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

Genetic diversity and phylogeography of the global Theileria orientalis isolates inferred from MPSP gene sequences

BACKGROUND/OBJECTIVE

Theileria orientalis is a non-transforming Theileria species infecting cattle and water buffaloes. Several outbreaks of oriental theileriosis accompanied by considerable economic loss were documented in Asia, Australia, and New Zealand. The major piroplasm surface protein (MPSP) gene has frequently been used to molecularly characterize T. orientalis isolates worldwide. Various MPSP genotypes were detected with significant virulence variations. The present study provides the first in silico analysis for all globally published T. orientalis MPSP isolates to evaluate their phylogeny, diversity, and population structure.

METHODS

All studies that tested T. orientalis isolates using PCR-MPSP protocols were systematically collected from various databases. Theileria orientalis MPSP-sequenced isolates on the GenBank were collected and the sequences were tested for their phylogenetic relatedness, genetic diversity, recombination, natural selection, and population structure using various software.

RESULTS

The collected T. orientalis-MPSP isolates (n = 795) were clustered into 12 genotypes, including types 1 (Chitose), 2 (Ikeda), 3 (Buffeli), 4, 5, 7, 8, and N1-N5. The previously identified type 6 belonged to a separate species (Theileria sinensis). The previously identified type 9 was transferred to type 4. Two unidentified isolates from water buffaloes in India were clustered into a new suggested genotype "type N5". Of the 12 genotypes, Ikeda (type 2) is the most virulent in cattle. However, a few clinical cases have also been linked to types 1 (Chitose) and 7. In water buffaloes, T. orientalis outbreaks have been linked to genotypes N2 and N5. Geographic mapping of various genotypes revealed the dispersal of types 1 and 3 worldwide. Overall, the 795 isolates comprised 532 haplotypes and displayed very high nucleotide (π = 0.14) and haplotype (Hd = 0.995) diversities. As a result, a very low sequence conservation value (C = 0.207) was determined. The twelve genotypes displayed comparable haplotype diversities accompanied by statistically significant negative Tajima's D and Fu's Fs values suggesting population expansion. A high value for the minimum number of recombination events (Rm = 65) was estimated for the 795 isolates, and this value varied from 0 to 23 at the genotype level. Most types also displayed significant positive selection (dn/ds ratio > 1). This suggests that both recombination and positive selection occur in T. orientalis MPSP gene, which could explain the very high genetic diversity among various T. orientalis types. Different patterns were detected for the gene flow among T. orientalis populations from various hosts and geographies; however, there is evidence for the genetic relatedness between populations from neighbouring countries.

CONCLUSION

The high genetic polymorphism and different associated pathogenicity in T. orientalis-MPSP genotypes highlight the need for further investigations employing whole genome sequencing technology to provide accurate comparative gene-level analyses and help further understand their pathogenicity.

Babesia infection in cattle and dogs in Suizhou City, Hubei Province, China

Background

Babesiosis is a zoonotic disease caused by the intraerythrocytic parasite Babesia, which poses a serious threat to public health. Currently, the prevalence of babesiosis in domestic animals and the genetic diversity of Babesia in Central China have not been comprehensively studied.

Methods

In this study, we collected 1093 ticks, including 95.24% (1041/1093) Haemaphysalis longicornis, 4.67% (51/1093) Rhipicephalus microplus, and 0.09% (1/1093) Ixodes sinensis. Blood samples from 216 goats, 56 cattle, and 25 dogs were collected from Suizhou City, Hubei Province, China, and animal blood DNA was extracted for the detection of Babesia with PCR.

Results

PCR results showed that 50.00% (28/56) of cattle and 32.00% (8/25) of dogs were Babesia-positive, including for Babesia bovis 3.57% (2/56), B. bigemina 3.57% (2/56), and B. ovata 42.86% (24/56) in cattle and B. gibsoni 32.00% (8/25) in dogs. All goats (216) and ticks (1093) were Babesia-negative.

Conclusions

Our findings showed that Babesia infections are prevalent in cattle and dogs in Central China, indicating that babesiosis should be monitored in animals and humans in Central China.

