A PCR-based survey of selected Babesia and Theileria parasites in cattle in Sri Lanka

Molecular detection of Anaplasma, Babesia, Theileria, and Trypanosoma infection in cattle and buffaloes in India

Tick-borne pathogens pose a significant global threat, causing substantial economic losses to the dairy industry. In India, tropical theileriosis, anaplasmosis, babesiosis, and trypanosomiasis are major hemo-parasitic diseases affecting bovines. A cross-sectional study was conducted to determine the prevalence of hemo-parasites in different farms in India. PCR assays were employed to detect carrier status, using gene targets msp1b, tams1, rap-1, ama1, and ITS1 for A. marginale, T. annulata, B. bovis, B. bigemina, and Trypanosoma species, respectively. Out of the 578 apparently healthy animals screened, 30.45% (95% CI: 26.84-34.32%) were infected with at least one hemo-parasite. Cattle showed an overall positivity of 32.87%, while buffaloes had a prevalence of 15.19%, which was statistically significant (p < 0.001). Interestingly, prevalence was higher in indigenous cattle (47.81%) compared to cross-breeds (25.53%) and exotics (14.62%), with a statistically significant difference (p < 0.001). The prevalence of hemo-parasites varied widely among the farms, ranging from 5.77 to 100%. A. marginale was the most prevalent parasite (23.70% of animals), followed by T. annulata (13.67%), Babesia species (1.90%), and Trypanosoma species (1.56%). Enzootic instability was observed in six of the eight farms, indicating a potential for future outbreaks. Co-infection was detected in 60 out of 176 animals positive for hemo-parasites, with 59 animals co-infected with A. marginale and T. annulata, and only one cross-breed cattle infected with both Anaplasma marginale and Babesia bigemina. The findings highlight the prevalence of hemo-parasites in farms, underscoring the need for whole-herd screening, treatment of infected animals, and improvement in farm management practices to prevent production losses caused by these pathogens.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12639-024-01673-3.

Unveiling genotypic diversity of Theileria orientalis in lethal outbreaks among bovines in Karnataka, India

Theileria orientalis, the causal agent of oriental theileriosis, is known to cause mild disease in cattle and buffalo across the world. Recently, different genotypes of T. orientalis have emerged as pathogenic, causing high reported morbidity in cattle. This study focuses on investigating three suspected outbreaks of oriental theileriosis that resulted in fatalities among crossbred and indigenous bulls in Karnataka, India. Examination of blood smears revealed the presence of T. orientalis piroplasms within erythrocytes. The genetic characterization of T. orientalis was conducted by targeting specific markers, including the mpsp gene, p23 gene, and ribosomal DNA markers (18S rRNA gene, ITS-1, and ITS-2). Analysis based on the 18S rRNA gene unveiled the presence of both Type A and Type E genotypes of T. orientalis in the outbreaks. The mpsp gene-based analysis identified genotype 7 of T. orientalis in crossbred cows, whereas genotype 1 (Chitose B) was found to be present in indigenous bulls. Haplotype network analysis based on the mpsp gene revealed the presence of 39 distinct haplotypes within the 12 defined genotypes of T. orientalis with a high haplotype diversity of 0.9545 ± 0.017. Hematological and biochemical analysis revealed a decrease in calcium, hemoglobin levels, red blood cell counts, and phosphorus. This study constitutes the initial documentation of a clinical outbreak of oriental theileriosis in indigenous bulls with genotype 1 (Chitose 1B). Substantial epidemiological investigations are imperative to gain a comprehensive understanding of the geographical distribution of distinct genotypes and the diverse clinical manifestations of the disease across various hosts.

Molecular detection and characterization of Theileria annulata, Babesia bovis, and Babesia bigemina infecting cattle and buffalo in southern Egypt

Tick-borne diseases have a major adverse effect on livestock worldwide, causing enormous economic losses in meat and milk production as well threatening animal and public health. In this study, we aimed to detect and characterize piroplasms isolated from cattle and buffalo in southern Egypt, using molecular techniques. Three hundred blood samples were collected from cattle and buffalo in two governorates in southern Egypt. All 300 samples (100%) were confirmed to contain DNA, as they exhibited bands of bovine β-actin gene at the expected 227 bp for cattle and buffalo. The samples were analyzed by PCR for the presence of piroplasms, specifically Babesia bovis, Babesia bigemina, and Theileria annulata. Samples positive for the piroplasma 18S ribosomal RNA gene were further examined for two additional genes, spherical body protein 4 gene, to provide an enhanced degree of specificity for the identification of B. bovis and B. bigemina, and the major merozoite surface antigen gene for T. annulata. The infection rate for piroplasma spp. was 60/300 (20%). The positivity rates were 10.7% (32/300) for T. annulata, 5.3% (16/300) for B. bovis, and 4% (12/300) for B. bigemina. By host species, 42/150 (28%) cattle and 18/150 (12%) buffalo were positive for piroplasms. None of the isolates sequenced for the B. bovis isolates from buffalo in this study showed 100% identity with any sequence deposited in GenBank for the small subunit ribosomal RNA gene (maximum identity value = 99.74%). Similarly, no T. annulata small subunit ribosomal RNA gene sequence identified in this study exhibited 100% identity with any sequence deposited in GenBank (maximum identity value = 99.89%). The current study provides a partial sequence of the T. annulata merozoite-piroplasm surface antigen gene, as well as the B. bovis and B. bigemina spherical body protein 4 genes, in cattle and buffalo in southern Egypt, and is the first report on these piroplasma genes in cattle and buffalo in southern Egypt.

