Explore the vast range of titles available.

Pakistan has a huge sheep population (37.2 million in 2024) that is largely unexplored for the presence of vector transmitted parasites. Present study was aimed to document the prevalence of Anaplasma sp. , Anaplasma ovis , Theileria ovis and Theileria lestoquardi in sheep blood samples (N = 329) that were collected from six districts (Muzaffargarh, Rajanpur, Dera Ghazi Khan, Layyah, Taunsa and Khanewal) during August till December 2024 and to report the genetic diversity of screened pathogens. Molecular analyses revealed that the prevalence of Anaplasma sp. , Anaplasma ovis and Theileria ovis in screened sheep was 11%, 20% and 21% respectively. None of the screened sheep was Theileria lestoquardi infected. Co-infection of the screened pathogens was also observed. Presence of the detected pathogens was confirmed by DNA sequencing and subsequent BLAST analysis. Phylogenetic analysis revealed that these pathogens displayed genetic similarities with the sequences that were deposited from various countries across the globe. Prevalence of all screened pathogens varied significantly between the sampling districts. Similarly, the Anaplasma sp., Anaplasma ovis and Theileria ovis prevalence varied significantly among the sheep breeds. Anaplasma ovis infection was more common in large herds and in un-infested sheep. Theileria ovis infection was more frequent in small herds. In conclusion, we are reporting the presence of Anaplasma sp., Anaplasma ovis and Theileria ovis in Pakistani sheep that were enrolled from all six districts. Large-scale studies are recommended in various geo-climatic regions of Pakistan to confirm the genetic diversity, epidemiology and host-pathogen interactions that will contribute towards effective control of these infections among the local sheep population.

Raising small ruminants is the main source of income for farmers in Pakistan especially in rural areas of Dera Ghazi Khan in Punjab. Despite having large sheep population, the prevalence of intra-erythrocytic protozoa, Theileria ( T .) lestoquardi , has never been reported from this area. This study was conducted to fill this knowledge gap and 333 blood samples of apparently healthy small ruminants (168 sheep and 165 goats) along with their epidemiological data were collected from Dera Ghazi Khan district during August till November 2022. The polymerase chain reaction (PCR) analysis amplified a 785 base pair amplicon specific for the Merozoite surface antigen ( ms 1–2 ) gene of T . lestoquardi in 2 out of the 168 (3.3%) sheep blood samples, while no goat blood sample out of 165 was found to be infected with T . lestoquardi . DNA sequencing confirmed the presence of Theileria lestoquardi in both samples and phylogenetic analysis revealed that these amplicon resembled the partial ms 1–2 gene sequences detected in small ruminants from Pakistan, India Iran and Egypt. All the studied epidemiological factors (age, sex, breed, size of herd, dogs with herd, composition of herd, size of herd and Tick burden on sheep) were not found associated with the prevalence of T . lestoquardi . In conclusion, this study reports a low prevalence of T . lestoquardi infection in the Dera Ghazi Khan District of Punjab, Pakistan. The data generated from this work will help pave the way for the prophylactic detection and control of ovine and caprine theileriosis in the region.

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. Cette étude a été menée dans quatre districts (Malakand, Swat, Bajaur et Shangla) du nord du Pakistan pour étudier la prévalence, les facteurs de risque associés et les analyses phylogénétiques des espèces de Theileria et Anaplasma chez les petits ruminants. Au total, 800 échantillons de sang, 200 de chaque district, ont été prélevés sur des animaux apparemment sains. Les tests PCR ont été réalisés en utilisant des amorces génériques pour Anaplasma spp. et Theileria spp. ainsi que des amorces spécifiques à l’espèce pour A. ovis et T. ovis . La prévalence globale de l’infection était de 361/800 (45,1 %). La prévalence de l’infection à Theileria spp. (187/800, 23,3 %) était plus élevée que celle d’ Anaplasma spp. (174/800, 21,7 %). Le gène de l’ARNr partiel 18S amplifié a été séquencé et les animaux concernés se sont révélés infectés par T. ovis (115/800, 14,3 %) et au moins deux autres espèces de Theileria (72/800, 9 %) étaient présentes ( T. lestoquardi et T. annulata ). Tous les échantillons de sang trouvés positifs pour Anaplasma spp. ont également été trouvés positifs pour A. ovis . La prévalence de l’infection était plus élevée chez les moutons (227/361, 28,3 %) que chez les chèvres (134/361, 16,6 %) ( p  < 0,005). Une analyse univariée des facteurs de risque a montré que l’hôte, l’âge, le système de pâturage et le traitement acaricide étaient des déterminants significatifs ( p  < 0,05) pour les infections à Theileria et Anaplasma . L’analyse multivariée des facteurs de risque a révélé que l’hôte, le sexe, l’âge, l’infestation par les tiques et le système de pâturage étaient des éléments de facteurs de risque importants ( p  < 0,005) pour les deux agents pathogènes. L’analyse phylogénétique a révélé des variantes parmi les échantillons d’ A. ovis et de T. annulata analysés indiquant que différents génotypes circulent sur le terrain tandis que T. ovis présentait le même génotype pour tous les échantillons analysés.

