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Zeineddine S, Jaber S, Saab SA, Nakhleh J, Dimopoulos G, Osta MA. Late sporogonic stages of Plasmodium parasites are susceptible to the melanization response in Anopheles gambiae mosquitoes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.31.596773. [PMID: 38853990 PMCID: PMC11160730 DOI: 10.1101/2024.05.31.596773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
The malaria-causing parasites have to complete a complex infection cycle in the mosquito vector that also involves attack by the insect's innate immune system, especially at the early stages of midgut infection. However, Anopheles immunity to the late Plasmodium sporogonic stages, such as oocysts, has received little attention as they are considered to be concealed from immune factors due to their location under the midgut basal lamina and for harboring an elaborate cell wall comprising an external layer derived from the basal lamina that confers self-properties to an otherwise foreign structure. Here, we investigated whether Plasmodium berghei oocysts and sporozoites are susceptible to melanization-based immunity in Anopheles gambiae . Silencing of the negative regulator of melanization response, CLIPA14, increased melanization prevalence without significantly increasing the numbers of melanized oocysts, while co-silencing CLIPA14 with CLIPA2, a second negative regulator of melanization, resulted in a significant increase in melanized oocysts and melanization prevalence. Only late-stage oocysts were found to be melanized, suggesting that oocyst rupture was a prerequisite for melanization-based immune attack, presumably due to the loss of the immune-evasive features of their wall. We also found melanized sporozoites inside oocysts and in the hemocoel, suggesting that sporozoites at different maturation stages are susceptible to melanization. Silencing the melanization promoting factors TEP1 and CLIPA28 rescued oocyst melanization in CLIPA2/CLIPA14 co-silenced mosquitoes. Interestingly, silencing of CTL4, that protects early stage ookinetes from melanization, had no effect on oocysts and sporozoites, indicating differential regulation of immunity to early and late sporogonic stages. Similar to previous studies addressing ookinete stage melanization, the melanization of Plasmodium falciparum oocysts was significantly lower than that observed for P. berghei . In summary, our results provide conclusive evidence that late sporogonic malaria parasite stages are susceptible to melanization, and we reveal distinct regulatory mechanisms for ookinete and oocyst melanization.
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Zeleke G, Duchateau L, Yewhalaw D, Suleman S, Devreese M. In-vitro susceptibility and ex-vivo evaluation of macrocyclic lactone endectocides sub-lethal concentrations against Plasmodium vivax oocyst development in Anopheles arabiensis. Malar J 2024; 23:26. [PMID: 38238768 PMCID: PMC10797976 DOI: 10.1186/s12936-024-04845-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 01/05/2024] [Indexed: 01/22/2024] Open
Abstract
BACKGROUND Asymptomatic malaria transmission has become a public health concern across malaria-endemic Africa including Ethiopia. Specifically, Plasmodium vivax is more efficient at transmitting earlier in the infection and at lower densities than Plasmodium falciparum. Consequently, a greater proportion of individuals infected with P. vivax can transmit without detectable gametocytaemia. Mass treatment of livestock with macrocyclic lactones (MLs), e.g., ivermectin and doramectin, was suggested as a complementary malaria vector tool because of their insecticidal effects. However, the effects of MLs on P. vivax in Anopheles arabiensis has not yet been fully explored. Hence, comparative in-vitro susceptibility and ex-vivo studies were conducted to evaluate the effects of ivermectin, doramectin and moxidectin sub-lethal concentrations on P. vivax oocyst development in An. arabiensis. METHODS The 7-day sub-lethal concentrations of 25% (LC25) and 5% (LC5) were determined from in-vitro susceptibility tests on female An. arabiensis in Hemotek® membrane feeding assay. Next, an ex-vivo study was conducted using P. vivax gametocytes infected patient's blood spiked with the LC25 and LC5 of the MLs. At 7-days post-feeding, each mosquito was dissected under a dissection stereo microscope, stained with 0.5% (w/v) mercurochrome solution, and examined for the presence of P. vivax oocysts. Statistical analysis was based on a generalized mixed model with binomially distributed error terms. RESULTS A 7-day lethal concentration of 25% (LC25, in ng/mL) of 7.1 (95% CI: [6.3;8.0]), 20.0 (95%CI:[17.8;22.5]) and 794.3 (95%CI:[716.4;1516.3]) were obtained for ivermectin, doramectin and moxidectin, respectively. Similarly, a lethal concentration of 5% (LC5, in ng/mL) of 0.6 (95% CI: [0.5;0.7]), 1.8 (95% CI:[1.6;2.0]) and 53.7 (95% CI:[ 48.4;102.5]) were obtained respectively for ivermectin, doramectin and moxidectin. The oocyst prevalence in treatment and control groups did not differ significantly (p > 0.05) from each other. Therefore, no direct effect of ML endectocides on P. vivax infection in An. arabiensis mosquitoes was observed at the sub-lethal concentration (LC25 and LC5). CONCLUSIONS The effects of ivermectin and doramectin on malaria parasite is more likely via indirect effects, particularly by reducing the vectors lifespan and causing mortality before completing the parasite's sporogony cycle or reducing their vector capacity as it affects the locomotor activity of the mosquito.
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Affiliation(s)
- Gemechu Zeleke
- Department of Pathobiology, Pharmacology and Zoological Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium
- Jimma University Laboratory of Drug Quality (JuLaDQ), and School of Pharmacy, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Luc Duchateau
- Biometrics Research Center, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium
| | - Delenasaw Yewhalaw
- School of Medical Laboratory Sciences, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Sultan Suleman
- Jimma University Laboratory of Drug Quality (JuLaDQ), and School of Pharmacy, Institute of Health, Jimma University, Jimma, Ethiopia
| | - Mathias Devreese
- Department of Pathobiology, Pharmacology and Zoological Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium.
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Kunkeaw N, Nguitragool W, Takashima E, Kangwanrangsan N, Muramatsu H, Tachibana M, Ishino T, Lin PJC, Tam YK, Pichyangkul S, Tsuboi T, Pardi N, Sattabongkot J. A Pvs25 mRNA vaccine induces complete and durable transmission-blocking immunity to Plasmodium vivax. NPJ Vaccines 2023; 8:187. [PMID: 38092803 PMCID: PMC10719277 DOI: 10.1038/s41541-023-00786-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/09/2023] [Indexed: 12/17/2023] Open
Abstract
Plasmodium vivax (P. vivax) is the major malaria parasite outside of Africa and no vaccine is available against it. A vaccine that interrupts parasite transmission (transmission-blocking vaccine, TBV) is considered highly desirable to reduce the spread of P. vivax and to accelerate its elimination. However, the development of a TBV against this pathogen has been hampered by the inability to culture the parasite as well as the low immunogenicity of the vaccines developed to date. Pvs25 is the most advanced TBV antigen candidate for P. vivax. However, in previous phase I clinical trials, TBV vaccines based on Pvs25 yielded low antibody responses or had unacceptable safety profiles. As the nucleoside-modified mRNA-lipid nanoparticle (mRNA-LNP) vaccine platform proved to be safe and effective in humans, we generated and tested mRNA-LNP vaccines encoding several versions of Pvs25 in mice. We found that in a prime-boost vaccination schedule, all Pvs25 mRNA-LNP vaccines elicited robust antigen-specific antibody responses. Furthermore, when compared with a Pvs25 recombinant protein vaccine formulated with Montanide ISA-51 adjuvant, the full-length Pvs25 mRNA-LNP vaccine induced a stronger and longer-lasting functional immunity. Seven months after the second vaccination, vaccine-induced antibodies retained the ability to fully block P. vivax transmission in direct membrane feeding assays, whereas the blocking activity induced by the protein/ISA-51 vaccine dropped significantly. Taken together, we report on mRNA vaccines targeting P. vivax and demonstrate that Pvs25 mRNA-LNP outperformed an adjuvanted Pvs25 protein vaccine suggesting that it is a promising candidate for further testing in non-human primates.
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Affiliation(s)
- Nawapol Kunkeaw
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wang Nguitragool
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Niwat Kangwanrangsan
- Department of Pathobiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Hiromi Muramatsu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Mayumi Tachibana
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Japan
| | - Tomoko Ishino
- Department of Parasitology and Tropical Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Paulo J C Lin
- Acuitas Therapeutics, Vancouver, BC, V6T 1Z3, Canada
| | - Ying K Tam
- Acuitas Therapeutics, Vancouver, BC, V6T 1Z3, Canada
| | - Sathit Pichyangkul
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Norbert Pardi
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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Andrade AO, Santos NAC, Bastos AS, Pontual JDC, Araújo JE, Silva AMV, Martinez LN, Lima AA, Aguiar ACC, G. Teles CB, Medeiros JF, Pereira DB, Vinetz JM, Gazzinelli RT, Araújo MS. Transmission-blocking activity of antimalarials for Plasmodium vivax malaria in Anopheles darlingi. PLoS Negl Trop Dis 2023; 17:e0011425. [PMID: 37327209 PMCID: PMC10310017 DOI: 10.1371/journal.pntd.0011425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 06/29/2023] [Accepted: 05/30/2023] [Indexed: 06/18/2023] Open
Abstract
Malaria is caused by parasite of the genus Plasmodium and is still one of the most important infectious diseases in the world. Several biological characteristics of Plasmodium vivax contribute to the resilience of this species, including early gametocyte production, both of which lead to efficient malaria transmission to mosquitoes. This study evaluated the impact of currently used drugs on the transmission of P. vivax. Participants received one of the following treatments for malaria: i) chloroquine [10 mg/kg on day 1 and 7.5 mg/kg on day 2 and 3] co-administered with Primaquine [0.5 mg/kg/day for 7 days]; ii) Chloroquine [10 mg/kg on day 1 and 7.5 mg/kg on day 2 and 3] co-administered with one-dose of Tafenoquine [300 mg on day 1]; and iii) Artesunate and Mefloquine [100 mg and 200 mg on day 1, 2 and 3] co-administered with Primaquine [0.5 mg/kg/day for 14 days]. Patient blood was collected before treatment and 4 h, 24 h, 48 h and 72 h after treatment. The blood was used to perform a direct membrane feeding assay (DMFA) using Anopheles darlingi mosquitoes. The results showed 100% inhibition of the mosquito infection after 4 h using ASMQ+PQ, after 24 h for the combination of CQ+PQ and 48 h using CQ+TQ. The density of gametocytes declined over time in all treatment groups, although the decline was more rapid in the ASMQ+PQ group. In conclusion, it was possible to demonstrate the transmission-blocking efficacy of the malaria vivax treatment and that ASMQ+PQ acts faster than the two other treatments.
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Affiliation(s)
- Alice O. Andrade
- Plataforma de Produção e Infecção de Vetores da Malária (PIVEM), Laboratório de Entomologia, Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
| | - Najara A. C. Santos
- Plataforma de Produção e Infecção de Vetores da Malária (PIVEM), Laboratório de Entomologia, Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
- Programa de Pós-Graduação em Biologia Experimental, Fundação Universidade Federal de Rondônia, FIOCRUZ Rondônia, Porto Velho, Rondônia, Brazil
| | - Alessandra S. Bastos
- Plataforma de Produção e Infecção de Vetores da Malária (PIVEM), Laboratório de Entomologia, Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
| | - José D. C. Pontual
- Plataforma de Produção e Infecção de Vetores da Malária (PIVEM), Laboratório de Entomologia, Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
| | - Jéssica E. Araújo
- Plataforma de Produção e Infecção de Vetores da Malária (PIVEM), Laboratório de Entomologia, Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
- Programa de Pós-Graduação em Biologia Experimental, Fundação Universidade Federal de Rondônia, FIOCRUZ Rondônia, Porto Velho, Rondônia, Brazil
| | - Alexia M. V. Silva
- Ambulatório de Malária, Centro de Pesquisa em Medicina Tropical, Porto Velho, Rondônia, Brazil
| | - Leandro N. Martinez
- Programa de Pós-Graduação em Biologia Experimental, Fundação Universidade Federal de Rondônia, FIOCRUZ Rondônia, Porto Velho, Rondônia, Brazil
- Plataforma de Bioensaios de Malária e Leishmaniose da Fiocruz (PBML), Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
| | - Alzemar A. Lima
- Ambulatório de Malária, Centro de Pesquisa em Medicina Tropical, Porto Velho, Rondônia, Brazil
| | | | - Carolina B. G. Teles
- Programa de Pós-Graduação em Biologia Experimental, Fundação Universidade Federal de Rondônia, FIOCRUZ Rondônia, Porto Velho, Rondônia, Brazil
- Plataforma de Bioensaios de Malária e Leishmaniose da Fiocruz (PBML), Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
| | - Jansen F. Medeiros
- Plataforma de Produção e Infecção de Vetores da Malária (PIVEM), Laboratório de Entomologia, Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
- Programa de Pós-Graduação em Biologia Experimental, Fundação Universidade Federal de Rondônia, FIOCRUZ Rondônia, Porto Velho, Rondônia, Brazil
| | - Dhelio B. Pereira
- Ambulatório de Malária, Centro de Pesquisa em Medicina Tropical, Porto Velho, Rondônia, Brazil
| | - Joseph M. Vinetz
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut, United States of America
| | - Ricardo T. Gazzinelli
- Laboratório de Imunopatologia, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Maisa S. Araújo
- Plataforma de Produção e Infecção de Vetores da Malária (PIVEM), Laboratório de Entomologia, Fiocruz Rondônia, Porto Velho, Rondônia, Brazil
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Kamiya T, Paton DG, Catteruccia F, Reece SE. Targeting malaria parasites inside mosquitoes: ecoevolutionary consequences. Trends Parasitol 2022; 38:1031-1040. [PMID: 36209032 PMCID: PMC9815470 DOI: 10.1016/j.pt.2022.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/13/2022] [Accepted: 09/13/2022] [Indexed: 11/05/2022]
Abstract
Proof-of-concept studies demonstrate that antimalarial drugs designed for human treatment can also be applied to mosquitoes to interrupt malaria transmission. Deploying a new control tool is ideally undertaken within a stewardship programme that maximises a drug's lifespan by minimising the risk of resistance evolution and slowing its spread once emerged. We ask: what are the epidemiological and evolutionary consequences of targeting parasites within mosquitoes? Our synthesis argues that targeting parasites inside mosquitoes (i) can be modelled by readily expanding existing epidemiological frameworks; (ii) provides a functionally novel control method that has potential to be more robust to resistance evolution than targeting parasites in humans; and (iii) could extend the lifespan and clinical benefit of antimalarials used exclusively to treat humans.