Molecular Detection and Identification of Piroplasm in Cattle from Kathmandu Valley, Nepal

BACKGROUND

Tick-borne protozoan parasites (TBPPs) cause significant problems for domestic animals' health in Nepal. TBPPs are routinely diagnosed by labor-intensive blood smear microscopy. In Nepal, there are some reports of Babesia and Theileria in cattle, although species identification is rarely performed. Therefore, we performed conventional nested PCR (nPCR) followed by sequence analysis to identify TBPP species infecting cattle in Nepal.

METHODS

One hundred and six blood samples were collected from cattle in the Kathmandu Valley. Thin blood smears were prepared for microscopic examination. Parasite DNA was extracted from the blood, and nPCR and sequencing were performed to identify the TBPPs present.

RESULTS

Among the 106 samples, 45 (42.5%) were positive for piroplasm (Babesia spp. and Theileria spp.) via microscope observation and 56 (52.8%) samples were positive via nPCR. The obtained PCR products were used for direct sequencing, and we identified the species as B. bigemina, B. bovis, T. annulate and T. orientalis. Phylogenetic analyses showed that the B. bovis, B. bigemina and T. orientalis sequences from this study belonged to each species clade. On the other hand, T. annulate was divided into two clades in the analysis, and our T. annulate sequences were also divided in these two clades. The piroplasm-positive cattle showed lower hemoglobin and red blood cells than healthy cattle.

CONCLUSIONS

To the best of our knowledge, this study is the first to apply molecular detection and species determination of TBPPs in cattle in Nepal. The results of this study may be used as a starting point for the development of successful TBPP surveillance and prevention programs in Nepal.

Incidence of hemoparasitic infections in cattle from central and northern Thailand

Background

Hemoparasites, such as Babesia spp., Theileria spp. and Anaplasma spp., can negatively affect the health of farm animals resulting in significant losses in production. These losses inherently affect the economics of the livestock industry. Since increases in the severity of vector-borne diseases in the southeast Asian region have been reported, investigations of parasitic epidemiology in Thailand will be necessary to improve the existing parasite control strategies for blood parasitic infections. This study aims to investigate incidences of bovine hemoparasites throughout central and northern Thailand by focusing on areas of high-density cattle populations.

Methods

Blood parasitic infections among cattle were screened and identified by microscopic examination. Anemia status was then determined by evaluation of the packed cell volume (PCV) of each animal. Furthermore, blood parasites were detected and identified by genus and species-specific primers through the polymerase chain reaction method. Amplicons were subjected to DNA sequencing; thereafter, phylogenetic trees were constructed to determine the genetic diversity and relationships of the parasite in each area.

Results

A total of 1,066 blood samples were found to be positive for blood parasitic infections as follows: 13 (1.22%), 389 (36.50%), and 364 (34.15%) for Babesia bovis, Theileria orientalis, and Anaplasma marginale, respectively. Furthermore, multiple hemoparasitic infections in the cattle were detected. The hematocrit results revealed 161 hemoparasitic infected samples from 965 blood samples, all of which exhibiting indications of anemia with no significant differences. Sequence analysis of the identified isolates in this study revealed that B. bovis rap-1, four separate clades of T. orientalis msps, and A. marginale msp4 exhibited considerable sequence similarity to homologous sequences from isolates obtained from other countries. Sequence similarity ranged between 98.57-100%, 83.96-100%, and 97.60-100% for B. bovis rap-1, T. orientalis msps, and A. marginale msp4, respectively.

Conclusion

In this study, the analyzed incidence data of cattle hemoparasitic infection in Thailand has provided valuable and basic information for the adaptation of blood-borne parasitic infections control strategies. Moreover, the data obtained from this study would be useful for future effective parasitic disease prevention and surveillance among cattle.

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.

First detection of Theileria equi in free-roaming donkeys (Equus africanus asinus) in Sri Lanka

Equine piroplasmosis (EP) is a tick-borne disease caused by Theileria equi and Babesia caballi in equids, including horses, donkeys, zebras, and mules. It is globally endemic with significant economic impact on the equine industry. Infected animals may serve as carriers, and they may be a source of infection for ticks, thereby posing a great challenge for disease management. Sri Lanka is a tropical country, where infections by various tick-borne parasites are common among livestock animals. However, infections by T. equi and B. caballi remain unstudied in Sri Lanka. Therefore, in the present study, we conducted an epidemiological survey to investigate the presence of T. equi and B. caballi in apparently healthy free-roaming donkeys. Blood samples were randomly taken from 111 donkeys in Mannar (n = 100) and Kilinochchi (n = 11) districts in Sri Lanka. Thin blood smears were prepared from the blood samples and subjected to microscopic examination. Additionally, blood DNA samples were prepared and screened for T. equi and B. caballi infections using species-specific PCR assays. Our results showed that 64 (57.7%) and 95 (85.6%) of the donkeys were positive for T. equi by microscopy and PCR, respectively. However, all samples were negative for B. caballi. Phylogenetic analysis of the T. equi 18S rRNA sequences detected two distinct genotypes, namely C and D. To our knowledge, this is the first report of T. equi in Sri Lanka and of genotype C in donkeys. The present study highlights the importance of monitoring the shrinking donkey population in Sri Lanka owing to EP caused by T. equi.

