Babesia Bigemina Research Articles

Tick-borne pathogens of zoonotic and veterinary importance in Nigerian cattle.

BackgroundTicks and tick-borne diseases undermine cattle fitness and productivity in the whole of sub-Saharan Africa, including Nigeria. In this West African country, cattle are challenged by numerous tick species, especially during the wet season. Consequently, several TBDs are known to be endemic in Nigerian cattle, including anaplasmosis, babesiosis, cowdriosis and theilerioris (by Theileria mutans and Theileria velifera). To date, all investigations on cattle TBDs in Nigeria have been based on cytological examinations and/or on serological methods. This study aimed to ascertain the occurrence of tick-borne pathogens of veterinary and zoonotic importance in cattle in Nigeria using molecular approaches.MethodsIn October 2008, 704 whole blood samples were collected from indigenous cattle in the Plateau State, Nigeria. Analysis for tick-borne pathogens was conducted by means of PCR-based reverse line blotting (RLB) and sequencing targeting a panel of five genera of microorganisms (i.e. Babesia, Theileria, Anaplasma, Ehrlichia and Rickettsia spp.).ResultsIn total, 561/704 (82.6 %) animals were found infected, with 465 (69.6 %) of them being infected by two or more microorganisms, with up to 77 possible combinations of pathogens detected. Theileria mutans was the most prevalent microorganism (66.3 %), followed by Theileria velifera (52.4 %), Theileria taurotragi (39.5 %), Anaplasma marginale (39.1 %), Anaplasma sp. (Omatjenne) (34.7 %), Babesia bigemina (7.9 %), Anaplasma centrale (6.3 %), Anaplasma platys (3.9 %), Rickettsia massiliae (3.5 %), Babesia bovis (2.0 %) and Ehrlichia ruminantium (1.1 %). Calves were found significantly less infected than juvenile and adult cattle.ConclusionsThis study provides updated, molecular-based information on cattle TBDs in Nigeria. The molecular approach employed allowed the diagnosis of numerous positive cases including carrier statuses, multiple infections and novel pathogen detections within the indigenous cattle population. Moreover, the RLB method here described enabled the detection of veterinary agents not only pertaining to bovine health, including also those of zoonotic importance.The high prevalence recorded for T. mutans, T. velifera, A. marginale, T. taurotragi and Anaplasma sp. (Omatjenne), suggests they may be endemically established in Nigeria, whereas the lower prevalence recorded for other microorganisms (i.e. A. centrale and B. bovis) highlights a less stable epidemiological scenario, requiring further investigations.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1504-7) contains supplementary material, which is available to authorized users.

Disaggregating Tropical Disease Prevalence by Climatic and Vegetative Zones within Tropical West Africa.

Tropical infectious disease prevalence is dependent on many socio-cultural determinants. However, rainfall and temperature frequently underlie overall prevalence, particularly for vector-borne diseases. As a result these diseases have increased prevalence in tropical as compared to temperate regions. Specific to tropical Africa, the tendency to incorrectly infer that tropical diseases are uniformly prevalent has been partially overcome with solid epidemiologic data. This finer resolution data is important in multiple contexts, including understanding risk, predictive value in disease diagnosis, and population immunity. We hypothesized that within the context of a tropical climate, vector-borne pathogen prevalence would significantly differ according to zonal differences in rainfall, temperature, relative humidity and vegetation condition. We then determined if these environmental data were predictive of pathogen prevalence. First we determined the prevalence of three major pathogens of cattle, Anaplasma marginale, Babesia bigemina and Theileria spp, in the three vegetation zones where cattle are predominantly raised in Ghana: Guinea savannah, semi-deciduous forest, and coastal savannah. The prevalence of A. marginale was 63%, 26% for Theileria spp and 2% for B. bigemina. A. marginale and Theileria spp. were significantly more prevalent in the coastal savannah as compared to either the Guinea savanna or the semi-deciduous forest, supporting acceptance of the first hypothesis. To test the predictive power of environmental variables, the data over a three year period were considered in best subsets multiple linear regression models predicting prevalence of each pathogen. Corrected Akaike Information Criteria (AICc) were assigned to the alternative models to compare their utility. Competitive models for each response were averaged using AICc weights. Rainfall was most predictive of pathogen prevalence, and EVI also contributed to A. marginale and B. bigemina prevalence. These findings support the utility of environmental data for understanding vector-borne disease epidemiology on a regional level within a tropical environment.