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Affiliation(s)
- Tsukushi Kamiya
- Centre for Interdisciplinary Research in Biology, Collège de France, Paris, France; HRB Clinical Research Facility, National University of Ireland, Galway, Ireland; Institute of Ecology and Evolution, and Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.
| | - Douglas G Paton
- Department of Immunology and Infectious Disease, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Flaminia Catteruccia
- Department of Immunology and Infectious Disease, Harvard T. H. Chan School of Public Health, Harvard University, Boston, MA, USA; Howard Hughes Medical Institute, Boston, MA, USA
| | - Sarah E Reece
- Institute of Ecology and Evolution, and Institute of Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK.
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Abate A, Kedir S, Bose M, Hassen J, Dembele L, Golassa L. Infectivity of Symptomatic Patients and Their Contribution for Infectiousness of Mosquitoes following a Membrane Feeding Assay in Ethiopia. Microbiol Spectr 2022; 10:e0062822. [PMID: 36066239 PMCID: PMC9602676 DOI: 10.1128/spectrum.00628-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 08/05/2022] [Indexed: 12/30/2022] Open
Abstract
The membrane feeding assay is widely used to evaluate the efficacy of transmission-blocking interventions (TBIs) and identify the reservoir of malaria. This study aimed to determine the infectivity of blood meals from symptomatic Plasmodium-infected patients to an Anopheles arabiensis colony in Ethiopia. A membrane feeding assay was conducted on a total of 63 Plasmodium falciparum- and/or Plasmodium vivax-infected clinical patients in East Shoa Zone, Ethiopia. Detection of P. falciparum and P. vivax in blood samples was done using microscopy. Mosquito infection rates were determined by dissection of mosquitoes' midguts, while mosquito infectiousness was observed by dissection of their salivary glands. The proportion of infectious symptomatic patients was 68.3% (43/63). Using the chi-square or Fisher's exact test, the oocyst infection levels were higher among patients infected with P. vivax, females, and rural residents. Nearly 57% (56.7%, 17/30) of assays produced sporozoites in the salivary glands of mosquitoes. Both oocyst and sporozoite infection rates had positive correlations with parasitemia and gametocytemia. High infectiousness of symptomatic patients was observed, with a greater proportion of infectious mosquitoes per assay. Demonstrating oocyst infection in the mosquitoes might confirm estimates of the infectiousness of mosquitoes, although some of the oocyst-infected mosquitoes failed to produce sporozoites. IMPORTANCE Malaria remains one of the most devastating infectious diseases globally, and transmission-blocking activities are needed. Plasmodium transmission from human to mosquitoes is poorly studied, particularly in endemic countries, and the membrane feeding assay allows it to be determined. In this study, we demonstrated human infectious reservoirs of malaria. Moreover, the effect of Plasmodium-infected patients on the infectiousness of mosquitoes was also observed. These findings are therefore important for designing future evaluation of transmission-blocking interventions that will support the malaria elimination program.
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Affiliation(s)
- Andargie Abate
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
- College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | - Soriya Kedir
- Adama Regional Laboratory, Oromia Region Health Bureau, Adama, Ethiopia
| | - Mitiku Bose
- Adama Regional Laboratory, Oromia Region Health Bureau, Adama, Ethiopia
| | - Jifar Hassen
- Adama Science and Technology University, Adama, Ethiopia
| | - Laurent Dembele
- Université des Sciences, des Techniques et des Technologies de Bamako (USTTB), Malaria Research and Training Center (MRTC), Bamako, Mali
| | - Lemu Golassa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, Addis Ababa, Ethiopia
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dos Santos NAC, Magi FN, Andrade AO, Bastos ADS, Pereira SDS, Medeiros JF, Araujo MDS. Assessment of antibiotic treatment on Anopheles darlingi survival and susceptibility to Plasmodium vivax. Front Microbiol 2022; 13:971083. [PMID: 36274692 PMCID: PMC9583876 DOI: 10.3389/fmicb.2022.971083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/14/2022] [Indexed: 11/13/2022] Open
Abstract
Antibiotic treatment has been used to enhance anopheline susceptibility to Plasmodium infection, because bacterial microbiota play a fundamental role in modulating the vector competence of mosquitoes that transmit Plasmodium parasites. However, few studies have examined the impact of antibiotic treatments on Plasmodium vivax sporogonic development in neotropical anopheline mosquitoes. Herein, we assessed the impact of antibiotic treatment on P. vivax development and survival in Anopheles darlingi, the main vector of malaria in the Amazon region. Female mosquitoes were treated continuously with antibiotics to impact the gut bacterial load and then tested for prevalence, infection intensity, and survival in comparison with untreated mosquitoes. Antibiotic-fed mosquitoes had not dramatic impact on P. vivax development previously observed in P. falciparum. However, antibiotic treatment increases mosquito survival, which is known to increase vectorial capacity. These findings raise questions about the effect of antibiotics on P. vivax development and survival in An. darlingi.
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Affiliation(s)
- Najara Akira Costa dos Santos
- Postgraduate Program in Experimental Biology, Federal University of Rondonia/Fiocruz Rondonia, Porto Velho, Brazil
- Platform of Production and Infection of Malaria Vectors (PIVEM), Laboratory of Entomology, Fiocruz Rondonia, Porto Velho, Brazil
| | - Felipe Neves Magi
- Platform of Production and Infection of Malaria Vectors (PIVEM), Laboratory of Entomology, Fiocruz Rondonia, Porto Velho, Brazil
| | - Alice Oliveira Andrade
- Platform of Production and Infection of Malaria Vectors (PIVEM), Laboratory of Entomology, Fiocruz Rondonia, Porto Velho, Brazil
| | - Alessandra da Silva Bastos
- Postgraduate Program in Experimental Biology, Federal University of Rondonia/Fiocruz Rondonia, Porto Velho, Brazil
- Platform of Production and Infection of Malaria Vectors (PIVEM), Laboratory of Entomology, Fiocruz Rondonia, Porto Velho, Brazil
| | | | - Jansen Fernandes Medeiros
- Postgraduate Program in Experimental Biology, Federal University of Rondonia/Fiocruz Rondonia, Porto Velho, Brazil
- Platform of Production and Infection of Malaria Vectors (PIVEM), Laboratory of Entomology, Fiocruz Rondonia, Porto Velho, Brazil
| | - Maisa da Silva Araujo
- Platform of Production and Infection of Malaria Vectors (PIVEM), Laboratory of Entomology, Fiocruz Rondonia, Porto Velho, Brazil
- *Correspondence: Maisa da Silva Araujo,
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Sukkanon C, Masangkay FR, Mala W, Kotepui KU, Wilairatana P, Chareonviriyaphap T, Kotepui M. Prevalence of Plasmodium spp. in Anopheles mosquitoes in Thailand: a systematic review and meta-analysis. Parasit Vectors 2022; 15:285. [PMID: 35933389 PMCID: PMC9357324 DOI: 10.1186/s13071-022-05397-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 07/14/2022] [Indexed: 11/12/2022] Open
Abstract
Background The entomological inoculation rate (EIR) is one of the key indices used to evaluate malaria transmission and vector control interventions. One of the components of the EIR is the sporozoite rate in Anopheles vectors. A systematic review and meta-analysis was performed to identify the prevalence of Plasmodium spp. in field-collected Anopheles species across Thailand. Methods This systematic review was registered under the PROSPERO number CRD42021297255. Studies that focused on the identification of Plasmodium spp. in Anopheles mosquitoes were identified from the electronic databases PubMed, Web of Science, and Scopus. The quality of the identified studies was determined using the Strengthening the Reporting of Observational Studies in Epidemiology approach. The proportion of Anopheles mosquitoes collected, Anopheles vectors for Plasmodium species, and specificity of Anopheles vectors for Plasmodium species were analyzed. The pooled prevalence of Plasmodium species among the primary vectors (Anopheles dirus, Anopheles minimus, and Anopheles maculatus) was estimated using the random-effects model. Results Of the 1113 studies identified, 31 were included in the syntheses. Of the 100,910 Anopheles mosquitoes identified for species and sibling species, An. minimus (40.16%), An. maculatus (16.59%), and Anopheles epiroticus (9.18%) were the most prevalent Anopheles species. Of the 123,286 Anopheles mosquitoes identified, 566 (0.46%) were positive for Plasmodium species. The highest proportions of Plasmodium species were identified in Anopheles hodgkini (2/6, 33.3%), Anopheles nigerrimus (2/24, 8.33%), Anopheles balabacensis (4/84, 4.76%), An. dirus (114/4956, 2.3%), Anopheles annularis (16/852, 1.88%), Anopheles kochi (8/519, 1.54%), Anopheles vagus (3/215, 1.4%), and Anopheles baimaii (1/86, 1.16%). The pooled prevalence of Plasmodium species identified in the main Anopheles vectors was 0.4% of that of Plasmodium species identified in An. dirus was 2.1%, that of Plasmodium species identified in An. minimus was 0.4%, and that of Plasmodium species identified in An. maculatus was 0.4%. Conclusions We found a low prevalence of Plasmodium infection in Anopheles mosquitoes across Thailand. Therefore, the use of EIR to determine the impact of vector control intervention on malaria parasite transmission and elimination in Thailand must be undertaken with caution, as a large number of Anopheles specimens may be required. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05397-2.
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Affiliation(s)
- Chutipong Sukkanon
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | | | - Wanida Mala
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - Kwuntida Uthaisar Kotepui
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand
| | - Polrat Wilairatana
- Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Theeraphap Chareonviriyaphap
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand.,Royal Society of Thailand, Sanam Suea Pa, Dusit, Bangkok, Thailand
| | - Manas Kotepui
- Medical Technology, School of Allied Health Sciences, Walailak University, Tha Sala, Nakhon Si Thammarat, Thailand.
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Tachibana M, Takashima E, Morita M, Sattabongkot J, Ishino T, Culleton R, Torii M, Tsuboi T. Plasmodium vivax transmission-blocking vaccines: Progress, challenges and innovation. Parasitol Int 2021; 87:102525. [PMID: 34896614 DOI: 10.1016/j.parint.2021.102525] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 12/04/2021] [Indexed: 12/12/2022]
Abstract
Existing control measures have significantly reduced malaria morbidity and mortality in the last two decades, although these reductions are now stalling. Significant efforts have been undertaken to develop malaria vaccines. Recently, extensive progress in malaria vaccine development has been made for Plasmodium falciparum. To date, only the RTS,S/AS01 vaccine has been tested in Phase 3 clinical trials and is now under implementation, despite modest efficacy. Therefore, the development of a malaria transmission-blocking vaccine (TBV) will be essential for malaria elimination. Only a limited number of TBVs have reached pre-clinical or clinical development with several major challenges impeding their development, including low immunogenicity in humans. TBV development efforts against P. vivax, the second major cause of malaria morbidity, lag far behind those for P. falciparum. In this review we summarize the latest progress, challenges and innovations in P. vivax TBV research and discuss how to accelerate its development.
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Affiliation(s)
- Mayumi Tachibana
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime 791-0295, Japan.
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan.
| | - Masayuki Morita
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan.
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.
| | - Tomoko Ishino
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime 791-0295, Japan.
| | - Richard Culleton
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime 791-0295, Japan.
| | - Motomi Torii
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime 791-0295, Japan; Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan.
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan.
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10
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Bantuchai S, Imad H, Nguitragool W. Plasmodium vivax gametocytes and transmission. Parasitol Int 2021; 87:102497. [PMID: 34748969 DOI: 10.1016/j.parint.2021.102497] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 08/14/2021] [Accepted: 10/30/2021] [Indexed: 10/19/2022]
Abstract
Malaria elimination means cessation of parasite transmission. At present, the declining malaria incidence in many countries has made elimination a feasible goal. Transmission control has thus been placed at the center of the national malaria control programs. The efficient transmission of Plasmodium vivax from humans to mosquitoes is a key factor that helps perpetuate malaria in endemic areas. A better understanding of transmission is crucial to the success of elimination efforts. Biological delineation of the parasite transmission process is important for identifying and prioritizing new targets of intervention. Identification of the infectious parasite reservoir in the community is key to devising an effective elimination strategy. Here we describe the fundamental characteristics of P. vivax gametocytes - the dynamics of their production, longevity, and the relationship with the total parasitemia - as well as recent advances in the molecular understanding of parasite sexual development. In relation to malaria elimination, factors influencing the human infectivity and the current evidence for a role of asymptomatic carriers in transmission are presented.