Cattle anaplasmosis and babesiosis: Major tick-borne diseases affecting the cattle industry in Khartoum State, Sudan

Tick-borne hemoparasitic (TBH) infections are a major problem affecting livestock industries worldwide, particularly in tropical and subtropical regions. This study was carried out in response to repeated reports from local veterinarians in Khartoum State, Sudan, where TBH infections are prevalent in dairy farms. This cross-sectional study was undertaken from October 2017 to April 2018 with the objective of assessing the prevalence and potential risk factors associated with cattle anaplasmosis and babesiosis in the localities of Omdurman, Khartoum, and Khartoum North, Khartoum State. A total of 292 cattle blood samples collected from apparently healthy animals were examined for the presence of A. marginale, Babesia bigemina, and B. bovis using PCR. The overall prevalence of A. marginale and B. bigemina was found to be 40.41% and 3.42%, respectively, while B. bovis was not detected. Mixed infections with A. marginale and B. bigemina were detected in four (1.37%) cattle. The prevalence of the two pathogens was found to be significantly higher in Khartoum and Omdurman than in Khartoum North. However, no significant difference was observed for the prevalence based on sex, age, breed, and mean packed cell volume values. Our findings indicated that A. marginale is a highly prevalent parasite in Khartoum State, which may be a primary constraint to the cattle industry. Inclusion of this pathogen in the diagnostic protocols, and consequent treatment and tick control are necessary. Moreover, the role of B. bigemina infection may exacerbate the situation to some extent in this region.

Targeted Next-Generation Sequencing and Informatics as an Effective Tool to Establish the Composition of Bovine Piroplasm Populations in Endemic Regions

Protists of the genera Babesia and Theileria (piroplasms) cause some of the most prevalent and debilitating diseases for bovines worldwide. In this study, we established and used a next-generation sequencing-informatic approach to explore the composition of Babesia and Theileria populations in cattle and water buffalo in a country (Pakistan) endemic for these pathogens. We collected individual blood samples from cattle (n = 212) and water buffalo (n = 154), extracted genomic DNAs, PCR-amplified the V4 hypervariable region of 18S small subunit rRNA gene from piroplasms, sequenced amplicons using Illumina technology, and then analysed data using bioinformatic platforms. The results revealed piroplasms in 68.9% (252/366) samples, with overall occurrence being markedly higher in cattle (85.8%) than in water buffaloes (45.5%). Babesia (B.) occultans and Theileria (T.) lestoquardi-like species were recorded for the first time in Pakistan, and, overall, T. annulata was most commonly detected (65.8%) followed by B. bovis (7.1%), B. bigemina (4.4%), and T. orientalis (0.5%), with the genetic variability within B. bovis being pronounced. The occurrence and composition of piroplasm species varied markedly across different agro-ecological zones. The high detection of T. annulata in asymptomatic animals suggested a relatively high level of endemic stability of tropical theileriosis in the bovine population.

Molecular detection of Theileria annulata infection in cattle by conventional PCR and quantitative real time PCR in India

Theileria annulata (T. annulata) is a tick-borne apicomplexan parasite that affects bovine. It is endemic in many tropical and subtropics areas, including Odisha, India. The objective of this study is to identify T. annulata infection in the peripheral blood of cattle as a biological sample by conventional PCR (cPCR) and quantitative PCR (qPCR). The phylogenetic analysis was done using the T. annulata merozoite surface antigen (Tams 1) gene. Out of 552 samples of examined blood smears by microscopy, 454 (82.24%) animals were positive for Theileria species. Out of 454 samples, 96 samples were further examined by both cPCR and qPCR, 52 samples (54.16%) were found positive for T. annulata in both PCR methodologies. Phylogenetic analysis revealed that T. annulata Odisha isolate was closely related to T. annulata Uttarakhand, India isolate (KM061799) and Hyderabad, India isolate (MK034702) with Nucleotide sequence identity 95.36%, 95.25%, respectively. This is the first study to detect T. annulata by qPCR in Odisha and supported that both PCR techniques were equally effective for the detection of Tams 1 gene of T. annulata in cattle's blood.

