INCIDENCE AND PHYLOGENETIC STUDY OF ANAPLASMA MARGINALE IN CATTLE OF CHHATTISGARH PLAINS

Anaplasma marginale, the most common aetiological agent of bovine anaplasmosis, is a highly pathogenic, intra-erythrocytic rickettsia. It is one of the causative agents of economic losses to livestock farming, both in tropical and in temperate regions. The present study was aimed at studying the incidence and molecular characterization of A. marginale in cattle of Chhattisgarh plains by Polymerase Chain Reaction (PCR). Microscopic investigation of Giemsa stained peripheral blood smears of 150 apparently healthy and clinically ill cattle revealed A. marginale organisms in 11.33% (17/150) animals. For molecular incidence studies, major surface protein-1β (msp1β) of A. marginale was selected as the target gene for amplification by PCR. The DNA samples of these cattle when subjected to conventional PCR resulted in amplicon of 265 bp in 59.33% (89/150) animals. The PCR results of the incidence of A. marginale were significantly higher (p<0.001) as compared to microscopy. Phylogenetic study of the two isolates collected locally from Chhattisgarh showed that these two isolates clustered in two clades. Considering that the cattle population of 9.983 million in Chhattisgarh is targeted for productivity improvement but faces the risk of anaplasmosis, it is essential to analyze incidence trends and develop appropriate control measures to manage anaplasmosis in livestock effectively.