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Affiliation(s)
- Sirasate Bantuchai
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok 10400, Thailand.
| | - Hisham Imad
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok 10400, Thailand.
| | - Wang Nguitragool
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok 10400, Thailand; Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok 10400, Thailand.
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11
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Broichhagen J, Kilian N. Chemical Biology Tools To Investigate Malaria Parasites. Chembiochem 2021; 22:2219-2236. [PMID: 33570245 PMCID: PMC8360121 DOI: 10.1002/cbic.202000882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/10/2021] [Indexed: 02/06/2023]
Abstract
Parasitic diseases like malaria tropica have been shaping human evolution and history since the beginning of mankind. After infection, the response of the human host ranges from asymptomatic to severe and may culminate in death. Therefore, proper examination of the parasite's biology is pivotal to deciphering unique molecular, biochemical and cell biological processes, which in turn ensure the identification of treatment strategies, such as potent drug targets and vaccine candidates. However, implementing molecular biology methods for genetic manipulation proves to be difficult for many parasite model organisms. The development of fast and straightforward applicable alternatives, for instance small-molecule probes from the field of chemical biology, is essential. In this review, we will recapitulate the highlights of previous molecular and chemical biology approaches that have already created insight and understanding of the malaria parasite Plasmodium falciparum. We discuss current developments from the field of chemical biology and explore how their application could advance research into this parasite in the future. We anticipate that the described approaches will help to close knowledge gaps in the biology of P. falciparum and we hope that researchers will be inspired to use these methods to gain knowledge - with the aim of ending this devastating disease.
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Affiliation(s)
- Johannes Broichhagen
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP)Robert-Roessle-Strasse 1013125BerlinGermany
| | - Nicole Kilian
- Centre for Infectious DiseasesParasitologyHeidelberg University HospitalIm Neuenheimer Feld 32469120HeidelbergGermany
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12
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Duffy PE. Transmission-Blocking Vaccines: Harnessing Herd Immunity for Malaria Elimination. Expert Rev Vaccines 2021; 20:185-198. [PMID: 33478283 PMCID: PMC11127254 DOI: 10.1080/14760584.2021.1878028] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 01/14/2021] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Transmission-blocking vaccines (TBV) prevent community spread of malaria by targeting mosquito sexual stage parasites, a life-cycle bottleneck, and will be used in elimination programs. TBV rely on herd immunity to reduce mosquito infections and thereby new infections in both vaccine recipients and non-recipients, but do not provide protection once an individual receives an infectious mosquito bite which complicates clinical development. AREAS COVERED Here, we describe the concept and biology behind TBV, and we provide an update on clinical development of the leading vaccine candidate antigens. Search terms 'malaria vaccine,' 'sexual stages,' 'transmission blocking vaccine,' 'VIMT' and 'SSM-VIMT' were used for PubMed queries to identify relevant literature. EXPERT OPINION Candidates targeting P. falciparum zygote surface antigen Pfs25, and its P. vivax orthologue Pvs25, induced functional activity in humans that reduced mosquito infection in surrogate assays, but require increased durability to be useful in the field. Candidates targeting gamete surface antigens Pfs230 and Pfs48/45, respectively, are in or nearing clinical trials. Nanoparticle platforms and adjuvants are being explored to enhance immunogenicity. Efficacy trials require special considerations, such as cluster-randomized designs to measure herd immunity that reduces human and mosquito infection rates, while addressing human and mosquito movements as confounding factors.
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Affiliation(s)
- Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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13
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Mhamilawa LE, Ngasala B, Morris U, Kitabi EN, Barnes R, Soe AP, Mmbando BP, Björkman A, Mårtensson A. Parasite clearance, cure rate, post-treatment prophylaxis and safety of standard 3-day versus an extended 6-day treatment of artemether-lumefantrine and a single low-dose primaquine for uncomplicated Plasmodium falciparum malaria in Bagamoyo district, Tanzania: a randomized controlled trial. Malar J 2020; 19:216. [PMID: 32576258 PMCID: PMC7310382 DOI: 10.1186/s12936-020-03287-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 06/12/2020] [Indexed: 11/19/2022] Open
Abstract
Background Artemisinin-based combination therapy (ACT) resistant Plasmodium falciparum represents an increasing threat to Africa. Extended ACT regimens from standard 3 to 6 days may represent a means to prevent its development and potential spread in Africa. Methods Standard 3-day treatment with artemether–lumefantrine (control) was compared to extended 6-day treatment and single low-dose primaquine (intervention); in a randomized controlled, parallel group, superiority clinical trial of patients aged 1–65 years with microscopy confirmed uncomplicated P. falciparum malaria, enrolled in Bagamoyo district, Tanzania. The study evaluated parasite clearance, including proportion of PCR detectable P. falciparum on days 5 and 7 (primary endpoint), cure rate, post-treatment prophylaxis, safety and tolerability. Clinical, and laboratory assessments, including ECG were conducted during 42 days of follow-up. Blood samples were collected for parasite detection (by microscopy and PCR), molecular genotyping and pharmacokinetic analyses. Kaplan–Meier survival analyses were done for both parasite clearance and recurrence. Results A total of 280 patients were enrolled, 141 and 139 in the control and intervention arm, respectively, of whom 121 completed 42 days follow-up in each arm. There was no difference in proportion of PCR positivity across the arms at day 5 (80/130 (61.5%) vs 89/134 (66.4%), p = 0.44), or day 7 (71/129 (55.0%) vs 70/134 (52.2%), p = 0.71). Day 42 microscopy determined cure rates (PCR adjusted) were 97.4% (100/103) and 98.3% (110/112), p = 0.65, in the control and intervention arm, respectively. Microscopy determined crude recurrent parasitaemia during follow-up was 21/121 (17.4%) in the control and 14/121 (11.6%) in the intervention arm, p = 0.20, and it took 34 days and 42 days in the respective arms for 90% of the patients to remain without recurrent parasitaemia. Lumefantrine exposure was significantly higher in intervention arm from D3 to D42, but cardiac, biochemical and haematological safety was high and similar in both arms. Conclusion Extended 6-day artemether–lumefantrine treatment and a single low-dose of primaquine was not superior to standard 3-day treatment for ACT sensitive P. falciparum infections but, importantly, equally efficacious and safe. Thus, extended artemether–lumefantrine treatment may be considered as a future treatment regimen for ACT resistant P. falciparum, to prolong the therapeutic lifespan of ACT in Africa. Trial registration ClinicalTrials.gov, NCT03241901. Registered July 27, 2017 https://clinicaltrials.gov/show/NCT03241901
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Affiliation(s)
- Lwidiko E Mhamilawa
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden. .,Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
| | - Billy Ngasala
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden.,Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Ulrika Morris
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Eliford Ngaimisi Kitabi
- Office of Clinical Pharmacology, Division of Pharmacometrics, Food and Drugs Administration, Silver Spring, MD, USA
| | - Rory Barnes
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Aung Paing Soe
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden.,Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Bruno P Mmbando
- Tanga Centre, National Institute for Medical Research, Tanga, Tanzania
| | - Anders Björkman
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Andreas Mårtensson
- Department of Women's and Children's Health, International Maternal and Child Health (IMCH), Uppsala University, Uppsala, Sweden
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14
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Ruiz JL, Gómez-Díaz E. The second life of Plasmodium in the mosquito host: gene regulation on the move. Brief Funct Genomics 2020; 18:313-357. [PMID: 31058281 DOI: 10.1093/bfgp/elz007] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 03/08/2019] [Accepted: 03/26/2019] [Indexed: 01/08/2023] Open
Abstract
Malaria parasites face dynamically changing environments and strong selective constraints within human and mosquito hosts. To survive such hostile and shifting conditions, Plasmodium switches transcriptional programs during development and has evolved mechanisms to adjust its phenotype through heterogeneous patterns of gene expression. In vitro studies on culture-adapted isolates have served to set the link between chromatin structure and functional gene expression. Yet, experimental evidence is limited to certain stages of the parasite in the vertebrate, i.e. blood, while the precise mechanisms underlying the dynamic regulatory landscapes during development and in the adaptation to within-host conditions remain poorly understood. In this review, we discuss available data on transcriptional and epigenetic regulation in Plasmodium mosquito stages in the context of sporogonic development and phenotypic variation, including both bet-hedging and environmentally triggered direct transcriptional responses. With this, we advocate the mosquito offers an in vivo biological model to investigate the regulatory networks, transcription factors and chromatin-modifying enzymes and their modes of interaction with regulatory sequences, which might be responsible for the plasticity of the Plasmodium genome that dictates stage- and cell type-specific blueprints of gene expression.
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Affiliation(s)
- José L Ruiz
- Instituto de Parasitología y Biomedicina López-Neyra (IPBLN), Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Elena Gómez-Díaz
- Instituto de Parasitología y Biomedicina López-Neyra (IPBLN), Consejo Superior de Investigaciones Científicas, Granada, Spain
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15
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Chali W, Ashine T, Hailemeskel E, Gashaw A, Tafesse T, Lanke K, Esayas E, Kedir S, Shumie G, Behaksra SW, Bradley J, Yewhalaw D, Mamo H, Petros B, Drakeley C, Gadisa E, Bousema T, Tadesse FG. Comparison of infectivity of Plasmodium vivax to wild-caught and laboratory-adapted (colonized) Anopheles arabiensis mosquitoes in Ethiopia. Parasit Vectors 2020; 13:120. [PMID: 32143713 PMCID: PMC7059271 DOI: 10.1186/s13071-020-3998-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/26/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mosquito-feeding assays that assess transmission of Plasmodium from man-to-mosquito typically use laboratory mosquito colonies. The microbiome and genetic background of local mosquitoes may be different and influence Plasmodium transmission efficiency. In order to interpret transmission studies to the local epidemiology, it is therefore crucial to understand the relationship between infectivity in laboratory-adapted and local mosquitoes. METHODS We assessed infectivity of Plasmodium vivax-infected patients from Adama, Ethiopia, using laboratory-adapted (colony) and wild-caught (wild) mosquitoes raised from larval collections in paired feeding experiments. Feeding assays used 4-6 day-old female Anopheles arabiensis mosquitoes after starvation for 12 h (colony) and 18 h (wild). Oocyst development was assessed microscopically 7 days post-feeding. Wild mosquitoes were identified morphologically and confirmed by genotyping. Asexual parasites and gametocytes were quantified in donor blood by microscopy. RESULTS In 36 paired experiments (25 P. vivax infections and 11 co-infections with P. falciparum), feeding efficiency was higher in colony (median: 62.5%; interquartile range, IQR: 47.0-79.0%) compared to wild mosquitoes (median: 27.8%; IQR: 17.0-38.0%; Z = 5.02; P < 0.001). Plasmodium vivax from infectious individuals (51.6%, 16/31) infected a median of 55.0% (IQR: 6.7-85.7%; range: 5.5-96.7%; n = 14) of the colony and 52.7% (IQR: 20.0-80.0%; range: 3.2-95.0%; n = 14) of the wild mosquitoes. A strong association (ρ(16) = 0.819; P < 0.001) was observed between the proportion of infected wild and colony mosquitoes. A positive association was detected between microscopically detected gametocytes and the proportion of infected colony (ρ(31) = 0.452; P = 0.011) and wild (ρ(31) = 0.386; P = 0.032) mosquitoes. CONCLUSIONS Infectivity assessments with colony and wild mosquitoes yielded similar infection results. This finding supports the use of colony mosquitoes for assessments of the infectious reservoir for malaria in this setting whilst acknowledging the importance of mosquito factors influencing sporogonic development of Plasmodium parasites.
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Affiliation(s)
- Wakweya Chali
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Temesgen Ashine
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Elifaged Hailemeskel
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia.,Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia.,Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands
| | - Abrham Gashaw
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Temesgen Tafesse
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Kjerstin Lanke
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands
| | - Endashaw Esayas
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Soriya Kedir
- Oromia Regional Laboratory, Oromia Regional Health Bureau, Adama, Ethiopia
| | - Girma Shumie
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Sinknesh Wolde Behaksra
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - John Bradley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, WC1E 7HT, London, UK
| | - Delenasaw Yewhalaw
- Tropical and Infectious Diseases Research Center, Jimma University, P.O.Box 5195, Jimma, Ethiopia
| | - Hassen Mamo
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia
| | - Beyene Petros
- Department of Microbial, Cellular and Molecular Biology, College of Natural and Computational Sciences, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, WC1E 7HT, London, UK
| | - Endalamaw Gadisa
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands.,Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, WC1E 7HT, London, UK
| | - Fitsum G Tadesse
- Malaria and Neglected Tropical Diseases Directorate, Armauer Hansen Research Institute, PO Box 1005, Addis Ababa, Ethiopia. .,Department of Medical Microbiology, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands. .,Institute of Biotechnology, Addis Ababa University, PO Box 1176, Addis Ababa, Ethiopia.