Molecular epidemiological survey of Babesia bovis, Babesia bigemina, and Babesia sp. Mymensingh infections in Mongolian cattle

Bovine babesiosis caused by Babesia species is an economically significant disease of cattle. Severe clinical babesiosis in cattle is caused by Babesia bovis, B. bigemina, and the recently discovered Babesia sp. Mymensingh. Mongolia is an agricultural country with a large cattle inventory. Although previous studies have detected active infections of B. bovis and B. bigemina in Mongolian cattle, only a few provinces were surveyed. Additionally, the endemicity of Babesia sp. Mymensingh in Mongolia remains unknown. We screened blood DNA samples from 725 cattle reared in 16 of the 21 Mongolian provinces using B. bovis-, B. bigemina-, and Babesia. sp. Mymensingh-specific PCR assays. The overall positive rates of B. bovis, B. bigemina, and Babesia sp. Mymensingh were 27.9% (n = 202), 23.6% (n = 171), and 5.4% (n = 39), respectively. B. bovis and B. bigemina were detected in cattle in all surveyed provinces; whereas Babesia sp. Mymensingh was detected in 11 of the 16 surveyed provinces. On a per province basis, the B. bovis- B. bigemina-, and Babesia sp. Mymensingh-positive rates were 5.9-52.0%, 9.1-76.3%, and 0-35.7%, respectively. In conclusion, this is the first report of Babesia sp. Mymensingh in Mongolia. In addition, we found that species of Babesia that are capable of causing bovine clinical babesiosis, including B. bovis, B. bigemina, and Babesia sp. Mymensingh, are widespread throughout the country.

Discovery of a new Theileria sp. closely related to Theileria annulata in cattle from Sri Lanka

Theileria annulata is a haemoprotozoan parasite that causes a cancer-like illness known as tropical theileriosis in cattle. In the course of analyzing the genetic diversity of T. annulata in Sri Lanka, we observed that merozoite-piroplasm surface antigen (tams1) and surface protein (tasp)-like gene sequences obtained from bovine blood DNA samples, which were PCR-positive for T. annulata, were conserved but shared low identity with T. annulata GenBank sequences. Moreover, the 18S rRNA sequences from the Sri Lankan samples contained ten unique single-nucleotide polymorphisms compared with all known T. annulata sequences. The cytochrome b (cob) gene sequences isolated from the Sri Lankan samples were highly conserved and shared low identity scores with similarly conserved T. annulata sequences from GenBank. Phylogenetic analysis showed that the Sri Lankan tams1-like, tasp-like, 18S rRNA, and cob sequences clustered together and formed sister clades to the common ancestors of all known T. annulata and Theileria lestoquardi sequences. These findings demonstrated that the Sri Lankan cattle were not infected with T. annulata but with a new Theileria sp. (designated as Theileria sp. Yokoyama) closely related to T. annulata.

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.

Diagnostic Tools for the Identification of Babesia sp. in Persistently Infected Cattle

Bovine babesiosis is a tick-borne disease of cattle caused by the protozoan parasites of the genus Babesia. Babesia bovis, Babesia bigemina and Babesia divergens are considered by International health authorities (OIE) as the principal species of Babesia that cause bovine babesiosis. Animals that recover from a babesial primo infection may remain as persistent carriers with no clinical signs of disease and can be the source of infection for ticks that are able to acquire Babesia parasites from infected cattle and to transmit Babesia parasites to susceptible cattle. Several procedures that have been developed for parasite detection and diagnosis of this infectious carrier state constitute the basis for this review: A brief description of the direct microscopic detection of Babesia-infected erytrocytes; PCR-based diagnostic assays, which are very sensitive particularly in detecting Babesia in carrier cattle; in-vitro culture methods, used to demonstrate presence of carrier infections of Babesia sp.; animal inoculation, particularly for B. divergens isolation are discussed. Alternatively, persistently infected animals can be tested for specific antibabesial antibodies by using indirect serological assays. Serological procedures are not necessarily consistent in identifying persistently infected animals and have the disadvantage of presenting with cross reactions between antibodies to Babesia sp.

First Molecular detection of Theileria annulata in Bangladesh

In South Asia, Theileria annulata is known to be less pathogenic to local breeds of Bos indicus cattle comparing to Bos taurus cattle and some of mix breeds between them. Seroepidemiological surveys have revealed high sero-prevalence of T. annulata in asymptomatic local breeds of cattle in Bangladesh. Therefore, these asymptomatic infection in local breeds can be infectious sources to more sensitive breeds. In this study, 59 bloods of cattle showing no symptom were screened by species specific PCRs for hemoto-protozoan parasites, to prove the existence of T. annulata parasite in asymptomatic cattle in Bangladesh. The T. annulata infection was confirmed along with other parasitic species, and this is the first report of T. annulata DNA detection in Bangladesh.

