CRISPR-Cas-Based Pen-Side Diagnostic Tests for Anaplasma marginale and Babesia bigemina

Anaplasma marginale and Babesia bigemina are tick-borne pathogens, posing significant threats to the health and productivity of cattle in tropical and subtropical regions worldwide. Currently, detection of Babesia bigemina and Anaplasma marginale in infected animals relies primarily on microscopic examination of Giemsa-stained blood or organ smears, which has limited sensitivity. Molecular methods offer higher sensitivity but are costly and impractical in resource-limited settings. Following the development of a pen-side test for detecting Theileria parva infections in cattle, we have created two additional CRISPR-Cas12a assays targeting Anaplasma marginale and Babesia bigemina. The assays target the major surface protein 5 (MSP5) for A. marginale and rhoptry-associated protein 1a (RAP1a) for B. bigemina. These additional tests involve a 20 min recombinase polymerase amplification (RPA) reaction followed by a 60 min CRISPR-Cas12a detection with a lateral strip readout. Results demonstrate high specificity, with no cross-reactivity against other tick-borne parasites, and a limit of detection down to 102 DNA copies/µL of each target marker. The findings pave the way for sensitive and user-friendly pen-side tests to diagnose A. marginale and B. bigemina infections.

Molecular detection and characterization of Anaplasma ovis, Theileria ovis, and Theileria lestoquardi in sheep and goats in Luxor, Egypt

BACKGROUND

Tick-borne diseases cause economically significant losses to animal production globally, and anaplasmosis and theileriosis are associated with the greatest losses. However, the spread of the relevant pathogens in flocks of domesticated animals in southern Egypt is little understood. Accordingly, in this study, we aimed to determine the prevalences of Anaplasma ovis, Theileria ovis, and Theileria lestoquardi in southern Egyptian sheep and goats through blood tests, and to make a molecular characterization of the A. ovis detected in sheep targeting a specific gene.

RESULTS

We collected blood samples collected from 300 sheep and goats (n=150 /species) in Luxor Province in southern Egypt, and analyzed them for the presence of A. ovis, T. ovis and T. lestoquardi with screening by conventional and nested PCR targeting the msp4 and msp5, 18S rRNA, and merozoite surface protein genes. For A. ovis 140/300 samples (46.66%) were positive overall, with 90/150 (60%) and 50/150 (33.33%) positive samples in sheep and goats, respectively. Two major surface protein genes of A. ovis, msp4 and msp5, were sequenced using DNA extracted from sheep and goat blood samples, for phylogenetic analysis and genotyping. The msp4 gene sequence revealed no significant genetic diversity, to contrast to data on A. ovis strains from other countries. For T. lestoquardi, 8/150 (5.33%) samples were positive in sheep, but no samples were positive in goats (0%). For T. ovis, 32/150 (21.33%) samples were positive in sheep, but no samples were positive in goats (0%). Sequencing targeting the merozoite surface protein gene for T. lestoquardi and the small subunit ribosomal RNA gene for T. ovis revealed no significant genetic diversity in the study, another contrast to data on A. ovis strains from other countries.

CONCLUSION

This study provides valuable data on phylogenetic and molecular classifications of A. ovis, T. ovis and T. lestoquardi found in southern Egyptian sheep and goats. It also represents the first report on detection and molecular characterization of T. lestoquardi in southern Egyptian sheep based on the specific merozoite surface protein gene, thus providing valuable data for molecular characterization of this pathogen in southern Egypt.

Molecular diagnosis and characterization of Anaplasma marginale and Ehrlichia ruminantium infecting beef cattle of Maputo Province, Mozambique

BACKGROUND

Members of the Anaplasmataceae family, such as the Anaplasma and Ehrlichia species, cause economic losses and public health risks. However, the exact economic impact has not been comprehensively assessed in Mozambique due to limited data available on its basic epidemiology. Therefore, we investigated the molecular occurrence and identity of Anaplasma and Ehrlichia spp. infecting beef cattle in Maputo province, Mozambique.

METHODS

A total of 200 whole blood samples were collected from apparently healthy beef cattle. Whole blood DNA was extracted and tested for presence of Anaplasma spp. and Ehrlichia ruminantium DNA through amplification of the 16S rRNA and map1 genes. Positive samples to Anaplasma spp. were subject to PCR assay targeting the A. marginale-msp5 gene. Amplicons obtained were purified, sequenced and subject to phylogenetic analyses.

RESULTS

Anaplasma spp., A. marginale and E. ruminantium were detected in 153 (76.5%), 142 (71%) and 19 (9.5%) of all the samples analyzed, respectively. On this same sample group, 19 (9.5%) were co-infected with A. marginale and E. ruminantium. The 16S rRNA sequences of Anaplasma spp. obtained were phylogenetically related to A. marginale, A. centrale and A. platys. Phylogenetic analysis revealed that A. marginale-msp5 nucleotide sequences were grouped with sequences from Asia, Africa and Latin America, whereas E. ruminantium-map1 DNA nucleotide sequences were positioned in multiple clusters.

CONCLUSION

Cattle in Maputo Province are reservoirs for multiple Anaplasma species. A high positivity rate of infection by A. marginale was observed, as well as high genetic diversity of E. ruminantium. Furthermore, five new genotypes of E. ruminantium-map1 were identified.

Molecular detection and diversity of tick-borne rickettsial pathogens in ticks collected from camel (Camelus dromedarius) in Upper Egypt

Tick-borne rickettsial pathogens pose significant threats to public and animal health. In Upper Egypt, limited information exists regarding the prevalence and diversity of such tick-borne pathogens. Therefore, this study aimed to conduct a comprehensive investigation to elucidate the presence and variety of tick-borne rickettsial pathogens in Upper Egyptian camels. Our results revealed a prevalence of 2.96 % for Anaplasma marginale and 0.34 % for Candidatus Anaplasma camelii among Hyalomma ticks. However, Ehrlichia spp. weren't detected in our study. The identification of Ca. A. camelii in H. dromedari ticks was documented for the first time, suggesting a potential mode of transmission in camels. Notably, this study marks the first documentation of Rickettsia aeschlimannii with a prevalence of 6.06 % in the study area. Furthermore, we detected Coxiella burnetii in a prevalence of 8.08 % in Hyalomma ticks, indicating a potential risk of Q fever transmission. Molecular techniques results were confirmed by sequencing and phylogenetic analysis and provided valuable insights into the epidemiology of these pathogens, revealing their diversity. This study is vital in understanding tick-borne rickettsial pathogens' prevalence, distribution, and transmission dynamics in Upper Egypt. In conclusion, our findings emphasize the importance of continued research to enhance our understanding of the epidemiology and impact of these pathogens on both animal and human populations.