Prevalence of hemoparasitic infections and influencing factors among fighting bulls in Southern Thailand: A retrospective analysis

Background

Hemoparasitic infections significantly threaten cattle health globally, leading to economic losses and welfare issues for farmers.

Aim

This retrospective study aimed to investigate the prevalence and associated factors of hemoparasitic infections in fighting bulls in southern Thailand over an 8-year period.

Methods

Laboratory records of 5,518 bulls from the Livestock Animal Hospital, Faculty of Veterinary Science, Rajamangala University of Technology Srivijaya, were reviewed for the period January 2016 to December 2023. Blood samples were analyzed using thin blood smear methods to identify hemoparasites, and packed cell volume was measured using the microhematocrit method. Detailed profiles and demographic data for each animal were recorded.

Results

Among the fighting bulls, 323 (5.85%) tested positive for hemoparasitic infections, with five hemoparasites identified: Trypanosoma spp. (TP), Microfilariae, Anaplasma spp. (AP), Babesia spp. (BB), and Theileria spp. (TR). TP was the most prevalent at 2.90%. Bulls aged 1-5 years showed the highest infection rates at 7.04%, with a decline in infections as age increased. Annual trends peaked in 2018 at 8.80%, with significant yearly fluctuations for most parasites (p < 0.05) except AP and BB. Monthly analyses revealed the highest infection rates in March, particularly for TP, with significant monthly variations for TR (p < 0.05). Geographical differences in infection rates between the East and West coasts were minor and not statistically significant. However, seasonal variations were significant for BB and TR on the east coast during summer (p < 0.05). Bulls with PCV below 30% had a higher prevalence of hemoparasitic infections (8.06%) compared to those with PCV above 30% (5.87%), with significant differences in the prevalence of AP and TR infections (p < 0.05).

Conclusion

This study adds to the understanding of hemoparasite infections in bulls, informing the development of educational materials for farmers and ultimately empowering them to make better herd health decisions.

A comprehensive molecular survey of vector-borne blood parasites in cattle in Kyrgyzstan with a note of the first molecular detection of Anaplasma bovis and Candidatus Anaplasma Camelii

Vector-borne pathogens continue to increase their impact on the livestock industry worldwide. To protect animals against these pathogens, it is very important to identify the species that cause the disease and understand their prevalence. This study aimed to investigate the presence and prevalence of vector-borne pathogens in apparently healthy cattle in different parts of Kyrgyzstan using molecular diagnostic techniques. For this purpose, 531 blood samples were collected from the Osh, Jalal-Abad, and Batken oblasts of Kyrgyzstan. The blood samples were investigated for vector-borne pathogens using PCR, RLB, and RFLP. Moreover, DNA sequence analyses were used to confirm the results of molecular techniques and phylogenetic analyses of these pathogens. 359 (67.61%) out of 531 samples were found to be infected with at least one pathogen, whereas 172 (32.39%) were detected to be negative. Thirteen vector-borne pathogens were detected in cattle blood samples, and the prevalence of these pathogens was as follows: Theileria orientalis (47.83%), T. annulata (25.61%), Babesia major (0.19%), B. occultans (0.38%), Anaplasma phagocytophilum-like 1 (3.20%), A. capra (3.01%), A. centrale (2.82%), A. bovis (1.13%), (A) ovis (0.19%), Candidatus Anaplasma camelii (0.94%), Trypanosoma theileri (19.21%), Mycoplasma wenyonii (6.03%), and Ca. Mycoplasma haemobos (2.64%). Among the positive samples, one pathogen was identified in 189 cattle (35.59%), and co-infections (two or more pathogens) were determined in 170 (32.01%) animals. Theileria parva, T. mutans, (B) bigemina, B. bovis, B. divergens, and A. marginale could not be detected in the study. Anaplasma bovis and Ca. Anaplasma camelii were detected for the first time in the country. This molecular survey provides important epidemiological and genetic data for the vector-borne pathogens in cattle. The results of the study showed that vector-borne pathogens have a significant spread and distribution in cattle in Kyrgyzstan.

Global prevalence and species diversity of tick-borne pathogens in buffaloes worldwide: a systematic review and meta-analysis

BACKGROUND

Buffaloes are important contributors to the livestock economy in many countries, particularly in Asia, and tick-borne pathogens (TBPs) commonly infect buffaloes, giving rise to serious pathologies other than their zoonotic potential.