Epidemiological survey of hemoprotozoan parasites in cattle from low-country wet zone in Sri Lanka

The diseases caused by hemoprotozoan parasites in cattle often result in economic losses. In Sri Lanka, previous studies found that the up-country wet zone, which is located in central Sri Lanka, was characterized by a high rate of Theileria orientalis and a low rate of Theileria annulata compared with the dry zone. In this study, DNA samples were prepared from the blood of 121 cattle in Galle, a coastal district located in low-country wet zone in Sri Lanka, and were PCR-screened for Babesia bovis, Babesia bigemina, T. annulata, T. orientalis, and Trypanosoma theileri. All the parasite species, except B. bovis, were detected among the surveyed cattle. The animals had a high rate of T. orientalis (100%) and a low rate of T. annulata (1.6%), as in the up-country wet zone. Babesia bigemina and Tr. theileri were detected in 19.0% and 20.6% of the animals, respectively, and their infection rates were higher in the animals reared in extensive management systems (32.8% and 27.9%, respectively) than in those managed in intensive/semi-intensive systems (5.0% and 13.3%, respectively). Genotypic analyses found that the T. orientalis mpsp type 5 was predominant similar to up-country wet zone, and that Tr. theileri consisted of seven catl genotypes, including two new genotypes (IL and IM) and four previously detected genotypes (IA, IB, II, and IK). These findings suggest that the hemoprotozoan infection profiles are largely conserved within the wet zone, despite differences in the geography, cattle breeds, and management practices between the up-country and low-country wet zones.

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.

Animal level risk factors associated with Babesia and Theileria infections in cattle in Egypt

In present study, blood samples were collected randomly from 439 cows at three main regions of Egypt (northern, central and southern). Molecular diagnosis of Babesia and Theileria infections by PCR amplification of DNA (gene) fragments, then cloning and sequencing of the positive samples were conducted. A questionnaire was created to imply the assumed risk factors and logistic regression statistical analysis was carried out to appraise the potential factors on the animal level. The results revealed that 49 (11.16%) and 45 (10.25%) cattle were infected with Babesia and Theileria parasites, respectively. B. bigemina (7.97%) and T. annulata (9.56%) were the most prevalent parasites. For Babesia sp., final multivariate logistic regression analysis showed a significant association between the infection and irregular use of antiprotozoal drugs (P = 0.003; OR: 0.28; 95% CI: 0.12-0.65), management practice (P = 0.029; OR: 6.66; 95% CI: 1.21-36.59) and ecology area (P = 0.006; OR: 5.62; 95% CI: 1.63-19.31). However, for Theileria sp. infection, animal breed (P = 0.003; OR: 0.44; 95% CI: .45-1.00) and irregular use of antiprotozoal drugs (P<0.001; OR: 4.22; 95% CI: 2.62-5.60) were the potential risk factors. The results of the present study declare the prevalent bovine Babesia and Theileria sp. in Egypt based on molecular description. An impression on the potential risk factors associated with infections was obtained. Recognition of the potential risk factors associated with tick borne disease may be helpful to construct the best preventive measures.

PCR diagnosis of tick-borne pathogens in Maharashtra state, India indicates fitness cost associated with carrier infections is greater for crossbreed than native cattle breeds

Tick-borne pathogens (TBP) are responsible for significant economic losses to cattle production, globally. This is particularly true in countries like India where TBP constrain rearing of high yielding Bos taurus, as they show susceptibility to acute tick borne disease (TBD), most notably tropical theileriosis caused by Theileria annulata. This has led to a programme of cross breeding Bos taurus (Holstein-Friesian or Jersey) with native Bos indicus (numerous) breeds to generate cattle that are more resistant to disease. However, the cost to fitness of subclinical carrier infection in crossbreeds relative to native breeds is unknown, but could represent a significant hidden economic cost. In this study, a total of 1052 bovine blood samples, together with associated data on host type, sex and body score, were collected from apparently healthy animals in four different agro-climatic zones of Maharashtra state. Samples were screened by PCR for detection of five major TBPs: T. annulata, T. orientalis, B. bigemina, B. bovis and Anaplasma spp.. The results demonstrated that single and co-infection with TBP are common, and although differences in pathogen spp. prevalence across the climatic zones were detected, simplistic regression models predicted that host type, sex and location are all likely to impact on prevalence of TBP. In order to remove issues with autocorrelation between variables, a subset of the dataset was modelled to assess any impact of TBP infection on body score of crossbreed versus native breed cattle (breed type). The model showed significant association between infection with TBP (particularly apicomplexan parasites) and poorer body condition for crossbreed animals. These findings indicate potential cost of TBP carrier infection on crossbreed productivity. Thus, there is a case for development of strategies for targeted breeding to combine productivity traits with disease resistance, or to prevent transmission of TBP in India for economic benefit.

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.