Molecular identification, risk factor assessment, and phylogenetic analysis of tick-borne pathogens in symptomatic and asymptomatic cattle from South-Eastern Iran

Tick-borne pathogens (TBPs) represent a substantial threat to cattle globally, exerting adverse impacts on production, health, and economic viability. This study delves into the prevalence and implications of TTBPs in cattle sourced from resource-limited smallholder livestock farms situated in southeastern Iran, proximate to Afghanistan and Pakistan. Blood and tick specimens were systematically collected from a cohort of 230 cattle, comprising 150 asymptomatic and 80 symptomatic individuals. Genomic DNA isolated from blood samples underwent rigorous examination for the presence of key TBPs, including Anaplasma marginale, A. phagocytophilum, A. bovis, A. centrale, Babesia bigemina, and Theileria annulata, utilizing multiple genetic markers. Nucleotide sequence analysis facilitated the reconstruction of phylogenetic relationships. The study also evaluated various potential risk factors, such as clinical status, gender, age, breed, tick infestation, and management practices, to elucidate their associations with TTBPs. Among the cattle cohort, a staggering 87.8% (202/230) tested positive for at least one pathogen. Prevalence statistics encompassed A. marginale (72.2%), T. annulata (68.3%), A. phagocytophilum/A. platys-like complex (66.1%), A. centrale (16.7%), B. bigemina (10.0%), and A. bovis (6.1%). Remarkably, mixed infections involving two, three, and four pathogens were detected in 23%, 52.1%, and 2.2% of animals, respectively. Notably, all asymptomatic cattle were positive for at least one TBP. Tick infestation was observed in 62.2% (143/230) of cattle, predominantly caused by Hyalomma anatolicum (82.5%), Rhipicephalus (Boophilus) annulatus (13.1%), and R. sanguineus sensu lato (4.4%). Risk factors linked to TBPs encompassed tick infestation, older age, and crossbred animals. Clinical presentations among symptomatic cattle encompassed fever, anemia, weight loss, anorexia, jaundice, and enlarged superficial lymph nodes. This study underscores the pivotal role of asymptomatic carriers in the propagation of TTBPs within endemic regions. Furthermore, it emphasizes the potential for the implementation of molecular diagnostics to unmask subclinical infections, thereby affording the opportunity for targeted interventions aimed at ameliorating the burden of TTBPs in resource-constrained smallholder dairy farms.

An epidemiological survey of vector-borne pathogens infecting cattle in Kyrgyzstan

Cattle production is a major contributor to the national economy of Kyrgyzstan. Most cattle in Kyrgyzstan are managed via extensive systems and graze in communal pastures. As a result, infestations with ectoparasites are widespread, implying that various vector-borne diseases might be common in cattle. However, methods to control such infectious diseases are not available in Kyrgyzstan because the epidemiology of vector-borne pathogens (VBPs) infecting cattle remains unclear. The present study was therefore designed to survey Kyrgyz cattle for VBPs. We prepared blood DNA samples from 319 cattle in Kyrgyzstan and screened them with specific PCR assays for detecting Babesia bovis, Babesia bigemina, Babesia naoakii, Theileria annulata, Theileria orientalis, Trypanosoma evansi, Trypanosoma theileri, and Anaplasma marginale infections. Our findings indicated that the surveyed cattle were infected with six of the eight pathogens targeted, with the exceptions being B. naoakii and Try. evansi. The most common pathogen was T. orientalis (84.3%), followed by B. bigemina (47.6%), T. annulata (16.6%), A. marginale (11.6%), Try. theileri (7.2%), and B. bovis (2.5%). Additional screening of the B. bovis- and B. bigemina-negative samples with a Babesia genus-specific 18S rRNA PCR identified two positive samples, and sequencing analysis confirmed that each of them was infected with either Babesia major or Babesia occultans. To the best of our knowledge, this is the first report of B. bovis, B. bigemina, B. occultans, Try. theileri, and A. marginale infections in cattle in Kyrgyzstan. Our findings suggest that cattle in Kyrgyzstan are at high risk of infectious diseases caused by VBPs.

Molecular prevalence of Anaplasma spp. in cattle and assessment of associated risk factors in Northeast Thailand

Background and Aim

Anaplasma spp. are common rickettsia species described in ruminant hosts, including cattle. The clinical signs of anaplasmosis range from asymptomatic to mortality. However, there are insufficient studies on epidemiology surveys of this blood pathogen. This study aimed to estimate the prevalence and risk factors of anaplasmosis in beef and dairy cattle in Northeast, Thailand.

Materials and Methods

A total of 187 blood samples of beef and dairy cattle were collected from five provinces in Northeast Thailand. Anaplasma spp. infections were screened by microscopic examination and polymerase chain reaction targeting specific genes (msp4 gene for Anaplasma marginale and 16S rRNA gene for Anaplasma platys and Anaplasma bovis). Moreover, the associated risk factors for the infections were evaluated.

Results

Overall, blood samples from cattle revealed that 17.6% (33/187) were positive for Anaplasma spp. by microscopic examination and 20.8% (39/187) were positive by DNA amplification. Of these 20.8%, 17.6% were A. marginale and 3.2% were A. platys. However, A. bovis infection was not detected. Infection with Anaplasma spp. and A. marginale showed a significant association with breed and gender (p < 0.05) while age and packed cell volume levels showed no significant statistical relationship between Anaplasma spp. infected and uninfected animals.

Conclusion

This study indicated that anaplasmosis is distributed in beef and dairy cattle in Thailand; therefore, prevention and control strategies for these pathogens should be improved. This information will benefit veterinarians and cowherds by avoiding vector exposure and eliminating tick breeding sites.

Molecular detection and characterization of Anaplasma marginale infecting cattle, buffalo, and camel populations in southern Egypt

Anaplasmosis is a severe tickborne disease of ruminants caused by Anaplasma marginale. A. marginale is distributed worldwide and attacks erythrocytes, resulting in an increased body temperature, anemia, jaundice, abortion, and, in some cases, death. Animals infected with this pathogen become lifelong carriers. In this study, we aimed to detect and characterize A. marginale isolated from cattle, buffalo, and camel populations using novel molecular techniques in southern Egypt. In total, 250 samples (from 100 cattle, 75 water buffaloes, and 75 camels) were analyzed by PCR for the presence of Anaplasmataceae, specifically A. marginale. The animals varied in breed, age, and gender, with most showing no signs of severe disease. By species, A. marginale was found in 61 out of 100 (61%) cattle, 9 out of 75 (12%) buffaloes, and only 5 out of 75 (6.66%) camels. All A. marginale-positive samples were examined for the heat-shock protein groEL gene and, additionally, for major surface protein 4 (msp4) and major surface protein 5 (msp5) genes to enhance specificity. Phylogenetic analysis of A. marginale targeted three genes (groEL, msp4, and msp5). This study provides the first report on using three genes for A. marginale detection in Camelus dromedarius in southern Egypt and generated new phylogenetic data for A. marginale infections in camels. A. marginale infection is endemic in different animal species in southern Egypt. Screening herds for A. marginale is recommended even when the signs of anaplasmosis are absent.

