Ribosomal small-subunit RNA gene-sequence analysis of Theileria lestoquardi and a Theileria species highly pathogenic for small ruminants in China

Identification, molecular characterization and risk factors of Theileria infection among sheep: a first comprehensive report from North India

The present study was aimed at the identification, molecular characterization, and risk factor assessment of Theileria infection among sheep of Haryana province, north India. A total of 402 blood samples were collected from three different climatic zones of Haryana from March 2020 to September 2021. Light microscopy of blood smears revealed Theileria spp. infection in 47.26% (n = 190), while 60.94% (n = 245) of blood samples were positive using nested PCR. Extensive molecular characterization of Theileria infection using four pairs of species-specific primers indicated the dominance of T. ovis (29.1%) followed by T. lestoquardi (12.69%), T. luwenshuni (5.97%) and T. annulata (1.49%). Mixed infection was detected in 11.69% of cases. Bidirectional sequencing and phylogeny further confirmed the presence of these four Theileria spp. in the investigated area under study. Hematology indicated a significant (p < 0.01) reduction in various haematological indices of animals infected with T. luwenshuni and T. lestoquardi compared to the healthy control group. Risk factors like age, sex, and zone were significantly associated with Theileria infection in sheep. The present investigation depicts the first comprehensive molecular report of ovine Theileria spp., which warrants further study to develop suitable control strategies against these haemoparasitic infections.

Comprehensive genetic diversity and molecular evolutionary analysis of Theileria annulata isolates based on TAMS 1 gene

Molecular epidemiological studies related to the phylogenetic characterization of Theileria annulata are important in delineating the evolutionary history of the parasite. In the current study, the Theileria annulata (T. annulata) merozoite surface antigen 1 (TAMS 1) gene from 14 bovine isolates of T. annulata originating from semi-arid zone of northern India were amplified and sequenced. TAMS 1 gene sequences (n= 337) reported from 16 countries were subsequently analyzed for haplotype network along with genetic diversity. A total of five haplotypes out of the 14 sequenced isolates and 92 haplotypes out of 337 worldwide sequences are documented in this study. Phylogenetic and molecular evolutionary analyses based on TAMS 1 gene sequences showed that T. annulata is dissipated across different countries and numerous strains are closely linked, even though they belong to different geographical locations. The nucleotide homology between 14 isolates from northern India varied between 91.3 and 100%, whereas it was between 31.5 and 100% when sequences across the globe were compared. Haplotype 14 was recognized as most widely distributed haplotype, with 46 isolates circulating in 10 countries. Globally, negligible genetic distance (FST˂0.15) and very high gene flow (Nm˃1) was found in the five populations of the world (South Asia, East Asia, West Asia, Europe and Africa), supporting the absence of clearly defined subgroups in the phylogenetic analysis. Significant negative values of neutrality tests; Tajima's D (D) and Fu and Li's F (F) provided evidence for recent population expansion through positive selection of advantageous variations.

Molecular epidemiology of Theileria species in ticks and its potential threat to livestock in the Republic of Korea

The purpose of this study was to investigate molecular epidemiology of Theileria spp. in ticks in Korea and assess their potential threat from wildlife animals to domestic animals. A total of 21152 hard ticks were collected from Chungcheong and Jeolla provinces of Korea from March to October 2021. Tick species were identified by microscopy and Theileria spp. were screened by nested PCR targeting 18S rRNA. Haemaphysalis spp. were the most abundant tick species, followed by H. longicornis, H. flava, Amblyomma testudinarium, and Ixodes nipponensis. Of the collected ticks, 6914 ticks (541 pools) were screened, and PCR showed 211 positive pools (39.0%; MIR: 3.05). The PCR and phylogenetic analysis identified two Theileria species, T. luwenshuni and Theileria sp., with T. luwenshuni (162/211, 76.78%; MIR: 2.34) being more abundant than Theileria sp. (36/211, 17.06%; MIR: 0.52); co-infection of the two species were noted (13/211, 6.16%; MIR: 0.19). Among the tick species, H. longicornis, especially nymphs, showed the highest prevalence. Regarding season, the highest prevalence was observed in May. Considering the tick and Theileria species identified in this study, H. longicornis nymph and cervine play a critical role in maintaining Theileria spp. in Korea and could be a potential threat to domestic animals, including deer and goats. In addition, there are significant correlations among tick distribution, region, season, and prevalence of Theileria.

Anaemia in Sheep Caused by Babesia and Theileria Haemoparasites

Piroplasmoses in sheep are caused by vector-borne apicomplexan protozoa, Babesia and Theileria. Different species are responsible for the disease; some species are more pathogenic than others and have a worldwide distribution. In this sense, these causative agents can cause anaemia in flocks. In general, these vector-borne diseases infect small ruminants and cause host-mediated pathology. In the case of Babesia species, a combination of different mechanisms is involved: red blood cell lysis due to intracellular parasite multiplication, activation of biogenic amines and the coagulation system with the possibility of disseminated intravascular coagulation. By contrast, less information is available on the different immunopathogenic mechanisms involved in the development of anaemia in sheep with theileriosis. However, the mechanisms of pathogenic action in theileriosis are similar to those studied in babesiosis. Diagnosis is based on compatible clinical signs, laboratory findings, specific diagnostic tests and the presence of the tick vector. Some of these tests detect the causative agent itself, such as direct identification by light microscopy and molecular analysis. In contrast, other tests detect the sheep's immune response to the organism by serology. Both diseases pose a significant diagnostic challenge for veterinary practitioners around the world. This review presents the most frequent clinical signs, pathogenesis and clinicopathological findings, diagnosis.

Molecular Detection and Differentiation of Different Theileria Species in Naturally Infected Goats Using Nested PCR-RFLP: A First Report from Northern India

PURPOSE

Theileriosis is an economically important tick-borne pathogen with a serious impact on livestock health and productivity. Despite the fact that bovine theileriosis has been widely investigated, there exists a paucity of information on these infections in small ruminants, especially in India. The present study was carried out to detect and differentiate different Theileria spp. in goats using nested PCR RFLP.

METHODS

Blood samples and ticks were collected from 405 goats in various agro-climatic zones of Haryana state, India. The blood samples were screened by microscopy, nested PCR-RFLP, and sequence analysis. The nested PCR-RFLP was performed with four restriction enzymes viz., Hpa II, Bsh 1285I, Hae II and Rsa I. Six nested PCR amplicons with different RFLP patterns were sequenced and submitted to NCBI (OM666861, MZ220430, OM666628, MZ220437, OM666637, OM721806).

