Molecular Detection of Brucella melitensis Associated Reproductive Failure in Native Sheep Flock: Potential Public Health Pathogen from Tropical Region of Tamil Nadu

Abstract

Brucellosis remains a global burden since the last century. In India, both animal and human brucella infections drastically increase every year. Outbreaks of 40 ewe’s abortion were investigated in native sheep’s from the tropical region of Tamil Nadu. Aborted maternal and fetal tissues were initially subjected to Stamps Modified Ziehl Neelsen (S-ZN) staining method. The DNA was extracted and screened for Brucella genome by Brucella cell surface salt extractable proteins (bcsp31) gene based PCR assay. Further, PCR positive samples were subjected for AMOS PCR for B. abortus, B. ovis, B. melitensis and B. suis identification and differentiation. S-ZN staining of aborted tissues revealed pink, coccobacilli organisms giving presumptive identification of Brucella sp. Molecular detection of brucellosis by bcsp31 gene based PCR in placental tissues and fetal abomasal contents of both the animals yielded a specific amplicon of 223 bp confirming it as Brucella genus infection. Molecular detection and differentiation by AMOS PCR revealed a specific amplicon of 731 bp indicating the involvement of B. meletensis infection in the native free-ranging sheep flock. It is a potent public health pathogen, highly essential to be monitored for the strategic control of brucellosis.