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

Global haplotype distribution of Babesia ovis inferred by 18S rRNA sequences; a phylogeographical systematic review

The genetic variability of apicomplexan parasite Babesia species is a principal strategy used by piroplasma to evade their hosts' immune responses. The purpose of this review was to evaluate our current knowledge on global haplotype distribution and phylogeography of Babesia ovis derived from sheep, goat, horse and ixodid (hard) ticks. Bibliographic English databases were searched from 2017 to 2023, identifying a total of 11 publications. The 18S ribosomal RNA (18S rRNA) sequences of B. ovis from Asia, Europe, and Africa were retrieved and subjected to estimate the genetic diversity and phylogenetic assessment. A haplotype network indicated a total of 29 haplotypes being classified into two distinct geographical haplogroups I and II including Nigeria and Uganda-derived B. ovis isolates. A moderately high level of genetic diversity was characterized in sheep/tick-derived B. ovis isolates originating from Iraq (Haplotype diversity: 0.781) and Turkey (Hd: 0.841). Based on the cladistic phylogenetic tree, two geographically different lineages of A and B were genetically differentiated except for Turkish isolates, indicating haplotype migration occurred between various geographical clades. In addition, the topology of UPGMA tree indicated that B. ovis population has a distinct clade compared to the rest clades of ovine babesiosis (B. crassa and B. motasi). The present results strengthen our knowledge to evaluate the evolutionary paradigms and transmission dynamics of B. ovis in different regions of the world; also it will provide groundwork for public health policy to control ovine babesiosis.

Clinical, hematological and molecular evaluation of piroplasma and Anaplasma infections in small ruminants and tick vectors from Kurdistan province, western Iran

Tick-borne haemoparasite infections are a major challenge in small ruminant (SR) production across tropical areas. The present study evaluated the prevalence of Theileria, Babesia and Anaplasma in SRs and their tick vectors and estimated the association between pathogen prevalence with clinical hematological findings among SR populations in Kurdistan province, western Iran. In total, 250 blood samples and 250 tick species (one per animal) were collected from SR populations, along with clinical and hematological examinations. Microscopy of blood smears and molecular analysis were performed to detect potential infection with Theileria, Babesia and Anaplasma. Moreover, haemoparasites were explored in the isolated ticks using semi-nested PCR. Based on microscopy, the prevalence of Theileria, Anaplasma and Babesia infections was 91.2%, 23.2% and 2.4%, respectively. Semi-nested PCR analysis of blood samples demonstrated 86.8%, 78.8% and 14% prevalence for T. ovis, A. ovis and B. ovis, respectively. Dermacentor marginatus and Rhipicephalus turanicus were predominant isolated tick vectors from SR, while D. marginatus was the most contaminated tick in all investigated counties. There were, also, a statistically significant association between the estimated molecular prevalence rates with semi-yellow conjunctiva (A. ovis), body temperature (T. ovis and A. ovis), heart rate (T. ovis and B. ovis), mean white blood cell count (T. ovis and A. ovis), mean red blood cell count (T. ovis and B. ovis), as well as mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration in all haemoparasite infections. Future studies are recommended to reveal the epidemiology of such infections in SRs in Iran.