METHODS

The present investigation focuses on the prevalence of TBPs infecting buffaloes worldwide. All published global data on TBPs in buffaloes were collected from different databases (e.g., PubMed, Scopus, ScienceDirect, and Google Scholar) and subjected to various meta-analyses using OpenMeta[Analyst] software, and all analyses were conducted based on a 95% confidence interval.

RESULTS

Over 100 articles discussing the prevalence and species diversity of TBPs in buffaloes were retrieved. Most of these reports focused on water buffaloes (Bubalus bubalis), whereas a few reports on TBPs in African buffaloes (Syncerus caffer) had been published. The pooled global prevalence of the apicomplexan parasites Babesia and Theileria, as well as the bacterial pathogens Anaplasma, Coxiella burnetii, Borrelia, Bartonella, and Ehrlichia in addition to Crimean-Congo hemorrhagic fever virus, were all evaluated based on the detection methods and 95% confidence intervals. Interestingly, no Rickettsia spp. were detected in buffaloes with scarce data. TBPs of buffaloes displayed a fairly high species diversity, which underlines the high infection risk to other animals, especially cattle. Babesia bovis, B. bigemina, B. orientalis, B. occultans and B. naoakii, Theileria annulata, T. orientalis complex (orientalis/sergenti/buffeli), T. parva, T. mutans, T. sinensis, T. velifera, T. lestoquardi-like, T. taurotragi, T. sp. (buffalo) and T. ovis, and Anaplasma marginale, A. centrale, A. platys, A. platys-like and "Candidatus Anaplasma boleense" were all were identified from naturally infected buffaloes.

CONCLUSIONS

Several important aspects were highlighted for the status of TBPs, which have serious economic implications for the buffalo as well as cattle industries, particularly in Asian and African countries, which should aid in the development and implementation of prevention and control methods for veterinary care practitioners, and animal owners.

Molecular Reports of Ruminant Babesia in Southeast Asia

The protozoon Babesia is a blood parasite transmitted by hard ticks and commonly parasitizes ruminants such as cattle, buffaloes, goats, and sheep. Babesiosis, the disease caused by Babesia infection, has been considered a potential threat to ruminant production due to the grave and enormous impact it brings. About 125 million ruminants are at risk of babesiosis in Southeast Asia (SEA), a region composed of 11 countries. In recent decades, molecular-based diagnostic platforms, such as polymerase chain reaction (PCR) assays, have been a reliable and broadly employed tool in Babesia detection. In this article, the authors compiled and summarized the molecular studies conducted on ruminant babesiosis and mapped the species, including B. bovis, B. bigemina, B. ovata, Babesia sp. Mymensingh, Babesia sp. Hue, and B. ovis, and determined the host diversity of ruminant Babesia in SEA.

Molecular Detection and Characterization of Babesia and Theileria in Cattle and Water Buffaloes from Southern Luzon, Philippines

Babesia and Theileria are tick-borne protozoan parasites that can cause significant economic losses in the cattle industry. This study aimed to contribute to the limited epidemiological data on Theileria orientalis as well as Babesia bigemina and B. bovis in large ruminants in the Philippines. Blood samples of 412 cattle and 108 water buffalo collected from four provinces in Southern Luzon, Philippines, were initially tested for the 18S rRNA gene of piroplasms through nested PCR. Positive samples were further subjected to species-specific PCR. The 18s rRNA of piroplasms was detected in 123 (29.9%) cattle and three (2.8%) water buffaloes. Theileria orientalis was found to be the most common piroplasm in cattle with a detection rate of 17.5%, followed by Babesia bovis and B. bigemina. Co-infections were also observed. Two water buffaloes were found infected with B. bovis, while one was positive for B. bigemina. The phylogenetic tree for B. bovis showed clustering of the isolates in two clades together with isolates from other countries, and a third separate clade. Meanwhile, the T. orientalis isolates in this study were distributed in three clades together with reported isolates from other countries. This study confirms the presence of T. orientalis in the Philippines and reports the genetic diversity of B. bovis and T. orientalis.

