Molecular detection of Anaplasma spp. in blood and milk of dairy cattle in the Philippines

Abstract

Anaplasmosis has become a major concern in the cattle industry throughout the world due to its great economic impact.The causative agents, Anaplasma species, are primarily transmitted by ticks, occurring intracellularly within blood cells, with somespecies being zoonotic. In this study, the presence of Anaplasma spp. was investigated in the blood and milk of dairy cattle in thePhilippines. Blood and milk samples were collected from 98 dairy cattle from selected farms in five provinces in the southern part ofLuzon Island in the Philippines. After DNA extraction, a conventional PCR for the control gene actin was performed, followed by nestedPCR for Anaplasma spp. Selected amplicons were purified and subjected to sequence analysis. It was found that 97 (98.97%) bloodsamples and 6 (6.12%) milk samples were positive for Anaplasma. Sequence analysis revealed that the positive amplicons from milksamples and their corresponding blood samples shared a high identity (98%–100%) with reported Anaplasma marginale isolates. To theauthors’ knowledge, this study provides the first molecular evidence of the presence of A. marginale in milk from dairy cattle under fieldconditions in the Philippines.