co-expression network provides a useful resource for network-based data mining to identify candidate genes for functional studies. This will enhance understanding of the molecular mechanisms that underlie important biological processes during parasite’s development in tsetse fly. Ultimately, these findings will be key in the identification of potential molecular targets for disease control.![]()
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Affiliation(s)
- Kennedy W Mwangi
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya. .,Jomo Kenyatta University of Agriculture and Technology, P.O. BOX 62000-00200, Nairobi, Kenya.
| | | | - Joel L Bargul
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya.,Jomo Kenyatta University of Agriculture and Technology, P.O. BOX 62000-00200, Nairobi, Kenya
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Mwangi SJ, Gwela A, Mwikali K, Bargul JL, Nduati EW, Ndungu FM, Bejon P, Rayner JC, Abdi AI. Impact of Plasmodium falciparum small-sized extracellular vesicles on host peripheral blood mononuclear cells. Wellcome Open Res 2020. [DOI: 10.12688/wellcomeopenres.16131.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Exagerated immune activation has a key role in the pathogenesis of malaria. During blood-stage infection, Plasmodium falciparum can interact directly with host immune cells through infected red blood cells (PfiRBCs), or indirectly by the release of extracellular vesicles (EVs). Here, we compared the impact of PfiRBCs and P. falciparum small-sized EVs (PfsEVs, also known as exosomes) from a Kenyan clinical isolate (PfKE12) adapted to short-term laboratory culture conditions on host peripheral blood mononuclear cells (PBMC). Methods: PfsEVs were isolated from cell-free culture-conditioned media by ultracentrifugation while mature trophozoite PfiRBCs were purified by magnetic column separation. The PfsEVs and the PfiRBCs were co-cultured for 18 hours with PBMC. Cellular responses were quantified by cell surface expression of activation markers (CD25, CD69) and cytokine/chemokine levels in the supernatant. Results: Relative to negative control conditions, PfsEVs induced CD25 expression on CD4+, CD19+ and CD14+ cells, while PfiRBCs induced on CD19+ and CD14+ cells. Both PfsEVs and PfiRBCs induced CD69 on CD4+, CD8+ and CD19+ cells. In addition, PfiRBCs induced higher expression of CD69 on CD14+ cells. CD69 induced by PfiRBCs on CD4+ and CD19+ cells was significantly higher than that induced by PfsEVs. Secretion of MIP1α, MIP1β, GM-CSF, IL-6, IL-8, and TNFα were significantly induced by both PfsEVs and PfiRBCs whereas MCP-1, IL-10, IL-17α were preferentially induced by PfsEVs and IP-10 and IFN-γ by PfiRBCs. Prior exposure to malaria (judged by antibodies to schizont extract) was associated with lower monocyte responses to PfsEVs. Conclusions: PfsEVs and PfiRBCs showed differential abilities to induce secretion of IL-17α and IFN-γ, suggesting that the former are better at inducing Th17, whilst the latter induce Th1 immune responses respectively. Prior exposure to malaria significantly reduces the ability of PfsEVs to activate monocytes, suggesting immune tolerance to PfsEVs may play a role in naturally acquired anti-disease immunity.