First Report of Trypanosoma theileri in Equine Host and Tabanus sp. in Malaysia

Trypanosoma (Megatrypanum) theileri is a non-pathogenic or weakly pathogenic parasite of domestic cattle that is cyclically transmitted by blood-sucking insects, mainly tabanid flies. It has been reported in several countries like Brazil, Venezuela, Japan, Taiwan, Thailand, Vietnam, and the Philippines. Although the ruminant industry is actively expanded in Malaysia, T. theileri and T. theileri-like trypanosomes have never been reported from Malaysia. The low pathogenicity of this species might be the main reason for overlooking T. theileri in this country. This paper describes an unforeseen finding of T. theileri from the outbreak of T. evansi in the state of Kelantan, Malaysia. This is the first time T. theileri reported in Malaysia, and also the first time T. theileri is reported in equid. Clinical signs compatible with infection by blood protozoa were observed; however, it was uncertain whether they were due to T. theileri infection. The detection of T. theileri from the blood sample and Tabanus sp. were confirmed through molecular analysis with PCR and DNA sequencing. In the present study, T. theileri from one horse and one Tabanus sp. were clustered with sequences of the previously described phylogenetic lineages from Japan, Chad and Brazil cattle. Even though this species is claimed to be host-specific with ruminant host restriction, the finding from this study suggested that T. theileri can infect equine whilst other isolates are known to infect ruminant species only. It is suspected there were two genotypes of T. theileri circulating in at least two districts of Kelantan. Thus, further study on multiple DNA regions should be conducted to determine the strains of detected T. theileri in Malaysia. Its impact on the horse and cattle industry should also be revised.

Genetic diversity of cervid Trypanosoma theileri in Honshu sika deer (Cervus nippon) in Japan

The taxonomy of ruminant Trypanosoma theileri and its relatives (Kinetoplastida: Trypanosomatidae) is controversial, with recent phylogenetic studies segregating T. theileri in cattle and other ruminants worldwide into two major genetic lineages (the TthI and TthII clades) based on genetic markers. In the present study, T. theileri-like trypanosomes isolated from Honshu sika deer (Cervus nippon) in the western Japan (YMG isolate) were genetically characterized using a number of genetic markers. Sika deer trypanosomes of the YMG isolate were genetically different from the Trypanosoma sp. TSD1 isolate previously recorded from Hokkaido sika deer in northern Japan, with the former trypanosome isolate being genetically closer to European cervid trypanosomes and the bovine T. theileri TthII lineage. In contrast, the latter isolate exhibited greater relatedness to North American cervid trypanosomes and the bovine T. theileri TthI lineage, although a clear genetic distinction between these was apparent. Furthermore, trypanosomes in Honshu sika deer from the central part of Japan harboured additional genetic diversity and were closer to either TSD1 or YMG isolates, while distinct from known T. theileri-related genotypes. Importantly, cervids and wild ruminants worldwide might harbour divergent descendants of a T. theileri ancestor, which exhibit rigid host specificity to either bovines or cervid species.

Laurent B, Fritz ML, Serre D. High-throughput detection of eukaryotic parasites and arboviruses in mosquitoes

Vector-borne pathogens cause many human infectious diseases and are responsible for high mortality and morbidity throughout the world. They can also cause livestock epidemics with dramatic social and economic consequences. Due to its high costs, vector-borne disease surveillance is often limited to current threats, and the investigation of emerging pathogens typically occurs after the reports of clinical cases. Here, we use high-throughput sequencing to detect and identify a wide range of parasites and viruses carried by mosquitoes from Cambodia, Guinea, Mali and the USA. We apply this approach to individual Anopheles mosquitoes as well as pools of mosquitoes captured in traps; and compare the outcomes of this assay when applied to DNA or RNA. We identified known human and animal pathogens and mosquito parasites belonging to a wide range of taxa, as well as DNA sequences from previously uncharacterized organisms. Our results also revealed that analysis of the content of an entire trap could be an efficient approach to monitor and identify rare vector-borne pathogens in large surveillance studies. Overall, we describe a high-throughput and easy-to-customize assay to screen for a wide range of pathogens and efficiently complement current vector-borne disease surveillance approaches.

