Phylogenetic analysis and molecular characterization of field isolates of Anaplasma spp. from cattle in India

Abstract

In India, the economic losses incurred due to ticks and tick-borne diseases are estimated around 498.7 million US dollars. Among these diseases, anaplasmosis causes significant mortality and morbidity in animals, leading to significant production losses. However, only scant information on the molecular characterization, phylogenetic and matrix analysis of Anaplasma spp in cattle is available. Therefore, the objective of the present study was to perform phylogenetic and molecular characterization of field isolates of Anaplasma spp. infecting dairy animals in Uttar Pradesh, India. Blood samples from 200 cattle showing the clinical signs of bovine anaplasmosis were collected from the western part of Uttar Pradesh, India. To detect Anaplasma spp., screening of blood smears and molecular confirmation by PCR was performed. The molecular characterization was done by sequencing the 16S rRNA gene and its bioinformatic analysis using MEGA version X. On the basis of microscopic examination, Anaplasma spp. were detected in 106 (53%) samples, while the 16S rRNA gene-based polymerase chain reactions revealed positive results in 176 (88%). The sequencing of the 16S rRNA gene and the bioinformatic analysis of sequences revealed the existence of three different populations of Anaplasma spp., viz., Anaplasma marginale and two other Anaplasma spp. genetically related to Anaplasma capra and Anaplasma ovis, circulating in the blood of infected cattle. All the field isolates of A. marginale and A. ovis from Uttar Pradesh, India, were clustered in a single clade with others isolated from Iran, Brazil, Thailand and Israel, while A. capra isolates from India, established in same clade of A. capra, have been reported from Japan, China and South Korea. To the best of the authors’ knowledge, this is the first report of Anaplasma capra and Anaplasma ovis from bovine in India, and indicates the potential of cattle to serve as reservoirs of these pathogens, leading to the requirement for further studies of these emerging zoonotic pathogens and their possible zoonotic potential.