Molecular survey of Babesia, Theileria, Trypanosoma, and Anaplasma infections in camels (Camelus dromedaries) in Egypt

The one-humped camel (Camelus dromedarius) or dromedary is an economically important domestic animal. However, infectious diseases, including those caused by vector-borne hemopathogens, frequently compromise the health and production of camels. In this study, we examined infections caused by Babesia, Theileria, Trypanosoma, and Anaplasma species in camels in Egypt. We analyzed blood DNA samples from 148 camels reared in six Egyptian governorates (Giza, Asyut, Sohag, Qena, Luxor, and the Red Sea) using pathogen-specific Polymerase Chain Reaction (PCR) assays. Our results indicated that 29 (19.6%), 22 (14.9%), 1 (0.7%), 2 (1.4%), 1 (0.7%), 2 (1.4%), and 28 (18.9%) of the surveyed animals were infected with Babesia bovis, B. bigemina, Babesia sp. Mymensingh, Theileria sp. Yokoyama, Theileria equi, Trypanosoma evansi, and Anaplasma marginale, respectively. We found that a total of 68 (45.9%) animals were infected with at least one of the detected hemopathogens. Sequencing analyses of PCR amplicons confirmed our diagnostic results. This study is the first to report Theileria sp. Yokoyama and Babesia sp. Mymensingh in Egypt. This is also the first report of infection with these two species in one-humped camel. In conclusion, this study found that camels in Egypt are infected with several vector-borne hemopathogens, including novel parasite species.

Protozoan and Rickettsial Pathogens in Ticks Collected from Infested Cattle from Turkey

Diseases caused by tick-transmitted pathogens including bacteria, viruses, and protozoa are of veterinary and medical importance, especially in tropical and subtropical regions including Turkey. Hence, molecular surveillance of tick-borne diseases will improve the understanding of their distribution towards effective control. This study aimed to investigate the presence and perform molecular characterization of Babesia sp., Theileria sp., Anaplasma sp., Ehrlichia sp., and Rickettsia sp. in tick species collected from cattle in five provinces of Turkey. A total of 277 adult ticks (males and females) were collected. After microscopic identification, tick pools were generated according to tick species, host animal, and sampling sites prior to DNA extraction. Molecular identification of the tick species was conducted through PCR assays. Out of 90 DNA pools, 57.8% (52/90) were detected to harbor at least 1 pathogen. The most frequently-detected pathogens were Babesia bovis, with a minimum detection rate of 7.9%, followed by Ehrlichia sp. (7.2%), Theileria annulata (5.8%), Coxiella sp. (3.3%), Anaplasma marginale (2.5%), Rickettsia sp. (2.5%), and B. occultans (0.7%). Rickettsia sp. identified in this study include Candidatus Rickettsia barbariae, R. aeschlimannii, and Rickettsia sp. Chad. All sequences obtained from this study showed 99.05−100% nucleotide identity with those deposited in GenBank (query cover range: 89−100%). This is the first molecular detection of Rickettsia sp. Chad, a variant of Astrakhan fever rickettsia, in Turkey. Results from this survey provide a reference for the distribution of ticks and tick-borne pathogens in cattle and expand the knowledge of tick-borne diseases in Turkey.

Tracking tick-borne diseases in Mongolian livestock using next generation sequencing (NGS)

The livestock industry in Mongolia accounts for 24% of national revenue, with one third of the population maintaining a pastoral lifestyle. This close connection between Mongolian population and livestock is a major concern for pathogen transfer, especially given the increase in vector-borne diseases globally. This study examines blood samples from livestock to assess the prevalence of tick-borne bacterial infections across three provinces in Mongolia (Dornogovi, Selenge, Töv). Whole blood samples from 243 livestock (cattle=38, camel=11, goat=85, horse=22, sheep=87) were analyzed with 16S metagenomics next-generation sequencing (NGS) to screen for bacterial pathogens. Positive-NGS samples for Anaplasma, Bartonella, Ehrlichia, Francisella, Leptospira, and Rickettsia were confirmed by conventional PCR and DNA sequencing. Prevalence rates of Anaplasma, Bartonella, and Ehrlichia were 57.6%, 12.8%, and 0.4%, respectively. A significant difference in the prevalence of Anaplasma spp. in livestock by province was observed, with a higher prevalence in Selenge (74.2%, p<0.001) and Töv (64.2% p = 0.006) compared to the semi-arid region of Dornogovi (39.8%). In contrast, no association was observed in Bartonella prevalence by provinces. All Anaplasma sequences (N = 139) were characterized as A. ovis. For Bartonella species characterization, phylogenetic analyses of gltA and rpoB genes identified three Bartonella species including B. bovis, B. melophagi and Candidatus B. ovis. Bartonella bovis was detected in all 22-positive cattle, while B. melophagi and Candidatus B. ovis were found in four and three sheep, respectively. This study identifies a high prevalence of tick-borne pathogens within the livestock population and to our knowledge, is the first time NGS methods have been used to explore tick-borne diseases in Mongolia. Further research is needed in Mongolia to better understand the clinical and economic burdens associated with tick-borne diseases in both livestock and pastoral herder populations.

Screening and Analysis of Anaplasma marginale Tunisian Isolates Reveal the Diversity of lipA Phylogeographic Marker and the Conservation of OmpA Protein Vaccine Candidate

Bovine anaplasmosis caused by Anaplasma marginale is a disease responsible for serious animal health problems and great economic losses all over the world. Thereby, the identification of A. marginale isolates from various bioclimatic areas in each country, the phylogeographic analysis of these isolates based on the most informative markers, and the evaluation of the most promising candidate antigens are crucial steps in developing effective vaccines against a wide range of A. marginale strains. In order to contribute to this challenge, a total of 791 bovine samples from various bioclimatic areas of Tunisia were tested for the occurrence of A. marginale DNA through msp4 gene fragment amplification. Phylogeographic analysis was performed by using lipA and sucB gene analyses, and the genetic relationship with previously characterized A. marginale isolates and strains was analyzed by applying similarity comparison and phylogenetic analysis. To evaluate the conservation of OmpA protein vaccine candidate, almost complete ompA nucleotide sequences were also obtained from Tunisian isolates, and various bioinformatics software were used in order to analyze the physicochemical properties and the secondary and tertiary structures of their deduced proteins and to predict their immunodominant epitopes of B and T cells. A. marginale DNA was detected in 19 bovine samples (2.4%). Risk factor analysis shows that cattle derived from subhumid bioclimatic area were more infected than those that originated from other areas. The analysis of lipA phylogeographic marker indicated a higher diversity of Tunisian A. marginale isolates compared with other available worldwide isolates and strains. Molecular, phylogenetic, and immuno-informatics analyses of the vaccine candidate OmpA protein demonstrated that this antigen and its predicted immunodominant epitopes of B and T cells appear to be highly conserved between Tunisian isolates and compared with isolates from other countries, suggesting that the minimal intraspecific modifications will not affect the potential cross-protective capacity of humoral and cell-mediated immune responses against multiple A. marginale worldwide strains.