Mixed species infections of Theileria spp. are common in nature. Experimental and epidemiological data suggest that mixed species infections elicit cross-immunity that can modulate pathogenicity and disease burden at the population level. The present study examined within-host interactions, over a period of 13 months during natural infections with two Theileria spp., pathogenic ( T. lestoquardi ) and non-pathogenic ( T. ovis ), amongst a cohort of naive sheep in Oman. In the first two months after exposure to infection, a high rate of mortality was seen among sheep infected with T. lestoquardi alone. However, subsequently mixed-infections of T. lestoquardi and T. ovis prevailed, and no further death occurred. The overall densities of both parasite species were significantly higher as single infection vs mixed infection and the higher relative density of pathogenic T. lestoquardi indicated a competitive advantage over T. ovis in mixed infection. The density of both species fluctuated significantly over time, with no difference in density between the very hot (May to August) and warm season (September to April). A high degree of genotype multiplicity was seen among T. lestoquardi infections, which increased with rising parasite density. Our results illustrate a potential competitive interaction between the two ovine Theileria spp., and a substantial reduction in the risk of mortality in mixed parasite infections, indicating that T. ovis confers heterologous protection against lethal T. lestoquardi infection.

Small ruminant theileriosis is an economically significant disease in tropical and subtropical countries caused by Theileria lestoquardi, Theileria ovis, and Theileria luwenshuni, of which T. lestoquardi is very pathogenic. The goal of the current study was to investigate the molecular epidemiology of T. lestoquardi and T. ovis in small ruminants in the Charsadda district of Khyber Pakhtunkhwa. A total of 150 whole blood samples (sheep, n=104, and goats, n=46) were collected for this study in various locations throughout the district of Charsadda from June to August 2021. Microscopically, Theileria piroplasms were observed in 10 samples (6.6%) while T. lestoquardi was identified through PCR in 37 samples (24.6%) and none of the samples was positive for T. ovis. T. lestoquardi target gene (i.e., 18srRNA) was sequenced and the results showed close homology with Iranian isolates of T. lestoquardi, indicating the possibility of cross-border transmission of the disease. Tick infestation and age were significant (p<0.05) among the several risk factors examined, however, species and sex were deemed to be non-significant (p>0.05). Analysis of clinical manifestation revealed that fever and lymphadenopathy were moderately related to small ruminant theileriosis, whereas anorexia was weakly associated with the disease. According to the current study results, T. lestoquardi is responsible for causing theileriosis in small ruminants in Charsadda, Khyber Pakhtunkhwa whereas PCR is a sensitive diagnostic test as compared to microscopy.