Identification and characterization of profilin antigen among Babesia species as a common vaccine candidate against babesiosis

We have characterized a member of the profilin (PROF) family protein as a common antigen in three pathogens—Babesia bovis (B. bovis), Babesia bigemina (B. bigemina), and Babesia microti (B. microti)—and evaluated its immunogenic and cross-protective properties against a challenge infection with B. microti in BALB/c mice. The recombinant PROF proteins of B. bovis, B. bigemina, and B. microti were successfully expressed in Escherichia coli (E. coli) as soluble GST fusion proteins (rBboPROF, rBbigPROF, and rBmPROF, respectively), and they were found to be antigenic. On probing with mouse anti-rPROF serum, green fluorescence was observed on the parasites’ cytosols by confocal laser microscopy. Immunization regimes in BALB/c mice using rPROFs induced cross-protective immunity against B. microti infection based on high levels of cytokines and immunoglobulin (IgG) titers, a reduction in peak parasitemia levels, and earlier clearance of the parasite as compared with control mice. The findings of the present study indicate that PROF is a common antigen among bovine and murine Babesia parasites, and it might be used as a common vaccine candidate against babesiosis.

Cholinesterases as markers of the inflammatory process associated oxidative stress in cattle infected by Babesia bigemina.

The objective of this study was to assess the influence of an asymptomatic experimental infection by Babesia bigemina on cholinesterase's as markers of the inflammatory process and biomarkers of oxidative imbalance. For this purpose, eight naive animals were used, as follows: four as controls or uninfected; and four infected with an attenuated strain of B. bigemina. Blood samples were collected on days 0, 7 and 11 post-inoculation (PI). Parasitemia was determined by blood smear evaluation, showing that the infection by B. bigemina resulted in mean 0.725 and 0.025% on day 7 and 11 PI, respectively, as well as mild anemia. The activities of acetylcholinesterase, butyrylcholinesterase and catalase were lower, while levels of thiobarbituric acid reactive substances and superoxide dismutase activity were higher in infected animals, when compared with the control group. This attenuated strain of B. bigemina induced an oxidative stress condition, as well as it reduces the cholinesterasés activity in infected and asymptomatic cattle. Therefore, this decrease of cholinesterase in infection by B. bigemina purpose is to inhibit inflammation, for thereby increasing acetylcholine levels, potent anti-inflammatory molecules.

Improvement of the cryopreservation method for the Babesia gibsoni parasite by using commercial freezing media

In vitro cultivation and cryopreservation under liquid nitrogen have already been reported and established for Babesia bovis and Babesia bigemina parasites. Although the in vitro cultivation methods for Babesia gibsoni have been reported and established, the cryopreservation methods for this parasite have not been established completely. In this paper, we compared several freezing media for the cryopreservation of B. gibsoni parasite. The CELLBANKER® series (1 plus and 2), STEM-CELLBANKER®, and CultureSure® were used for commercial freezing media; 10% dimethyl sulfoxide in 90% fetal bovine serum, 20% polyvinylpyrrolidone in phosphate-buffered saline (established for bovine Babesia parasites), and 28% glycerol supplemented with 3% sorbitol and 0.65% NaCl dissolved in water (established for Plasmodium parasites) were used for conventional media. Our results demonstrated that the CELLBANKER® series (1 plus and 2), STEM-CELLBANKER®, and CultureSure® are effective freezing media for B. gibsoni parasite compared to the cryopreservation methods of bovine Babesia and Plasmodium parasites. Our improved method of cryopreservation would contribute to the stability of the in vitro cultivation of B. gibsoni parasite.