Molecular Prevalence of Anaplasma marginale and Ehrlichia in Domestic Large Ruminants and Rhipicephalus (Boophilus) microplus Ticks From Southern Luzon, Philippines

Anaplasmosis and ehrlichiosis are tick-borne rickettsial diseases that cause significant economic losses in the livestock industry worldwide. Although bovine anaplasmosis is known to be endemic in the Philippines, epidemiological data is fragmented. Moreover, little is known about bovine ehrlichiosis in the country. In this study, the prevalence of Anaplasma marginale and Ehrlichia in cattle and water buffalo from provinces in the southern part of Luzon, Philippines, was investigated through PCR. Blood samples from 620 animals comprised of 512 cattle and 108 water buffalo and 195 tick samples were subjected to nested PCR targeting the groESL gene of Anaplasmataceae. Positive samples were further subjected to another nested PCR and conventional PCR to amplify the A. marginale groEL gene and the Ehrlichia dsbA gene, respectively. Selected A. marginale-positive samples were also subjected to nested PCR targeting the msp5 gene. Regardless of the animal host, the overall prevalence in blood samples obtained was 51.9% for Anaplasmataceae, 43% for A. marginale, and 1.1% for Ehrlichia. No water buffalo were positive for Ehrlichia. Meanwhile, 15.9, 6.7, and 2% of the tick samples, all morphologically identified as Rhipicephalus (Boophilus) microplus, were positive for Anaplasmataceae, A. marginale, and Ehrlichia, respectively. Sequence analysis of selected A. marginale msp5 amplicons showed that the isolates from the region share 94–98% identity to reported A. marginale from other countries. The phylogenetic tree showed clustering of isolates in the region and a close relationship with A. marginale isolates from other countries. Sequences of Ehrlichia amplicons from cattle and ticks were 97–100% similar to reported Ehrlichia minasensis isolates. This study showed the high prevalence of A. marginale in Luzon, Philippines, and provided the first molecular evidence of E. minasensis in the country.

Molecular detection of selected tick-borne pathogens infecting cattle at the wildlife-livestock interface of Queen Elizabeth National Park in Kasese District, Uganda

In Uganda, ticks and tick-borne diseases (TBDs) pose a big challenge to farmers. They reduce cattle productivity and cause severe economic damage. Several studies have documented the prevalence of tick-borne pathogens in cattle; however, their genetic characteristics and the role of wildlife-livestock interaction in the epidemiology of the TBDs are not well documented. This study assessed the prevalence and genetic diversity of various tick-borne pathogens (TBPs) as well as the risk factors associated with the occurrence of TBPs in blood samples of 208 randomly selected cattle from 16 farms located around Queen Elizabeth National Park (QENP) in Kasese District in western Uganda. Farming practices, disease challenges, and the level of wildlife-livestock interactions were assessed by a questionnaire survey amongst farm owners. Polymerase chain reaction (PCR) assays revealed that 62.9% (131/208) cattle samples were positive for one or more pathogens. Using specific PCR assays, we detected Theileria spp., Theileria parva, Anaplasma marginale, Anaplasma platys-like, and Babesia bigemina at 50.5%, 27.9%, 19.2%, 11.5% and 8.7%, respectively. We also confirmed the infection of samples by Theileria velifera and Theileria mutans after sequencing the Theileria spp. 18S rRNA gene. The risk factors associated with the occurrence of TBPs included communal grazing, herd size, age, and proximity to QENP. Phylogenetic analysis of the T. parva p104 gene showed a high identity to the previous isolates from Uganda and other East African countries and clustered closer to the buffalo (Syncerus caffer) isolates, suggesting a possible cross-species transmission. The sequences of A. marginale groEL and B. bigemina RAP-1a formed well-supported clades with high identities to the previous isolates identified from central and eastern Uganda. The isolates obtained from A. phagocytophilum 16S rRNA gene sequences showed relationship with A. platys-like, Anaplasma sp., uncultured Anaplasma species and A. phagocytophilum isolates from Africa, Asia, Europe, and the USA. The findings of the present study showed that TBDs are still a burden to farmers and that management practices in this area may increase the transmission of pathogens between livestock and wildlife.

A molecular prevalence survey on Anaplasma infection among domestic ruminants in Khartoum State, Sudan

This study was conducted in Khartoum State, Sudan to determine the prevalence and the risk factors associated with Anaplasma and Ehrlichia species infections in domestic ruminants. Blood samples were collected from a total of 594 animals from 32 different farms distributed in the three provinces of Khartoum State. Among the 196 cattle, 200 sheep, and 198 goats examined using PCR, 13.27%, 32.50%, and 35.86% were infected with Anaplasma spp., respectively, with an overall prevalence of 27.27%. Cattle were infected with A. marginale (10.71%), A. centrale (2.04%), and A. ovis (0.51%), while sheep and goats were infected with A. ovis being significantly higher compared with cattle. No Ehrlichia spp. was detected in domestic ruminant in Khartoum State. Prevalence rates of Anaplasma infections were highly associated with breed, location, season, and sex. The prevalence rates of Anaplasma infection were significantly higher in exotic goat breeds compared with indigenous, and the infection in sheep and cattle was significantly higher in summer and in autumn in goats. The Anaplasma spp. infection rate in goats was significantly higher in females. The infection rate was also significantly higher in Khartoum North in both sheep and goats. It could be concluded that Anaplasma infection is prevalent in small and large ruminants in Khartoum State. Therefore, further studies on the epidemiology of anaplasmosis, possible tick, lice, and flea vectors and reservoirs in Sudan are important.

Genetic diversity of Anaplasma and Ehrlichia bacteria found in Dermacentor and Ixodes ticks in Mongolia

Anaplasma and Ehrlichia are tick-borne bacterial pathogens that cause human granulocytic anaplasmosis, human monocytic ehrlichiosis, and are severe threats to livestock economies like Mongolia. In this study, ticks were collected, identified, and pooled (n = 299) from three distinct environments across central Mongolia. Each pool was initially tested for Anaplasma/Ehrlichia using a 16S rRNA PCR assay that detects both genera, and specific PCR testing was done to identify those positive samples. Maximum likelihood estimation (MLE) of infection rates of ticks collected from the environment in Selenge aimag (province) found infection rates of Ixodes persulcatus ticks to be 2.0% (95% CI: 0.7, 4.3%) for A. phagocytophilum and 0.8% (95% CI: 0.1, 2.5%) for both nonspecific Ehrlichia and Anaplasma. Ehrlichia muris was only detected in I. persulcatus ticks collected from the Selenge aimag, where the MLE was 1.2% (95% CI: 0.1, 2.5%). The calculated MLE infection rate of Anaplasma spp. in questing Dermacentor nuttalli ticks ranged from 1.9% (95% CI: 1.1, 9.1%) in the Tov aimag to 2.3% (95% CI: 1.3, 10.8%) in the Selenge aimag. However, when examining MLE in ticks removed from livestock, estimates increase substantially, ranging from 7.8% (95% CI: 4.2, 13.3%) in Dornogovi to 22.5% (95% CI: 14.3, 34.3%) in Selenge, suggesting that livestock play a key role in disease maintenance. Considering the collective economic losses that can result from these pathogens and the potential for illness in nomadic herdsmen, these results highlight the need for enhanced TBD surveillance and prevention measures within Mongolia.

Epidemiological survey of Anaplasma marginale in cattle and buffalo in Sri Lanka

Bovine anaplasmosis caused by Anaplasma marginale represents a serious threat to cattle farming worldwide, especially in the tropics and subtropics. In the present study, archived DNA samples from the blood of cattle (n=437) in the Nuwara Eliya, Galle, Ampara, Polonnaruwa, and Jaffna districts and buffalo (n=327) in the Galle, Polonnaruwa, Mannar, and Mullaitivu districts in Sri Lanka, were screened for A. marginale using a major surface protein 5 (msp5) gene-based PCR assay. The findings showed that 32.7 and 57.5% of cattle and buffalo, respectively, were A. marginale-positive. The rate of positivity differed significantly among geographical regions. In conclusion, the high rates of A. marginale infection in cattle and buffalo highlight the importance of effective control measures in Sri Lanka.