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Isebe TI, Bargul JL, Gichuki BM, Njunge JM, Tuju J, Rono MK. Molecular characterization of Plasmodium falciparum PHISTb proteins as potential targets of naturally-acquired immunity against malaria. Wellcome Open Res 2020. [DOI: 10.12688/wellcomeopenres.15919.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Plasmodium falciparum causes the deadliest form of malaria in humans. Upon infection, the host’s infected red blood cells (iRBCs) are remodelled by exported parasite proteins in order to provide a niche for parasite development and maturation. Methods: Here we analysed the role of three PHISTb proteins Pf3D7_0532400, Pf3D7_1401600, and Pf3D7_1102500 by expressing recombinant proteins and evaluated antibody responses against these proteins using immune sera from malaria-exposed individuals from Kenya and The Gambia in Africa. Results: Our findings show that children and adults from malaria-endemic regions recognized the three PHISTb proteins. Responses against the PHISTb proteins varied with malaria transmission intensity in three different geographical sites in Kenya (Siaya and Takaungu) and The Gambia (Sukuta). Antibody responses against PHISTb antigens Pf3D7_1102500 and Pf3D7_1401600 were higher in Sukuta, a low transmission region in the Gambia, as compared to Siaya, a high transmission region in western Kenya, unlike Pf3D7_0532400. Anti-PHIST responses show a negative correlation between antibody levels and malaria transmission intensity for two PHIST antigens, Pf3D7_1102500 and Pf3D7_1401600. However, we report a correlation in antibody responses between schizont extract and Pf3D7_0532400 (p=0.00582). Acquisition of anti-PHIST antibodies was correlated with exposure to malaria for PHISTb protein Pf3D7_0532400 (p=0.009) but not the other PHIST antigens Pf3D7_1102500 and Pf3D7_1401600 (p=0.507 and p=0.15, respectively, CI=95%). Children aged below 2 years had the lowest antibody levels, but the responses do not correlate with age differences. Conclusions: Collectively, these findings provide evidence of natural immunity against PHISTb antigens that varies with level of malaria exposure and underscore potential for these parasite antigens as possible serological markers to P. falciparum infection aimed at contributing to malaria control through vaccine development.
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Mburu H, Cortada L, Haukeland S, Ronno W, Nyongesa M, Kinyua Z, Bargul JL, Coyne D. Potato Cyst Nematodes: A New Threat to Potato Production in East Africa. Front Plant Sci 2020; 11:670. [PMID: 32523602 PMCID: PMC7261874 DOI: 10.3389/fpls.2020.00670] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 04/29/2020] [Indexed: 05/20/2023]
Abstract
Potato cyst nematodes (PCN), such as Globodera rostochiensis and Globodera pallida, are quarantine restricted pests of potato causing major yield and financial losses to farmers. G. rostochiensis was first reported from Kenya's key potato growing area in 2015. We sought to determine the diversity, prevalence and distribution of PCN species across the country by conducting a country-wide survey between 2016 and 2018, which included a more focused, follow-up assessment in three key potato growing counties. A total of 1,348 soil samples were collected from 20 potato growing counties. Information regarding local potato farming practices, potato cultivar use, their diversity and availability was also recorded. PCN cysts were obtained from 968 samples (71.8%) in all the counties surveyed, with Nyandarua County recording the highest PCN field-incidence at 47.6%. The majority of PCN populations, 99.9%, were identified as G. rostochiensis, while G. pallida was recovered from just one field, in a mixed population with G. rostochiensis. Inconsistencies in PCR amplification efficiency was observed for G. rostochiensis using the recommended EPPO primers, compared with ITS primers AB28/TW81, indicating that this protocol cannot be entirely relied upon to effectively detect PCN. Egg density in Nyandarua County varied between 30.6 and 158.5 viable eggs/g soil, with an average egg viability of 78.9 ± 2.8% (min = 11.6%, max = 99.9%). The PCN-susceptible potato cultivar named Shangi was the most preferred and used by 65% of farmers due to its shorter dormancy and cooking time, while imported cultivars (Destiny, Jelly, Manitou, and Markies) with resistance to G. rostochiensis were used by 7.5% of farmers due to unavailability and/or limited access to seeds. Thus, most farmers preferred using their own farm-saved seeds as opposed to purchasing certified seeds. Establishing the distribution and prevalence of PCN and elucidating the local farming practices that could promote the spread of PCN is a necessary precursor to the implementation of any containment or management strategy in the country and ultimately across the region.
