DETECTION OF Anaplasma marginale INFECTION IN A DAIRY CATTLE FARM BY STAINED BLOOD SMEAR EXAMINATION AND NESTED POLYMERASE CHAIN REACTION

Abstract

Bovine anaplasmosis is caused by Anaplasma marginale. The study was con­ducted to detect the presence of A. marginale in a dairy cattle farm using stained blood smear examination (SBSE) and nested polymerase chain reaction (nPCR). Blood samples from 281 dairy cattle were collected and subjected to SBSE and nPCR. Based on the results, 73.7% and 67.3% A. marginale-infected cattle were detected using SBSE and nPCR, respectively. The higher detection rate of SBSE was attributed to false positives. Detection of infection rate using SBSE was significantly higher than nPCR. Detection of A. marginale infection using SBSE and nPCR showed a 77% agreement with a kappa coefficient of 0.44. The results of the study would help in assessing the infection status of the herd and help establish diagnostic protocols for the detection of A. marginale specific for acute and carrier state of infection.