Molecular detection of tick-borne pathogens in bovine blood and ticks from Khentii, Mongolia

Recent studies reported the detection of DNA from tick-borne pathogens (TBPs) of veterinary relevance such as Anaplasma marginale, Babesia bigemina, Babesia bovis and Theileria orientalis in bovine blood samples from Mongolia. These findings were unexpected, as the known tick vectors of these pathogens are not known to occur in Mongolia. We therefore conducted a study in May and June 2013 in six districts of Khentii province where DNA of the said TBPs was previously found. Ticks collected from the vegetation and rodents, as well as blood samples from cattle, were screened for the presence of TBPs by reverse line blot (RLB) hybridization. Tick larvae collected from rodents were pooled. A total of 310 adult ticks were collected from the vegetation, and 249 tick larvae were collected from 24 rodents. Adult ticks (n = 2,318) and blood samples were collected from 481 heads of cattle. All adult ticks were identified as Dermacentor nuttalli. DNA from Rickettsia raoultii (252/310; 81.3%), an uncharacterized Anaplasma species preliminary named Anaplasma sp. Mongolia (26/310; 8.4%), Candidatus Midichloria sp. (18/310; 5.8%), Theileria equi (16/310; 5.2%), Babesia caballi (5/310; 1.6%), T. orientalis (1/310; 0.3%), Borrelia afzelii (1/310; 0.3%) and Candidatus Neoehrlichia mikurensis (1/310; 0.3%) was detected in ticks collected from the vegetation. DNA of R. raoultii (27/28; 96.4%) and Midichloria sp. (2/28; 7.1%) was detected in the pooled tick larvae. Anaplasma sp. Mongolia, a species related to Anaplasma ovis based on a multi-locus analysis, was also detected in 153/481 (31.8%) of the bovine blood samples. DNA of B. bovis, B. bigemina and A. marginale was not detected in the ticks or bovine blood samples from Khentii district.

Discrepancies between self-reported tick bites and evidence of tick-borne disease exposure among nomadic Mongolian herders

Twenty-six per cent of Mongolians live pastoral lifestyles, increasing their likelihood of exposure to ticks and placing them at a higher risk for contracting tick-borne diseases (TBDs). Anaplasma spp. and Rickettsia spp. have been identified in ticks, livestock and humans in Mongolia, but no known qualitative research has been conducted investigating the association between nomadic herder characteristics, tick bite history and exposure to TBDs. To better understand the association between self-reported tick bites and symptoms versus actual exposure to TBDs, this study paired serological data with 335 surveys administered to Mongolian herders, ages 12-69, from 2014 to 2015. Logistic regression results identified no significant associations between reported tick bites or symptoms with serological evidence of Anaplasma spp. and Rickettsia spp. controlling for age, gender and aimag. Among the 335 respondents who were seropositive to either Anaplasma spp. or Rickettsia spp., 32.9% self-reported experiencing abnormal symptoms such as redness, inflammation, headache, arthritis or fever after being bitten. Alternatively, 17.3% (58/335) of individuals reported experiencing symptoms following a tick bite in instances where serological results indicated no exposure to Anaplasma spp. or Rickettsia spp. Results also identified inconsistencies in reporting and seroprevalence among different age groups, with children having the highest reporting and treatment seeking rates but low levels of exposure in comparison with other groups. While survey results showed that individuals were aware of peak tick seasons and tick species that inhabit specific areas, 58% of heads of households (49/84) were unaware that ticks can cause disease in livestock or dogs. This study suggests that herders are an at-risk population in Mongolia with gaps in awareness of TBD risk. Increased surveillance paired with focused outreach to prevent TBDs targeted to the herder population is encouraged.

Molecular investigation of tick-borne infections in cattle from Xinjiang Uygur Autonomous Region, China

Tick-borne diseases cause significant losses to livestock production in tropical and subtropical regions. However, information about the tick-borne infections in cattle in Xinjiang Uygur Autonomous Region (XUAR), northwestern China, is scarce. In this study, nested polymerase chain reaction (PCR) assays and gene sequencing were used to detect and analyze epidemiological features of Babesia bovis, B. bigemina, Coxiella burnetii and Anaplasma bovis infections in XUAR. Out of 195 samples tested, 24 (12.3%), 67 (34.4%), 40 (20.5%) and 10 (5.1%) were positive for B. bovis, B. bigemina, C. burnetii and A. bovis, respectively. Sequencing analysis indicated that B. bovis SBP-4, B. bigemina Rap1a, C. burnetii htpB and A. bovis 16S rRNA genes from XUAR showed 99%-100% identity with documented isolates from other countries. Phylogenetic analyses revealed that B. bovis SBP-4, B. bigemina Rap1a, C. burnetii htpB and A. bovis 16S rRNA gene sequences clustered in the same clade with isolates from other countries. To the best of our knowledge, this is the first report of C. burnetii infection of cattle in XUAR. Furthermore, this study provides important data for understanding the distribution of tick-borne pathogens, and is expected to improve the approach for prevention and control of tick-borne diseases in China.

Genetic characterization of tick-borne pathogens in ticks infesting cattle and sheep from three South African provinces

Ticks are involved in the transmission of many public health and veterinary important pathogens. Although tick-borne pathogens are widely distributed in South Africa, information on tick-pathogen relationship needs to be updated particularly using modern molecular techniques. This study used PCR and sequencing to confirm the identity of the tick species collected from cattle and sheep from KwaZulu-Natal, Free State and Eastern Cape. Furthermore, presence of Babesia spp., Theileria spp., Anaplasma marginale, Rickettsia spp., Ehrlichia ruminantium and Coxiella burnetii was detected from tick DNA using species-specific PCR or nested PCRs. The study samples consisted of 390 adult ticks (male and female) which were pooled according to species, host animal and sampling site (three ticks per pool) for DNA extraction. The PCR results revealed that out of 130 tick DNA pools, 30 (23.1%) were positive for at least one pathogen. The most frequent pathogen was C. burnetii (9.2%), followed by Rickettsia spp. (7.7%), A. marginale (3.8%), T. mutans (3.1%), T. taurotragi (2.3%) and E. ruminantium (1.5%). The highest prevalence of pathogens was observed in ticks collected from cattle in Eastern Cape (16/42) and the lowest was in ticks obtained from sheep in Free State (1/21). Infected ticks were identified as Rhipicephalus evertsi evertsi (n = 13), R. appendiculatus (n = 3), R. decoloratus (n = 7) and Amblyomma hebraeum (n = 7). Coinfection with two pathogens was found in 21% of pathogen-positive pools. Analysis of Theileria taurotragi 18S rRNA, T. mutans 18S rRNA, C. burnetii htpB, Rickettsia spp. gltA, Rickettsia spp. ompA, E. ruminantium pCS20 and A. marginale Msp5 sequences showed that the pathogens detected in this study were genetically related to isolates previously reported in Africa. These findings provide important information on distribution of ticks and tick-borne pathogens of ruminants and will contribute in the formulation of future control strategies in South Africa.