Babesia bovis and Babesia bigemina infection levels estimated by qPCR in Angus cattle from an endemic area of São Paulo state, Brazil

The levels of infection by Babesia bovis and Babesia bigemina were estimated by absolute quantification through the quantitative PCR technique (qPCR). Fifty-one contemporaneous Angus cattle were evaluated on two occasions. The number of standard female Rhipicephalus microplus ticks present on the left side of the body was counted and blood samples were drawn from the tail vein into tubes containing the anticoagulant EDTA. The blood samples were submitted to DNA extraction and used to quantify the number of copies (NC) of DNA from B. bovis and B. bigemina by qPCR. The data on tick count and number of DNA copies were transformed for normalization and analyzed by a mixed model method. A multivariate model with repeated measures of the same animal, including the effects of collection, parasite species and their interaction, was used. The repeatability values were obtained from the matrix of (co)variances and were expressed for each species. The correlations between the counts of different species on the same animal, in the same collection or different collections, were also estimated. The results showed the qPCR could distinguish the two between infection by the two Babesia species. Infection levels by B. bovis and B. bigemina were detected in 100% and 98% of the animals, respectively. Significant differences were found (P<0.05) between the NC of the two Babesia species, B. bovis 1.49±0.07 vs. B. bigemina 0.82±0.06. Low repeatabilities were found for the counts of R. microplus and NC of B. bovis and B. bigemina: 0.05, 0.10 and 0.02, respectively. The correlations between R. microplus count and NC of B. bovis and B. bigemina were both very near zero. However, an association was observed between the NC of the two species, with a correlation coefficient of 0.30 for measures from the same collection. The absence of associations between the quantity of DNA from B. bovis and B. bigemina and the tick counts suggests that the variation of parasitemia by the hemoparasites did not depend on the tick infestation levels at the moment of each collection. The repeatability values estimated indicate that under the study conditions, the variations in the tick infestation levels and of parasitemia by B. bovis and B. bigemina depend more on factors related to each collection than on intrinsic factors of the animal.

Rapid and sensitive detection of Babesia bovis and Babesia bigemina by loop-mediated isothermal amplification combined with a lateral flow dipstick

Babesia spp. are apicomplexan protozoan parasites of the red blood cells of mammals and are transmitted by ticks. Bovine babesiosis mainly caused by Babesia bovis and Babesia bigemina occurs worldwide, which is a great threat to animal health. Microscopy examination is a gold standard for the diagnosis of babesiosis. However, its sensitivity is too low. This study was conducted to establish a simple, efficient and fast LAMP-LFP method used for early diagnosis of animal babesiosis. LAMP was developed with a set of four primers targeting and amplifying six distinct regions of cytochrome b gene of Babesia spp. under isothermal conditions. Afterwards, a chromatographic lateral-flow dipstick (LFD) was used to detect LAMP products that were labeled with FITC at the 5′ end, avoiding gel electrophoresis. The LAMP-LFD method was very specific, yielding no positive results with DNA templates of Theileria sergenti, Thenileria ovis, Theileria equi and Toxoplasma gondii. The LAMP-LFP was highly sensitive and could detect 0.85fg B. bigemina DNA and 0.14fg B. bovis DNA, 100-fold higher than a conventional PCR assay. This method could be adapted for quick and accurate diagnosis of bovine babesiosis in the fields in case the whole blood could be directly used, especially for identifying carrier animals with very low parasitaemia.

A promising new ELISA diagnostic test for cattle babesiosis based on Babesia bigemina Apical Membrane Antigen-1.