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Affiliation(s)
- Harrison Mburu
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- East Africa Hub, International Institute of Tropical Agriculture (IITA), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya
| | - Laura Cortada
- East Africa Hub, International Institute of Tropical Agriculture (IITA), Nairobi, Kenya
- Nematology Section, Department of Biology, Ghent University, Ghent, Belgium
| | - Solveig Haukeland
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Biotechnology and Plant Health Division, Norwegian Institute for Bioeconomy Research, Ås, Norway
| | - Wilson Ronno
- Food and Agriculture Organization (FAO), Nairobi, Kenya
| | - Moses Nyongesa
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | - Zachary Kinyua
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | - Joel L. Bargul
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya
| | - Danny Coyne
- East Africa Hub, International Institute of Tropical Agriculture (IITA), Nairobi, Kenya
- Nematology Section, Department of Biology, Ghent University, Ghent, Belgium
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Kidambasi KO, Masiga DK, Villinger J, Carrington M, Bargul JL. Detection of blood pathogens in camels and their associated ectoparasitic camel biting keds, Hippobosca camelina: the potential application of keds in xenodiagnosis of camel haemopathogens. AAS Open Res 2020; 2:164. [PMID: 32510036 PMCID: PMC7243205 DOI: 10.12688/aasopenres.13021.2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2020] [Indexed: 12/31/2022] Open
Abstract
Background: Major constraints to camel production include pests and diseases. In northern Kenya, little information is available about blood-borne pathogens circulating in one-humped camels (
Camelus dromedarius) or their possible transmission by the camel haematophagous ectoparasite,
Hippobosca camelina, commonly known as camel ked or camel fly. This study aimed to: (i) identify the presence of potentially insect-vectored pathogens in camels and camel keds, and (ii) assess the potential utility of keds for xenodiagnosis of camel pathogens that they may not vector. Methods: In Laisamis, northern Kenya, camel blood samples (n = 249) and camel keds (n = 117) were randomly collected from camels. All samples were screened for trypanosomal and camelpox DNA by PCR, and for
Anaplasma, Ehrlichia, Brucella, Coxiella, Theileria, and
Babesia by PCR coupled with high-resolution melting (PCR-HRM) analysis. Results: In camels, we detected
Trypanosoma vivax (41%),
Trypanosoma evansi (1.2%), and “
Candidatus Anaplasma camelii” (68.67%). In camel keds, we also detected
T. vivax (45.3%),
T. evansi (2.56%),
Trypanosoma melophagium (1/117) (0.4%), and “
Candidatus Anaplasma camelii” (16.24 %). Piroplasms (
Theileria spp. and
Babesia spp.),
Coxiella burnetii,
Brucella spp.,
Ehrlichia spp., and camel pox were not detected in any samples. Conclusions: This study reveals the presence of epizootic pathogens in camels from northern Kenya. Furthermore, the presence of the same pathogens in camels and in keds collected from sampled camels suggests the potential use of these flies in xenodiagnosis of haemopathogens circulating in camels.
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Affiliation(s)
- Kevin O Kidambasi
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Nairobi, P.O.Box 62000-00200, Kenya.,Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Nairobi, P.O.Box 62000-00200, Kenya.,Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya.,Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya
| | - Daniel K Masiga
- Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya.,Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya
| | - Jandouwe Villinger
- Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya.,Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK.,Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Nairobi, P.O.Box 62000-00200, Kenya.,Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Nairobi, P.O.Box 62000-00200, Kenya.,Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya.,Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya
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Kidambasi KO, Masiga DK, Villinger J, Carrington M, Bargul JL. Detection of blood pathogens in camels and their associated ectoparasitic camel biting keds, Hippobosca camelina: the potential application of keds in xenodiagnosis of camel haemopathogens. AAS Open Res 2020; 2:164. [PMID: 32510036 DOI: 10.12688/aasopenres.13021.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2019] [Indexed: 11/20/2022] Open
Abstract
Background: Major constraints to camel production include pests and diseases. In northern Kenya, little information is available about blood-borne pathogens circulating in one-humped camels ( Camelus dromedarius) or their possible transmission by the camel haematophagous ectoparasite, Hippobosca camelina, commonly known as camel ked or camel fly. This study aimed to: (i) identify the presence of potentially insect-vectored pathogens in camels and camel keds, and (ii) assess the potential utility of keds for xenodiagnosis of camel pathogens that they may not vector. Methods: In Laisamis, northern Kenya, camel blood samples (n = 249) and camel keds (n = 117) were randomly collected from camels. All samples were screened for trypanosomal and camelpox DNA by PCR, and for Anaplasma, Ehrlichia, Brucella, Coxiella, Theileria, and Babesia by PCR coupled with high-resolution melting (PCR-HRM) analysis. Results: In camels, we detected Trypanosoma vivax (41%), Trypanosoma evansi (1.2%), and " Candidatus Anaplasma camelii" (68.67%). In camel keds, we also detected T. vivax (45.3%), T. evansi (2.56%), Trypanosoma melophagium (1/117) (0.4%), and " Candidatus Anaplasma camelii" (16.24 %). Piroplasms ( Theileria spp. and Babesia spp.), Coxiella burnetii, Brucella spp., Ehrlichia spp., and camel pox were not detected in any samples. Conclusions: This study reveals the presence of epizootic pathogens in camels from northern Kenya. Furthermore, the presence of the same pathogens in camels and in keds collected from sampled camels suggests the potential use of these flies in xenodiagnosis of haemopathogens circulating in camels.