Genetic Analysis of Babesia Isolates from Cattle with Clinical Babesiosis in Sri Lanka

Bovine babesiosis is a serious threat to the cattle industry. We prepared blood DNA samples from 13 cattle with clinical babesiosis from the Badulla (n = 8), Jaffna (n = 3), and Kilinochchi (n = 2) districts in Sri Lanka. These DNA samples tested positive in PCR assays specific for Babesiabovis (n = 9), Babesia bigemina (n = 9), and Babesiaovata (n = 1). Twelve cattle were positive for B. bovis and/or B. bigemina One cow was negative for the tested Babesia species but was positive for Babesia on microscopic examination; the phylogenetic positions of 18S rRNA and cytochrome oxidase subunit III gene sequences suggested that the cow was infected with Babesia sp. Mymensingh, which was recently reported from a healthy cow in Bangladesh. We then developed a novel Babesia sp. Mymensingh-specific PCR assay and obtained positive results for one other sample. Analysis of gene sequences from the cow with positive B. ovata-specific PCR results demonstrated that the animal was infected not with B. ovata but with Babesia sp. Hue-1, which was recently reported from asymptomatic cattle in Vietnam. The virulence of Babesia sp. Hue-1 is unclear, as the cow was coinfected with B. bovis and B. bigemina However, Babesia sp. Mymensingh probably causes severe clinical babesiosis, as it was the sole Babesia species detected in a clinical case. The present study revealed the presence of two bovine Babesia species not previously reported in Sri Lanka, plus the first case of severe bovine babesiosis caused by a Babesia species other than B. bovis, B. bigemina, and Babesiadivergens.

Identification and genetic characterization of Piroplasmida and Anaplasmataceae agents in feeding Amblyomma variegatum ticks from Benin

In many African countries including Benin, the reluctance of some livestock owners to blood collection from their cattle makes epidemiological surveys cumbersome and prevents regular monitoring of tick-borne diseases. In the present study, Amblyomma variegatum ticks were used to find out more about bovine tick-borne pathogens. DNA extracts from 910 adult ticks collected off cattle in North East Benin were examined for Babesia bigemina, B. bovis, Theileria taurotragi, T. annulata, T. orientalis, T. parva, T. mutans, Anaplasma marginale and Ehrlichia ruminantium using pathogen-specific PCR assays and sequence analyses. Altogether, 21.6% of the ticks carried at least one pathogen. A. marginale (142/910) was the most frequent pathogen, followed by E. ruminantium (57/910), B. bovis (10/910), T. mutans (3/910) and B. bigemina (1/910). Theileria taurotragi, T. annulata, T. orientalis, T. parva were not detected in the samples. Babesia bigemina, B. bovis and T. mutans were present in only one location whereas A. marginale and E. ruminantium were found in ticks from 7/8 locations surveyed. Coinfections occurred in 7.1% of all positive ticks. The analyses of partial sequences of B. bovis spherical body protein 4, B. bigemina rhoptry-associated protein-1a, T. mutans 18S rRNA and A. marginale major surface protein 5 showed high sequence conservation and homologies between Benin isolates and those from other African countries. However, E. ruminantium pCS20 partial sequences were different from published West African isolates and presented similar genetic variation with South and East African isolates. These results provide information on the pathogens circulating in North East Benin and suggest that Am. variegatum, one of the most abundant ticks in Africa, may play a role in the transmission of A. marginale.

Evidence for transovarial transmission of tick-borne rickettsiae circulating in Northern Mongolia

Transstadial transmission of tick-borne rickettsiae has been well documented. Few studies, however, have evaluated the role of transovarial transmission of tick-borne rickettsiae, particularly in nature within the host-vector ecosystem. This cross-sectional study aimed to understand the role of transovarial transmission of tick-borne rickettsiae among feeding ticks at different life stages. Tick eggs laid by engorged wild-caught adult female ticks were pooled and tested for Rickettsia spp. and Anaplasma/Ehrlichia spp. using molecular techniques, while adult fed ticks were tested individually. Additionally, larval and nymphal ticks were collected in the wild from small mammals, pooled and tested for Rickettsia spp. and Anaplasma/Ehrlichia spp. There were 38 fed adult and 618 larvae/nymphs (60 pools total) Dermacentor spp. ticks collected from livestock and rodents. All individual adult ticks and tick pools were positive for Rickettsia spp. While none of the larvae/nymphs were positive for Anaplasma/Ehrlichia spp., two adult fed ticks were positive. Rickettsia spp. DNA was detected in 91% (30/33) of the pooled eggs tested, and one pool of eggs tested positive for Anaplasma/Ehrlichia spp. Sequencing data revealed Rickettsia spp. shared ≥99% identity with R. raoultii ompA. Anaplasma/Ehrlichia spp. shared ≥89% identity with A. ovis 16S ribosomal RNA. This study identified potential transovarial transmission of Rickettsia spp. and Anaplasma spp. among D. nuttalli ticks. Additional studies are needed to further assess the proportion of transovarial transmission occurring in nature to better understand the burden and disease ecology of tick-borne rickettsiae in Mongolia.

In this study, we evaluate the probability or likelihood that tick-borne rickettsiae might be transmitted vertically from wild engorged adult female ticks collected throughout the Northern region of Mongolia during the summer of 2016. While significant effort has been directed to study tick-borne rickettsiae, this public health challenge is complicated by the limited knowledge and understanding of tick and tick-borne rickettsiae ecology within Mongolia. Tick-borne rickettsiae of concern to humans and animals in this region of the world are Rickettsia spp., Anaplasma spp., and Ehrlichia spp. Using molecular techniques, we detected rickettsiae among all Dermacentor spp. tick life stages and demonstrated potential vertical transmission of Rickettsia spp., and Anaplasma spp. among wild engorged adult female Dermacentor nuttalli ticks. We believe our findings provide important information regarding the ecology of key rickettsiae associated with tick-borne disease in Mongolia.

Molecular epidemiology of Babesia species, Theileria parva, and Anaplasma marginale infecting cattle and the tick control malpractices in Central and Eastern Uganda

East Coast fever, babesiosis, and anaplasmosis are the major tick-borne diseases affecting cattle productivity in Uganda. The emergence of acaricide-resistant ticks is suspected to have caused a rise in hemoparasites. This study sought to detect and characterize hemoparasites among farms in acaricide-failure hotspots of central as compared to the acaricide-failure naïve areas in Eastern Uganda. Nested PCR assays were performed to determine the prevalences of Babesia bovis, Babesia bigemina, Theileria parva, and Anaplasma marginale in cattle blood samples sourced from randomly selected farms. Randomly selected isolates were sequenced to determine the genetic diversity of the parasites using the following marker genes: B. bovis spherical body protein 4, B. bigemina rhoptry-associated protein 1a, T. parva 104 kDa microneme-rhoptry antigen, and A. marginale major surface protein 5. Furthermore, partially and fully engorged adult ticks were collected for taxonomy, and tick-control practices were assessed using a semi-structured questionnaire. The prevalences of B. bigemina, T. parva, and A. marginale in cattle were 17.2, 65.1, and 22.0%, and 10.0, 26.5, and 3% in the central and eastern region, respectively. Whilst, B. bovis was not detected in the farms involved. The sequences for B. bigemina, T. parva, and A. marginale from the central region showed 99% identity with those from the eastern region. Of the 548 ticks collected, 319, 147, 76, and 6 were Rhipicephalus (Boophilus) decoloratus, Rhipicephalus appendiculatus, Amblyomma variegatum, and Rhipicephalus evertsi evertsi, respectively. The Rhipicephalus ticks were more abundant in the central region, whereas A. variegatum ticks were more abundant in the eastern region. Tick control malpractices were found in both Central and Eastern Uganda, and 42 of the 56 surveyed farms lacked appropriate restraining facilities and so they utilized either ropes or a 'boma' (enclosure). In summary, B. bigemina, T. parva, A. marginale and their co-infections were more prevalent in the central than eastern region; even though, tick control malpractices were observed in both regions. Therefore, an urgent tick and TBD control strategy is needed.