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16
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Balasubramanian S, Rahman RS, Lon C, Parobek C, Ubalee R, Hathaway N, Kuntawunginn W, My M, Vy D, Saxe J, Lanteri C, Lin FC, Spring M, Meshnick SR, Juliano JJ, Saunders DL, Lin JT. Efficient Transmission of Mixed Plasmodium falciparum/vivax Infections From Humans to Mosquitoes. J Infect Dis 2020; 221:428-437. [PMID: 31549156 PMCID: PMC7184918 DOI: 10.1093/infdis/jiz388] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 07/23/2019] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND In Southeast Asia, people are often coinfected with different species of malaria (Plasmodium falciparum [Pf] and Plasmodium vivax [Pv]) as well as with multiple clones of the same species. Whether particular species or clones within mixed infections are more readily transmitted to mosquitoes remains unknown. METHODS Laboratory-reared Anopheles dirus were fed on blood from 119 Pf-infected Cambodian adults, with 5950 dissected to evaluate for transmitted infection. Among 12 persons who infected mosquitoes, polymerase chain reaction and amplicon deep sequencing were used to track species and clone-specific transmission to mosquitoes. RESULTS Seven of 12 persons that infected mosquitoes harbored mixed Pf/Pv infection. Among these 7 persons, all transmitted Pv with 2 transmitting both Pf and Pv, leading to Pf/Pv coinfection in 21% of infected mosquitoes. Up to 4 clones of each species were detected within persons. Shifts in clone frequency were detected during transmission. However, in general, all parasite clones in humans were transmitted to mosquitoes, with individual mosquitoes frequently carrying multiple transmitted clones. CONCLUSIONS Malaria diversity in human hosts was maintained in the parasite populations recovered from mosquitoes fed on their blood. However, in persons with mixed Pf/Pv malaria, Pv appears to be transmitted more readily, in association with more prevalent patent gametocytemia.
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Affiliation(s)
- Sujata Balasubramanian
- Institute of Global Health and Infectious Diseases, University of North Carolina, Chapel Hill
| | - Rifat S Rahman
- Institute of Global Health and Infectious Diseases, University of North Carolina, Chapel Hill
| | - Chanthap Lon
- Armed Forces Research Institute of Medical Sciences, Phnom Penh, Cambodia
| | - Christian Parobek
- Institute of Global Health and Infectious Diseases, University of North Carolina, Chapel Hill
| | - Ratawan Ubalee
- Department of Entomology, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Nicholas Hathaway
- Department of Bioinformatics and Integrated Biology, University of Massachusetts, Worcester
| | - Worachet Kuntawunginn
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Mok My
- Royal Cambodian Armed Forces, Phnom Penh, Cambodia
| | - Dav Vy
- Royal Cambodian Armed Forces, Phnom Penh, Cambodia
| | - Jeremy Saxe
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill
| | - Charlotte Lanteri
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Feng-Chang Lin
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill
| | - Michele Spring
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
| | - Steven R Meshnick
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill
| | - Jonathan J Juliano
- Institute of Global Health and Infectious Diseases, University of North Carolina, Chapel Hill
| | - David L Saunders
- Department of Bacterial and Parasitic Diseases, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand
- US Army Medical Materiel Development Activity, Fort Detrick, Maryland
| | - Jessica T Lin
- Institute of Global Health and Infectious Diseases, University of North Carolina, Chapel Hill
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17
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Hamerly T, Tweedell RE, Hritzo B, Nyasembe VO, Tekwani BL, Nanayakkara NPD, Walker LA, Dinglasan RR. NPC1161B, an 8-Aminoquinoline Analog, Is Metabolized in the Mosquito and Inhibits Plasmodium falciparum Oocyst Maturation. Front Pharmacol 2019; 10:1265. [PMID: 31708786 PMCID: PMC6823860 DOI: 10.3389/fphar.2019.01265] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 09/30/2019] [Indexed: 11/26/2022] Open
Abstract
Malaria is a major global health threat, with nearly half the world’s population at risk of infection. Given the recently described delayed clearance of parasites by artemisinin-combined therapies, new antimalarials are needed to facilitate the global effort toward elimination and eradication. NPC1161 is an 8-aminoquinoline that is derived from primaquine with an improved therapeutic profile compared to the parent compound. The (R)-(−) enantiomer (NPC1161B) has a lower effective dose that results in decreased toxic side effects such as hemolysis compared to the (S)-(+)-enantiomer, making it a promising compound for consideration for clinical development. We explored the effect of NPC1161B on Plasmodium falciparum oocyst and sporozoite development to evaluate its potential transmission-blocking activity viz. its ability to cure mosquitoes of an ongoing infection. When mosquitoes were fed NPC1161B 4 days after P. falciparum infection, we observed that total oocyst numbers were not affected by NPC1161B treatment. However, the sporozoite production capacity of the oocysts was impaired, and salivary gland sporozoite infections were completely blocked, rendering the mosquitoes non-infectious. Importantly, NPC1161B did not require prior liver metabolism for its efficacy as is required in mammalian systems, suggesting that an alternative metabolite is produced in the mosquito that is active against the parasite. We performed liquid chromatography–mass spectrometry (LC-MS)/MS analysis of methanol extracts from the midguts of mosquitoes fed on an NPC1161B (434.15 m/z)-treated blood meal and identified a compound with a mass of 520.2 m/z, likely a conjugate of NPC1161B or an oxidized metabolite. These findings establish NPC1161B, and potentially its metabolites, as transmission-blocking candidates for the treatment of P. falciparum.
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Affiliation(s)
- Timothy Hamerly
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States.,Department of Infectious Diseases & Immunology, Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
| | - Rebecca E Tweedell
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States.,Department of Infectious Diseases & Immunology, Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
| | - Bernadette Hritzo
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Vincent O Nyasembe
- Department of Infectious Diseases & Immunology, Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
| | - Babu L Tekwani
- Division of Drug Discovery, Department of Infectious Diseases, Southern Research, Birmingham, AL, United States
| | - N P Dhammika Nanayakkara
- National Center for Natural Products Research, University of Mississippi School of Pharmacy, Oxford, MS, United States
| | - Larry A Walker
- Division of Drug Discovery, Department of Infectious Diseases, Southern Research, Birmingham, AL, United States
| | - Rhoel R Dinglasan
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States.,Department of Infectious Diseases & Immunology, Emerging Pathogens Institute, University of Florida, Gainesville, FL, United States
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Miura K, Swihart BJ, Deng B, Zhou L, Pham TP, Diouf A, Fay MP, Long CA. Strong concordance between percent inhibition in oocyst and sporozoite intensities in a Plasmodium falciparum standard membrane-feeding assay. Parasit Vectors 2019; 12:206. [PMID: 31060594 PMCID: PMC6501457 DOI: 10.1186/s13071-019-3470-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 04/29/2019] [Indexed: 11/22/2022] Open
Abstract
Background Effective malaria transmission-blocking vaccines (TBVs) can support malaria eradication programmes, and the standard membrane-feeding assay (SMFA) has been used as a “gold standard” assay for TBV development. However, in SMFA, the inhibitory activity is commonly measured at oocyst stage of parasites, while it is the sporozoites which transmit malaria from a mosquito to a human. A handful of studies have shown that there is a positive correlation between oocyst and sporozoite intensities. However, no study has been completed to compare inhibition levels in oocyst and sporozoite intensities in the presence of transmission-blocking (TB) antibodies. Results Plasmodium falciparum NF54 gametocytes were fed to Anopheles stephensi mosquitoes with or without anti-Pfs25 or anti-Pfs48/45 TB antibodies in 15 independent assays. For each group, a portion of the mosquitoes was dissected for oocyst counts (day 8 after feed), and a portion of the remaining mosquitoes was dissected for sporozoite counts (day 16). This study covered a large range of oocyst and sporozoite intensities: 0.2 to 80.5 on average for oocysts, and 141 to 77,417 for sporozoites. The sporozoite data were well explained by a zero-inflated negative binomial model, regardless of the presence or absence of TB antibodies. Inhibition levels in both oocyst and sporozoite intensities were determined within the same groups in 9 independent assays. When the level of inhibition in sporozoite number (expressed as Log Mean Ratio, LMR; average number in a control group was divided by the one in a test group, then took a log of the ratio) was plotted against LMR in oocyst number, the best-fit slope of a linear regression was not different from 1 (the best estimate, 1.08; 95% confidence interval, 0.87 to 1.29). Furthermore, a Bland–Altman analysis showed a strong agreement between inhibitions in oocysts and in sporozoites. Conclusions The results indicate that percent inhibition in oocyst intensity of a test sample can be directly converted to % inhibition in sporozoite intensity in P. falciparum SMFA. Therefore, if sporozoite intensity determines transmission rate from mosquitoes to humans, the percent inhibition in oocyst intensity measured by SMFA can be used to estimate the TBV efficacy. Electronic supplementary material The online version of this article (10.1186/s13071-019-3470-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, 20852, USA.
| | - Bruce J Swihart
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 5601 Fishers Lane, Rockville, MD, 20852, USA
| | - Bingbing Deng
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, 20852, USA
| | - Luwen Zhou
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, 20852, USA
| | - Thao P Pham
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, 20852, USA
| | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, 20852, USA
| | - Michael P Fay
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 5601 Fishers Lane, Rockville, MD, 20852, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD, 20852, USA
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Mohanty AK, Nina PB, Ballav S, Vernekar S, Parkar S, D'souza M, Zuo W, Gomes E, Chery L, Tuljapurkar S, Valecha N, Rathod PK, Kumar A. Susceptibility of wild and colonized Anopheles stephensi to Plasmodium vivax infection. Malar J 2018; 17:225. [PMID: 29871629 PMCID: PMC5989471 DOI: 10.1186/s12936-018-2343-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 05/07/2018] [Indexed: 11/16/2022] Open
Abstract
Background As much as 80% of global Plasmodium vivax infections occur in South Asia and there is a shortage of direct studies on infectivity of P. vivax in Anopheles stephensi, the most common urban mosquito carrying human malaria. In this quest, the possible effects of laboratory colonization of mosquitoes on infectivity and development of P. vivax is of interest given that colonized mosquitoes can be genetically less divergent than the field population from which they originated. Methods Patient-derived P. vivax infected blood was fed to age-matched wild and colonized An. stephensi. Such a comparison requires coordinated availability of same-age wild and colonized mosquito populations. Here, P. vivax infection are studied in colonized An. stephensi in their 66th–86th generation and fresh field-caught An. stephensi. Wild mosquitoes were caught as larvae and pupae and allowed to develop into adult mosquitoes in the insectary. Parasite development to oocyst and sporozoite stages were assessed on days 7/8 and 12/13, respectively. Results While there were batch to batch variations in infectivity of individual patient-derived P. vivax samples, both wild and colonized An. stephensi were roughly equally susceptible to oocyst stage Plasmodium infection. At the level of sporozoite development, significantly more mosquitoes with sporozoite load of 4+ were seen in wild than in colonized populations.
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Affiliation(s)
- Ajeet Kumar Mohanty
- National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India
| | - Praveen Balabaskaran Nina
- Departments of Chemistry and Global Health, University of Washington, Seattle, WA, 98195, USA.,Department of Epidemiology and Public Health, Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, 610005, India
| | - Shuvankar Ballav
- National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India
| | - Smita Vernekar
- National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India
| | - Sushma Parkar
- National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India
| | - Maria D'souza
- National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India
| | - Wenyun Zuo
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Edwin Gomes
- Goa Medical College and Hospital, Bambolim, Goa, 403202, India
| | - Laura Chery
- Departments of Chemistry and Global Health, University of Washington, Seattle, WA, 98195, USA
| | | | - Neena Valecha
- National Institute of Malaria Research (ICMR), Sector 8, Dwarka, New Delhi, 110077, India
| | - Pradipsinh K Rathod
- Departments of Chemistry and Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Ashwani Kumar
- National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India.
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Moreno M, Tong-Rios C, Orjuela-Sanchez P, Carrasco-Escobar G, Campo B, Gamboa D, Winzeler EA, Vinetz JM. Continuous Supply of Plasmodium vivax Sporozoites from Colonized Anopheles darlingi in the Peruvian Amazon. ACS Infect Dis 2018; 4:541-548. [PMID: 29465219 PMCID: PMC5902790 DOI: 10.1021/acsinfecdis.7b00195] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In vitro culture of Plasmodium vivax liver stages underlies key understandings of the fundamental biology of this parasite, particularly the latent, hyponozoite stage, toward drug and vaccine development. Here, we report systematic production of Plasmodium vivax sporozoites in colonized Anopheles darlingi mosquitoes in the Peruvian Amazon. Human subject-derived P. vivax-infected blood was fed to Anopheles darlingi females using standard membrane feedings assays. Optimizing A. darlingi infection and sporozoite production included replacement of infected patient donor serum with naïve donor serum, comparing anticoagulants in processing blood samples, and addition of penicillin-streptomycin and ATP to infectious blood meals. Replacement of donor serum by naïve serum in the P. vivax donor blood increased oocysts in the mosquito midgut, and heparin, as anticoagulant, was associated with the highest sporozoite yields. Maintaining blood-fed mosquitoes on penicillin-streptomycin in sugar significantly extended mosquito survival which enabled greater sporozoite yield. In this study, we have shown that a robust P. vivax sporozoite production is feasible in a malaria-endemic setting where infected subjects and a stable A. darlingi colony are brought together, with optimized laboratory conditions.