Babesiosis due to Babesia bigemina is a relevant tick-borne disease, affecting cattle worldwide. Many surface proteins of the pathogen including the Apical Membrane Antigen 1 (AMA-1) - have been analysed for vaccine and diagnostic purposes. This study focused on B. bigemina AMA-1 and on its use for the assessment of diagnostic tests. After bioinformatic analyses, AMA-1 codifying region was amplified and cloned into an expression vector used to induce protein synthesis in Escherichia coli cells. AMA-1 was purified by affinity chromatography and used to set up the best condition for an ELISA protocol. Bovine field sera positive to B. bigemina were used to evaluate the presence of anti-AMA-1 antibodies. In order to verify the assay specificity, sera positive to Babesia bovis or to the piroplasm Theileria annulata were also included. Significant differences were obtained between sera negative to both B. bigemina and B. bovis and samples positive to B. bigemina, to B. bovis or to both pathogens. No significant reaction was observed with T. annulata positive sera. The results showed that AMA-1 protein is suitable to be used as antigen in diagnostic assays for babesiosis diagnosis in cattle, as it does not show any cross reaction with anti-T. annulata antibodies.

Seroprevalence of Babesia bigemina and Anaplasma marginale in domestic animals of district Ganderbal

The present study of seroprevalence of B. bigemina and A. marginale in cattle, sheep and goats was studied in Ganderbal district of Kashmir, between January to December 2012. A total of 153 blood samples were collected randomly from 40 cattle, 52 sheep and 61 goats for the preparation of blood smears and serum samples in four consecutive seasons and tested against B. bigemina and A. marginale using the SVANOVIR ® B. bigemina -Abs and A. marginale -Abs ELISA Kit. Samples were also examined by Giemsa's stained blood smear method. The effect of topography, season, age, gender and breed was observed in cattle during this study. The overall prevalence of B. bigemina infection was 3 (7.5%), 2 (3.84%) and 3 (4.91%) in cattle, sheep and goats and for A. marginale 2 (5%), 1 (1.92%) and1 (1.63%) respectively. The mixed infections between B. bigemina and A. marginale were 5% in cattle, 1.92% in sheep and 3.27% in goats. The seasonal prevalence of B.bigemina , A. marginale and mixed infection between them peaked in summer as revealed by blood smear examination and ELISA.

Molecular and serological detection of Babesia bovis- and Babesia bigemina-infection in bovines and water buffaloes raised jointly in an endemic field

Babesia bovis and Babesia bigemina are causative agents of bovine babesiosis, a tick-borne disease of cattle in tropical and subtropical regions. Babesia spp. infection adversely affects cattle health and can be fatal resulting in considerable economic loss worldwide. Under endemic stability conditions, herds contain high numbers of chronically infected, asymptomatic carrier animals, in which no parasitemia is detected by microscopic blood smear examination. In addition to bovines, also water buffaloes are infected by both Babesia spp. commonly leading to a subclinical infection. The infection rate (by nPCR) and herd exposure (by IFAT) of bovines and water buffaloes reared under similar field conditions in an area of endemic stability were determined and compared. In order to optimize direct parasite detection, highly sensitive nPCR assays were developed and applied, allowing the detection of as little as 0.1fg DNA of each Babesia pathogen. Significantly lower percentages (p<0.001) of seropositive water buffaloes compared to bovines were observed for B. bovis (71.4% vs. 98%) and B. bigemina (85% vs. 100%). Interestingly, in comparison, differences noticed between water buffaloes and bovines were considerably larger with direct parasite detection by nPCR (16.2% vs. 82.3% and 24% vs. 94.1% for B. bovis and B. bigemina, respectively).As expected, bovines subjected to monthly acaricide applications exhibited a significant lower infection rate as determined by nPCR than bovines not subjected to these measures (B. bovis 33.3% vs. 90.7%, p<0.001; B. bigemina 80% vs. 96.5%, p<0.001, for treated vs. untreated animals). Interestingly no differences between these groups were observed with respect to seropositivity, suggesting similar rates of parasite exposure (B. bovis 100% vs. 97.7%, p<0.001; B. bigemina 100% vs. 100%, p<0.001). Importantly, a significantly higher number of water buffaloes as determined by nPCR were infected when reared jointly with bovines not subjected to tick control than when reared jointly with bovines subjected to tick control (B. bovis 31.6% vs. 9.5%, p<0.01; B. bigemina 42.1% vs. 9.5%, p<0.01, for water buffaloes reared with untreated vs. treated bovines) and/or when reared without bovines (B. bovis 31.6% vs. 11.6%, p<0.01; B. bigemina 42.1% vs. 20%, p<0.01). An accumulation of seropositivity and a decline of infection rates were observed in older animals, while differences observed with regard to gender may warrant further investigation. In summary, our findings suggest that water buffaloes are much more capable to limit or eliminate Babesia infection, possibly due to a more capable immune defense. Furthermore, an increased Babesia spp. parasite reservoir of bovines seems to increase the infection rate of water buffaloes when both are reared on the same pasture.