Estimated seroprevalence of Anaplasma spp. and spotted fever group Rickettsia exposure among herders and livestock in Mongolia

BACKGROUND

To better understand the epidemiology of tick-borne disease in Mongolia, a comprehensive seroprevalence study was conducted investigating exposure to Anaplasma spp. and spotted fever group (SFG) Rickettsia spp. in nomadic herders and their livestock across three provinces from 2014 to 2015.

METHODS

Blood was collected from 397 herders and 2370 livestock, including sheep, goats, cattle, horses and camels. Antibodies against Anaplasma spp. and SFG Rickettsia were determined by indirect immunofluorescence using commercially available slides coated with Anaplasma phagocytophilum and Rickettsia rickettsii antigens. Logistic regression was used to determine if the odds of previous exposure differed by gender, location, and species, with or without adjustment for age. To examine the association between seroprevalence and environmental variables we used ArcGIS to circumscribe the five major clusters where human and animal data were collected.

RESULTS

Anaplasma spp. exposure was detected in 37.3% (136/365) of humans and 47.3% (1120/2370) of livestock; SFG Rickettsia exposure was detected in 19.5% (73/374) humans and 20.4% (478/2342) livestock. Compared to the southern province (aimag) of Dornogovi, located in the Gobi Desert, humans were significantly more likely to be exposed to Anaplasma spp. and SFG Rickettsia in the northern provinces of Tov (OR=7.3, 95% CI: 3.5, 15.1; OR=3.3, 95% CI: 1.7, 7.5), and Selenge (OR=6.9, 95% CI: 3.4, 14.0; OR=2.2, 95% CI: 1.1, 4.8).

CONCLUSION

The high seroprevalence of Anaplasma spp. and SFG Rickettsia in humans and livestock suggests that exposure to tick-borne pathogens may be common in herders and livestock in Mongolia, particularly in the more northern regions of the country. Until more is known about these pathogens in Mongolia, physicians and veterinarians in the countryside should consider testing for Anaplasma and SFG Rickettsia infections and treating clinically compatible cases, while public health authorities should expand surveillance efforts for these emerging infections.

Historical review and insights on the livestock tick-borne disease research of a developing country: The Philippine scenario

Tick-borne diseases (TBDs) remain to be a global animal health threat. Developing countries like the Philippines is not exempt to this. Despite the potential impact TBDs can give to these countries, local government initiatives and researches remain to be limited. In the Philippines, most epidemiological studies were confined only to specific areas, and predominantly in the Northern Area. Due to its unique geography and limited studies, the current nationwide status of most TBDs could not be clearly established. This review mainly covered published studies and presented challenges in the conduct of TBD research in the Philippines, which may be similar to other Southeast Asian or developing countries. To date, reported livestock TBD pathogens in the Philippines include Anaplasma, Babesia, Theileria, and Mycoplasma spp. With the ubiquitous presence of the Rhipicephalus microplus ticks in the country, it is highly probable that other pathogens transmitted by these vectors could be present. Despite studies on different TBDs in the livestock sector, the Philippine government has not yet heightened its efforts to implement tick control measures as part of the routine animal health program for local farmers. Further studies might be needed to determine the nationwide prevalence of TBDs and the presence of other possible tick species and TBD pathogens. The Philippine scenario may present situations that are similar to other developing countries.

Molecular survey and genetic characterization of Anaplasma centrale, A. marginale and A. bovis in cattle from Algeria

Bovine anaplasmosis could be caused by several Anaplasma species. The causative agents are transmitted by ticks and haematophagous arthropods with a high impact on both human and animal health. This study was conducted to estimate the infection rate and to characterize Anaplasma spp. in cattle from Algeria. A molecular survey was performed in Setif district (Northeast Algeria) where a total number of 180 cattle blood samples were collected and tested for the presence of Anaplasma spp. by PCR. Positive samples were genetically characterized based on the 16S rRNA and msp4 genes. PCRs revealed that the infection rates of Anaplasma spp., Anaplasma centrale, Anaplasma marginale and Anaplasma bovis were 42.2%; 39.4%; 11.1% and 4.4%, respectively. All tested animals were negative for A. phagocytophilum. Co-infection occurred in 10% (18/180) of the tested animals, and the most common co-infection pattern was an association between A. centrale and A. marginale (5.5%). Five cattle (2.7%) were co-infected by the three Anaplasma species. Holstein animals (58.1%) were more infected by A. centrale than the other breeds (p = .01). The molecular prevalence of A. centrale was significantly higher in males (54.2%) than in females (34.1%) (p = .001). A. marginale msp4 genetic analysis indicated a high sequence diversity of Algerian strains, suggesting the importation of live cattle from different origins. Phylogenetic analysis of the 16S rRNA gene of A. bovis and A. centrale revealed a low degree of genetic diversity. Our study suggests that different species of Anaplasma are simultaneously present in the Algerian cattle. To the best of our knowledge, this is the first molecular study and genetic characterization of Anaplasma spp. in Algerian cattle.

Molecular Epidemiological Survey and Genetic Characterization of Anaplasma Species in Mongolian Livestock

Anaplasma species are obligate intracellular rickettsial pathogens that cause great economic loss to the animal industry. Few studies on Anaplasma infections in Mongolian livestock have been conducted. This study examined the prevalence of Anaplasma marginale, Anaplasma ovis, Anaplasma phagocytophilum, and Anaplasma bovis by polymerase chain reaction assay in 928 blood samples collected from native cattle and dairy cattle (Bos taurus), yaks (Bos grunniens), sheep (Ovis aries), and goats (Capra aegagrus hircus) in four provinces of Ulaanbaatar city in Mongolia. We genetically characterized positive samples through sequencing analysis based on the heat-shock protein groEL, major surface protein 4 (msp4), and 16S rRNA genes. Only A. ovis was detected in Mongolian livestock (cattle, yaks, sheep, and goats), with 413 animals (44.5%) positive for groEL and 308 animals (33.2%) positive for msp4 genes. In the phylogenetic tree, we separated A. ovis sequences into two distinct clusters based on the groEL gene. One cluster comprised sequences derived mainly from sheep and goats, which was similar to that in A. ovis isolates from other countries. The other divergent cluster comprised sequences derived from cattle and yaks and appeared to be newly branched from that in previously published single isolates in Mongolian cattle. In addition, the msp4 gene of A. ovis using same and different samples with groEL gene of the pathogen demonstrated that all sequences derived from all animal species, except for three sequences derived from cattle and yak, were clustered together, and were identical or similar to those in isolates from other countries. We used 16S rRNA gene sequences to investigate the genetically divergent A. ovis and identified high homology of 99.3-100%. However, the sequences derived from cattle did not match those derived from sheep and goats. The results of this study on the prevalence and molecular characterization of A. ovis in Mongolian livestock can facilitate the control of infectious diseases in livestock.

