Predominant Prevalence of Brucella abortus biovar-4 in Small Ruminants in Tamilnadu

Brucellosis being a global zoonotic disease and animal health problem most of the studies has been oriented towards bovine than small ruminants. Hence the present study is conducted to identify the biotype of predominant Brucella spp. in small ruminants for defined control and eradication strategies. The study was carried out by random collection of the vaginal swab, milk, blood samples from the 315 sheep and goat. The samples were subjected for isolation and identification by biochemical tests followed by bio-typing with mono-specific A and M anti-sera and confirmed by multiplex AMOS PCR. Out of 195 goats and 120 sheep, 20 (10.25%) goats and 22 (18.33%) sheep were positive by culture with overall prevalence 13.33%. Fifteen isolates from goats and 20 isolates from sheep were typed as B. abortus biovars-4, 3 isolates from goats were typed as B. melitensis biovars-2, and 2 isolates from goats were positive for B. ovis and also 2 isolates from sheep were un-typed biovars. The confirmation was carried out by using multiplex AMOS-PCR. The study revealed that the B. abortus biovar-4 was predominant in small ruminants. Since most of the control strategies are directed towards bovine brucellosis this study indicates that small ruminant brucellosis control strategy must be redefined since it is the potential source of zoonosis.