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Affiliation(s)
- Kevin O Kidambasi
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Nairobi, P.O.Box 62000-00200, Kenya.,Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Nairobi, P.O.Box 62000-00200, Kenya.,Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya.,Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya
| | - Daniel K Masiga
- Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya.,Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya
| | - Jandouwe Villinger
- Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya.,Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK.,Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QW, UK
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Nairobi, P.O.Box 62000-00200, Kenya.,Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Nairobi, P.O.Box 62000-00200, Kenya.,Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya.,Animal Health Department/Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, P.O. Box 30772-00100, Kenya
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35
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Ouso DO, Otiende MY, Jeneby MM, Oundo JW, Bargul JL, Miller SE, Wambua L, Villinger J. Three-gene PCR and high-resolution melting analysis for differentiating vertebrate species mitochondrial DNA for biodiversity research and complementing forensic surveillance. Sci Rep 2020; 10:4741. [PMID: 32179808 PMCID: PMC7075967 DOI: 10.1038/s41598-020-61600-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 02/27/2020] [Indexed: 11/09/2022] Open
Abstract
Reliable molecular identification of vertebrate species from morphologically unidentifiable tissue is critical for the prosecution of illegally-traded wildlife products, conservation-based biodiversity research, and identification of blood-meal hosts of hematophagous invertebrates. However, forensic identification of vertebrate tissue relies on sequencing of the mitochondrial cytochrome oxidase I (COI) 'barcode' gene, which remains costly for purposes of screening large numbers of unknown samples during routine surveillance. Here, we adapted a rapid, low-cost approach to differentiate 10 domestic and 24 wildlife species that are common in the East African illegal wildlife products trade based on their unique high-resolution melting profiles from COI, cytochrome b, and 16S ribosomal RNA gene PCR products. Using the approach, we identified (i) giraffe among covertly sampled meat from Kenyan butcheries, and (ii) forest elephant mitochondrial sequences among savannah elephant reference samples. This approach is being adopted for high-throughput pre-screening of potential bushmeat samples in East African forensic science pipelines.
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Affiliation(s)
- Daniel O Ouso
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
- Biochemistry Department, Jomo Kenyatta University of Agriculture and Technology (JKUAT), P.O. Box 62000-00200, Nairobi, Kenya
| | - Moses Y Otiende
- Kenya Wildlife Service, Veterinary Department, P.O. Box 40241-00100, Nairobi, Kenya
| | - Maamun M Jeneby
- Institute of Primate Research, National Museums of Kenya, Department of Tropical and Infectious Diseases, P. O. Box 24481-00502, Karen, Nairobi, Kenya
| | - Joseph W Oundo
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
| | - Joel L Bargul
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
- Biochemistry Department, Jomo Kenyatta University of Agriculture and Technology (JKUAT), P.O. Box 62000-00200, Nairobi, Kenya
| | - Scott E Miller
- National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - Lillian Wambua
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
- International Livestock Research Institute, Department of Animal Biosciences, P.O. Box 30709-00100, Nairobi, Kenya
| | - Jandouwe Villinger
- International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya.