A longitudinal study of Babesia and Theileria infections in cattle in Sri Lanka

Throughout the world, infections with the Babesia and Theileria parasites often result in economically significant clinical disease in cattle. We conducted a longitudinal survey of Babesia and Theileria infections in cattle from the Polonnaruwa (n=75; dry zone) and Nuwara Eliya (n=161; wet zone) districts of Sri Lanka. DNA from blood samples collected in June, September, and December 2014 and March 2015 was screened for Babesia bovis, Babesia bigemina, Theileria annulata and Theileria orientalis using specific polymerase chain reactions (PCRs). Additionally, serum samples collected from the animals were screened using enzyme-linked immunosorbent assays (ELISAs) to detect B. bovis- and B. bigemina-specific antibodies. All of the animals surveyed in Polonnaruwa and 150 (93.2%) of the animals surveyed in Nuwara Eliya were PCR-positive for Babesia and/or Theileria at least once during the study period. A greater percentage of the cattle in Polonnaruwa were positive for T. annulata and T. orientalis than B. bovis or B. bigemina at all time points. T. orientalis was the most common infection in Nuwara Eliya. Additionally, more cattle were seropositive for B. bigemina than B. bovis in both districts. Although significant variations were sometimes observed in the rates of animals that were positive for B. bigemina, T. annulata, and T. orientalis at the different sampling time points, the rates of new infections with these parasites (by PCR or ELISA) on second, third, and fourth time points among the parasite-negative samples at the first, second, and third time points, respectively, did not differ between the sampling in either district-suggesting that the parasite species infected cattle at a constant rate in these locations. However, in Polonnaruwa, the rates of new infection with T. annulata were higher than the rates of new infection with T. orientalis. The rates were also higher than those in Nuwara Eliya. In Nuwara Eliya, the rates of new infection with T. orientalis were higher than the rates of new infection with T. annulata. The rates were also higher than those in T. orientalis in Polonnaruwa. These differences might be due to variations in the density and activity of the specific tick vectors within and between the districts. Our findings suggest the need for year-round control measures against bovine Babesia and Theileria infection in Sri Lanka. Further studies to determine the densities of the vector tick species in the different geographical areas of the country are warranted.

Molecular characterisation of Theileria orientalis in imported and native bovines from Pakistan

The epidemiological aspects of Theileria orientalis in Pakistan are unknown; therefore, investigations using sensitive and precise molecular techniques are required. This study reports the first molecular characterisation of T. orientalis detected from imported (Bos taurus) and native cattle (Bos indicus×Bos taurus) and buffaloes (Bubalus bubalis) selected from four districts of Punjab, Pakistan. DNA samples from blood (n=246) were extracted and tested using conventional PCR utilising the major piroplasm surface protein (MPSP) gene and multiplexed tandem PCR (MT-PCR). Theileria orientalis DNA was detected (15%; 22/147) only in imported cattle by conventional PCR, whereas 24.5% (36/147), 6% (3/50) and 6.1% (3/49) of the imported cattle and native Pakistani cattle and buffaloes, respectively were test-positive for T. orientalis using MT-PCR. Using MT-PCR, the prevalence of T. orientalis was significantly higher (P<0.0001) in imported cattle compared to that of detected in native Pakistani bovines. The prevalence of T. orientalis and DNA copies of chitose and ikeda were significantly higher (P<0.05) in imported cattle than those detected in native Pakistani bovines. DNA sequencing of amplicons of the conventional PCR revealed the presence of buffeli, chitose and ikeda genotypes of T. orientalis. Phylogenetic analysis revealed that the MPSP sequences of buffeli, chitose and ikeda from imported cattle were closely related to those sequences reported previously from Australia and other regions. This study provides the first survey of T. orientalis infection in imported and native bovines in Pakistan, and highlights the need for future studies to understand the spread of transboundary animal diseases.

Epidemiology of bovine hemoprotozoa parasites in cattle and water buffalo in Vietnam

A PCR-based survey of hemoprotozoa parasites detected Babesia bigemina, Theileria orientalis and Trypanosoma theileri among cattle and water buffalo in Vietnam, and a new Babesia sp. closely related to Babesia ovata was detected in cattle only. In addition, Theileria annulata and Trypanosoma evansi were not detected in both cattle and water buffalo. Phylogenetic analysis detected T. orientalis MPSP genotypes 3, 5, 7 and N3 in cattle and 5, 7, N1 and N2 in water buffalo. Additionally, water buffalo-derived T. theileri CATL sequences clustered together with a previously reported cattle-derived sequence from Vietnam. This is the first report of a new Babesia sp. in cattle, and T. orientalis MPSP genotype 7 and T. theileri in water buffalo in Vietnam.

Type-specific PCR assays for Babesia bovis msa-1 genotypes in Asia: Revisiting the genetic diversity in Sri Lanka, Mongolia, and Vietnam

Babesia bovis is the most virulent Babesia organism, resulting in a high mortality rate in cattle. The genetic diversity of B. bovis merozoite surface antigens (MSAs), such as MSA-1, MSA-2b, and MSA-2c, might be linked to altered immune profiles in the host animals. The present study aimed to develop type-specific PCR assays for Asian msa-1 genotypes, thereby re-analyzing the genetic diversity of msa-1 in Sri Lanka, Mongolia, and Vietnam. Specific primers were designed for nine Asian msa-1 genotypes, which had been detected based on the phylogeny constructed using msa-1 gene sequences retrieved from the GenBank database. Specificity of the type-specific PCR assays was confirmed using plasmids containing the inserts of msa-1 gene fragments that represent Asian genotypes. Furthermore, no amplicons were observed by these PCR assays when DNA samples of Babesia bigemina, Babesia ovata, Theileria annulata, Theileria orientalis, Trypanosoma evansi, Trypanosoma theileri, Anaplasma marginale, and Anaplasma bovis, and non-infected bovine blood were analyzed. In total, 109 B. bovis-positive blood DNA samples sourced from Sri Lanka (44 cattle), Mongolia (26 cattle), and Vietnam (23 cattle and 16 water buffaloes) were then screened by the type-specific PCR assays. The sequences derived from all of the PCR amplicons were phylogenetically analyzed. Out of 109 DNA samples, 23 (20 from cattle and 3 from water buffaloes) were positive for at least one genotype. In agreement with previous studies, five and four different genotypes were detected among the DNA samples from Sri Lanka and Vietnam, respectively. In contrast, four genotypes, including three novel genotypes, were detected from Mongolia. Five DNA samples were found to be co-infected with multiple genotypes. The sequences of the PCR amplicons clustered phylogenetically within the corresponding clades. These findings indicated that the type-specific PCR assays described herein are useful for the determination of genotypic diversity of the B. bovis msa-1 gene in Asia.