A PCR-based survey of animal African trypanosomosis and selected piroplasm parasites of cattle and goats in Zambia.

We screened cattle and goats from the districts of Chama, Monze and Mumbwa in Zambia for animal African trypanosomes, Babesia bigemina and Theileria parva using PCRs; 38.1% of the samples tested positive for at least one of the parasite species. The most common parasite was Trypanosoma vivax (19.8%). Its incidence was significantly higher in goats than in cattle, (P<0.05). B. bigemina was found in samples from all the three areas, making it the most widespread of the parasites in Zambia. Among the tested samples, 12.0% of the positive samples were mixed infections. There were significant differences in the infection rates of T. vivax (Mumbwa had a significantly higher infection rate [39.6%, P<0.0001]), Th. parva (Monze had the only cases [P<0.0004]) and B. bigemina (Monze had a significantly higher infection rate [40.5%, P<0.0001]). According to the hematocrit values, the packed cell volume (%) among the cattle with mixed infections was significantly lower than that of the other cattle. The presence of multiple parasite species and mixed infections among the Zambian cattle and goat populations is of both clinical and economic importance to livestock farming. The absence of trypanosomosis among the samples from Monze can be attributed to tsetse eradication efforts that took place around Lake Kariba. This shows that the prevention and control of these parasitic diseases can have a significant impact on the disease status, which can translate directly into the improvement of the livestock sector in Zambia.

Seroepidemiological survey of bovine tick-borne infections in theBlack Sea Region of Turkey

Babesiosis, theileriosis, and anaplasmosis are the tick-borne diseases of cattle in most of the tropical areas and Turkey. A total of 270 cattle were randomly selected from 27 villages and 77 farms in the Black Sea Region of Turkey for the determination of infections by Babesia bigemina and Anaplasma marginale by using the indirect fluorescent antibody (IFA) test and the competitive enzyme-linked immunosorbent assay (cELISA). Of those, 242 and 256 sera were also analyzed for antibodies against Theileria annulata and Babesia bovis infections using the IFA test, respectively, during the period of June 2006 to June 2007. Of the 256 tested sera, 99 (38.6%) were positive for B. Bovis; from the total 270 sera, 40 (14.8%) were positive for B. Bigemina; of the 242 sera tested, 31 (12.8%) were positive for T. Annulata by IFA; and from the total 270 sera, 102 (37.8%) were positive for A. Marginale by cELISA. A total of 1125 ixodid ticks were collected and 10 species were identified. Antibodies produced by infections with Babesia spp., Anaplasma spp., and Theileria spp. Were found highly prevalent. Infections caused by the agents and the tick species may cause severe economic damage to cattle production from the Black Sea Region of Turkey.

Molecular Detection of Pathogens in Ticks Infesting Camels in Matrouh Governorate, Egypt