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Affiliation(s)
- Marta Moreno
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Carlos Tong-Rios
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, San Martín de Porres, Lima, 15102, Peru
| | - Pamela Orjuela-Sanchez
- Department of Pediatrics, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Gabriel Carrasco-Escobar
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, San Martín de Porres, Lima, 15102, Peru
| | - Brice Campo
- Medicines for Malaria Venture, Route de Pré-Bois 20, Meyrin, 1215, Switzerland
| | - Dionicia Gamboa
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, San Martín de Porres, Lima, 15102, Peru
- Instituto de Medicina Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima, 15102, Peru
| | - Elizabeth A. Winzeler
- Department of Pediatrics, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Joseph M. Vinetz
- Division of Infectious Diseases, Department of Medicine, School of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
- Laboratorio ICEMR-Amazonia, Laboratorios de Investigacion y Desarrollo, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Av. Honorio Delgado 430, San Martín de Porres, Lima, 15102, Peru
- Instituto de Medicina Tropical “Alexander von Humboldt”, Universidad Peruana Cayetano Heredia, Lima, 15102, Peru
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Reduction of Mosquito Survival in Mice Vaccinated with Anopheles stephensi Glucose Transporter. BIOMED RESEARCH INTERNATIONAL 2017; 2017:3428186. [PMID: 28804714 PMCID: PMC5540378 DOI: 10.1155/2017/3428186] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 06/12/2017] [Indexed: 01/14/2023]
Abstract
Despite the fact that recent efforts to control/eradicate malaria have contributed to a significant decrease in the number of cases and deaths, the disease remains a global health challenge. Vaccines based on mosquito salivary gland antigens are a potential approach for reducing vector populations and malaria parasites. The Anopheles AGAP007752 gene encodes for a glucose transporter that is upregulated during Plasmodium infection, and its knockdown decreases the number of sporozoites in mosquito salivary glands. These results together with the fact that glucose is a vital source of energy suggested that a glucose transporter is a candidate protective antigen for the control of mosquito infestations and Plasmodium infection. To address this hypothesis, herein we investigate the effect of mice vaccination with an immunogenic peptide from mosquito glucose transporter on Anopheles stephensi fitness and Plasmodium berghei infection. We showed that vaccination with a peptide of glucose transporter reduced mosquito survival by 5% when compared to controls. However, the reduction in Plasmodium infection was not significant in mosquitoes fed on vaccinated mice. The effect of the peptide vaccination on mosquito survival is important to reduce infestation by malaria vectors. These results support further research on developing glucose transporter-based vaccines to reduce mosquito fitness.
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22
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Balabaskaran Nina P, Mohanty AK, Ballav S, Vernekar S, Bhinge S, D'souza M, Walke J, Manoharan SK, Mascarenhas A, Gomes E, Chery L, Valecha N, Kumar A, Rathod PK. Dynamics of Plasmodium vivax sporogony in wild Anopheles stephensi in a malaria-endemic region of Western India. Malar J 2017; 16:284. [PMID: 28693607 PMCID: PMC5504555 DOI: 10.1186/s12936-017-1931-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 07/04/2017] [Indexed: 11/16/2022] Open
Abstract
Background In global efforts to track mosquito infectivity and parasite elimination, controlled mosquito-feeding experiments can help in understanding the dynamics of parasite development in vectors. Anopheles stephensi is often accepted as the major urban malaria vector that transmits Plasmodium in Goa and elsewhere in South Asia. However, much needs to be learned about the interactions of Plasmodium vivax with An. stephensi. As a component of the US NIH International Center of Excellence for Malaria Research (ICEMR) for Malaria Evolution in South Asia (MESA), a series of membrane-feeding experiments with wild An. stephensi and P. vivax were carried out to better understand this vector-parasite interaction. Methods Wild An. stephensi larvae and pupae were collected from curing water in construction sites in the city of Ponda, Goa, India. The larvae and pupae were reared at the MESA ICEMR insectary within the National Institute of Malaria Research (NIMR) field unit in Goa until they emerged into adult mosquitoes. Blood for membrane-feeding experiments was obtained from malaria patients at the local Goa Medical College and Hospital who volunteered for the study. Parasites were counted by Miller reticule technique and correlation between gametocytaemia/parasitaemia and successful mosquito infection was studied. Results A weak but significant correlation was found between patient blood gametocytaemia/parasitaemia and mosquito oocyst load. No correlation was observed between gametocytaemia/parasitaemia and oocyst infection rates, and between gametocyte sex ratio and oocyst load. When it came to development of the parasite in the mosquito, a strong positive correlation was observed between oocyst midgut levels and sporozoite infection rates, and between oocyst levels and salivary gland sporozoite loads. Kinetic studies showed that sporozoites appeared in the salivary gland as early as day 7, post-infection. Conclusions This is the first study in India to carry out membrane-feeding experiments with wild An. stephensi and P. vivax. A wide range of mosquito infection loads and infection rates were observed, pointing to a strong interplay between parasite, vector and human factors. Most of the present observations are in agreement with feeding experiments conducted with P. vivax elsewhere in the world. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1931-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Ajeet Kumar Mohanty
- National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India
| | - Shuvankar Ballav
- National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India
| | - Smita Vernekar
- National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India
| | - Sushma Bhinge
- National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India
| | - Maria D'souza
- National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India
| | - Jayashree Walke
- Departments of Chemistry and of Global Health, University of Washington, Seattle, WA, 98195, USA.,Goa Medical College and Hospital, Bambolim, Goa, 403202, India
| | - Suresh Kumar Manoharan
- Departments of Chemistry and of Global Health, University of Washington, Seattle, WA, 98195, USA.,Goa Medical College and Hospital, Bambolim, Goa, 403202, India
| | - Anjali Mascarenhas
- Departments of Chemistry and of Global Health, University of Washington, Seattle, WA, 98195, USA.,Goa Medical College and Hospital, Bambolim, Goa, 403202, India
| | - Edwin Gomes
- Goa Medical College and Hospital, Bambolim, Goa, 403202, India
| | - Laura Chery
- Departments of Chemistry and of Global Health, University of Washington, Seattle, WA, 98195, USA
| | - Neena Valecha
- National Institute of Malaria Research (ICMR), Sector 8, Dwarka, New Delhi, 110077, India
| | - Ashwani Kumar
- National Institute of Malaria Research, Field Unit, Campal, Goa, 403001, India
| | - Pradipsinh K Rathod
- Departments of Chemistry and of Global Health, University of Washington, Seattle, WA, 98195, USA.
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23
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Kiattibutr K, Roobsoong W, Sriwichai P, Saeseu T, Rachaphaew N, Suansomjit C, Buates S, Obadia T, Mueller I, Cui L, Nguitragool W, Sattabongkot J. Infectivity of symptomatic and asymptomatic Plasmodium vivax infections to a Southeast Asian vector, Anopheles dirus. Int J Parasitol 2017; 47:163-170. [PMID: 28043858 PMCID: PMC5725394 DOI: 10.1016/j.ijpara.2016.10.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Revised: 10/06/2016] [Accepted: 10/12/2016] [Indexed: 12/13/2022]
Abstract
Plasmodium vivax is now the predominant species causing malarial infection and disease in most non-African areas, but little is known about its transmission efficiency from human to mosquitoes. Because the majority of Plasmodium infections in endemic areas are low density and asymptomatic, it is important to evaluate how well these infections transmit. Using membrane feeding apparatus, Anopheles dirus were fed with blood samples from 94 individuals who had natural P. vivax infections with parasitemias spanning four orders of magnitude. We found that the mosquito infection rate was positively correlated with blood parasitemia and that infection began to rise when parasitemia was >10parasites/μl. Below this threshold, mosquito infection is rare and associated with very few oocysts. These findings provide useful information for assessing the human reservoir of transmission and for establishing diagnostic sensitivity required to identify individuals who are most infective to mosquitoes.
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Affiliation(s)
- Kirakorn Kiattibutr
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wanlapa Roobsoong
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Patchara Sriwichai
- Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Teerawat Saeseu
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nattawan Rachaphaew
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Chayanut Suansomjit
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Sureemas Buates
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Thomas Obadia
- Malaria: Parasites & Hosts Unit, Department of Parasites & Insect Vectors, Institut Pasteur, Paris, France; Bioinformatics and Biostatistics Hub, Institut Pasteur, Paris, France
| | - Ivo Mueller
- Malaria: Parasites & Hosts Unit, Department of Parasites & Insect Vectors, Institut Pasteur, Paris, France; Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Liwang Cui
- Department of Entomology, Pennsylvania State University, University Park, PA, USA
| | - Wang Nguitragool
- Department of Molecular Tropical Medicine & Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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Ubalee R, Kim HC, Schuster AL, McCardle PW, Phasomkusolsil S, Takhampunya R, Davidson SA, Lee WJ, Klein TA. Vector Competence of Anopheles kleini and Anopheles sinensis (Diptera: Culicidae) From the Republic of Korea to Vivax Malaria-Infected Blood From Patients From Thailand. JOURNAL OF MEDICAL ENTOMOLOGY 2016; 53:1425-1432. [PMID: 27493248 DOI: 10.1093/jme/tjw109] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 06/03/2016] [Indexed: 06/06/2023]
Abstract
In total, 1,300 each of Anopheles kleini Rueda and Anopheles sinensis Wiedemann sensu stricto (s.s.) females (colonized from the Republic of Korea) and Anopheles dirus Peyton & Harrison (Thai strain) were allowed to feed on blood from Thai malaria patients naturally infected with Plasmodium vivax The overall oocyst infection rates for An. dirus, An. kleini, and An. sinensis s.s. were 77.4, 46.1, and 45.9%, respectively. The mean number of oocysts was significantly higher for An. dirus (82.7) compared with An. kleini (6.1) and An. sinensis s.s. (8.6), whereas the mean number of oocysts for An. kleini and An. sinensis s.s. was similar. The overall sporozoite infection rates for An. dirus, An. kleini, and An. sinensis s.s. dissected on days 14-15, 21, and 28 days post-feed were significantly higher for An. dirus (90.0%) than An. kleini (5.4%), whereas An. kleini sporozoite rates were significantly higher than An. sinensis s.s. (<0.1%). The overall sporozoite indices for positive females with +3 (100-1,000 sporozoites) and +4 (>1,000 sporozoites) salivary gland indices were significantly higher for An. dirus (85.7%), compared with An. kleini (47.1%). Only one An. sinensis s.s. had sporozoites (+2; >10-100 sporozoites). These results indicate that An. kleini is a competent vector of vivax malaria. Although An. sinensis s.s. develops relatively high numbers of oocysts, it is considered a very poor vector of vivax malaria due to a salivary gland barrier.
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Affiliation(s)
- Ratawan Ubalee
- Department of Entomology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences, 315/6 Rajvithi, Phayathai, Bangkok 10400, Thailand (; ; ; , ; )
| | - Heung-Chul Kim
- 5th Medical Detachment, 168th Multifunctional Medical Battalion, 65th Medical Brigade, Unit 15247 APO AP 96205-5247
| | - Anthony L Schuster
- Department of Entomology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences, 315/6 Rajvithi, Phayathai, Bangkok 10400, Thailand (; ; ; , ; )
- Current Address: Preventive Health Services Office, Fort Sam Houston, TX, 78234
| | - Patrick W McCardle
- Department of Entomology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences, 315/6 Rajvithi, Phayathai, Bangkok 10400, Thailand (; ; ; , ; )
- Current Address: Walter Reed Army Institute of Research, Forest Glen, MD, 20910
| | - Siriporn Phasomkusolsil
- Department of Entomology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences, 315/6 Rajvithi, Phayathai, Bangkok 10400, Thailand (; ; ; , ; )
| | - Ratree Takhampunya
- Department of Entomology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences, 315/6 Rajvithi, Phayathai, Bangkok 10400, Thailand (; ; ; , ; )
| | - Silas A Davidson
- Department of Entomology, US Army Medical Component, Armed Forces Research Institute of Medical Sciences, 315/6 Rajvithi, Phayathai, Bangkok 10400, Thailand (; ; ; , ; )
| | - Won-Ja Lee
- Korea National Institute of Health, Cheongju-Si, Chungbuk Province, 28159, Republic of Korea
| | - Terry A Klein
- Medical Department Activity-Korea (MEDDAC-K)/65th Medical Brigade, Unit 15281, Box 754, AP, 96205
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Infection of laboratory colonies of Anopheles mosquitoes with Plasmodium vivax from cryopreserved clinical isolates. Int J Parasitol 2016; 46:679-83. [PMID: 27456552 DOI: 10.1016/j.ijpara.2016.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 06/08/2016] [Accepted: 06/21/2016] [Indexed: 01/17/2023]
Abstract
Plasmodium vivax is the most geographically widespread malaria parasite. Unique features of transmission biology complicate P. vivax control. Interventions targeting transmission are required for malaria eradication. In the absence of an in vitro culture, transmission studies rely on live isolates from non-human primates or endemic regions. Here, we demonstrate P. vivax gametocytes from both India and Brazil are stable during cryopreservation. Importantly, cryopreserved gametocytes from Brazil were capable of infecting three anopheline mosquito species in feedings done in the United States. These findings create new opportunities for transmission studies in diverse locales.