RESULTS

Microscopy revealed 18.27% (n = 74) infection with Theileria spp., while 33.58% (n = 136) of blood samples were confirmed positive by nested PCR. Out of 136 positive samples, 43.38% (n = 59), 11.02% (n = 15) and 20.58% (n = 28), were positive for T. ovis, T. lestoquardi and T. luwenshuni (Theileria sp. China 1), respectively. Mixed infection was detected in 25% (n = 34) cases. Based upon Hpa II digestion pattern, 13 samples with T. lestoquardi and T. ovis, and 21 samples with T. ovis and T. luwenshuni were detected. Sequence study further confirmed their identity. The majority of ticks collected from goats were identified as Rhipicephalus spp., Hyalomma anatolicum and Hemaphysalis spp.

CONCLUSION

This study represents the first confirmed molecular report of goats infected with T. ovis, T. lestoquardi, and T. luwenshuni from northern India.

Tick-borne haemoparasitic diseases in small ruminants in Pakistan: Current knowledge and future perspectives

Livestock industry is an essential part of Pakistan’s economy, and a variety of ruminants (including sheep and goats) are reared for the increasing demand of milk, meat and hide products. Haemoparasitic illnesses such as theileriosis, anaplasmosis, and babesiosis are a significant health risk for small ruminants in our country. Information regarding distribution patterns, the tick species involved and effective strategies to control tick-borne diseases (TBD) in goats and sheep of Pakistan is limited. To this end, it is required to assess the present rank of TBDs in small ruminants of Pakistan with a note on their vector ticks in order to control and identify the gaps in the knowledge of TBDs. This will recommend areas for future research and will add to the understanding of these diseases and will draw attention to the need for better-quality tools for the diagnosis and control of TBDs in small ruminants of Pakistan.

Molecular identification of Theileria species in naturally infected sheep using nested PCR-RFLP

Ovine theileriosis is an important tick-borne haemoprotozoan disease of sheep in tropical and subtropical regions, causing severe productivity and economic loss. There is a paucity of information related to molecular studies of ovine theileriosis from India. The present study identified different Theileria spp. in naturally infected sheep using nested PCR-restriction fragment length polymorphism (nPCR-RFLP). Blood samples and ticks were collected from 204 sheep in different agro-climatic zones of Haryana state, India, during the tick active season. Microscopic examination of thin blood smears revealed 33.3% (68/204) infections with Theileria spp., while 44.6% (91/204) of blood samples were positive by nPCR assay. Different Theileria spp. were identified based upon RFLP patterns using four restriction enzymes: Hpa II, Bsh 1285I, Hae II and Rsa I. Out of 91 positive samples, 50.5% (46/91), 23.08% (21/91), 11% (10/91) and 2.2% (2/91) were positive for T. ovis, T. lestoquardi, T. luwenshuni (Theileria sp. China 1/Theileria sp. China) and T. annulata, respectively. Mixed infection was detected in 13.2% (12/91) of cases. Based upon HpaII enzymatic digestion pattern, two samples with T. lestoquardi and T. annulata, nine samples with T. lestoquardi and T. ovis and one sample with T. ovis and T. annulata were detected. The presence of these Theileria spp. was further confirmed by sequence analysis. The majority of ticks collected from sheep were identified as Rhipicephalus spp. followed by Hyalomma anatolicum and Hemaphysalis spp. The present investigation depicts the first comprehensive molecular report of naturally infected sheep with T. ovis, T. lestoquardi, T. annulata and T. luwenshuni from northern India.

Identification of Theileria spp. in sheep and goats from Jeddah, Saudi Arabia, using molecular techniques

Background

Thileriosis is a tick -born disease caused by hemoprotozoan parasites which has global veterinary and economic implications.

Methods

Blood samples were collected from 216 sheep and 83 goats from Jeddah, Saudi Arabia, were analyzed to determine whether the animals were infected with Theileria spp. parasites. The parasites were detected using a polymerase chain reaction (PCR) targeting the gene of 18S rRNA followed by sequencing.

Results

According to obtained findings, Theileria spp. were detected in sheep (57.8%, 48/83) and goats (51.9%, 112/216). Phylogenetic analysis to sequence data showed that T. ovis identified in this study were found to be closely connected to an isolate from Turkey, with 84.4–99.8% pairwise identity and 52.35–99.79% coverage.

Mitochondrial genome of Theileria uilenbergi endemic in sheep and goats in China

Mitochondrial genomes provide new insights that help elucidating biological features, genetic evolution, and classification of protozoans. Theileria uilenbergi (T. uilenbergi), transmitted by Haemaphysalis qinghaiensis and H. longicornis, is considered as highly pathogenic to sheep and goats in China. This study reports and outlines features of its mitochondrial genome. The T. uilenbergi mitochondrial genome is a linear monomeric molecule of 6.0 kb length, which encodes three protein-coding genes named cytochrome c oxidase I (cox1), cytochrome b (cob), and cytochrome c oxidase III (cox3), as well as six large subunit (LSU) rRNA gene fragments, and ends in terminal inverted repeats (TIRs). The array structure and organization of the mitochondrial genome of T. uilenbergi is identical to that of T. parva. Phylogenetic analysis based on the amino acid sequences of cox1, cob, and cox3 genes suggests that T. uilenbergi is distantly related to the group of transforming Theileria species such as T. parva. This study contributes to a comprehensive understanding of the phylogeny and evolution of the mitochondrial genome of piroplasms and provides useful information of diagnostic marker for T. uilenbergi.

Molecular prevalence, characterization and associated risk factors of Anaplasma spp. and Theileria spp. in small ruminants in Northern Pakistan

This study was conducted in four districts (Malakand, Swat, Bajaur and Shangla) of Northern Pakistan to investigate the prevalence, associated risk factors and phylogenetic analyses of Theileria and Anaplasma species in small ruminants. A total of 800 blood samples, 200 from each district, were collected from apparently healthy animals. PCR assays were performed using generic primers for Anaplasma spp. and Theileria spp. as well as species specific primers for A. ovis and T. ovis. Overall infection prevalence was 361/800 (45.1%). Theileria spp. infection prevalence (187/800, 23.3%) was higher than Anaplasma spp. (174/800, 21.7%). Amplified partial 18S rRNA genes were sequenced and enrolled animals were found to be infected by T. ovis (115/800, 14.3%), and at least two more Theileria species (72/800, 9%) were present (T. lestoquardi and T. annulata). All blood samples that were found to be positive for Anaplasma spp. were also positive for A. ovis. Infection prevalence was higher in sheep (227/361, 28.3%) compared to goats (134/361, 16.6%) (p < 0.005). Univariable analysis of risk factors showed that host, age, grazing system and acaricide treatment were significant determinants (p < 0.05) for both Theileria and Anaplasma infections. Multivariable analysis revealed that host, sex, age, tick infestation and grazing system were significant risk factors (p < 0.005) for both pathogens. Phylogenetic analysis revealed variants among the A. ovis and T. annulata samples analysed, indicating that different genotypes are circulating in the field while T. ovis presented the same genotype for the samples analysed.