Tick-borne pathogens become healthy important as the incidence of tick-borne diseases increases and the geographic areas in which they are found expand. A relatively little information is available on ticks infesting camels in Matrouh Governorate, Egypt, and the role of ticks as disease vectors. Thus rendering PCR assay the only viable alternative to demonstrate their presence. For this purpose, a surveillance was carried out from May 2011 to April 2013 to identify ticks parasitize camels, and tested part of them for the presence of parasitic, rickettsial and bacterial pathogens using specific primers targeting fragments of their genes. Out of 249 studied camels, 212 (85.14%) were infested by five species of ticks that increased in numbers during dry seasons. Hyalomma dromedarii was the predominant tick species (73.65%), followed by H. rufipes (12.03%), H. truncatum (6.62%), and low numbers were H. anatolicum excavatum (4.73%), and H. impeltatum (1.62%), besides 1.35% were belong to other species. PCR results revealed that the majority of samples were found co-infected with at least five pathogens. It evidenced the presence of Trypanosoma evansi, Trypanosoma brucei, Babesia bovis, Babesia bigemina, Theileria camelensis and Anaplasma marginale. Borrelia burgdorferi, Rickettsial DNA, and Theileria annulata were absent. Pasteurella multocida, Histophilus somni and Mycoplasma sp. were detected in ticks DNAs, but not known if transmitted by ticks or not. We conclude that several pathogens are present in ticks in this area, phylogeny is required in order to validate the PCR results, and special attention should be given to tick control programs.

Haematological response of Sokoto Gudali heifers to Babesia infection and tick control measures in a humid tropical environment

Sixteen Sokoto Gudali heifers weighing 184±16 kg were used to assess the haematological response of zebu cattle to babesia infection under different tick control measures. Animals were grazed inside tick-infested pastures and subjected to different cypermethrin treatments as follows: no treatment/control (NT); treatment of animal (TA); treatment of pasture (TP) and treatment of animal and pasture (TAP). Tick count and babesia infection in blood were assessed at 21-day intervals. Erythrocyte sedimentation rate (ESR), packed cell volume (PCV), haemoglobin (Hb), red blood cell (RBC) and white blood cell (WBC) count were also determined in the animals at pre-treatment and post-treatment periods. Tick species found on the animals include Amblyomma variegatum (8.6 %), Boophilus decoloratus (25.2 %) and Boophilus geigyi (66.2%). Tick count reduced from an average of 34 to less than 8 by the 12th week of study. Babesia parasite (Babesia bigemina) was not detected in the blood of treated animals by the 6th week. The ESR of heifers at the 12th week was 8.36, 2.10, 2.65, 1.65 mm/h; RBC, 6.05, 8.20, 8.26, 9.30 x 1012/L; and WBC, 12.37, 6.06, 7.08, 4.89 x 109/L for NT, TA, TP. and TAP respectively. The ESR and WBC values obtained shows that infection rates increased in untreated animals and decreased in animals under tick control measures. The RBC count also indicates improvement in health status of heifers when cypermethrin treatments were applied regularly. Babesia bigemina

Evaluation of in vitro inhibitory effect of enoxacin on Babesia and Theileria parasites

Enoxacin is a broad-spectrum 6-fluoronaphthyridinone antibacterial agent (fluoroquinolones) structurally related to nalidixic acid used mainly in the treatment of urinary tract infections and gonorrhea. Also it has been shown recently that it may have cancer inhibiting effect. The primary antibabesial effect of Enoxacin is due to inhibition of DNA gyrase subunit A, and DNA topoisomerase. In the present study, enoxacin was tested as a potent inhibitor against the in vitro growth of bovine and equine Piroplasms. The in vitro growth of five Babesia species that were tested was significantly inhibited (P < 0.05) by micro molar concentrations of enoxacin (IC50 values = 33.5, 15.2, 7.5 and 23.2 μM for Babesia bovis, Babesia bigemina, Babesia caballi, and Theileria equi, respectively). Enoxacin IC50 values for Babesia and Theileria parasites were satisfactory as the drug is potent antibacterial drug with minimum side effects. Therefore, enoxacin might be used for treatment of Babesiosis and Theileriosis especially in case of mixed infections with bacterial diseases or incase of animal sensitivity against diminazin toxicity.

What's in your next-generation sequence data? An exploration of unmapped DNA and RNA sequence reads from the bovine reference individual.