Anaplasma species of veterinary importance in Japan

Anaplasma species of the family Anaplasmataceae, order Rickettsiales are tick-borne organisms that can cause disease in animals and humans. In Japan, all recognized species of Anaplasma (except for Anaplasma ovis) and a potentially novel Anaplasma sp. closely related to Anaplasma phagocytophilum have been reported. Most of these detected tick-borne pathogens are believed to be lowly pathogenic in animals in Japan although the zoonotic A. phagocytophilum has recently been reported to cause clinical signs in a dog and in humans. This review documents the studies and reports about Anaplasma spp. in Japan.

Alpha proteobacteria of genusAnaplasma(Rickettsiales: Anaplasmataceae): Epidemiology and characteristics ofAnaplasmaspecies related to veterinary and public health importance

TheAnaplasmaspecies are important globally distributed tick-transmitted bacteria of veterinary and public health importance. These pathogens, cause anaplasmosis in domestic and wild animal species including humans.Rhipicephalus, Ixodes, DermacentorandAmblyommagenera of ticks are the important vectors ofAnaplasma.Acute anaplasmosis is usually diagnosed upon blood smear examination followed by antibodies and nucleic acid detection. All age groups are susceptible but prevalence increases with age. Serological cross-reactivity is one of the important issues amongAnaplasmaspecies. They co-exist and concurrent infections occur in animals and ticks in same geographic area. These are closely related bacteria and share various common attributes which should be considered while developing vaccines and diagnostic assays. Movement of susceptible animals from non-endemic to endemic regions is the major risk factor of bovine/ovine anaplasmosis and tick-borne fever. Tetracyclines are currently available drugs for clearance of infection and treatment in humans and animals. Worldwide vaccine is not yet available. Identification, elimination of reservoirs, vector control (chemical and biological), endemic stability, habitat modification, rearing of tick resistant breeds, chemotherapy and tick vaccination are major control measures of animal anaplasmosis. Identification of reservoirs and minimizing the high-risk tick exposure activities are important control strategies for human granulocytic anaplasmosis.

Molecular detection and characterization of Babesia bovis, Babesia bigemina, Theileria species and Anaplasma marginale isolated from cattle in Kenya

Background

Infections with Babesia bovis, Babesia bigemina, Theileria species and Anaplasma marginale are endemic in Kenya yet there is a lack of adequate information on their genotypes. This study established the genetic diversities of the above tick-borne hemoparasites infecting cattle in Kenya.

Methods

Nested PCR and sequencing were used to determine the prevalence and genetic diversity of the above parasites in 192 cattle blood samples collected from Ngong and Machakos farms. B. bovis spherical body protein 4, B. bigemina rhoptry-associated protein 1a, A. marginale major surface protein 5, Theileria spp. 18S rRNA, T. parva p104 and T. orientalis major piroplasm surface protein were used as the marker genes.

Results

B. bovis, B. bigemina, T. parva, T. velifera, T. taurotragi, T. mutans and A. marginale were prevalent in both farms, whereas T. ovis, Theileria sp. (buffalo) and T. orientalis were found only in Ngong farm. Co-infections were observed in more than 50 % of positive samples in both farms. Babesia parasites and A. marginale sequences were highly conserved while T. parva and T. orientalis were polymorphic. Cattle-derived T. parva was detected in Machakos farm. However, cattle and buffalo–derived Theileria were detected in Ngong farm suggesting interactions between cattle and wild buffaloes. Generally, the pathogens detected in Kenya were genetically related to the other African isolates but different from the isolates in other continents.

Conclusions

The current findings reaffirm the endemicity and co-infection of cattle with tick-borne hemoparasites, and the role of wildlife in pathogens transmission and population genetics in Kenya.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-015-1106-9) contains supplementary material, which is available to authorized users.

First molecular survey and novel genetic variants' identification of Anaplasma marginale, A. centrale and A. bovis in cattle from Tunisia

Few data are available about the presence and distribution of Anaplasma species in cattle in North African countries. In this study prevalence, co-infections, risk factors and genetic diversity of Anaplasma species were evaluated in bovines from Northern Tunisia. A total of 232 cattle from 36 randomly selected farms in three Tunisian localities were investigated for the presence of Anaplasma species in blood by Real-time PCR and/or nested PCR. Overall infection rates of Anaplasma spp., Anaplasma marginale, Anaplasma centrale and Anaplasma bovis were 34.9%, 25.4%, 15.1%, and 3.9%, respectively. Anaplasma phagocytophilum was not detected in cattle. The most common co-infection pattern was an association of A. marginale and A. centrale (11.2%). Five cattle (2.1%) all reared in the sub-humid bioclimatic area, were co-infected by the three Anaplasma species. Molecular prevalence of Anaplasma infection varied significantly according to locality, bioclimatic area, tick infestation and type of breeding. Animals of the Holstein breed were less infected by A. marginale and A. centrale than other breeds. Genetic analysis of A. marginale msp4 gene indicated a high sequence diversity of Tunisian strains, suggesting a multiple introduction of infected cattle from different origins. Phylogenetic studies based on the 16S rRNA gene showed that the most prevalent A. centrale strains were closely related to the A. centrale vaccine strain. Moreover, all A. bovis variants clustered with other A. bovis sequences obtained from domestic and wild ruminant strains. This is the first molecular investigation on Anaplasma species in Tunisian cattle providing pivotal background for designing epidemiological studies and to develop control strategies in the country.

Molecular diagnosis of Anaplasma marginale in cattle: quantitative evaluation of a real-time PCR (Polymerase Chain Reaction) based on msp5 gene

The rickettsia Anaplasma marginale is considered the main agent of bovine anaplasmosis. Due the nonspecific clinical signs of the anaplasmosis, the diagnosis of infection depends of laboratory confirmation. In recent years, molecular diagnostic methods have been used to detect A. marginale in cattle. However, the existence of a large number of assays of different sensitivity and cost makes the choice of an appropriate test difficult. In the present study, a real-time Polymerase Chain Reaction (PCR) based on the msp5 target gene was quantitatively assessed and compared to an end point PCR. Both reactions were subjected to sensitivity and specificity evaluation using plasmid DNA and samples from cattle experimentally infected with A. marginale. A comparative field trial of the tests was carried out using samples of cattle from a stable enzootic area for A. marginale. The real-time PCR showed a higher sensitivity than the end point PCR. This reaction (i.e. real-time PCR) was able to detect one copy of the msp5 gene in 100 ηg of plasmidial DNA, and more than 80% of its results were positive among experimentally infected animals seven days after infection. In addition, based on in silico analysis, the real-time PCR evaluated in the present study appears to be useful for the detection of A. ovis.