Molecular detection and genetic characterisation of pathogenic Theileria, Anaplasma and Ehrlichia species among apparently healthy sheep in central and western Kenya

Tick-borne diseases (TBDs) caused by Theileria, Babesia, Anaplasma and Ehrlichia species are common in tropical and subtropical regions. In this study, we investigated the presence and genetic diversity of Theileria spp., Anaplasma ovis, B. ovis, E. ruminantium and Anaplasma spp. in sheep from the Machakos and Homa Bay counties of Kenya. In order to improve the diagnosis and control of ovine TBDs, a total of 76 blood samples from apparently healthy sheep were screened using a polymerase chain reaction (PCR). The assays were conducted using primers based on Theileria spp. 18S rRNA, Anaplasma ovis Major surface protein-4 (AoMSP4), B. ovis 18S rRNA, E. ruminantium pCS20 and Anaplasma spp. 16S rRNA. The overall infection rates for Theileria spp., A. ovis, E. ruminantium and Anaplasma spp. were 39/76 (51.3%), 26/76 (34.2%), 6/76 (7.9%) and 31/76 (40.8%), respectively. The overall co-infection was 47/76 (61.8%). All Theileria spp. positive samples were confirmed to be of Theileria ovis on sequencing. A phylogenetic analysis of the 18S rRNA gene sequences of T. ovis revealed that all isolates of this study clustered with T. ovis sequences extracted from the GenBank suggesting this gene is highly conserved. E. ruminantium pCS20 sequences were in the same clade on the phylogenetic tree. However, three AoMSP4 sequences from this study appeared in the same clade, while one sequence formed a separate branch revealing genetic divergence. The 16S rRNA sequencing revealed uncharacterised Anaplasma spp. and A. ovis. The phylogenetic analyses of the uncharacterised Anaplasma spp. revealed that the two sequences from this study appear in an independent clade from other sequences extracted from the GenBank. This study provides important information regarding the occurrence of tick-borne pathogens and their degree of genetic diversity among sheep in Kenya, which is useful for the diagnosis and control of TBDs.

Molecular characterization of Theileria spp. in livestock and the first report on the occurrence of Theileria sp. OT3 in Iran

Theileria lestoquardi, T. ovis, and T. annulata are recognized as major causative agents for ovine and cattle theileriosis in Iran, respectively. Recently, there have been reports on the presence of Theileria spp. (Theileria sp. OT1, Theileria sp. OT3, and Theileria sp.). In this study, 37 blood samples were collected from sheep and cattle with clinically suspected Theileria infection in the Northwest of Iran. The samples were analyzed using a light microscope. DNA samples were amplified via nested-polymerase chain reaction (PCR) of 18S rRNA gene. The amplicons were digested with HpaII, following restriction fragment length polymorphism (RFLP) and sequenced to reconfirm Theileria species. The microscopic examination indicated that 4 out of 37 (10.8%) blood samples were infected with Theileria spp. Based on the nested PCR-RFLP and sequencing data, 5.4%, 13.5%, and 27% of blood samples were infected with Theileria sp. OT3, T. ovis, and T. annulata, respectively. The pairwise distance matrix of Theileria sp. OT3 showed 99.8-100% identity and 0-0.2% divergence in comparison with the registered sequences. The present study is the first report of Theileria sp. OT3 in Iran. To the evaluate evolution of Theileria spp. and providing resultant genetic data, further research with a larger sample is necessary in the region.

First molecular detection of Theileria luwenshuni from goats in Myanmar

Tick-borne intracellular protozoan parasites of the Theileria genus infect a wide range of both domestic and wild animals. In the present study, we describe the first PCR detection of Theileria luwenshuni in the blood of goats in Myanmar. Nested PCR targeting the Theileria 18S rRNA gene resulted in seven positive goats in central and northern Myanmar. Nucleotide sequencing of the PCR products revealed that all seven sequences were identical and showed 100% identity with T. luwenshuni sequences in GenBank from goats and sheep in China. Since T. luwenshuni parasites have recently been discovered and shown to have nationwide distribution in China, they might have been introduced into Myanmar via transboundary movement of infected domestic small ruminants and/or wild animals from China.

Detection of Theileria lestoquardi cross infection in cattle with clinical theileriosis in Iran

Theileriosis caused by Theileria lestoquardi (malignant ovine theileriosis) in sheep and Theileria annulata (tropical theileriosis) in cattle is an important hemoprotozoal tick-borne disease in Iran. Due to major biologic and phylogenic similarities of these two species, this study was carried out to investigate the occurrence of natural infections with T.lestoquardi and T.annulata in cattle with clinical theileriosis in Ahvaz, southwest Iran. Fifty one cattle were selected based on clinical signs of theileriosis and confirmation by microscopic examination of blood smears. Blood samples were collected from each animal and hematologic and microscopic examinations were performed. Theileria piroplasmic forms were detected in all affected cattle. Pale mucous membranes (43.14%), icterus (11.76%) and fever (70.6%) were also observed. PCR-RFLP analysis revealed T. annulata infection in all tested cattle while coinfections with T. lestoquardi were found in two samples (3.92%). All sampled cattle including the two with mixed species Theileria infection were anemic. This is the first report of Theileria species cross infections in cattle with clinical theileriosis in Iran. It can be concluded that cattle can be infected with both pathogenic Theileria species, T. lestoquardi and T. annulata which can be an important issue in the epidemiology and spread of ovine malignant theileriosis.

Molecular surveillance of Theileria ovis, Theileria lestoquardi and Theileria annulata infection in sheep and ixodid ticks in Iran

A molecular study was undertaken to detect Theileria ovis, Theileria lestoquardi and Theileria annulata in sheep and tick vectors. Investigation was conducted from 2010 to 2011 in the south of Khorasan Razavi Province, Iran. A total of 150 blood samples were collected from 30 different sheep flocks. In addition, ixodid ticks were sampled from the same flocks. The stained blood smears were microscopically examined for the presence of piroplasms and a semi-nested polymerase chain reaction-restriction (PCR) was used for subsequent molecular speciation. Salivary glands were isolated from the ticks and subsequently analysed by semi-nested PCR. polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to differentiate between T. lestoquardi and T. annulata from PCR-positive samples. Theileria species infection was microscopically detected in 18.6% of blood smears. The presence of T. ovis and T. lestoquardi or T. annulata was detected by semi-nested PCR in 58.6% and 6.6% of blood samples respectively. In total, 169 ixodid ticks were collected from different areas of the province. The most prevalent ticks were Rhipicephalus turanicus (n = 155; 91.7% of the total), followed by Hyalomma anatolicum anatolicum (n = 8; 4.7%) and Hyalomma marginatum turanicum (n = 6; 3.5%). From an organ pooling of 33 ticks, three pools of salivary glands from R. turanicus were positive for Theileria species by semi-nested PCR. Of the three R. turanicus samples testing positive for Theileria species, two (6.1%) were positive for T. ovis and one (3.0%) for T. lestoquardi or T.annulata. Amongst the 11 PCR-positive samples for T. lestoquardi or T. annulata, 10 were positive for T. lestoquardi and one sample was positive for both T. lestoquardi and T. annulata using PCR-RFLP. The results also demonstrated that PCR-RFLP could be used for the detection of T. ovis. Based on the results, it can be concluded that T. ovis has a higher prevalence than T. lestoquardi, and that R. turanicus could be a possible vector for T. ovis and T. lestoquardi. Finally, the PCR-RFLP based on Msp1 restriction enzyme is a simple method for differentiation of Theileria species in sheep and ixodid ticks.