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36
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Mokaya HO, Bargul JL, Irungu JW, Lattorff HMG. Bioactive constituents, in vitro radical scavenging and antibacterial activities of selected Apis mellifera honey from Kenya. Int J Food Sci Technol 2019; 55:1246-1254. [PMID: 33071471 PMCID: PMC7540667 DOI: 10.1111/ijfs.14403] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 09/30/2019] [Indexed: 12/30/2022]
Abstract
There is limited information about the relative composition and health benefits of various honey consumed across Africa. This study aimed at estimating the bioactive constituents, in vitro radical scavenging and antibacterial activities of 16 kinds of honey obtained from different geographical locations in Kenya. Manuka 5 + honey was included for comparison. Some of the tested honey had biochemicals and bioactivities similar to or higher than Manuka 5 + honey. The honey exhibited DPPH radical scavenging ability, with several types of honey showing superior scavenging potential than Manuka 5 + honey, owing to their high phenol content. All types of honey inhibited the growth of E. coli and further showed a substantial amount of nonperoxide antimicrobial activity. The geographical origin of honey had an influence on its bioactive contents. Overall, these findings suggest that Kenyan honey has great therapeutic potential, and thus, its clinical application should not be overlooked.
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Affiliation(s)
- Hosea O Mokaya
- International Centre of Insect Physiology and Ecology (icipe) P.O. Box 30772-00100 Nairobi Kenya.,Biochemistry Department Jomo Kenyatta University of Agriculture and Technology P.O. Box 62000-00200 Nairobi Kenya
| | - Joel L Bargul
- International Centre of Insect Physiology and Ecology (icipe) P.O. Box 30772-00100 Nairobi Kenya.,Biochemistry Department Jomo Kenyatta University of Agriculture and Technology P.O. Box 62000-00200 Nairobi Kenya
| | - Janet W Irungu
- International Centre of Insect Physiology and Ecology (icipe) P.O. Box 30772-00100 Nairobi Kenya
| | - Hans Michael G Lattorff
- International Centre of Insect Physiology and Ecology (icipe) P.O. Box 30772-00100 Nairobi Kenya.,German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig Deutscher Platz 5e 04103 Leipzig Germany.,Naturwissenschaftliche Fakultät I Martin-Luther-Universität Halle-Wittenberg 06099 Halle (Saale) Germany
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37
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Muema JM, Bargul JL, Njeru SN, Onyango JO, Imbahale SS. Prospects for malaria control through manipulation of mosquito larval habitats and olfactory-mediated behavioural responses using plant-derived compounds. Parasit Vectors 2017; 10:184. [PMID: 28412962 PMCID: PMC5392979 DOI: 10.1186/s13071-017-2122-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 03/29/2017] [Indexed: 11/14/2022] Open
Abstract
Malaria presents an overwhelming public health challenge, particularly in sub-Saharan Africa where vector favourable conditions and poverty prevail, potentiating the disease burden. Behavioural variability of malaria vectors poses a great challenge to existing vector control programmes with insecticide resistance already acquired to nearly all available chemical compounds. Thus, approaches incorporating plant-derived compounds to manipulate semiochemical-mediated behaviours through disruption of mosquito olfactory sensory system have considerably gained interests to interrupt malaria transmission cycle. The combination of push-pull methods and larval control have the potential to reduce malaria vector populations, thus minimising the risk of contracting malaria especially in resource-constrained communities where access to synthetic insecticides is a challenge. In this review, we have compiled information regarding the current status of knowledge on manipulation of larval ecology and chemical-mediated behaviour of adult mosquitoes with plant-derived compounds for controlling mosquito populations. Further, an update on the current advancements in technologies to improve longevity and efficiency of these compounds for field applications has been provided.
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Affiliation(s)
- Jackson M Muema
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya.