Background Tick-borne diseases cause economically significant losses to animal production globally, and anaplasmosis and theileriosis are associated with the greatest losses. However, the spread of the relevant pathogens in flocks of domesticated animals in southern Egypt is little understood. Accordingly, in this study, we aimed to determine the prevalences of Anaplasma ovis , Theileria ovis , and Theileria lestoquardi in southern Egyptian sheep and goats through blood tests, and to make a molecular characterization of the A. ovis detected in sheep targeting a specific gene. Results We collected blood samples collected from 300 sheep and goats ( n =150 /species) in Luxor Province in southern Egypt, and analyzed them for the presence of A. ovis, T. ovis and T. lestoquardi with screening by conventional and nested PCR targeting the msp4 and msp5, 18S rRNA, and merozoite surface protein genes. For A. ovis 140/300 samples (46.66%) were positive overall, with 90/150 (60%) and 50/150 (33.33%) positive samples in sheep and goats, respectively. Two major surface protein genes of A. ovis, msp4 and msp5, were sequenced using DNA extracted from sheep and goat blood samples, for phylogenetic analysis and genotyping. The msp4 gene sequence revealed no significant genetic diversity, to contrast to data on A. ovis strains from other countries. For T. lestoquardi , 8/150 (5.33%) samples were positive in sheep, but no samples were positive in goats (0%). For T. ovis, 32/150 (21.33%) samples were positive in sheep, but no samples were positive in goats (0%). Sequencing targeting the merozoite surface protein gene for T. lestoquardi and the small subunit ribosomal RNA gene for T. ovis revealed no significant genetic diversity in the study, another contrast to data on A. ovis strains from other countries. Conclusion This study provides valuable data on phylogenetic and molecular classifications of A. ovis, T. ovis and T. lestoquardi found in southern Egyptian sheep and goats. It also represents the first report on detection and molecular characterization of T. lestoquardi in southern Egyptian sheep based on the specific merozoite surface protein gene, thus providing valuable data for molecular characterization of this pathogen in southern Egypt.

Background Theileriosis is a haemoparasitic disease of domestic and wild ruminants, caused by Theileria species, transmitted by Ixodid tick species, particularly prevalent in tropical and subtropical regions. This study aimed to investigate the prevalence of Theileria ovis and Theileria lestoquardi in sheep and goats in Siirt province using molecular methods and to analyse their evolutionary relationships with published sequences. Materials and Methods The animal material of the study consisted of 350 sheep and 350 goats in Siirt province and its districts. Blood samples were collected from the jugular veins of the animals and put into EDTA tubes. DNA extraction, PCR amplification and sequence analyses were performed on the collected samples. Results According to the analysis results, the prevalence of T. ovis was found to be 5.43% (19/350, 95% confidence interval [CI] = 3.50%–8.32%) in sheep, 4.57% (16/350, 95% CI = 2.83%–7.30%) in goats and 5% (35/700) in total. A higher prevalence was determined in females (5.20%) and in the 2–3 age group (5.52%). Among sheep breeds, the highest prevalence was detected in Hamdani sheep (8.26%), while in goats, it was detected in Aleppo goats (7.27%). Among locations, the highest prevalence was determined in the Tillo district (10.34%). As a result of the research, Theileria lestoquardi was not found in either sheep or goats. Conclusion This research confirmed the presence of T. ovis in sheep and goats in Siirt province, but T. lestoquardi was not detected. In future studies, a more detailed investigation of the presence of vector ticks and the development of regional control strategies is recommended. According to the analysis results, the prevalence of T. ovis was found to be 5.43% in sheep, 4.57% in goats and 5% in total. Theileria lestoquardi was not found in either sheep or goats.

The establishment of good experimental models for Theileria sp. infection is important for theileriosis research. Routinely, infection of ticks is accomplished by feeding on parasite-infected animals (sheep, cows and horses), which raises practical and ethical problems, driving the search for alternative methods of tick infection. Artificial tick feeding systems are based mainly on rearing ticks on host-derived or hand-made artificial membranes. We developed a modified feeding assay for infecting nymphal stages of Hyalomma anatolicum ticks with Theileria lestoquardi, a highly pathogenic parasite of sheep. We compared two different membranes: an artificial silicone membrane and a natural alternative using mouse skin. We observed high attachment rates with mouse skin, whereas in vitro feeding of H. anatolicum nymphs on silicone membranes was unsuccessful. We could infect H. anatolicum nymphs with T. lestoquardi and the emerging adult ticks transmitted infective parasites to sheep. In contrast, similar infections with Rhipicephalus bursa, a representative tick with short mouth-parts that was proposed as a vector for T. lestoquardi, appeared not to be a competent vector tick species. This is the first report of an experimentally controlled infection of H. anatolicum with T. lestoquardi and opens avenues to explore tick-parasite dynamics in detail.