Development of an immunochromatographic strip for the serodiagnosis of Theileria infection in sheep

Background

Theileria uilenbergi and T. luwenshuni are tick-borne protozoan parasites, transmitted by Haemaphysalis qinghaiensis and H. longicornis, respectively. They are the main causative agents of theileriosis in small ruminants in China. The disease has resulted in severe economic losses and hindered the development of sheep and goat husbandry industry in the endemic regions.

Methods

In this study, a colloidal gold-based immunochromatographic strip (ICS) was developed for the detection of T. uilenbergi and/or T. luwenshuni infections. A recombinant T. uilenbergi immunodominant protein (rTuIP) was used as antigen for the ICS. The nitrocellulose membrane was incubated with rTuIP on the test (T) line and anti-rTuIP antiserum on the control (C) line, respectively. The rTuIP conjugated to colloidal gold particles was used as the detection system for visualization of the lines. Then the sample pad, conjugate pad, nitrocellulose membrane and absorbent pad were assembled onto a backing plate in the appropriate order.

Results

The ICS was able to detect antibodies in the sera of animals experimentally infected with T. uilenbergi from 14 to 85 days. It also reacted with the serum from T. luwenshuni infected sheep. However, there was no cross-reactivity with sera from animals infected with Babesia motasi and Anaplasma ovis. Comparison of the ICS with the rTuIP antigen based indirect enzyme-linked immunosorbent assays (ELISA) using test field samples showed good correlations with 93.1 % (81/87) sensitivity and 100 % (40/40) specificity, respectively, with an almost perfect agreement (Kappa = 0.895, P < 0.01).

Conclusion

An immunochromatographic strip test based on a recombinant T. uilenbergi immunodominant protein (rTuIP) was developed. This is a rapid test (approximately 15 min to completion) for the detection of T. uilenbergi and/or T. luwenshuni infection that is easy to perform and; delivers results that are visible to the naked eye.

Coinfection of sheep with Anaplasma, Theileria and Babesia species in the Kurdistan Region, Iraq

Infections of small ruminants with Anaplasma, Theileria and Babesia species are widely distributed in the old world and are of great economic impact. In Iraq, data on disease occurrence in sheep caused by above-mentioned infectious agents are scarce. This study provides information on various haemoparasitic agents infecting sheep in the Kurdistan Region, Iraq, using molecular diagnostic tools. Altogether, 195 samples originating from three governorates in the Kurdistan Region, namely Duhok, Erbil and Sulaimaniya, were analysed. The following pathogens were identified: Anaplasma ovis (62.6%), Theileria ovis (14.35%), T. lestoquardi (7.7%), T. uilenbergi (5.6%) and Babesia ovis (1.5%). T. uilenbergi is detected for the first time in Iraq. Coinfection of sheep with different pathogens could be observed in this study, and it was found that 45 of 195 (23%) of the samples contained more than one pathogen. Even triple-positive samples were identified in 3% of the investigated animals. In conclusion, we confirm the coinfection of sheep with various haemoparasitic pathogen species in the Kurdistan Region of Iraq. Further investigations are needed to reveal the epidemiology of the diseases, the respective tick vectors, and, in the case of coinfection, pathogens' interaction and possible cross-protection.

Three Novel Haplotypes of Theileria bicornis in Black and White Rhinoceros in Kenya

Piroplasms, especially those in the genera Babesia and Theileria, have been found to naturally infect rhinoceros. Due to natural or human-induced stress factors such as capture and translocations, animals often develop fatal clinical piroplasmosis, which causes death if not treated. This study examines the genetic diversity and occurrence of novel Theileria species infecting both black and white rhinoceros in Kenya. Samples collected opportunistically during routine translocations and clinical interventions from 15 rhinoceros were analysed by polymerase chain reaction (PCR) using a nested amplification of the small subunit ribosomal RNA (18S rRNA) gene fragments of Babesia and Theileria. Our study revealed for the first time in Kenya the presence of Theileria bicornis in white (Ceratotherium simum simum) and black (Diceros bicornis michaeli) rhinoceros and the existence of three new haplotypes: haplotypes H1 and H3 were present in white rhinoceros, while H2 was present in black rhinoceros. No specific haplotype was correlated to any specific geographical location. The Bayesian inference 50% consensus phylogram recovered the three haplotypes monophyleticly, and Theileria bicornis had very high support (BPP: 0.98). Furthermore, the genetic p-uncorrected distances and substitutions between T. bicornis and the three haplotypes were the same in all three haplotypes, indicating a very close genetic affinity. This is the first report of the occurrence of Theileria species in white and black rhinoceros from Kenya. The three new haplotypes reported here for the first time have important ecological and conservational implications, especially for population management and translocation programs and as a means of avoiding the transport of infected animals into non-affected areas.

An epidemiological survey of Theileria infections in small ruminants in central China

Here, we conducted an epidemiological study in five regions in central China to assess the impact of theileriosis on small ruminants. PCR analysis and microscopic evaluations of blood smears to detect ovine and caprine theileriosis was conducted, in which 256 blood samples and 250 ticks were collected from sheep and goats, and tested for Theileria uilenbergi, T. luwenshuni, and T. ovis. The 18S rRNA gene sequences were deduced from positive samples and used for phylogenetic analysis. The results showed that T. luwenshuni was found most frequently in the five investigated regions and the prevalence of T. luwenshuni was found to be very high by PCR analysis. In contrast, T. uilenbergi and T. ovis infections were not detected in these regions. Phylogenetic tree analysis showed that all of the newly isolated Theileria spp. was in the same clade as T. luwenshuni. Haemaphysalis longicornis, which can transmit T. luwenshuni, was also detected in the sampled sheep and goats in these regions. Our results provide important data to increase the understanding of the epidemiology of ovine and caprine theileriosis, and will aid in the implementation of measures to control theileriosis transmission to small ruminants in central China.