Pan-American Trypanosoma (Megatrypanum) trinaperronei n. sp. in the white-tailed deer Odocoileus virginianus Zimmermann and its deer ked Lipoptena mazamae Rondani, 1878: morphological, developmental and phylogeographical characterisation

BACKGROUND

The subgenus Megatrypanum Hoare, 1964 of Trypanosoma Gruby, 1843 comprises trypanosomes of cervids and bovids from around the world. Here, the white-tailed deer Odocoileus virginianus (Zimmermann) and its ectoparasite, the deer ked Lipoptena mazamae Rondani, 1878 (hippoboscid fly), were surveyed for trypanosomes in Venezuela.

RESULTS

Haemoculturing unveiled 20% infected WTD, while 47% (7/15) of blood samples and 38% (11/29) of ked guts tested positive for the Megatrypanum-specific TthCATL-PCR. CATL and SSU rRNA sequences uncovered a single species of trypanosome. Phylogeny based on SSU rRNA and gGAPDH sequences tightly cluster WTD trypanosomes from Venezuela and the USA, which were strongly supported as geographical variants of the herein described Trypanosoma (Megatrypanum) trinaperronei n. sp. In our analyses, the new species was closest to Trypanosoma sp. D30 from fallow deer (Germany), both nested into TthII alongside other trypanosomes from cervids (North American elk and European fallow, red and sika deer), and bovids (cattle, antelopes and sheep). Insights into the life-cycle of T. trinaperronei n. sp. were obtained from early haemocultures of deer blood and co-culture with mammalian and insect cells showing flagellates resembling Megatrypanum trypanosomes previously reported in deer blood, and deer ked guts. For the first time, a trypanosome from a cervid was cultured and phylogenetically and morphologically (light and electron microscopy) characterised.

CONCLUSIONS

In the analyses based on SSU rRNA, gGAPDH, CATL and ITS rDNA sequences, neither cervids nor bovids trypanosomes were monophyletic but intertwined within TthI and TthII major phylogenetic lineages. One host species can harbour more than one species/genotype of trypanosome, but each trypanosome species/genotype was found in a single host species or in phylogenetically closely related hosts. Molecular evidence that L. mazamae may transmit T. trinaperronei n. sp. suggests important evolutionary constraints making tight the tripartite T. trinaperronei-WTD-deer ked association. In a plausible evolutionary scenario, T. trinaperronei n. sp. entered South America with North American white-tailed deer at the Pliocene-Pleistocene boundary following the closure of the Panama Isthmus.

Molecular Survey and Genetic Diversity of Babesia spp. and Theileria spp. in Cattle in Gansu Province, China

PURPOSE

Babesia spp. and Theileria spp. are tick-borne pathogens of livestock globally. In this study, we investigated the presence and distribution of these pathogens in cattle from 20 locations in 4 Counties of Wuwei City. The aim of the present research was to evaluate the spread of piroplasms, so as to provide the epidemiological information for control piroplasmosis in the region.

METHODS

The authors provided the molecular data for Babesia spp. and Theileria spp. and analyzed the obtained sequences of the 18S rRNA gene, Tams1 gene and MPSP gene by using the ClustalW program in MEGA version 6.06 software and BLASTn tool of NCBI GenBank database.

RESULTS

The total infection rates were detected by nPCR with 1.8% for T. orientalis, 3% for T. sinensis, 0.6% for T. annulata, 1.8% for B. motasi and 0.6% for B. bigemina.

CONCLUSIONS

To the best of our knowledge, this is the first report investigating T. sinensis from cattle by PCR in Wuwei City. In particular, ovine B. motasi has been for the first time detected in cattle in our study and its impact is worth discussing to figure out the potential reasons.