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya.,Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
| | - Sospeter N Njeru
- Department of Medicine, Faculty of Health Sciences, Kisii University, P.O. Box 408-40200, Kisii, Kenya.,Present Address: Fritz Lipmann Institute (FLI) - Leibniz Institute of Aging Research, D-07745, Jena, Germany
| | - Joab O Onyango
- Department of Chemical Science and Technology, Technical University of Kenya, P.O. Box 52428-00200, Nairobi, Kenya
| | - Susan S Imbahale
- Department of Applied and Technical Biology, Technical University of Kenya, P.O. Box 52428-00200, Nairobi, Kenya
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Muema JM, Nyanjom SG, Mutunga JM, Njeru SN, Bargul JL. Green tea proanthocyanidins cause impairment of hormone-regulated larval development and reproductive fitness via repression of juvenile hormone acid methyltransferase, insulin-like peptide and cytochrome P450 genes in Anopheles gambiae sensu stricto. PLoS One 2017; 12:e0173564. [PMID: 28301607 PMCID: PMC5354366 DOI: 10.1371/journal.pone.0173564] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/23/2017] [Indexed: 12/03/2022] Open
Abstract
Successful optimization of plant-derived compounds into control of nuisance insects would benefit from scientifically validated targets. However, the close association between the genotypic responses and physiological toxicity effects mediated by these compounds remains underexplored. In this study, we evaluated the sublethal dose effects of proanthocyanidins (PAs) sourced from green tea (Camellia sinensis) on life history traits of Anopheles gambiae (sensu stricto) mosquitoes with an aim to unravel the probable molecular targets. Based on the induced phenotypic effects, genes selected for study targeted juvenile hormone (JH) biosynthesis, signal transduction, oxidative stress response and xenobiotic detoxification in addition to vitellogenesis in females. Our findings suggest that chronic exposure of larval stages (L3/L4) to sublethal dose of 5 ppm dramatically extended larval developmental period for up to 12 days, slowed down pupation rates, induced abnormal larval-pupal intermediates and caused 100% inhibition of adult emergence. Further, females exhibited significant interference of fecundity and egg hatchability relative to controls (p < 0.001). Using reverse transcription quantitative polymerase chain reaction (RT-qPCR), our findings show that PA-treated larvae exhibited significant repression of AgamJHAMT (p < 0.001), AgamILP1 (p < 0.001) and AgamCYP6M2 (p < 0.001) with up-regulation of Hsp70 (p < 0.001). Females exposed as larvae demonstrated down-regulation of AgamVg (p = 0.03), AgamILP1 (p = 0.009), AgamCYP6M2 (p = 0.05) and AgamJHAMT (p = 0.02). Our findings support that C. sinensis proanthocyanidins affect important vectorial capacity components such as mosquito survival rates and reproductive fitness thus could be potentially used for controlling populations of malaria vectors.
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Affiliation(s)
- Jackson M. Muema
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
- * E-mail:
| | - Steven G. Nyanjom
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - James M. Mutunga
- Malaria Research Programme, International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Sospeter N. Njeru
- Department of Medicine, Faculty of Health Sciences, Kisii University, Kisii, Kenya
| | - Joel L. Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
- Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, Kenya
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39
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Muema JM, Bargul JL, Nyanjom SG, Mutunga JM, Njeru SN. Potential of Camellia sinensis proanthocyanidins-rich fraction for controlling malaria mosquito populations through disruption of larval development. Parasit Vectors 2016; 9:512. [PMID: 27660043 PMCID: PMC5034625 DOI: 10.1186/s13071-016-1789-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 09/02/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Anopheles arabiensis and A. gambiae (sensu stricto) are the most prolific Afrotropical malaria vectors. Population control efforts of these two vectors have been hampered by extremely diverse larval breeding sites and widespread resistance to currently available insecticides. Control of mosquito larval stages using bioactive compounds of plant origin has the potential to suppress vector populations leading to concomitant reduction in disease transmission rates. In this study, we evaluated the efficacy of Camellia sinensis crude leaf extract and its fraction against the larvae of A. arabiensis and A. gambiae (s.s.). METHODS Late third/early fourth instar larvae (L3/L4) of A. arabiensis and A. gambiae (s.s.) were exposed to increasing doses of C. sinensis leaf extract and its active fraction for 72 h, with mortality rates recorded every 24 h in both control and test groups. Ultra performance liquid chromatography electron spray ionization quadruple time of flight coupled with mass spectrometry (UPLC/ESI-Qtof/MS) was used to determine the main active constituents in the fraction. RESULTS The major bioactive chemical constituents in the C. sinensis leaf extract were identified to be proanthocyanidins. The extract significantly interfered with larval survival and adult emergence in both species (ANOVA, F (5,24) = 1435.92, P < 0.001). Additionally, larval exposure to crude extract at 250 ppm and 500 ppm for 24 h resulted in larval mortality rates of over 90 % in A. gambiae (s.s.) and 75 % in A. arabiensis. A relatively lower concentration of 100 ppm resulted in moderate mortality rates of < 50 % in both species, but induced growth disruption effects evident as abnormal larval-pupal intermediates and disrupted adult emergence. The estimated LC50 concentrations of the crude leaf extract against A. arabiensis and A. gambiae (s.s.) larvae at 24 h were 154.58 ppm (95 % CI: 152.37-158.22) and 117.15 ppm (95 % CI: 112.86-127.04), respectively. The bioactive polar fraction caused 100 % larval mortality in both vector species at 25 ppm. CONCLUSIONS Our findings demonstrate the potential of green tea extract and its active constituents in disrupting mosquito larval development. This could contribute to the control of mosquito populations and improved management of malaria.