Molecular detection of Theileria species in sheep from northern China

Ovine theileriosis is a tick-borne disease that restricts the development of small ruminant husbandry in northern China. In this study, we report on a molecular epidemiological survey of ovine Theileria spp. in 198 blood samples taken from sheep in northern China. The DNA samples were screened by a nested polymerase chain reaction (PCR) targeting the 18S rRNA gene of ovine Theileria spp. The prevalence of ovine Theileria spp. in Yanji, Nongan, Longjing, Toudao and Jinchang was 80%, 40%, 37%, 24% and 32%, respectively. The sequencing analyses approved the present of the T. orientalis and/or T. luwenshuni in these regions. Taken together, we have demonstrated a high incidence of Theileria spp. in northern China that calls for the need to design effective control programs for ovine theileriosis.

Babesia bigemina infection in yak (Poephagus grunniens L.): molecular detection and characterization

Yaks contribute significantly in the Himalayan high land economy. Specific information on prevalence of babesiosis in yaks is lacking. A fast and reliable PCR assay targeting Babesia bigemina small subunit ribosomal RNA sequence (SS rRNA) was laboratory standardized for molecular detection of B. bigemina in yaks. Restriction digestion of the PCR amplified 675 bp target sequence with Vsp I confirmed the prevalent species of Babesia as B. bigemina. Nucleotide sequencing and phylogenetic analysis of PCR amplified 675 bp SS rRNA sequence revealed a close genetic relationship with other bovine isolates of B. bigemina. A PCR based survey involving 94 blood samples of yak from the National Research Centre on Yak, Dirang, Arunachal Pradesh detected infection in 5.32% of yak blood samples, which was significantly higher in comparison to microscope based detection of infection in 2.13% blood smears. This is the first report on sensitive PCR based detection of B. bigemina infection in yaks and PCR-RFLP and nucleotide sequence analysis based molecular characterization of the B. bigemina isolated from yaks.

Babesia ovis as the main causative agent of sheep babesiosis in Iran

Babesiosis is a haemoparasitic disease with high economical losses in livestock industry worldwide. The early diagnosis and successful therapy of babesiosis belong to the key steps of control and health management of livestock. Ethanol-fixed blood samples of 400 sheep were analyzed for Babesia infection. Reverse line blot (RLB) was established specifically for Theileria lestoquardi, Theileria (China 1), Theileria (China 2), Theileria ovis, Theileria separata, Babesia ovis, Babesia motasi, Babesia crassa, and Babesia (Lintan). The DNA was extracted from the ethanol-fixed blood samples and amplified with a common primer pair derived from 18S rRNA gene, amplifying both Theileria spp. as well as Babesia spp. Regarding the differences in the length of nucleotide sequences of the polymerase chain reaction (PCR) products obtained from Theileria spp. and Babesia spp., the PCR products derived from Babesia spp. were out screened and analyzed by RLB. The RLB analysis showed that 28 samples within the 400 blood samples were B. ovis positive. No B. motasi, B. crassa, or Babesia (Lintan) could be detected. The sequence analysis of one PCR product as a representative for other B. ovis-positive PCR products confirmed the results of RLB. Our results and the results of other investigators showed that B. ovis could be considered as a main causative agent of sheep babesiosis in Iran. Furthermore, our results also showed that RLB can be used as a reliable method for a simultaneous differentiation of Theileria and Babesia species from each other.

Theileria ovis discovered in China

A polymerase chain reaction (PCR) using 989/990 primers was conducted to identify a newly isolated Theileria sp. in Xinjiang Province of China. The target DNA fragments of the complete 18S rRNA gene were cloned and sequenced. The phylogenetic relationship of newly isolated Theileria spp. was inferred based on the 18S rRNA gene. The results showed that the new Theileria sp. belonged to the cluster of Theileria ovis. Moreover, the findings were confirmed by T. ovis species-specific PCR. An expected 520 bp fragment of T. ovis DNA was obtained from 25 out of 320 (8%) field blood samples, and blood of an experimental sheep infested by Hyalomma anatolicum anatolicum collected in Xinjiang. The infection rate of T. ovis was 78% (25/32) in Xinjiang province. The investigation did not find T. ovis positive samples from the field samples collected from the other twelve provinces. This study indicates that T. ovis is prevalent in Xinjiang province of China and its transmission vector is H. anatolicum anatolicum.

Detecting and differentiating Theileria sergenti and Theileria sinensis in cattle and yaks by PCR based on major piroplasm surface protein (MPSP)

Theileria sergenti and Theileria sinensis are closely related members of benign Theileria species found in cattle and yaks in China. They are morphologically indistinguishable. A polymerase chain reaction (PCR) targeting major piroplasm surface protein of T. sergenti and T. sinensis was developed in this study. The newly developed oligonucleotide primer set was able to specifically amplify the DNA of T. sinensis and in conjunction with primers for T. sergenti and these two species could be detected and distinguished. Specificity testing also revealed that there was no cross-reaction with the other tick-borne diseases Theileria annulata, Babesia ovata, Anaplasma marginale as well as bovine white blood cells. Phylogenetic analysis based on the MPSP gene sequences confirmed the specificity of PCR assays. The sensitivity of the methods was 0.1pg DNA for the T. sergenti PCR and 1pg DNA for T. sinensis PCR. Two hundred and thirty-six field blood samples from of cattle and yaks were collected from five different geographical regions in China where benign Theileria species have been found. T. sergenti was found in all five provinces but was absent from one county in Gansu Province. T. sinensis was only found in Gansu Province. In both counties in Gansu where the parasites co-existed, mixed infections were detected. Our results indicate that the PCR methods developed in this study are suitable for the detection and differentiation of T. sergenti and T. sinensis.

Experimental transmission of Theileria ovis by Hyalomma anatolicum anatolicum

The experimental transmission of a newly isolated Theileria ovis is described. Hyalomma anatolicum anatolicum nymphs developed from larvae engorged on sheep infected with T. ovis were able to transmit the T. ovis to splenectomized sheep. Meanwhile, H. anatolicum anatolicum adults developed from nymphs engorged on sheep infected with T. ovis were also able to transmit T. ovis to splenectomized sheep. These experiments suggested that T. ovis could be transmitted by a H. anatolicum anatolicum, and the mode of transmission is from stage to stage.

Molecular phylogenetic studies on Theileria spp. isolates (China) based on small subunit ribosomal RNA gene sequences

Six Theileria spp. from cattle, buffalo and black goat were identified in the Hubei province of China. In order to study the taxonomic status of these parasites, phylogenetic analysis of 18S rRNA genes were carried out. The 18S rRNA genes from each isolate were amplified by the polymerase chain reaction and the approximate 1.75 kb products were cloned and sequenced. Phylogenetic analysis of these gene sequences revealed that the five parasites from buffalo and cattle belonged to the Theileria sergenti/buffeli/orientalis group. The parasite from the Chinese goat (Macheng-Hubei, DQ286802) was closely related to Theileria luwenshuni isolated from sheep in the north of China. This represent the first report on the use of molecular phylogeny to classify Theileria spp. obtained in the Hubei province, showing that Theileria spp. from ruminants found in Hubei province belongs to the benign group of Theileria spp.