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A semi-automated luminescence based standard membrane feeding assay identifies novel small molecules that inhibit transmission of malaria parasites by mosquitoes. Sci Rep 2015; 5:18704. [PMID: 26687564 PMCID: PMC4685452 DOI: 10.1038/srep18704] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 11/24/2015] [Indexed: 12/27/2022] Open
Abstract
Current first-line treatments for uncomplicated falciparum malaria rapidly clear the asexual stages of the parasite, but do not fully prevent parasite transmission by mosquitoes. The standard membrane feeding assay (SMFA) is the biological gold standard assessment of transmission reducing activity (TRA), but its throughput is limited by the need to determine mosquito infection status by dissection and microscopy. Here we present a novel dissection-free luminescence based SMFA format using a transgenic Plasmodium falciparum reporter parasite without resistance to known antimalarials and therefore unrestricted in its utility in compound screening. Analyses of sixty-five compounds from the Medicines for Malaria Venture validation and malaria boxes identified 37 compounds with high levels of TRA (>80%); different assay modes allowed discrimination between gametocytocidal and downstream modes of action. Comparison of SMFA data to published assay formats for predicting parasite infectivity indicated that individual in vitro screens show substantial numbers of false negatives. These results highlight the importance of the SMFA in the screening pipeline for transmission reducing compounds and present a rapid and objective method. In addition we present sixteen diverse chemical scaffolds from the malaria box that may serve as a starting point for further discovery and development of malaria transmission blocking drugs.
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27
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A comparison of Plasmodium falciparum circumsporozoite protein-based slot blot and ELISA immuno-assays for oocyst detection in mosquito homogenates. Malar J 2015; 14:451. [PMID: 26573271 PMCID: PMC4647817 DOI: 10.1186/s12936-015-0954-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 10/21/2015] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND The infectivity of Plasmodium gametocytes is typically determined by microscopically examining the midguts of mosquitoes that have taken a blood meal containing potentially infectious parasites. Such assessments are required for the development and evaluation of transmission-reducing interventions (TRI), but are limited by subjectivity, technical complexity and throughput. The detection of circumsporozoite protein (CSP) by enzyme-linked immunosorbent assay (ELISA) and enhanced chemiluminescent slot-blot (ECL-SB) may be used as objective, scalable alternatives to microscopy for the determination of infection prevalence. METHODS To compare the performance of the CSP ELISA and ECL-SB for the detection of mosquito infection, four groups of Anopheles stephensi mosquitoes were infected with cultured Plasmodium falciparum gametocytes. At day-8 post-infection (PI), parasite status was determined by microscopy for a sample of mosquitoes from each group. At days 8 and 10 PI, the parasite status of separate mosquito samples was analysed by both CSP ELISA and ECL-SB. RESULTS When mosquito samples were analysed 8 days PI, the ECL-SB determined similar infection prevalence to microscopy; CSP ELISA lacked the sensitivity to detect CSP in all infected mosquitoes at this early time point. When mosquitoes were analysed 48 h later (10 days PI) both assays performed as well as microscopy for infection detection. CONCLUSIONS Whilst microscopical examination of mosquito guts is of great value when quantification of parasite burden is required, ECL-SB and CSP ELISA are suitable alternatives at day 10 PI when infection prevalence is the desired endpoint, although CSP ELISA is not suitable at day 8 PI. These results are important to groups considering large-scale implementation of TRI.
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Pinheiro-Silva R, Borges L, Coelho LP, Cabezas-Cruz A, Valdés JJ, do Rosário V, de la Fuente J, Domingos A. Gene expression changes in the salivary glands of Anopheles coluzzii elicited by Plasmodium berghei infection. Parasit Vectors 2015; 8:485. [PMID: 26395987 PMCID: PMC4580310 DOI: 10.1186/s13071-015-1079-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 09/09/2015] [Indexed: 11/10/2022] Open
Abstract
Background Malaria is a devastating infectious disease caused by Plasmodium parasites transmitted through the bites of infected Anopheles mosquitoes. Salivary glands are the only mosquito tissue invaded by Plasmodium sporozoites, being a key stage for the effective parasite transmission, making the study of Anopheles sialome highly relevant. Methods RNA-sequencing was used to compare differential gene expression in salivary glands of uninfected and Plasmodium berghei-infected Anopheles coluzzii mosquitoes. RNA-seq results were validated by quantitative RT-PCR. The transmembrane glucose transporter gene AGAP007752 was selected for functional analysis by RNA interference. The effect of gene silencing on infection level was evaluated. The putative function and tertiary structure of the protein was assessed. Results RNA-seq data showed that 2588 genes were differentially expressed in mosquitoes salivary glands in response to P. berghei infection, being 1578 upregulated and 1010 downregulated. Metabolism, Immunity, Replication/Transcription/Translation, Proteolysis and Transport were the mosquito gene functional classes more affected by parasite infection. Endopeptidase coding genes were the most abundant within the differentially expressed genes in infected salivary glands (P < 0.001). Based on its putative function and expression level, the transmembrane glucose transporter gene, AGAP007752, was selected for functional analysis by RNA interference. The results demonstrated that the number of sporozoites was 44.3 % lower in mosquitoes fed on infected mice after AGAPP007752 gene knockdown when compared to control (P < 0.01). Conclusions Our hypothesis is that the protein encoded by the gene AGAPP007752 may play a role on An. coluzzii salivary glands infection by Plasmodium parasite, working as a sporozoite receptor and/or promoting a favorable environment for the capacity of sporozoites. Electronic supplementary material The online version of this article (doi:10.1186/s13071-015-1079-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Lara Borges
- Instituto de Higiene e Medicina Tropical (IHMT), Lisbon, Portugal. .,Global Health and Tropical Medicine (GHMT), Instituto de Higiene e Medicina Tropical (IHMT), Lisbon, Portugal.
| | - Luís Pedro Coelho
- Unidade de Biofísica e Expressão Genética, Instituto de Medicina Molecular (IMM), Lisbon, Portugal.
| | - Alejandro Cabezas-Cruz
- Center for Infection and Immunity of Lille (CIIL), Institut Pasteur de Lille, Lille, France. .,SaBio. Instituto de Investigación de Recursos Cinegéticos, IREC-CSIC-UCLM-JCCM, Ciudad Real, Spain.
| | - James J Valdés
- Institute of Parasitology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic.
| | | | - José de la Fuente
- SaBio. Instituto de Investigación de Recursos Cinegéticos, IREC-CSIC-UCLM-JCCM, Ciudad Real, Spain. .,Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, USA.
| | - Ana Domingos
- Instituto de Higiene e Medicina Tropical (IHMT), Lisbon, Portugal. .,Global Health and Tropical Medicine (GHMT), Instituto de Higiene e Medicina Tropical (IHMT), Lisbon, Portugal.
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Wang Y, Zhong D, Cui L, Lee MC, Yang Z, Yan G, Zhou G. Population dynamics and community structure of Anopheles mosquitoes along the China-Myanmar border. Parasit Vectors 2015; 8:445. [PMID: 26338527 PMCID: PMC4559305 DOI: 10.1186/s13071-015-1057-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 08/26/2015] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Understanding the ecology of malaria vectors such as species composition and population dynamics is essential for developing cost-effective strategies to control mosquito vector populations. METHODS Adult mosquitoes (n = 79,567) were collected in five villages along the China-Myanmar border from April 2012 to September 2014 using the CDC light trap without bait method. Mosquito community structure, Anopheles species composition and diversity were analyzed. RESULTS Twenty species of Anopheles mosquitoes were identified, with An. minimus s.l. accounting for 85% of the total collections. Mosquito densities varied from 0.05 females per trap per night (f/t/n) to 3.00 f/t/n, with strong seasonality in all sites and densities peaked from June to August. An. minimus s.l. was predominant (accounting for 54-91% of total captures) in four villages, An. maculatus s.l. was predominant (71%) in the high elevation village of Dao Nong, and An. culicifacies accounted for 15% of total captures in the peri-urban area of Simsa Lawk. All 20 species have been captured in the Mung Seng Yang village, 18 and 15 species in Ja Htu Kawng and Na Bang respectively, and nine species in both Simsa Lawk and Dao Nong. Species richness peaked from April to August. Species diversity, species dominance index, and species evenness fluctuated substantially from time to time with no clear seasonality, and varied greatly amongst villages. CONCLUSIONS Mosquitoes were abundant in the China-Myanmar bordering agricultural area with clear seasonality. Species composition and density were strongly affected by natural environments. The targeted intervention strategy should be developed and implemented so as to achieve cost-effectiveness for malaria control and elimination along the border areas.
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Affiliation(s)
- Ying Wang
- Institute of Tropical Medicine, Third Military Medical University, Chongqing, China.
| | - Daibin Zhong
- Program in Public Health, University of California at Irvine, Irvine, CA, USA.
| | - Liwang Cui
- Department of Entomology, Pennsylvania State University, University Park, PA, USA.
| | - Ming-Chieh Lee
- Program in Public Health, University of California at Irvine, Irvine, CA, USA.
| | - Zhaoqing Yang
- Department of Pathogen Biology and Immunology, Kunming Medical University, Kunming, China.
| | - Guiyun Yan
- Program in Public Health, University of California at Irvine, Irvine, CA, USA.
| | - Guofa Zhou
- Program in Public Health, University of California at Irvine, Irvine, CA, USA.
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Stone WJR, Bousema T. The Standard Membrane Feeding Assay: Advances Using Bioluminescence. Methods Mol Biol 2015; 1325:101-12. [PMID: 26450383 DOI: 10.1007/978-1-4939-2815-6_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In preclinical development, the efficacy of agents with putative effects on Plasmodium transmission is determined using the standard membrane feeding assay (SMFA). Because the end-point of the SMFA is normally the enumeration of oocysts on the mosquito midgut, the assays reliance on mosquito dissections and microscopy makes it slow, labor-intensive, and subjective. Below, we describe a novel method of assessing the transmission of a Plasmodium falciparum strain expressing the firefly luciferase protein in the SMFA. The use of a transgenic parasite strain allows for the elimination of mosquito dissections in favor of a simple approach where whole mosquitoes are homogenized and examined directly for luciferase activity. Measuring the mean luminescence intensity of groups of individual or pooled mosquitoes provides comparable estimates of transmission reducing activity at 5-10-fold the throughput capacity of the standard microscopy based SMFA. This high efficiency protocol may be of interest to groups screening novel drug compounds, vaccine candidates, or sera from malaria exposed individuals for transmission reducing activity (TRA).
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Affiliation(s)
- Will J R Stone
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, GA 6525, The Netherlands
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, GA 6525, The Netherlands. .,Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
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Neal AT, Taylor PD. Local mate competition and transmission bottlenecks: A new model for understanding malaria parasite and other sex ratios. J Theor Biol 2014; 363:381-9. [DOI: 10.1016/j.jtbi.2014.08.037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 08/08/2014] [Accepted: 08/19/2014] [Indexed: 01/22/2023]
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Mathias DK, Jardim JG, Parish LA, Armistead JS, Trinh HV, Kumpitak C, Sattabongkot J, Dinglasan RR. Differential roles of an Anopheline midgut GPI-anchored protein in mediating Plasmodium falciparum and Plasmodium vivax ookinete invasion. INFECTION GENETICS AND EVOLUTION 2014; 28:635-47. [PMID: 24929123 DOI: 10.1016/j.meegid.2014.05.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 05/19/2014] [Accepted: 05/23/2014] [Indexed: 12/14/2022]
Abstract
Novel strategies to directly thwart malaria transmission are needed to maintain the gains achieved by current control measures. Transmission-blocking interventions (TBIs), namely vaccines and drugs targeting parasite or mosquito molecules required for vector-stage parasite development, have been recognized as promising approaches for preventing malaria transmission. However, the number of TBI targets is limited and their degree of conservation among the major vector-parasite systems causing human disease is unclear. Therefore, discovery and characterization of novel proteins involved in vector-stage parasite development of Plasmodium falciparum and Plasmodium vivax is paramount. We mined the recent Anopheles gambiae midgut lipid raft proteome for putative mosquito-derived TBI targets and characterized a secreted glycoconjugate of unknown function, AgSGU. We analyzed molecular variation in this protein among a range of anopheline mosquitoes, determined its transcriptomic and proteomic profiles, and conducted both standard and direct membrane feeding assays with P. falciparum (lab/field) and P. vivax (field) in An. gambiae and Anopheles dirus. We observed that α-AgSGU antibodies significantly reduced midgut infection intensity for both lab and field isolates of P. falciparum in An. gambiae and An. dirus. However, no transmission-reducing effects were noted when comparable concentrations of antibodies were included in P. vivax-infected blood meals. Although antibodies against AgSGU exhibit transmission-reducing activity, the high antibody titer required for achieving 80% reduction in oocyst intensity precludes its consideration as a malaria mosquito-based TBI candidate. However, our results suggest that P. falciparum and P. vivax ookinetes use a different repertoire of midgut surface glycoproteins for invasion and that α-AgSGU antibodies, as well as antibodies to other mosquito-midgut microvillar surface proteins, may prove useful as tools for interrogating Plasmodium-mosquito interactions.