BackgroundNext-generation sequencing projects commonly commence by aligning reads to a reference genome assembly. While improvements in alignment algorithms and computational hardware have greatly enhanced the efficiency and accuracy of alignments, a significant percentage of reads often remain unmapped.ResultsWe generated de novo assemblies of unmapped reads from the DNA and RNA sequencing of the Bos taurus reference individual and identified the closest matching sequence to each contig by alignment to the NCBI non-redundant nucleotide database using BLAST. As expected, many of these contigs represent vertebrate sequence that is absent, incomplete, or misassembled in the UMD3.1 reference assembly. However, numerous additional contigs represent invertebrate species. Most prominent were several species of Spirurid nematodes and a blood-borne parasite, Babesia bigemina. These species are either not present in the US or are not known to infect taurine cattle and the reference animal appears to have been host to unsequenced sister species.ConclusionsWe demonstrate the importance of exploring unmapped reads to ascertain sequences that are either absent or misassembled in the reference assembly and for detecting sequences indicative of parasitic or commensal organisms.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-2313-7) contains supplementary material, which is available to authorized users.

Molecular epidemiology of bovine Babesia spp. and Theileria orientalis parasites in beef cattle from northern and northeastern Thailand

Beef cattle production represents the largest cattle population in Thailand. Their productivity is constrained by tick-borne diseases such as babesiosis and theileriosis. In this study, we determined the prevalence of Babesia bigemina, Babesia bovis and Theileria orientalis using polymerase chain reaction (PCR). The genetic markers that were used for detection of the above parasites were sequenced to determine identities and similarity for Babesia spp. and genetic diversity of T. orientalis. Furthermore the risk factors for the occurrence of the above protozoan parasites in beef cattle from northern and northeastern parts of Thailand were assessed. A total of 329 blood samples were collected from beef cattle in 6 provinces. The study revealed that T. orientalis was the most prevalent (30.1%) parasite in beef cattle followed by B. bigemina (13.1%) and B. bovis (5.5%). Overall, 78.7% of the cattle screened were infected with at least one of the above parasites. Co-infection with Babesia spp. and T. orientalis was 30.1%. B. bigemina and T. orientalis were the most prevalent (15.1%) co-infection although triple infection with the three parasites was observed in 3.0% of the samples. Sequencing analysis revealed that B. bigemina RAP1 gene and B. bovis SBP2 gene were conserved among the parasites from different cattle samples. Phylogenetic analysis showed that the T. orientalis MPSP gene from parasites isolated from cattle in north and northeast Thailand was classified into types 5 and 7 as reported previously. Lack of tick control program was the universal risk factor of the occurrence of Babesia spp. and T. orientalis infection in beef cattle in northern and northeastern Thailand. We therefore recommend training of farmers on appropriate tick control strategies and further research on potential vectors for T. orientalis and elucidate the effect of co-infection with Babesia spp. on the pathogenicity of T. orientalis infection on beef in northern and northeastern Thailand.

Molecular survey of Babesia infections in cattle from different areas of Myanmar

Cattle babesiosis is one of the most important tick-borne diseases worldwide. The present study reports a molecular survey of Babesia infections in cattle in Myanmar. Nested PCR assays based on the Babesia bigemina apical membrane antigen-1 gene (AMA-1) and B. bovis rhoptry associated protein-1 gene (RAP-1) revealed that the overall percentage of B. bigemina and B. bovis infection were 9.8% (70/713) and 17.1% (122/713), respectively. A mixed infection was detected in 4.6% (33/713) of animals. Animals <1 year (OR=13.66, CI=5.15–36.26) and 1–5 years of age (OR=3.91, CI=1.50–10.17) were identified as potential risk factors for B. bigemina infection. For B. bovis infection, age <1 year (OR=3.06, CI=1.63–5.75) and 1–5 years (OR=2.08, CI=1.21–3.57), Friesian–Zebu crossbreeds (OR=2.04, CI=1.26–3.30) and grazing (OR=1.59, CI=1.06–2.38) were identified as potential risk factors. This is the first report on a nationwide survey of bovine Babesia infections in Myanmar, providing useful information for the management and control of the disease.