Molecular identification of ovine Theileria species by a new PCR-RFLP method

Theileria spp. infect wild and domestic ruminants in the tropical and subtropical regions of the world. Two species, T. lestoquardi and T. ovis, are suspected to cause ovine theileriosis in Iran. The epidemiological aspects of ovine theileriosis in Iran are poorly understood, and further investigations by sensitive and precise techniques are required. In this study, the use of a nested PCR for amplification of a fragment of the 18S ribosomal DNA from virtually all species of Theileria is described. For differentiation of various Theileria spp. a RFLP assay was developed as a diagnostic tool enabling direct, concurrent, highly specific and sensitive identification of Theileria spp. The sensitivity of the nested PCR for Theileria species was 10(-5)% parasitemia. Restriction fragment length polymorphism (RFLP) of the PCR products allowed differentiation between three different Theileria species (T. annulata, T. lestoquardi and T. ovis) and seems to be useful for differentiation of other species such as T. separata and Theileria spp. china. From 100 field blood samples obtained from sheep in East and South-East Iran, 56% were positive for Theileria spp. by nested-PCR compared with 21% by microscopic examination. Out of 56 positive samples, 12.5% (7/56) were positive for T. ovis and 87/5% (49/56) were positive for T. lestoquardi. This is the first report in which T. ovis has been detected in Iran using molecular identification techniques.

Experimental transmission of Theileria uilenbergi infective for small ruminants by Haemaphysalis longicornis and Haemaphysalis qinghaiensis

The experimental transmission of a recently designated Theileria uilenbergi pathogenic for sheep and goats in Northern China is described. Haemaphysalis qinghaiensis nymphs and adults developed from larvae and nymphs engorged on sheep infected with T. uilenbergi were able to respectively transmit the latter to sheep. However, when H. longicornis ticks picked up T. uilenbergi either at larval or nymphal, only the subsequent adult could transmit the parasites to sheep, the subsequent nymph could not transmit the parasites to sheep. This experiment suggested that the T. uilenbergi could be transmitted by at least two species of Haemaphysalis sp. ticks, H. longicornis and H. qinghaiensis, and the mode of transmission is stage to stage.

Detection and differentiation of Theileria luwenshuni and T. uilenbergi infection in small ruminants by PCR

Theileria luwenshuni and T. uilenbergi are newly identified Theileria species highly pathogenic for sheep and goats in China. As they are morphologically indistinguishable and poorly characterized, there is no easily applicable method available to differentiate between these species. In the present study, PCR assays are described for the differentiation and detection of T. luwenshuni and T. uilenbergi using species-specific primers, which were designed based on the hypervariable region of the small subunit ribosomal RNA gene sequences. By testing 100 field blood samples of sheep collected from five geographically different regions where the Theileria species were described to be prevalent, the PCR assays not only detected infected samples but also identified mixed infection. This suggests that these PCR assays are useful tools for the detection of and differentiation between T. luwenshuni and T. uilenbergi.

Identification of a novel Babesia sp. from a sable antelope (Hippotragus niger Harris, 1838)

Babesiosis in a sable antelope (Hippotragus niger Harris, 1838) was first reported in 1930; the parasite was named Babesia irvinesmithi. Recently, specimens from an adult sable that presented with a sudden onset of disease and that subsequently died during immobilization were submitted for molecular characterization. Microscopic examination of thin blood smears revealed the presence of small piroplasms. DNA was extracted from blood samples; the V4 variable region of the 18S rRNA gene was amplified and analyzed using the reverse line blot (RLB) assay. Amplicons did not hybridize with any of the Babesia or Theileria species-specific probes present on the blot and hybridized only with a Babesia or Theileria genus-specific probe, suggesting the presence of a novel species. The full-length 18S rRNA gene sequence was obtained and aligned with published sequences of related genera, and phylogenetic trees were constructed. Sequence similarity analyses indicated that a Babesia species, designated Babesia sp. (sable), was present. The sequence showed its highest similarity to B. orientalis and to an unnamed Babesia species previously detected in bovine samples. The latter was later established to be Babesia occultans. A Babesia sp. (sable)-specific RLB oligonucleotide probe was designed and used to screen 200 South African sable samples, but so far, no other sample has been found to be positive for the presence of Babesia sp. (sable) DNA. In summary, we identified a novel piroplasm parasite from a sable antelope that died from an unknown illness. While the parasite was observed in blood smears, there is no direct evidence that it was the cause of death.

Evaluation of a PCR and comparison with RLB for detection and differentiation of Theileria sp. MK and other Theileria and Babesia species of small ruminants

Theileria sp. MK in sheep and goats were detected first time by polymerase chain reaction (PCR) and detection limit of PCR and reverse line blotting (RLB) were compared. A part of 18S ssu rRNA gene was amplified from blood samples that were taken from sheep and goats naturally infected with Theileria sp. MK by PCR. Detection limit of both PCR and RLB methods was one infected cell in 10(7) sheep erythrocytes. Nine hundred twenty field samples that had been tested previously by RLB were evaluated by the PCR assay. As found by RLB previously, 12 of 920 (1.30%) samples were detected as positive by PCR. Two positive PCR products, one of which was from sheep and the other from goat, were sequenced. These sequences were identical to the reported nucleotide sequence of Theileria sp. MK. It is concluded that the PCR described in this study will be useful for epidemiological studies and for discrimination between Theileria sp. MK and other Theileria species. In addition, PCR has superiority over RLB because of its ease of use and time period required.

Ovine theileriosis in China: a new look at an old story

A fatal disease of sheep and goats in the northwestern part of China has in the past been reported to be due to Theileria lestoquardi. However, some characteristics of the causative agent are not in accordance with attributes ascribed to this parasite. We therefore determined the nucleotide sequence of the 18 small subunit ribosomal RNA (18S rRNA) gene of T. lestoquardi and the parasite identified in China and compared it with that of other Theileria and Babesia species. In the inferred phylogenetic tree, the 18S rRNA sequence of the Chinese parasite falls inside the clade consisting of Theileria species evidencing that it belongs to this genus. The 18S rRNA sequence of the Chinese parasite was found to be most closely related to Theileria buffeli and clearly divergent to T. lestoquardi, suggesting that it was a yet unrecognized Theileria species. The phylogenetic relationship of Theileria species infecting sheep and goats on the basis of their 18S rRNA gene structure was addressed. We report on the existence of at least two additional ovine and caprine piroplasm species, designated T. luwenshuni and T. uilenbergi.

