Detection and genotypes of piroplasms affecting ruminants in the New Valley Governorate, Egypt.

Abstract

BACKGROUND: Piroplasms, which include the two genera Babesia and Theileria, are protozoan parasites transmitted by Ixodid ticks that infect the erythrocytes of vertebrate hosts, including humans, domestic animals, and wild animals. The present study examined how common and distinct genotypes of the above tick-borne parasites are in the New Valley Governorate in Egypt, which covers 440,098 km². MATERIALS AND METHODS: It was conducted on 321 randomly selected live animals (89 cattle, 55 goats, and 177 sheep), regardless of sex and age. Of these, 203 were found to be infested with ticks, and 269 ticks were collected to determine the prevalent tick species microscopically. Giemsa-stained blood films and conventional polymerase chain reaction (cPCR) assays targeted the Babesia 18 S rRNA gene for Babesia species and the T. annulata tams1 gene for T. annulata, used for the detection of piroplasms. Then, we sequenced the eleven highest positivity-generated bands (6 for Babesia and 5 for T. annulata), performed a phylogenetic analysis on them, and submitted their data to the GenBank database. RESULTS: The infestation rate was 63.2%, and three tick species were identified. Rhipicephalus annulatus was the most common tick species on cattle (67.7%), followed by Hyalomma excavatum (17.8%) and Rhipicephalus sanguineus (14.5%), which preferred sheep and goats. Babesia has been detected in 22.12%, T. annulata in 16.5%, and mixed infections in 7.79% of samples under a microscope. The percentages increased by PCR to 32.7% for Babesia and 22.1% for T. annulata, with mixed infections in 13.4%. Molecular analyses confirmed four Babesia subspecies introduced in the GenBank database under accession numbers PP892244, PP892245 (as B. bigemina), PP892249 (as B. motasi), PP892246 (as B. bovis), and PP892247, PP892248 (as B. ovis). Their identities to GenBank references range from 71.3% to 100% with divergence from 0.0 to 24. Whereas the five submitted isolates of T. annulata were distributed into two clades within a cluster (one contained PP894805, PP894806, and PP894807), and the other contained PP894808 and PP894809. Their identities range from 98.4 to 100%, with a divergence of 0.0 to 1.6 between each other and from 0.0 to 8.0 from others in GenBank. CONCLUSIONS: This study reveals that T. annulata were genetically identical to the other isolates from other continents with no significant genotypic differences between them, contrary to the Babesia spp., which were found to belong to four different subspecies and scattered across different clades.