Molecular characterization of a new Trypanosoma (Megatrypanum) theileri isolate supports the two main phylogenetic lineages of this species in Japanese cattle

Trypanosoma (Megatrypanum) theileri is a cosmopolitan, usually non-pathogenic, trypanosome of cattle transmitted by blood-sucking arthropods, mainly tabanid flies. Several T. theileri strains isolated from domestic and wild ruminants via co-culturing with mammalian feeder cells or blood cells have been characterized morphologically and genetically. Here, we cultured a new trypanosome isolate from a Holstein cow in Hokkaido, Japan, and performed morphological and molecular characterization studies. The new isolate (Obihiro strain) was co-cultivated with Madin-Darby bovine kidney (MDBK) cells in GIT medium supplemented with 10% fetal bovine serum. Trypomastigotes and epimastigotes, but not intracellular parasites, were identified in the culture. Analysis of the V7-V8 region of 18S rRNA sequences showed that the Obihiro strain is positioned within the subgenus Megatrypanum. A dendrogram based on whole internal transcribed spacer rDNA sequence showed that the Obihiro strain clustered in the lineage TthII together with the Japanese isolates of T. theileri, Esashi 9, and Esashi 12, and isolates from Zambia and the USA. T. theileri of the KM strain and a T. theileri-like trypanosome isolated from deer (TSD1 strain) clustered in the lineage TthI, separate from the Obihiro strain. Based on a partial cathepsin L-like protein gene analysis, the Obihiro strain clustered with isolates of the TthIIF genotype, which includes T. theileri from Vietnam, Sri Lanka, and Brazil. Our analyses of the T. theileri Obihiro strain provide relevant insights into its genetic diversity in Japanese cattle and corroborate the host specificity of cattle and deer trypanosomes of the subgenus Megatrypanum.

First molecular detection and characterization of tick-borne pathogens in water buffaloes in Bohol, Philippines

The water buffalo industry is a vital part of the Philippine livestock economy and is an essential contributor to the developing local dairy industry. Although relatively less susceptible to diseases, water buffaloes can still be infected and can act as reservoirs of tick-borne pathogens (TBPs). However, limited information is available regarding the prevalence of tick-borne infections in water buffaloes in the Philippines. This study was conducted to identify TBPs harbored by water buffaloes and to characterize these pathogens molecularly. One hundred water buffalo blood samples collected from three areas in Bohol, Visayas region, Philippines were screened for various TBPs using pathogen-specific PCR assays. TBPs were detected in 46% of the samples (39% singly infected, 7% coinfected). The pathogens detected were Anaplasma marginale (29%), Babesia bovis (21%), and B. bigemina (3%). None of the blood samples were positive for Theileria annulata, T. orientalis, and B. ovata. A. marginale infection rates were significantly higher (37.5%) among water buffaloes aged ≤6 years (P = 0.046) than those >6 years old (18.2%) and was detected only in Bulgarian Murrah (36.1%) and US Murrah (25.9%) breeds. Phylogenetic analyses revealed that groEL sequences of A. marginale were 100% identical with isolates from the Philippines (Batangas and Cebu) and China. Two B. bigemina RAP-1a gene sequences were identical to each other and were homologous with previous isolates from Thailand, Indonesia, Uruguay, and the Philippines. Moreover, four B. bovis SBP-2 partial sequences obtained in this study had 92.4-99.7% identities. This study is the first molecular detection and characterization of A. marginale, B. bigemina and B. bovis in water buffaloes in the Visayas region, and the first molecular confirmation of B. bovis infection in water buffaloes in the country. The findings presented in this study may serve as baseline data for crafting effective tick-borne disease surveillance and prevention programs in Bohol and in the Philippines.

Molecular characterization of South Indian field isolates of bovine Babesia spp. and Anaplasma spp