Serological investigation of ovine theileriosis by ELISA in Gannan Tibet Region of Gansu Province in China

The Gannan Tibet Autonomous Region is the biggest and most important stock-raising region of Gansu Province, People's Republic of China. Many sheep and goats from this region suffer from Theileria challenge each year, resulting in inestimable economical losses. A first large-scale serological investigation by enzyme-linked immunosorbent assay of ovine theileriosis in this region was performed by testing a total of 1,165 sera samples collected from seven districts of three counties. The results showed that seroprevalence of reactive antibodies varied from 27.8 to 83.3%, whereby the average was 70.1% in the disease-endemic areas. Another 44 sera samples collected every month from July 2004 to June 2005 from a stable flock of sheep in Biandu Town of Lintan County were analysed to evaluate the seasonal kinetics of anti-Theileria antibodies. The results indicated that anti-Theileria antibody seroprevalence rose from March, reaching a peak value of 68.2% in May, declining in October and reaching the lowest value of 36.4% in January. The data indicate that seroprevalence of anti-Theileria antibodies correlate to the known activities of its transmitting vector and also imply that chemical therapy of animals should be performed during May to June in these Theileriosis-epidemic regions.

Determination of Rhipicephalus spp. as vectors for Babesia ovis in Iran

The tick-borne diseases of livestock constitute a complex of several diseases with different etiological agents, such as protozoa, rickettsia, bacteria, and viruses. One problem discussed in protozoan infection is the determination and characterization of the transmitter agent. Because many analyses were performed with the salivary gland smears using the methyl-green-pyronin staining method or the Feulgen staining method, the transfer vector remains unanswered in some cases. The aim of this study is to recognize Babesia ovis in the salivary gland of Rhipicephalus spp. using polymerase chain reaction (PCR). Deoxyribonucleic acid (DNA) was isolated from 269 salivary gland of Rhipicephalus spp. (108 R. bursa, 87 R. turanicus, 74 R. sanguineus) collected from sheep with suspected to babesiosis. The isolated DNA was then analyzed with the primers derived from the hypervariable region V4 of 18S ribosomal ribonucleic acid (rRNA) of the Babesia species. For the specificity of the PCR product and discriminating from Babesia motasi and Babesia crassa, nested PCR and restriction fragment length polymorphism was performed. As positive control for the DNA extraction procedure, the DNA was analyzed with the common primers designed from the 18S rRNA of the Ticks (Rhipicephalus, Hyalomma, Haemophysalis, Dermacentor, Ixodes, Boophilus). B. ovis was detected in salivary gland of 18.5% R. bursa, 9.1% R .turanicus, and 8.1% R. sanguineus, respectively.

Phylogenetic position of small-ruminant infecting piroplasms

Theileria and Babesia are tick-transmitted protozoa that cause great economical losses in livestock. Recently, interest has risen in sheep-infecting piroplasms and a number of previously unidentified pathogens were described, particularly in China. To address the phylogenetic relationship of Theileria and Babesia species infecting sheep, the complete sequences of the 18 S small subunit ribosomal RNA genes of a panel of piroplasm isolates, including T. lestoquardi, T. ovis, T. separata, B. ovis, B. motasi, B. crassa, and several novel species, were compared. The classification based on the established phylogenetic tree corresponded with traditional systematics and revealed that sheep/goat piroplasm species are of a polyphyletic origin. In addition, these studies revealed the existence of at least two novel sheep/goat piroplasm species, designated Theileria sp. (China 1) and Theileria sp. (China 2).

Experimental transmission of Theileria sp. (China 1) infective for small ruminants by Haemaphysalis longicornis and Haemaphysalis qinghaiensis

The experimental transmission of a recently identified new Theileria (China 1) species pathogenic for sheep and goats in northern China is described. Haemaphysalis qinghaiensis nymphs and adults developed from larvae and nymph engorged on sheep infected with Theileria sp. (China 1) were able to respectively transmit the Theileria sp. to splenectomized sheep. Meanwhile, H. longicornis nymphs and adults developed from larvae and nymphs engorged on sheep infected with Theileria sp. (China 1) were also able to respectively transmit this new Theileria sp. (China 1) to splenectomized sheep. These experiments suggested that the Theileria sp. (China 1) could be transmitted by at least two species of Haemaphysalis sp. ticks, H. longicornis and H. qinghaiensis, and the mode of transmission is stage to stage.

Establishment of optimal conditions for long-term culture of erythrocytic stages of Theileria uilenbergi

OBJECTIVE

To establish optimal conditions for long-term culture of the erythrocytic stage of Theileria uilenbergi.

SAMPLE POPULATION

Red blood cells from 3 splenectomized sheep experimentally infected with a blood stabilate of T uilenbergi.

PROCEDURES

Cultures of T uilenbergi were initiated by use of blood from experimentally infected sheep collected when parasites were detected in Giemsa-stained thin blood smears. Different culture conditions were tested to optimize in vitro growth of the organisms. Subcultures were performed at a ratio of 1:2, 1:4, and 1:8 when the percentage of parasitized erythrocytes (PPE) was at least 1% or when the initial PPE was doubled.

RESULTS

The optimal culture medium was HL-1 medium (a complete chemically defined medium) supplemented with 20% sheep serum and 0.75% chemically defined lipids. Optimal culture conditions included incubation in a humidified 2% O(2), 5% CO(2), and 93% N(2) atmosphere at 37 degrees C. Cultures of the merozoite stage of the parasite were continuously propagated in vitro for > 1 year. The PPE reached values of up to 3%.

CONCLUSIONS AND CLINICAL RELEVANCE

Optimization of culture conditions to reach a high PPE seems worthwhile. The continuous propagation of T uilenbergi in culture allows the production of parasite material without infecting animals and provides a continuous laboratory source of parasites for further studies.

Identification and Characterization of Merozoite Antigens of aTheileriaSpecies Highly Pathogenic for Small Ruminants in China

A new pathogenic Theileria species transmitted by Haemaphysalis qinghaiensis was identified in the Northwestern part of China and was shown to be highly pathogenic for small ruminants. The present article aimed at identifying merozoite antigens that might be suitable for developing diagnostic methods and designing a potential vaccine. Absence of other theilerial or babesial infections was confirmed by reverse line blot in all antigen samples used. Extensive Western blot analyses using serum from infected and noninfected animals led to the identification of four potential merozoite immunoreactive proteins at different molecular weights. Further protein characterization using peptide mass mapping by matrix-assisted laser desorption/ionization (MALDI) followed by database searching resulted in two significant hits that identified two proteins of parasite origin, one homologous to a possible MO25-family protein from Cryptosporidium parvum and the other with an HSP70 from Theileria annulata. Another protein was also identified as a parasite protein but without significant homology. Immunization of rabbits with selected proteins produced antisera that reacted specifically on Western blots with merozoite antigens of the corresponding sizes. This article represents the first identification and characterization of potential antigenic proteins of Theileria sp. (China) for veterinary purposes.