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Affiliation(s)
- Derrick K Mathias
- W. Harry Feinstone Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health & Malaria Research Institute, Baltimore, MD 21205, USA.
| | - Juliette G Jardim
- W. Harry Feinstone Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health & Malaria Research Institute, Baltimore, MD 21205, USA.
| | - Lindsay A Parish
- W. Harry Feinstone Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health & Malaria Research Institute, Baltimore, MD 21205, USA.
| | - Jennifer S Armistead
- W. Harry Feinstone Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health & Malaria Research Institute, Baltimore, MD 21205, USA.
| | - Hung V Trinh
- W. Harry Feinstone Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health & Malaria Research Institute, Baltimore, MD 21205, USA.
| | | | | | - Rhoel R Dinglasan
- W. Harry Feinstone Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health & Malaria Research Institute, Baltimore, MD 21205, USA.
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Stone WJR, Eldering M, van Gemert GJ, Lanke KHW, Grignard L, van de Vegte-Bolmer MG, Siebelink-Stoter R, Graumans W, Roeffen WFG, Drakeley CJ, Sauerwein RW, Bousema T. The relevance and applicability of oocyst prevalence as a read-out for mosquito feeding assays. Sci Rep 2013; 3:3418. [PMID: 24301557 PMCID: PMC4894383 DOI: 10.1038/srep03418] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 11/20/2013] [Indexed: 12/02/2022] Open
Abstract
Mosquito feeding assays are important in evaluations of malaria transmission-reducing interventions. The proportion of mosquitoes with midgut oocysts is commonly used as an outcome measure, but in natural low intensity infections the effect of oocyst non-rupture on mosquito infectivity is unclear. By identifying ruptured as well as intact oocysts, we show that in low intensity P. falciparum infections i) 66.7–96.7% of infected mosquitoes experienced oocyst rupture between 11–21 days post-infection, ii) oocyst rupture led invariably to sporozoite release, iii) oocyst rupture led to salivary gland infections in 97.8% of mosquitoes, and iv) 1250 (IQR 313-2400) salivary gland sporozoites were found per ruptured oocyst. These data show that infectivity can be predicted with reasonable certainty from oocyst prevalence in low intensity infections. High throughput methods for detecting infection in whole mosquitoes showed that 18s PCR but not circumsporozoite ELISA gave a reliable approximation of mosquito infection rates on day 7 post-infection.
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Affiliation(s)
- Will J R Stone
- 1] Department of Medical Microbiology, Radboud university medical center, Nijmegen, The Netherlands [2]
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Zhu G, Xia H, Zhou H, Li J, Lu F, Liu Y, Cao J, Gao Q, Sattabongkot J. Susceptibility of Anopheles sinensis to Plasmodium vivax in malarial outbreak areas of central China. Parasit Vectors 2013; 6:176. [PMID: 23768077 PMCID: PMC3695883 DOI: 10.1186/1756-3305-6-176] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 06/10/2013] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Anopheles sinensis, Anopheles anthropophagus, Anopheles minimus and Anopheles dirus are the major vectors of malaria transmission in China. Anopheles sinensis is considered a secondary vector due to its relatively low malaria-transmission ability. However, in 2005, an outbreak of over 40,000 Plasmodium vivax malaria cases was reported in areas where Anopheles sinensis was the only major vector. Therefore, it is necessary to reassess the malaria transmission ability of this vector species in China. METHODS Laboratory colonies of An. sinensis and An. anthropophagus, and first-generation progeny (F1) of An. sinensis that had been collected in central China, were infected by direct membrane feeding assay with mono-vivax gametocyte-containing blood collected from vivax-infected patients. The mosquitoes were kept for 7 to 14 days post-blood feeding to allow parasites to develop into oocysts and sporozoites. Infectivity was measured by dissecting midguts and salivary glands. The presence of oocysts and sporozoites was determined by microscopy at 7 and 14 days post-blood feeding, and the numbers of gametocytes and asexual parasites, as well as mosquito parasite infections, were determined. RESULTS The positive oocyst and sporozoite feed rates of the 142 pairs of lab-colony An. sinensis and An. anthropophagus were not significantly different, and the same results were found with the 10 pairs of laboratory and F1 An. sinensis. An. sinensis had more oocysts/midgut at 7 days post-feeding than An. anthropophagus, but the gametocytemia, asexual parasitemia, and ratio of macrogametocytes to microgametocytes, did not correlate with either oocyst or sporozoite infection. However, in the oocyst-positive mosquitoes, there was a correlation between gametocytemia and the average oocyst number/midgut. CONCLUSIONS The susceptibility of An. sinensis (both laboratory and F1) to P. vivax-infected blood is similar to Anopheles anthropophagus, when evaluated by membrane feeding assay under laboratory conditions. In recent years, in central China, the vivax malaria transmission ability of An. sinensis has probably been underestimated. Further studies of this species in other regions are needed. An. sinensis could also be a good candidate vector for evaluating candidate malaria transmission-blocking vaccines (TBV).
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Mehrunissa A, Sharma A, Parasher H, Dhayal D, Singh OP, Nanda N, Adak T. Comparative susceptibilities of species T and U of the Anopheles fluviatilis complex to Plasmodium vinckei petteri sporogony. JOURNAL OF MEDICAL ENTOMOLOGY 2013; 50:594-597. [PMID: 23802454 DOI: 10.1603/me12161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Anopheles fluviatilis James is an important malaria vector in Indian subcontinent. An. fluviatilis exists as a complex of three sibling species, of which two species, T and U, have been colonized so far. Attempts were made to study the comparative susceptibility of species T and U of the An. fluviatilis complex to rodent malaria parasite Plasmodium vinckei petteri by using Anopheles stephensi Liston as calibrator for variable infectivity in different isolates. An. stephensi, which was used as control, became readily infected, with 60-65% mosquitoes carrying developing oocysts, whereas in species T and species U, approximately 50 and 63%, respectively, of mosquitoes carried oocyts. An. fluviatilis species T was found comparatively less susceptible to P. v. petteri sporogonic development compared with species U. Moreover, significantly lesser sporozoites rate (11%) was observed in species T compared with 31% in species U. Species T and species U are not considered as malaria vectors in India in the field. However, in the laboratory, both these species are able to support the malaria sporogony.
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Affiliation(s)
- A Mehrunissa
- National Institute of Malaria Research, Sector-08, Dwarka, New Delhi 110077, India
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Measuring the blockade of malaria transmission--an analysis of the Standard Membrane Feeding Assay. Int J Parasitol 2012; 42:1037-44. [PMID: 23023048 DOI: 10.1016/j.ijpara.2012.09.002] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/13/2012] [Accepted: 09/17/2012] [Indexed: 01/11/2023]
Abstract
The standard membrane feeding assay (SMFA) is currently considered to be the 'gold standard' for assessing the effectiveness of malaria transmission blocking interventions (TBIs) in vivo. The operation and analysis of SMFAs has varied between laboratories: field scientists often measure TBI efficacy as a reduction in the prevalence of infected mosquitoes whilst laboratory scientists are more likely to quote efficacy as a change in the number of oocysts within the mosquito. These metrics give outputs that differ widely, resulting in a need for greater understanding of how the SMFA informs TBI assessment. Using data from 536 different assays (conducted on Plasmodium falciparum and Plasmodium berghei, in either Anopheles gambiae or Anopheles stephensi) it is shown that the relationship between these metrics is complex, yet predictable. Results demonstrate that the distribution of oocysts between mosquitoes is highly aggregated, making efficacy estimates based on reductions in intensity highly uncertain. Analysis of 30 SMFAs carried out on the same TBI confirms that the observed reduction in prevalence depends upon the parasite exposure (as measured by oocyst intensity in the control group), with assays which have lower exposure appearing more effective. By contrast, if efficacy is estimated as a reduction in oocyst intensity, then this candidate demonstrated constant efficacy, irrespective of the exposure level. To report transmission-blockade efficacy accurately, the results of SMFAs should give both the prevalence and intensity of oocysts in both the control and intervention group. Candidates should be assessed against a range of parasite exposures to allow laboratory results to be extrapolated to different field situations. Currently, many studies assessing TBIs are underpowered and uncertainties in efficacy estimates rarely reported. Statistical techniques that account for oocyst over-dispersion can reduce the number of mosquitoes that need to be dissected and allow TBI candidates from different laboratories to be accurately compared.
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Bounkeua V, Li F, Chuquiyauri R, Abeles SR, McClean CM, Neyra V, Llanos-Cuentas A, Yori PP, Vinetz JM. Lack of molecular correlates of Plasmodium vivax ookinete development. Am J Trop Med Hyg 2011; 85:207-13. [PMID: 21813836 DOI: 10.4269/ajtmh.2011.10-0729] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Previous studies of Plasmodium vivax transmission to Anopheles spp. mosquitoes have not been able to predict mosquito infectivity on the basis of microscopic or molecular quantification of parasites (total parasites in the sample or total number of gametocytes) in infected blood. Two methods for production of P. vivax ookinete cultures in vitro, with yields of 10(6) macrogametocytes, 10(4) zygotes, and 10(3) ookinetes, respectively, per 10 mL of P. vivax-infected patient blood with approximately 0.01% parasitemia, were used to study P. vivax sexual stage development. The quantity of gametocytes, determined by counting Giemsa-stained blood smears, and quantity and type of gametocyte as determined by quantitative reverse transcriptase-polymerase chain reaction for Pvalpha tubulin II and macrogametocyte-specific pvg377 did not predict ookinete yield. Factors that affect the efficiency of in vitro P. vivax ookinete transformation remain poorly understood.
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Affiliation(s)
- Viengngeun Bounkeua
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
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Noden BH, Vaughan JA, Pumpuni CB, Beier JC. Mosquito ingestion of antibodies against mosquito midgut microbiota improves conversion of ookinetes to oocysts for Plasmodium falciparum, but not P. yoelii. Parasitol Int 2011; 60:440-6. [PMID: 21763778 DOI: 10.1016/j.parint.2011.07.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 06/07/2011] [Accepted: 07/04/2011] [Indexed: 11/25/2022]
Abstract
The mosquito midgut is a site of complex interactions between the mosquito, the malaria parasite and the resident bacterial flora. In laboratory experiments, we observed significant enhancement of Plasmodium falciparum oocyst production when Anopheles gambiae (Diptera: Culicidae) mosquitoes were membrane-fed on infected blood containing gametocytes from in vitro cultures mixed with sera from rabbits immunized with A. gambiae midguts. To identify specific mechanisms, we evaluated whether the immune sera was interfering with the usual limiting activity of gram-negative bacteria in An. gambiae midguts. Enhancement of P. falciparum infection rates occurred at some stage between the ookinete and oocyst stage and was associated with greater numbers of oocysts in mosquitoes fed on immune sera. The same immune sera did not affect the sporogonic development of P. yoelii, a rodent malaria parasite. Not only did antibodies in the immune sera recognize several types of midgut-derived gram-negative bacteria (Pseudomonas spp. and Cedecea spp.), but gentamicin provided in the sugar meal 3 days before an infectious P. falciparum blood meal mixed with immune sera eliminated the enhancing effect. These results suggest that gram-negative bacteria, which normally impair P. falciparum development between the ookinete and oocyst stage, were altered by specific anti-bacterial antibodies produced by immunizing rabbits with non-antibiotic-treated midgut lysates. Because of the differences in developmental kinetics between human and rodent malaria species, the anti-bacterial antibodies had no effect on P. yoelii because their ookinetes leave the midgut much earlier than P. falciparum and so are not influenced as strongly by resident midgut bacteria. While this study highlights the complex interactions occurring between the parasite, mosquito, and midgut microbiota, the ultimate goal is to determine the influence of midgut microbiota on Plasmodium development in anopheline midguts in malaria endemic settings.
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Affiliation(s)
- Bruce H Noden
- Department of Biomedical Science, School of Health and Applied Sciences, Polytechnic of Namibia, Windhoek, Namibia.
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McClean CM, Alvarado HG, Neyra V, Llanos-Cuentas A, Vinetz JM. Optimized in vitro production of Plasmodium vivax ookinetes. Am J Trop Med Hyg 2011; 83:1183-6. [PMID: 21118919 DOI: 10.4269/ajtmh.2010.10-0195] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Previous reports have described obtaining mature Plasmodium vivax ookinetes in vitro using blood from infected patients using a simplified, field-based protocol. Here, we report protocols that produce improved P. vivax ookinete yields and morphological development. Optimal conditions included induction of gametogenesis using 10 mM Tris, 170 mM NaCl, 10 mM glucose, 25 mM NaHCO(3), and 100 μM xanthurenic acid for 90 minutes at pH 8.0-8.2, followed by culture in RPMI-1640, 50 mg/mL hypoxanthine, 25 mM HEPES, 29 mM NaHCO(3), 2 mM L-glutamine, and 20% fetal bovine serum at pH 8.4 for 36 hours. Ookinetes were produced in 86% (18/21) of optimized in vitro cultures; yields ranged from 6.5 × 10(4) to 2.8 × 10(6); percent gametocyte conversion ranged from 1.4% to 4.7%. This improved method is suitable for preparation of P. vivax ookinetes in quantities sufficient for biochemical, molecular, and cell biological analysis where basic laboratory facilities are in proximity to patients with vivax malaria.
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Affiliation(s)
- Colleen M McClean
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, California 92093-0741, USA.