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Affiliation(s)
- Jackson M Muema
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya.
| | - Joel L Bargul
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya.,Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
| | - Steven G Nyanjom
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya
| | - James M Mutunga
- Malaria Research Programme, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
| | - Sospeter N Njeru
- Present Address: Fritz Lipmann Institute (FLI) - Leibniz Institute for Age Research, D-07745, Jena, Germany
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40
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Bargul JL, Jung J, McOdimba FA, Omogo CO, Adung’a VO, Krüger T, Masiga DK, Engstler M. Species-Specific Adaptations of Trypanosome Morphology and Motility to the Mammalian Host. PLoS Pathog 2016; 12:e1005448. [PMID: 26871910 PMCID: PMC4752354 DOI: 10.1371/journal.ppat.1005448] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 01/20/2016] [Indexed: 11/24/2022] Open
Abstract
African trypanosomes thrive in the bloodstream and tissue spaces of a wide range of mammalian hosts. Infections of cattle cause an enormous socio-economic burden in sub-Saharan Africa. A hallmark of the trypanosome lifestyle is the flagellate's incessant motion. This work details the cell motility behavior of the four livestock-parasites Trypanosoma vivax, T. brucei, T. evansi and T. congolense. The trypanosomes feature distinct swimming patterns, speeds and flagellar wave frequencies, although the basic mechanism of flagellar propulsion is conserved, as is shown by extended single flagellar beat analyses. Three-dimensional analyses of the trypanosomes expose a high degree of dynamic pleomorphism, typified by the 'cellular waveform'. This is a product of the flagellar oscillation, the chirality of the flagellum attachment and the stiffness of the trypanosome cell body. The waveforms are characteristic for each trypanosome species and are influenced by changes of the microenvironment, such as differences in viscosity and the presence of confining obstacles. The distinct cellular waveforms may be reflective of the actual anatomical niches the parasites populate within their mammalian host. T. vivax displays waveforms optimally aligned to the topology of the bloodstream, while the two subspecies T. brucei and T. evansi feature distinct cellular waveforms, both additionally adapted to motion in more confined environments such as tissue spaces. T. congolense reveals a small and stiff waveform, which makes these parasites weak swimmers and destined for cell adherence in low flow areas of the circulation. Thus, our experiments show that the differential dissemination and annidation of trypanosomes in their mammalian hosts may depend on the distinct swimming capabilities of the parasites.
