author(s)
B Subramanian, P Vijayalakshmi, S Venkatesa Perumal and D Selvi

abstract
Polymerase chain reaction (PCR) assay is considered the “gold standard” for detection of persistently infected cattle with Anaplasma marginale infection. Major surface protein 4 gene is a stable marker for the genetic classification of A. marginale strains. The present study was conducted for the molecular diagnosis of anaplasmosis in cattle infected with Anaplasma marginale in the Puducherry state. Each blood sample was subjected for Deoxyribonucleic Acid (DNA) extraction as per HiPurA^TM SPP Blood DNA Isolation Kit (Himedia^®). On Basic Local Alignment Search Tool analysis, the sequence showed 100% identity with the sequence of A. marginale and GenBank accession number: MG720555. Out of 73 anaplasmosis suspected samples, 15 were found to be positive for A. marginale by PCR. PCR was found highly sensitive and best diagnostic tool in the diagnosis of anaplasmosis, when compared to blood smear examination.