An insight into misidentification of the small-subunit ribosomal RNA (18S rRNA) gene sequences of Theileria spp. as Theileria annulata

Molecular detection of tick-borne piroplasmids in camel blood samples collected from Cairo and Giza governorates, Egypt

Piroplasmosis, a tick-borne disease affecting livestock, including camels, is caused by intracellular apicomplexan parasites belonging to the order Piroplasmida. Despite its importance, there's limited research on piroplasmosis among Egyptian camels. This study aimed to fill this gap by investigating tick-borne piroplasmids in camels from Cairo and Giza Governorates. Out of 181 blood samples collected between October 2021 and March 2022 from apparently healthy one-humped camels (Camelus dromedarius), PCR assays revealed a 41.4 % infection rate with various piroplasmids. Detected species included B. bovis (17.7 %), B. bigemina (12.2 %), B. caballi (8.3 %), B. naoakii (11.6 %), B. microti (1.7 %), T. equi (4.4 %), and Theileria spp. (28.7 %). Phylogenetic analysis revealed the first detection of T. equi genotype E in Egypt and identified a novel B. caballi genotype. Additionally, B. microti isolates were identified as the US-type. These findings shed lights on piroplasmosis among Egyptian camels, and provide valuable information for devising effective control strategies, especially B. microti, a pathogen with potential human health risks.

Molecular Epidemiology and Phylogeny of Theileria ovis and Theileria lestoquardi in Sheep and Goats from Southern Punjab, Pakistan

Background: Theileria spp. are responsible for ovine and caprine theileriosis, leading to significant morbidity and mortality in small ruminants. The present study aims to investigate Theileria spp. infections in small ruminants from Southern Punjab in Pakistan, and genetic characterize revealed Theileria spp. isolates. Methods: A total of 93 sheep and 107 goats were sampled between May and August 2022. Blood smears were examined microscopically, and PCR amplification targeting the 18S rRNA gene was performed to detect Theileria spp. Additionally, specific PCR assays targeting 18S rRNA and ms1 partial sequences were used to identify Theileria ovis and T. lestoquardi, respectively.  Results: The prevalence of Theileria spp. was significantly higher using PCR (13.5%) compared to microscopic screening (5%). Sheep showed a higher prevalence rate (19.4%) compared to goats (8.4%) (p = 0.024). Young sheep aged ≤ 1 year were more commonly infected with Theileria spp. (41%) compared to older sheep (p = 0.006). The prevalence of Theileria spp. was higher in sheep-only herds (37.3%) compared to goat-only herds (18%) or mixed-species herds (8.1%) (p = 0.015). The prevalence rates of T. ovis and T. lestoquardi were 9% and 2.5%, respectively, with four animals (2 goats and 2 sheep) showing co-infection. Phylogenetic analysis revealed that our T. ovis 18S rRNA sequence clustered with previously reported sequences from sheep in Turkey, China, Spain, and goats in Tanzania. The obtained T. lestoquardi ms1 partial sequence formed a distinct cluster from other T. lestoquardi isolates in Pakistan and neighboring countries.  Conclusion: Theileria spp. co-circulation in Pakistani small ruminants, particularly the presence of T. ovis and T. lestoquardi, highlights the need for attention from animal health decision-makers due to their financial and health impacts.

Population genetic characterization of Theileria annulata based on the cytochrome b gene, with genetic insights into buparvaquone susceptibility in Haryana (India)

The present investigation was aimed at population genetic characterization of Theileria annulata on the basis of the cytochrome b (cyt b) gene along with the evaluation of status of buparvaquone resistance in Haryana (India). The sequences originating from China, Egypt, India, Iran, Iraq, Tunisia, Turkey and Sudan were included in the analysis. The maximum likelihood tree based on the Tamura-Nei (TN93+G) model placed all the sequences of T. annulata into a single clade. The median-joining haplotype network exemplified geographical clustering between T. annulata haplotypes originating from each country. Only five haplotypes (7.81 %) were shared between any two countries, while the remaining 59 haplotypes (92.19 %) were singleton and unique to one country. The values of pairwise genetic distance (FST) between all the populations indicated huge genetic differentiation (> 0.25) between different T. annulata populations, barring the FST value between Iraq and Turkey (0.14454) which suggested a moderate differentiation. Contrary to the FST index, the values of gene flow (Nm) between T. annulata populations were very low. The neutrality indices and mismatch distributions indicated a population expansion in the Indian T. annulata population. Furthermore, the secondary structure and homology modeling of the partial cyt b protein is also reported. The molecular analysis of newly generated sequences for buparvaquone resistance revealed that all the isolates were susceptible to buparvaquone treatment. However, two novel mutations at positions V203I and V219I in between the Q01 and Q02 drug-binding regions of the cyt b gene were observed for the first time.

Phylogenetic analysis and haplotype networking of Hepatozoon felis infecting wild animals in Gir National Park, Gujarat, India

The present study was aimed to determine the phylogenetic relationship, haplotype network, and demographic dynamics of H. felis infecting the endangered Asiatic lions in Gir National Park, Gujarat, India, on the basis of partial 18S rRNA gene. The phylogenetic analysis based on the partial 18S rRNA gene sequences of H. felis exhibited the presence of two distinct genotypes of H. felis (HfG1 and HfG2) infecting the Indian wild felids, viz., the Asiatic lion, Royal Bengal tiger, and Indian leopard. The HfG1 and HfG2 genotypes exhibited 97.6-100% and 99.7-100%, and 96.9-98.7% nucleotide identity within and between themselves, respectively. The HfG1 genotype exhibited a higher genetic diversity as compared to HfG2. A total of 22 molecular signatures were identified in the 18S rRNA gene between these genotypes. Further, analysis of a total 67 sequences of H. felis (13 different host species from 13 countries of Africa, South America, Asia, and Europe) that were downloaded from GenBankTM, generated 30 haplotypes. Among all the haplotypes, Hap_17 (h=12) was the most frequent followed by Hap_12 (h=09) and Hap_4 (h=05). Out of 13 location-wise populations, India (h=12) shared the highest number of haplotypes followed by Japan (h=08), and the least number of haplotypes were found in Hungary (h=02). Population dynamics study involving neutrality tests and mismatch distribution, and genetic differentiation indices, revealed the presence of phylogeographic population structure and a constant population size indicating a uniform gene flow among the populations worldwide. In conclusion, a high genetic diversity along with the presence of two distinct genotypes of H. felis were observed on the basis of 18S rRNA gene sequence analysis.