PCR-based detection of Theileria ovis in Rhipicephalus bursa adult ticks

Tick-borne diseases in ruminants are common in tropical and subtropical regions and lead to meat and milk production losses. In this study, polymerase chain reaction (PCR) was used to assess the presence of Theileria ovis in Rhipicephalus bursa ticks. We have demonstrated that the PCR enabled detection of T. ovis in field isolates of R. bursa collected from naturally infested sheep and goats in eastern Turkey. The sampling was done in spring season (between May and June 2004). A total of 420 R. bursa were collected and randomly selected 192 number of them (97 female and 95 male) were dissected. Primers specific for 520 bp fragments small subunit ribosomal RNA (ssu rRNA) gene of T. ovis amplified products from 37 of the 192 (19.27%) samples. The parasite was detected in 17 (17.52%) female and in 20 (21.05%) male ticks. Two T. ovis amplicons from the tick samples were purified and sequenced. The resulting sequences were identical to the nucleotide sequence of the Turkish sheep strain of T. ovis. These results showed that R. bursa might play an important role in the field as a natural vector of T. ovis.

Development of a recombinant indirect ELISA for the diagnosis of Theileria sp. (China) infection in small ruminants

Theileria sp. (China) causes severe limitations on the development of the livestock industry in the north-west of China. An enzyme-linked immunosorbent assay (ELISA) based on merozoite homogenate of the parasite for diagnosis of infection has been established; however, cross-reactivity with other small ruminant-infecting piroplasms could not be excluded. Thus, a prerequisite for epidemiological surveys and diagnosis was the establishment of a recombinant protein-based ELISA. To this end, serum from Theileria sp. (China)-infected sheep was used to screen a Theileria lestoquardi expression library, resulting in the identification of a specifically reacting clone with a high identity to the heat shock protein 70 (HSP70) of Theileria parva and Theileria annulata and thus named TlHSP70. An HSP70 homologue was also confirmed to be expressed by Theileria sp. (China) merozoites (TcHSP70). A part of the TlHSP70 protein, found to be conserved in TcHSP70, was recombinantly expressed and used to establish an ELISA. A total of 260 field serum samples tested resulted in a sensitivity and specificity of 94.3 and 89.5%, respectively, in comparison with the merozoite homogenate ELISA. The potentials of the application of the test in epidemiological surveys to map out the prevalence of the disease and for routine diagnostics are described.

Development of a polymerase chain reaction method for diagnosis of Babesia ovis infection in sheep and goats

In this study, a pair of oligonucleotide primers were designed according to the nucleotide sequence of the small subunit ribosomal RNA (ssu rRNA) gene of Babesia ovis isolated from sheep in eastern Turkey. The primers were used to detect parasite DNA from blood samples of B. ovis-infected sheep and goats by polymerase chain reaction (PCR). A 549-bp DNA fragment was specifically amplified from blood samples from sheep and goats, naturally infected with B. ovis. No PCR products resulted from Babesia motasi, T. ovis, Theileria sp. OT1, Theileria sp. OT3, T. lestoquardi, B. canis, B. microti,T. annulata or normal sheep leucocytes DNA using these specific primers. B. ovis-infected erythrocytes with 1% parasitemia were subjected to 10-fold serial dilutions (from 10(-1) to 10(-9)) using an uninfected sheep erythrocytes, and DNA was extracted from each diluted sample for testing the sensitivity of the PCR. The PCR was sensitive enough to detect parasite DNA from the dilution of 10(-5) with 0.00001% parasitemia. This is more sensitive than examining 200 fields under light microscopy. In addition, 98 field samples collected from small ruminanats in eastern Turkey were tested for B. ovis infection. Four samples were positive Babesia spp. in blood smears, 21 samples were positive for B. ovis DNA by PCR. These results indicate that the PCR provides a useful diagnostic tool for the detection of B. ovis infection in sheep and goats.

Simultaneous differentiation between Theileria spp. and Babesia spp. on stained blood smear using PCR

The tick-borne diseases of livestock constitute a complex of several diseases with different etiological agents. Theileriosis and babesiosis belong to this complex and are severe and often fatal protozoan tick-borne diseases of ruminants worldwide. This results in high economical losses yearly in Iran. The most common diagnostic method for the identification of piroplasms in Iran is Giemsa staining of blood smear, which is unspecific, accompanied by some technical problems and, in some cases, impossible, due to the carriers. In contrast, immunostaining is more specific and can only be performed with suitably prepared blood smears, but cannot be used also for the carriers. The most specific method for the differential diagnosis of piroplasms is the method of polymerase chain reaction. We extracted DNA from different sources of blood samples, including from already stained blood smears. The extracted DNA was subsequently amplified using specific primers derived from Theileria heat shock protein hsp70, Theileria lestoquardi ms1-2 gene, Babesia rhoptry protein gene and piroplasms hyper variable region V4 of 18S rRNA gene. The results show that it is possible to detect piroplasms in already stained blood smears as well enabling a simpler method to be developed for the collection of the samples. Furthermore, it is possible to analyse the already stained and registered blood smears from the patients with unclear differential diagnosis, e.g. in the carriers. In addition, the results revealed that using a primer designed from the hyper variable region V4 of 18S rRNA, it is possible to detect and differentiate simultaneously the genera Theileria and Babesia in DNA samples isolated from already stained blood smears.

Detection of Theileria ovis in naturally infected sheep by nested PCR

A nested polymerase chain reaction (PCR) for the detection of Theileria ovis in sheep using oligonucleotide primers designed from the small subunit ribosomal RNA (SSU rRNA) gene sequence of T. ovis from sheep in eastern Turkey is described. A 398-bp DNA fragment was specifically amplified from blood samples from sheep, naturally infected with T. ovis. No PCR products resulted from T. lestoquardi, T. annulata, T. parva, T. buffeli and Babesia spp. DNA using these specific primers. The sensitivity of the nested PCR for T. ovis, which was assessed showed that one infected cell in 10(7) sheep erythrocytes, equivalent to a blood parasitemia of 0.00001%, could be detected. This is more sensitive than examining 200 fields under light microscopy. In addition, of the 124 field samples obtained from sheep in eastern Turkey tested, 19.35% (24/124) were positive for the presence of Theileria spp. by microscopic examination compared to 54.03% (67/124) positive for T. ovis by nested PCR. The primer pairs described in this study will be useful for epidemiological studies on ovine theileriosis and for discrimination between T. lestoquardi and T. ovis infections in sheep.