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Affiliation(s)
- Joel L. Bargul
- Lehrstuhl für Zell- und Entwicklungsbiologie, Biozentrum, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg, Germany
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and technology, Nairobi, Kenya
- Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Jamin Jung
- Lehrstuhl für Zell- und Entwicklungsbiologie, Biozentrum, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg, Germany
| | - Francis A. McOdimba
- Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Collins O. Omogo
- Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Vincent O. Adung’a
- Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, Kenya
- Department of Biochemistry and Molecular Biology, Egerton University, Egerton, Kenya
| | - Timothy Krüger
- Lehrstuhl für Zell- und Entwicklungsbiologie, Biozentrum, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg, Germany
| | - Daniel K. Masiga
- Molecular Biology and Bioinformatics Unit, International Centre of Insect Physiology and Ecology, Nairobi, Kenya
| | - Markus Engstler
- Lehrstuhl für Zell- und Entwicklungsbiologie, Biozentrum, Julius-Maximilians-Universität Würzburg, Am Hubland, Würzburg, Germany
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41
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Benoit JB, Hansen IA, Attardo GM, Michalková V, Mireji PO, Bargul JL, Drake LL, Masiga DK, Aksoy S. Aquaporins are critical for provision of water during lactation and intrauterine progeny hydration to maintain tsetse fly reproductive success. PLoS Negl Trop Dis 2014; 8:e2517. [PMID: 24762803 PMCID: PMC3998938 DOI: 10.1371/journal.pntd.0002517] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 09/20/2013] [Indexed: 12/26/2022] Open
Abstract
Tsetse flies undergo drastic fluctuations in their water content throughout their adult life history due to events such as blood feeding, dehydration and lactation, an essential feature of the viviparous reproductive biology of tsetse. Aquaporins (AQPs) are transmembrane proteins that allow water and other solutes to permeate through cellular membranes. Here we identify tsetse aquaporin (AQP) genes, examine their expression patterns under different physiological conditions (blood feeding, lactation and stress response) and perform functional analysis of three specific genes utilizing RNA interference (RNAi) gene silencing. Ten putative aquaporins were identified in the Glossina morsitans morsitans (Gmm) genome, two more than has been previously documented in any other insect. All organs, tissues, and body parts examined had distinct AQP expression patterns. Two AQP genes, gmmdripa and gmmdripb ( = gmmaqp1a and gmmaqp1b) are highly expressed in the milk gland/fat body tissues. The whole-body transcript levels of these two genes vary over the course of pregnancy. A set of three AQPs (gmmaqp5, gmmaqp2a, and gmmaqp4b) are expressed highly in the Malpighian tubules. Knockdown of gmmdripa and gmmdripb reduced the efficiency of water loss following a blood meal, increased dehydration tolerance and reduced heat tolerance of adult females. Knockdown of gmmdripa extended pregnancy length, and gmmdripb knockdown resulted in extended pregnancy duration and reduced progeny production. We found that knockdown of AQPs increased tsetse milk osmolality and reduced the water content in developing larva. Combined knockdown of gmmdripa, gmmdripb and gmmaqp5 extended pregnancy by 4–6 d, reduced pupal production by nearly 50%, increased milk osmolality by 20–25% and led to dehydration of feeding larvae. Based on these results, we conclude that gmmDripA and gmmDripB are critical for diuresis, stress tolerance and intrauterine lactation through the regulation of water and/or other uncharged solutes. Glossina sp. are responsible for transmission of African trypanosomes, the causative agents of sleeping sickness in humans and Nagana in cattle. Blood feeding and nutrient provisioning through lactation during intrauterine progeny development are periods when considerable water movement occurs within tsetse flies. With the completion of the tsetse fly genome, we sought to characterize the role of aquaporins in relation water homeostasis during blood feeding, stress tolerance and the lactation cycle. We provide evidence that specific AQPs are 1. critical during diuresis following a bloodmeal, 2. important in the regulation of dehydration resistance and heat tolerance and 3. crucial in the allocation of water within tsetse milk that is necessary for progeny hydration. Specifically, we discovered a novel tsetse AQP that is imperative to lactation and may represent a potential target for population control of this disease vector.
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Affiliation(s)
- Joshua B. Benoit
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, United States of America
- * E-mail:
| | - Immo A. Hansen
- Department of Biology and Institute of Applied Biosciences, New Mexico State University, Las Cruces, New Mexico, United States of America
| | - Geoffrey M. Attardo
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, United States of America
| | - Veronika Michalková
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, United States of America
- Institute of Zoology, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Paul O. Mireji
- Department of Biochemistry and Molecular Biology, Egerton University, Njoro, Kenya
| | - Joel L. Bargul
- Molecular Biology and Bioinformatics Unit, International Center of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya
| | - Lisa L. Drake
- Department of Biology and Institute of Applied Biosciences, New Mexico State University, Las Cruces, New Mexico, United States of America
| | - Daniel K. Masiga
- Molecular Biology and Bioinformatics Unit, International Center of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, United States of America
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