Theileria and Babesia infection in cattle - First molecular survey in Kazakhstan.

ABSTRACT

Central Asia, including Kazakhstan, is an endemic area of Theileria and Babesia infections in cattle. Current data on the geographic distribution, prevalence, and genetic diversity of these pathogens in vertebrate hosts are lacking in Kazakhstan. The present study aimed to fill this gap, using molecular techniques for the first time. A cross-sectional survey was performed on adult cattle from 40 villages in nine administrative districts of the provinces of Turkistan and Zhambyl, southern Kazakhstan, in summer 2020. A total of 766 blood samples were screened for Theileria annulata (enolase gene), Theileria orientalis (major piroplasm surface protein gene, MPSP) and Babesia spp. (18 S ribosomal RNA gene) using polymerase chain reaction. The genetic variability of Theileria spp. was assessed by sequencing one amplicon from each village. All Babesia spp. positive amplicons were sequenced to identify the species involved. The overall prevalence of infections with T. annulata, T. orientalis and Babesia spp. was 83.0% (40 villages positive), 33.3% (31 villages) and 13.5% (36 villages), respectively. Co-infections with two or three species were present in 48.9% of all positive cattle. Theileria annulata showing a high polymorphism of the enolase gene occurred with similar frequency in both provinces. Theileria orientalis was detected for the first time in Kazakhstan being significantly (P = 0.014) more prevalent in Zhambyl than in Turkistan. Fourteen genotypes of T. orientalis were identified; two belonged to the moderately virulent MPSP-type 1 ('Chitose') and the others to MPSP-type 3 ('Buffeli') which is considered avirulent. The prevalence of Babesia infection was significantly (P < 0.000) higher in Turkistan than in Zhambyl. An unequivocal identification of the species involved was possible in 127 sequenced samples Babesia occultans was the most common species, followed by Babesia bigemina and Babesia major, the latter being the first record in the country. The results show that Theileria and Babesia infections in cattle are widespread and occur with remarkably high prevalence in the southern Kazakhstan. They also provide first data on the genetic diversity of the species involved.