Ticks and tick-borne diseases (TTBDs) are considered major causes of economic loss in the livestock sector which incur an annual control cost estimated at US$ 498.7 million in India. Among these diseases, babesiosis, theileriosis and anaplasmosis are listed among the top ten livestock diseases in India and cause significant mortality and morbidity among cattle. However, molecular characterization of bovine Babesia and Anaplasma species are scant; thus, the aim of this study is to perform molecular characterization of field isolates of Babesia spp. and Anaplasma spp. infecting bovines in Kerala, South India. Blood smears and whole blood samples were collected from a total of 199 apparently healthy adult female cattle in Kerala. Based on microscopy, Babesia spp., Theileria orientalis and Anaplasma spp. organisms were detected in 9 (4.5%), 40 (20%) and 6 (3%) samples, respectively. Genus-specific polymerase chain reactions for amplification of 18S rRNA of Babesia spp. and 16S rRNA of Anaplasma spp. revealed positive results with 18 (9%) and 14 (7%) samples. The phylogenetic analysis of 18S rRNA gene sequences of Babesia spp. confirmed the existence of two different populations of Babesia spp. circulating in the blood of infected cattle viz., Babesia bigemina and a Babesia sp. genetically related to Babesia ovata. Further phylogenetic analysis using rap-1a sequences of isolates of B. bigemina revealed higher levels of genetic heterogeneity. However, the field isolates of B. bigemina displayed only slight heterogeneity when the rap-1c gene was examined. Polymerase chain reaction followed by sequencing and phylogenetic analysis of 16S rRNA gene of Anaplasma spp. revealed the existence of Anaplasma marginale, Anaplasma bovis and Anaplasma platys in bovines in South India. Based on msp4 gene sequences, all the field isolates of A. marginale from Kerala were clustered in a single clade with others isolated from around the world. To our knowledge, this study forms the first report on occurrence of B. ovata-like parasites and A. platys in cattle from India.

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.

Molecular detection and genetic diversity of Theileria orientalis in cattle in China

The apicomplexan parasite Theileria orientalis is a tick-borne intracellular protozoan parasite that is widely distributed throughout China. It causes bovine theileriosis in infected cattle, which results in huge economic losses to the cattle industry. In this study, the infection status of T. orientalis was determined in 260 blood samples from cattle from seven provinces across China. Results of a major piroplasm surface protein (MPSP)-PCR assay revealed that an average of 36.5% (95/260) of cattle was positive for T. orientalis infection. Based on the MPSP gene sequences, phylogenetic analysis revealed that these isolates of T. orientalis comprised of eight MPSP types, 1, 2, 3, 4, 5, 7, N1, and N2. This is the first report of new T. orientalis MPSP genotypes N1 and N2 in cattle in China.

Serological and molecular surveys of Babesia bovis and Babesia bigemina among native cattle and cattle imported from Thailand in Hue, Vietnam

Serum and DNA from blood samples collected from Vietnamese yellow cattle (n=101) and cattle imported from Thailand (n=54) at a Vietnamese slaughter house were screened for Babesia bovis and Babesia bigemina infections by enzyme-linked immunosorbent assay (ELISA) and PCR. The positive rates determined by ELISA (B. bovis and B. bigemina) or PCR (B. bigemina) in the Vietnamese cattle were significantly higher than those found in Thai cattle. Some PCR-positive Vietnamese animals were ELISA-negative, whereas all PCR-positive Thai cattle were ELISA-positive, suggesting that the animals were infected in Thailand. Importing Babesia-infected cattle may lead to the introduction of new parasite strains, possibly compromising the development of anti-Babesia immune control strategies in Vietnam.

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.

Babesia ovata: Taxonomy, phylogeny and epidemiology

Babesia ovata, which is transmitted by Haemaphysalis longicornis, is an intraerythrocytic protozoan parasite of cattle. Based on its morphology, B. ovata is classified as a large-type Babesia. The developmental stages of B. ovata have been described both in cattle and the tick vector. In infected adult female ticks, the parasite is transovarially transmitted to the tick eggs. The sexual reproduction of B. ovata has been demonstrated in the tick midgut. The diagnostic tools that are currently available for the specific detection of B. ovata in cattle include microscopy and polymerase chain reaction assays. The development of improved molecular and serological diagnostic tools has been constrained by the limited availability of genetic data. B. ovata has been reported in cattle populations in Japan, Korea, China, Mongolia and Thailand. B. ovata was thought to be a benign parasite; however, infections in immuno compromised or Theileria orientalis-infected animals are clinically significant. Thus, control strategies aimed at minimizing the prevalence of B. ovata are vital. The taxonomy of B. ovata is unclear, and the phylogenetic position has not been well defined. Consequently, non-B. ovata species have sometimes been classified as B. ovata. In this review, we provide an outline of the lifecycle, geographical distribution, and control of B. ovata, and critically discuss the taxonomy and phylogeny of this bovine Babesia.