Genetic characterization and molecular survey of Babesia bovis, Babesia bigemina and Babesia ovata in cattle, dairy cattle and yaks in China.

BackgroundBabesiosis is an important haemoparasitic disease, caused by the infection and subsequent intra-erythrocytic multiplication of protozoa of the genus Babesia that impacts the livestock industry and animal health. The distribution, epidemiology and genetic characterization of B. bigemina, B. bovis, and B. ovata in cattle in China as well as the prevalence of these protozoan agents were assessed.MethodsA total of 646 blood specimens from cattle, dairy cattle and yaks from 14 provinces were collected and tested for the presence of the three Babesia species via a specific nested PCR assay based on the rap-1 and ama-1 genes. The PCR results were confirmed by DNA sequencing. Gene sequences and the genetic characterization were determined for selected positive samples from each sampling area.ResultsOf a total of 646 samples, 134 (20.7 %), 60 (9.3 %) and 10 (1.5 %) were positive for B. bovis, B. bigemina and B. ovata infections, respectively. Mixed infections were found in 7 of 14 provinces; 43 (6.7 %) samples were infected with B. bovis and B. bigemina. Three samples (0.5 %) exhibited a co-infection with B. bovis and B. ovata, and 6 (0.9 %) were infected with all three parasites. The rap-1a gene of B. bovis indicated a high degree of sequence heterogeneity compared with other published rap-1a sequences worldwide and was 85–100 % identical to B. bovis rap-1a sequences in Chinese isolates. B. bigemina rap-1c and B. ovata ama-1 genes were nearly identical, with 97.8–99.3 % and 97.8–99.6 % sequence identity, respectively, in GenBank.ConclusionsPositive rates of B. bovis and B. bigemina infection are somewhat high in China. The B. bovis infection in yaks was first reported. The significant sequence heterogeneity in different variants of the rap-1a gene from Chinese B. bovis isolates might be a great threat to the cattle industry if RAP-1a protein is used as immunological antigen against Babesia infections in China. The data obtained in this study can be used to plan effective control strategies against babesiosis in China.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-1110-0) contains supplementary material, which is available to authorized users.

Séroprévalence et facteurs de risque des hémoparasitoses (theilériose, babésiose et anaplasmose) chez les bovins dans quatre grandes régions d’élevage du Maroc

Les hémoparasitoses (theilériose, babésiose et anaplasmose) sont des maladies vectorielles graves dont l’impact économique et sur la santé des élevages bovins au Maroc est considérable. L’objectif de cette étude, réalisée dans quatre régions d’élevage bovin laitier, a été de déterminer la séroprévalence et les facteurs de risque de ces infections. Au total 1 040 bovins ont été examinés dans 96 exploitations. La technique competitive enzyme-linked immunosorbent assay (cELISA) et la réaction d’immunofluorescence indirecte ont été utilisées pour la détermination de la séroprévalence, et le test statistique V de Cramer a permis d’analyser les facteurs de risque d’infection des bovins par les hémoparasites. Sur 1 040 sérums analysés, 689 (66,3 p. 100) ont été séropositifs ; la séroprévalence a varié selon le parasite considéré : Theileria annulata (35,4 p. 100), Anaplasma marginale (20,5 p. 100), Babesia bigemina (13,6 p. 100) et B. bovis (12,0 p. 100). Par ailleurs, 155 sérums (14,9 p. 100) ont présenté des infections mixtes (deux ou trois hémoparasites simultané- ment). L’analyse statistique a montré que l’âge (C = 0,62) et le type d’élevage (C = 0,60) ont eu une forte influence sur la séroprévalence, tandis que la race (C = 0,46) et le sexe (C = 0,29) ont eu une influence moindre. Le climat (C = 0,06) n’a pas semblé avoir d’impact. Ces résultats aideront à comprendre la situation épizootique des hémoparasitoses vectorielles chez les bovins afin d’établir une stratégie adéquate pour leur contrôle.