Emergence of oriental theileriosis in cattle and its transmission through Rhipicephalus (Boophilus) microplus in Assam, India

Aim:

The aim of the present study was to investigate the presence of Theileria in blood samples of crossbred and indigenous adult cows raised under unorganized small scale farming system in a Babesia and Anaplasma endemic geographical area from Assam, India and to see its transmission through Rhipicephalus (Boophilus) microplus ticks.

Materials and Methods:

For the present study, 57 clinical cases of cattle suspected to be of hemoparasitic infections were taken into consideration. The parasites were identified based on morphology in giemsa stained blood smear followed by polymerase chain reaction (PCR). Sera samples were tested for T. annulata antibodies in plate and Dot-ELISA. PCR was also conducted in eggs of Rhipicephalus (Boophilus) microplus tick collected from a Theileria orientalis positive animal.

Results:

PCR amplified 1124, 776, and 160 bp DNA fragments of B. bigemina (64.91%), T. orientalis (21.05%) and A. marginale (14.03%), respectively. This assay further conducted in 12 T. orientalis positive blood samples with primers of Buffeli, Chitose, and Ikeda variants of T. orientalis showed 3 samples positive to Ikeda type and none for Buffeli and Chitose. Babesia bovis and Theileria annulata specific primers also did not amplify any fragment during the PCR assay of the blood samples. Further, all sera samples tested negative to T. annulata antibodies in Plate and Dot-ELISA. PCR conducted in eggs of R (B).microplus tick collected from a T. orientalis positive animal revealed presence of the parasite DNA. Gradual improvement in physical condition leading to complete recovery in 10 out of 12 T. orientalis infected clinical cases treated with buparvaquone(at 2.5mg/kg.b.wt I/M) was the feedback obtained from field veterinarians and the cattle owners.

Conclusion:

The present investigation represents the first report of occurrence of T. orientalis in cattle of Assam with involvement of pathogenic Ikeda strain in clinical outbreaks and its possible natural transmission by R (B). microplus through the transovarian mode.

Tick-borne diseases of bovines in Pakistan: major scope for future research and improved control

Ticks and tick-borne diseases (TBDs) affect the productivity of bovines in tropical and subtropical regions of the world, leading to a significant adverse impact on the livelihoods of resource-poor farming communities. Globally, four main TBDs, namely anaplasmosis, babesiosis, theileriosis, and cowdriosis (heartwater) affect bovines, and the former three are of major economic importance in bovines in Pakistan. Given that the livestock sector has become an integral part of Pakistan’s economy and a large number of dairy cattle are being imported into the country, in order to meet an increasing demand of milk and milk products, it is timely to review current status of bovine TBDs in Pakistan and to identify gaps in the knowledge of TBDs and their control. Although there has been a recent increase in the number of studies of TBDs in this country, information on their prevalence, distribution, tick vectors, and control is limited. This article provides a brief background on key bovine TBDs and ticks and reviews the current status of bovine TBDs in Pakistan to identify gaps in knowledge and understanding of these diseases, propose areas for future research and draw attention to the need for improved tools for the diagnosis and control of TBDs in this country.

Differentiation between Israeli B. bovis vaccine strain and field isolates

The present study demonstrated for the first time the ability to distinguish between the Israeli Babesia bovis vaccine strain and field isolates. The existence of an additional EcoRI restriction site in the rhoptry-associated protein-1 (rap-1) gene, which is unique to the Israeli vaccine strain, and the abolition of one of the HaeIII restriction sites in the rap-1 gene of the vaccine strain enabled distinction between the Israeli B. bovis vaccine strain and field isolates, and this was the basis for polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) development. ClustalW sequence alignment of RAP-1-deduced amino acids of the Israeli B. bovis strains and of field isolates showed that the total sequence identity among the RAP-1 amino acid sequences ranged from 97.5% to 100%. However, comparison between amino acids of RAP-1 of the Israeli vaccine strain and of field isolates, on the one hand, and B. bovis strains from Argentina, Mexico, Brazil, and USA, on the other hand, revealed 90% identity. The PCR-RFLP assay offered the great advantage of being able to distinguish between vaccine and field isolates in mixtures and provide new insight into the molecular epidemiology of B. bovis infections in Israel.