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Bounkeua V, Li F, Vinetz JM. In vitro generation of Plasmodium falciparum ookinetes. Am J Trop Med Hyg 2011; 83:1187-94. [PMID: 21118920 DOI: 10.4269/ajtmh.2010.10-0433] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Plasmodium transmission from the human host to the mosquito depends on the ability of gametocytes to differentiate into ookinetes, the invasive form of the parasite that invades and establishes infection in the mosquito midgut. The biology of P. falciparum ookinetes is poorly understood, because sufficient quantities of this stage of this parasite species have not been obtained for detailed study. This report details methods to optimize production of P. falciparum sexual stage parasites, including ookinetes. Flow cytometric sorting was used to separate diploid/tetraploid zygotes and ookinetes from haploid gametetocytes and unfertilized gametes based on DNA content. Consistent production of 10(6)-10(7) P. falciparum ookinetes per 10 mL culture was observed, with ookinete transformation present in 10-40% of all parasite forms. Transmission electron micrographs of cultured parasites confirmed ookinete development.
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Affiliation(s)
- Viengngeun Bounkeua
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, California 92093-0741, USA
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Shimizu S, Osada Y, Kanazawa T, Tanaka Y, Arai M. Suppressive effect of azithromycin on Plasmodium berghei mosquito stage development and apicoplast replication. Malar J 2010; 9:73. [PMID: 20219090 PMCID: PMC2846956 DOI: 10.1186/1475-2875-9-73] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 03/10/2010] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Azithromycin (AZM) is a macrolide antibiotic that displays an excellent safety profile even in children and pregnant women and has been shown to have anti-malarial activity against blood stage Plasmodium falciparum. This study evaluated the transmission-blocking effect of AZM using a rodent malaria model. METHODS AZM-treated mice infected with Plasmodium berghei were exposed to Anopheles stephensi mosquitoes, followed by the observation of parasite development at different phases in the mosquito, i.e., ookinetes in the midgut, oocysts on the midgut, and sporozoites in the midgut and salivary glands. Furthermore, to evaluate the effect on organelle replication of each stage, quantitative real-time PCR analysis was performed. RESULTS The inhibitory effect of AZM was noticeable in both gametocyte-ookinete transformation in the midgut and sporozoite production in the oocyst, while the latter was most remarkable among all the developmental phases examined. Real-time PCR analysis revealed that AZM suppressed apicoplast replication at the period of sporozoite production in oocysts. CONCLUSIONS AZM inhibits parasite development in the mosquito stage, probably through the same mechanism as in the liver and blood stages. Such a multi-targeting anti-malarial, along with its safety, would be ideal for mass drug administration in malaria control programmes.
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Affiliation(s)
- Shoichi Shimizu
- Department of Immunology and Parasitology, University of Occupational and Environmental Health, Yahatanishi-ku, Kitakyushu, Japan
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Poudel SS, Newman RA, Vaughan JA. Rodent Plasmodium: population dynamics of early sporogony within Anopheles stephensi mosquitoes. J Parasitol 2009; 94:999-1008. [PMID: 18576764 DOI: 10.1645/ge-1407.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Accepted: 02/13/2008] [Indexed: 02/05/2023] Open
Abstract
Early sporogony of Plasmodium parasites involves 2 major developmental transitions within the insect vector, i.e., gametocyte-to-ookinete and ookinete-to-oocyst. This study compared the population dynamics of early sporogony among murine rodent Plasmodium (Plasmodium berghei, Plasmodium chabaudi, Plasmodium vinckei, and Plasmodium yoelii) developing within Anopheles stephensi mosquitoes. Estimates of absolute densities were determined for gametocytes, ookinetes, and oocysts for 108 experimental infections. Total losses throughout early sporogony were greatest in P. vinckei (ca. 250,000-fold loss), followed by P. yoelii (ca. 70,000-fold loss), P. berghei (ca. 45,000-fold loss), and P. chabaudi (ca. 15,000-fold loss). The gametocyte-to-ookinete transition represented the most severe population bottleneck. Numerical losses during this transition (ca. 3,000- to 30,000-fold, depending on species) were orders of magnitude greater than losses incurred during the ookinete-to-oocyst transition (3- to 14-fold). There were no significant correlations between gametocyte and ookinete densities. Significant correlations between ookinete and oocyst densities existed for P. berghei, P. chabaudi, and P. yoelii (but not for P. vinckei), and were best described by nonlinear functions (P. berghei = sigmoid, P. chabaudi = hyperbolic, P. yoelii = sigmoid), indicating that conversion of ookinetes to oocysts in these species is density dependent. The upper theoretical limit for oocyst density on the mosquito midgut for P. chabaudi and P. yoelii (ca. 300 oocysts per midgut) was higher than for P. berghei (ca. 30 oocysts per midgut). This study provides basic information about population processes that occur during the early sporogonic development of some common laboratory model systems of malaria.
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Affiliation(s)
- Shreekanta S Poudel
- Department of Biology, University of North Dakota, Grand Forks, North Dakota 58202, USA
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Malaria: some considerations regarding parasite productivity. Trends Parasitol 2008; 24:487-91. [PMID: 18805735 DOI: 10.1016/j.pt.2008.07.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 07/17/2008] [Accepted: 07/31/2008] [Indexed: 11/20/2022]
Abstract
The complicated life cycle of Plasmodium is characterized by proliferative stages in each of its hosts--mosquito and vertebrate--that are interrupted by restrictive steps as it moves from one to the other. Productivity at each stage affects not only pathology but also the probability for successful transmission. This Opinion article briefly assesses what is known about productivity at each step and attempts, with limited success, to put each in the context of an entire cycle, sporozoite to sporozoite.
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Basseri HR, Doosti S, Akbarzadeh K, Nateghpour M, Whitten MM, Ladoni H. Competency of Anopheles stephensi mysorensis strain for Plasmodium vivax and the role of inhibitory carbohydrates to block its sporogonic cycle. Malar J 2008; 7:131. [PMID: 18627630 PMCID: PMC2500038 DOI: 10.1186/1475-2875-7-131] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2007] [Accepted: 07/15/2008] [Indexed: 12/17/2022] Open
Abstract
Background Despite the abundance of studies conducted on the role of mosquitoes in malaria transmission, the biology and interaction of Plasmodium with its insect host still holds many mysteries. This paper provides the first study to follow the sporogonic cycle of Plasmodium vivax in a wild insecticide-resistant mysorensis strain of Anopheles stephensi, a major vector of vivax malaria in south-eastern Iran. The study subsequently demonstrates that host-parasite sugar binding interactions are critical to the development of this parasite in the salivary glands of its mosquito host. The identity of the receptors or sugars involved was revealed by a receptor "pre-saturation" strategy in which sugars fed to the mosquitoes inhibited normal host-parasite interactions. Methods Anopheles stephensi mysorensis mosquitoes were artificially infected with P. vivax by feeding on the blood of gametocytaemic volunteers reporting to local malaria clinics in the Sistan-Baluchistan province of south-eastern Iran. In order to determine the inhibitory effect of carbohydrates on sporogonic development, vector mosquitoes were allowed to ingest blood meals containing both gametocytes and added carbohydrates. The carbohydrates tested were GlcNAc, GalNAc, arabinose, fucose, mannose, lactose, glucose and galactose. Sporogonic development was assessed by survival of the parasite at both the oocyst and sporozoite stages. Results Oocyst development was observed among nearly 6% of the fed control mosquitoes but the overall number of mosquitoes exhibiting sporozoite invasion of the salivary glands was 47.5% lower than the number supporting oocysts in their midgut. Of the tested carbohydrates, only arabinose and fucose slightly perturbed the development of P. vivax oocysts at the basal side of the mosquito midgut, and the remaining sugars caused no reductions in oocyst development. Strikingly however, sporozoites were completely absent from the salivary glands of mosquitoes treated with mannose, GalNAc, and lactose. Conclusion The study indicates that An. stephensi in southern Iran has the potential to survive long enough to be re-infected and transmit vivax malaria several times, based on the average adult female longevity (about 30 days) and its gonotrophic cycle (2–3 days) during the malaria transmission season. Certain sugar binding interactions are important for the development of P. vivax sporozoites, and this information may be instrumental for the development of transmission blocking strategies.
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Affiliation(s)
- Hamid R Basseri
- Department of Medical Entomology, School of Public Health, Tehran University of Medical Science, Iran.
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Nacer A, Underhill A, Hurd H. The microneme proteins CTRP and SOAP are not essential for Plasmodium berghei ookinete to oocyst transformation in vitro in a cell free system. Malar J 2008; 7:82. [PMID: 18489758 PMCID: PMC2427035 DOI: 10.1186/1475-2875-7-82] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Accepted: 05/19/2008] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Two Plasmodium berghei ookinete micronemal proteins, circumsporozoite and TRAP related protein (CTRP) and secreted ookinete adhesive protein (SOAP) both interact with the basal lamina component laminin. Following gene disruption studies it has been proposed that, apart from their role in motility, these proteins may be required for interactions leading to ookinete-to-oocyst transformation. METHODS CTRP and SOAP null mutant P. berghei ookinetes were compared to P. berghei ANKA wild-type for their ability to transform and grow in vitro. To confirm in vitro findings for P. berghei CTRP-KO ookinetes were injected into the haemocoel of Anopheles gambiae female mosquitoes. RESULTS Transformation, growth, and viability were comparable for the gene disrupted and wild-type parasites. P. berghei CTRP-KO ookinetes were able to transform into oocysts in the haemocoel of An. gambiae mosquitoes. CONCLUSION Neither CTRP nor SOAP is required for parasite transformation in vitro. By-passing the midgut lumen allows for the transformation of P. berghei CTRP-KO ookinetes suggesting that it is not required for transformation in vivo.
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Affiliation(s)
- Adéla Nacer
- Centre for Applied Entomology and Parasitology, Institute of Science and Technology in Medicine, School of Life Sciences, Keele University, Staffordshire, ST5 5BG, UK
| | - Ann Underhill
- Centre for Applied Entomology and Parasitology, Institute of Science and Technology in Medicine, School of Life Sciences, Keele University, Staffordshire, ST5 5BG, UK
| | - Hilary Hurd
- Centre for Applied Entomology and Parasitology, Institute of Science and Technology in Medicine, School of Life Sciences, Keele University, Staffordshire, ST5 5BG, UK
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Progression of Plasmodium berghei through Anopheles stephensi is density-dependent. PLoS Pathog 2008; 3:e195. [PMID: 18166078 PMCID: PMC2156095 DOI: 10.1371/journal.ppat.0030195] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Accepted: 11/05/2007] [Indexed: 01/15/2023] Open
Abstract
It is well documented that the density of Plasmodium in its vertebrate host modulates the physiological response induced; this in turn regulates parasite survival and transmission. It is less clear that parasite density in the mosquito regulates survival and transmission of this important pathogen. Numerous studies have described conversion rates of Plasmodium from one life stage to the next within the mosquito, yet few have considered that these rates might vary with parasite density. Here we establish infections with defined numbers of the rodent malaria parasite Plasmodium berghei to examine how parasite density at each stage of development (gametocytes; ookinetes; oocysts and sporozoites) influences development to the ensuing stage in Anopheles stephensi, and thus the delivery of infectious sporozoites to the vertebrate host. We show that every developmental transition exhibits strong density dependence, with numbers of the ensuing stages saturating at high density. We further show that when fed ookinetes at very low densities, oocyst development is facilitated by increasing ookinete number (i.e., the efficiency of ookinete–oocyst transformation follows a sigmoid relationship). We discuss how observations on this model system generate important hypotheses for the understanding of malaria biology, and how these might guide the rational analysis of interventions against the transmission of the malaria parasites of humans by their diverse vector species. Malaria, one of the world's most devastating parasitic diseases, is caused by protozoan parasites of the genus Plasmodium and is transmitted between mammalian hosts by Anopheles mosquitoes. Within the mosquito, the parasite undergoes four sequential developmental transformations as it passes from the bloodmeal through the mosquito's midgut epithelium to the salivary glands, from where the parasite is inoculated when the mosquito bites the vertebrate host. This study demonstrates, in a laboratory model, that parasite input density at every developmental stage in the mosquito regulates output to the ensuing form. Statistical models were fitted to experimental data to identify and describe the most appropriate functional relationships. In all cases, the relationships between two consecutive parasite stages can saturate at high parasite densities, suggesting that at high parasite densities parasite numbers may have to be reduced substantially to effect an appreciable decrease in parasite transmission. These results may help establish a rational basis for new studies on species of medical importance and further our understanding of how interventions designed to reduce parasite survival within the mosquito might be expected to impact upon transmission.
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Vaughan JA. Population dynamics of Plasmodium sporogony. Trends Parasitol 2006; 23:63-70. [PMID: 17188574 DOI: 10.1016/j.pt.2006.12.009] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Revised: 11/02/2006] [Accepted: 12/11/2006] [Indexed: 11/20/2022]
Abstract
Malaria transmission relies on the sporogonic development of Plasmodium parasites within insect vectors. Sporogony is a complex process that involves several morphologically distinct life-stages and can be described in terms of population dynamics: changes in the abundance and distribution of successive life-stages throughout development. Recent publications on the population dynamics of sporogony are reviewed, with special attention to the differences and similarities among the parasite-vector systems examined thus far. Understanding the population dynamics of malaria parasites within their natural vectors will lead to a better understanding of how malaria parasites survive and are maintained within mosquitoes.
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Affiliation(s)
- Jefferson A Vaughan
- Department of Biology, University of North Dakota, Grand Forks, ND 58201-9019, USA.
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