Caprine theileriosis is a major production problem in regions of the world that rely on goats as a major source of milk, meat, and other means of economic income. Theileria ovis and Theileria lestoquardi are responsible for caprine theileriosis in Pakistan. The present study examined the prevalence of Theileria spp. infection using polymerase chain reaction (PCR) and light microscopy of blood collected from goats from Multan, Pakistan. In addition, the prevalence and identity of the genus of ticks feeding on these goats was determined on specimens collected at the time of blood sampling. The current project hypothesized that Theileria spp. prevalence would be higher in goats infested with ticks than goats without tick infestation. Four hundred and sixty-three blood samples from goats were analyzed, and the prevalence of infection was 16.0% (95% confidence interval [CI] = ±5.96) 74 of 463 by PCR and 5.4% (95% CI = ±7.79) 25 of 463 by microscopic examination. Thirty-six (48.6%, 95% CI = ±4.96) and 30 (40.5%, 95% CI = ±7.10) of 74 samples were positive by PCR for T. ovis and T. lestoquardi, respectively. Eight samples (10.0%, 95% CI = ±9.61) had mixed infections of these Theileria species. Infection was observed significantly (P < 0.05) more often in male 22.8%, 95% CI = ±3.85 (23/101) than in female 14%, 95% CI = ±2.36 (51/362) goats. No statistical (P > 0.05) difference in prevalence was present among the three age groups of ≤1 yr (12.6%, 95% CI = ±6.70), 1–4 yr (16.2%, 95% CI = ±8.24), and ≥4 yr (17.7%, 95% CI = ±11.30) goats examined.Two hundred and one (43.4%, 95% CI = ±7.45) goats were infested with ticks, Rhipicephalus spp. and Haemaphysalis spp., which are capable of transmitting Theileria spp.Tick infestation was found to be a significant (P < 0.05) risk factor for infection. Prevalence of Theileria infection in goats was significantly higher (P < 0.05) in the summer compared with the other three seasons. Data from this study support our hypothesis and demonstrate that both T. ovis and T. lestoquardi are highly prevalent in goats from Multan, Pakistan.

Background Epidemiological surveys in Oman have revealed a high prevalence of the co-occurrence of the pathogenic Theileria lestoquardi  and the non-pathogenic  Theileria ovis among sheep in the Barka region, Oman. Our most recent data illustrated an interaction and reduced mortality risk in animals co-infected with T. lestoquardi and T. ovis , suggesting that the latter confers protection against pathogenicity of T. lestoquardi . The present study extends the above findings and examines disease outcomes; clinical markers, hematological parameters, and parasite density in mixed and single T. lestoquardi infections. Methods A total of 390 blood samples were collected from 16 sheep pens located in Barka, Oman between July and November 2019. Theileria spp. were detected and quantified using qPCR assay targeting 18S rRNA , and the extent of genetic diversity was estimated by a panel of T. lestoquardi specific micro- and mini-satellites. The association of some disease markers with the presence of Theileria spp. and genetic diversity was tested. Results Theileria spp. were detected in 75 (19.2%) sheep; of these 65 (86.7%) had mixed infections ( T. lestoquardi plus T. ovis ), 8 (10.6%) were infected with T. lestoquardi alone, and 2 (2.7%) with only T. ovis . Exotic breeds had a higher risk for Theileria spp. infection. The density ( 18S rRNA gene copies) of both parasites was higher in single infection against mixed infection, and there was a relatively lower density of T. lestoquardi in mixed infections. However, there was no difference in hematological indices between single T. lestoquardi and mixed infections. High genetic diversity was observed among T. lestoquardi in Barka, with no differences of T. lestoquardi in single and mixed infections. The extent of diversity seen in Barka was higher ( He  = 0.772) than that reported in Oman in 2019 ( He  = 0.582), with distinct T. lestoquardi genotypes. Conclusion The lower density of T. lestoquardi as mixed infection with T. ovis compared to single infection supports the hypothesis that T. ovis confers protection against lethal T. lestoquardi infection. However, there were no differences in disease correlations (clinical markers, hematological parameters, and density of parasites) or the extent of diversity of T. lestoquardi between the two types of infection. The presence of distinct T. lestoquardi genotypes in Barka, compared to that reported earlier in Oman, likely reflects movement of carrier animals and highlights the need for further analysis of the parasite populations to inform novel approaches for controlling malignant ovine theileriosis. Graphical Abstract