Genetic diversity in Trypanosoma theileri from Sri Lankan cattle and water buffaloes

Trypanosoma theileri is a hemoprotozoan parasite that infects various ruminant species. We investigated the epidemiology of this parasite among cattle and water buffalo populations bred in Sri Lanka, using a diagnostic PCR assay based on the cathepsin L-like protein (CATL) gene. Blood DNA samples sourced from cattle (n=316) and water buffaloes (n=320) bred in different geographical areas of Sri Lanka were PCR screened for T. theileri. Parasite DNA was detected in cattle and water buffaloes alike in all the sampling locations. The overall T. theileri-positive rate was higher in water buffaloes (15.9%) than in cattle (7.6%). Subsequently, PCR amplicons were sequenced and the partial CATL sequences were phylogenetically analyzed. The identity values for the CATL gene were 89.6-99.7% among the cattle-derived sequences, compared with values of 90.7-100% for the buffalo-derived sequences. However, the cattle-derived sequences shared 88.2-100% identity values with those from buffaloes. In the phylogenetic tree, the Sri Lankan CATL gene sequences fell into two major clades (TthI and TthII), both of which contain CATL sequences from several other countries. Although most of the CATL sequences from Sri Lankan cattle and buffaloes clustered independently, two buffalo-derived sequences were observed to be closely related to those of the Sri Lankan cattle. Furthermore, a Sri Lankan buffalo sequence clustered with CATL gene sequences from Brazilian buffalo and Thai cattle. In addition to reporting the first PCR-based survey of T. theileri among Sri Lankan-bred cattle and water buffaloes, the present study found that some of the CATL gene fragments sourced from water buffaloes shared similarity with those determined from cattle in this country.

An epidemiological survey of bovine Babesia and Theileria parasites in cattle, buffaloes, and sheep in Egypt

Cattle, buffaloes, and sheep are the main sources of meat and milk in Egypt, but their productivity is thought to be greatly reduced by hemoprotozoan parasitic diseases. In this study, we analyzed the infection rates of Babesia bovis, Babesia bigemina, Theileria annulata, and Theileria orientalis, using parasite-specific PCR assays in blood-DNA samples sourced from cattle (n=439), buffaloes (n=50), and sheep (n=105) reared in Menoufia, Behera, Giza, and Sohag provinces of Egypt. In cattle, the positive rates of B. bovis, B. bigemina, T. annulata, and T. orientalis were 3.18%, 7.97%, 9.56%, and 0.68%, respectively. On the other hand, B. bovis and T. orientalis were the only parasites detected in buffaloes and each of these parasites was only found in two individual DNA samples (both 2%), while one (0.95%) and two (1.90%) of the sheep samples were positive for B. bovis and B. bigemina, respectively. Sequence analysis showed that the B. bovis Rhoptry Associated Protein-1 and the B. bigemina Apical Membrane Antigen-1 genes were highly conserved among the samples, with 99.3-100% and 95.3-100% sequence identity values, respectively. In contrast, the Egyptian T. annulata merozoite surface antigen-1 gene sequences were relatively diverse (87.8-100% identity values), dispersing themselves across several clades in the phylogenetic tree containing sequences from other countries. Additionally, the T. orientalis Major Piroplasm Surface Protein (MPSP) gene sequences were classified as types 1 and 2. This is the first report of T. orientalis in Egypt, and of type 2 MPSP in buffaloes. Detection of MPSP type 2, which is considered a relatively virulent genotype, suggests that T. orientalis infection may have veterinary and economic significance in Egypt. In conclusion, the present study, which analyzed multiple species of Babesia and Theileria parasites in different livestock animals, may shed an additional light on the epidemiology of hemoprotozoan parasites in Egypt.

Epidemiological survey following oriental theileriosis outbreaks in Victoria, Australia, on selected cattle farms

This study investigated Theileria orientalis following outbreaks of oriental theileriosis in cattle in the state of Victoria, Australia, from September 2010 to January 2012, using traditional and molecular methods of diagnosis. A questionnaire was used to collect epidemiological information from cattle farms. Blood samples (n=301), collected from individual symptomatic and asymptomatic cattle from 19 cattle farms, were examined for the presence of Theileria on stained blood smears and tested using a PCR-based approach, employing a region within the major piroplasm surface protein (MPSP) gene as a marker. The microscopic examination of stained blood smears detected stages consistent with Theileria piroplasms in 28.1% (79/281) of the samples. PCR products were amplified from 70.8% (213/301) of the samples. Mutation scanning analysis of all amplicons displayed seven distinct profiles. Following the direct sequencing of representative amplicons, the genotypes ikeda, chitose, buffeli and type 5 were detected in 91.1%, 32.9%, 2.4% and 1.4% of 213 blood samples, respectively. The distribution of these four genotypes varied among the 19 farms; genotype ikeda was detected on all farms, whereas genotypes chitose, buffeli and type 5 were detected on 14, 3 and 2 farms, respectively. Mix infections with genotypes ikeda and chitose were common (21.6%). Survey results revealed that oriental theileriosis affected mainly beef cows of more than two years of age, prior to calving, and disease was associated with abortion and cow deaths. Future investigations should focus on developing improved tools for investigating and managing oriental theileriosis.