Contamination of bovine, sheep and goat meat with Brucella spp.

A study was conducted in order to evaluate the contamination by Brucella spp. of meat from animals slaughtered because they had resulted positive for brucellosis at some time during their life. After slaughter and before delivery to market outlets, swab samples were taken from 307 carcasses of infected animals: 40 cattle, 60 sheep and 207 goats. The swabs were subsequently analysed by means of polymerase chain reaction (PCR) tests. In addition, bacteriological tests were carried out on the lymph nodes and internal organs of the same animals. Brucella spp. was detected by means of PCR in 25/307 carcasses (8%): 1 bovine (2.5%), 9 sheep (15%) and 15 goats (7.2%) and was isolated by means of a cultural method in 136/307 carcasses (44%). Moreover, additional analysis, performed on lymph nodes from the same carcasses that had proved positive by PCR, allowed highlighting type 3 Brucella abortus in the bovine carcass and type 3 Brucella melitensis in the sheep and goat carcasses. The study shows that cattle, sheep and goats meat of animals slaughtered because they had tested positive for brucellosis may be contaminated by Brucella spp. As this could constitute a real risk of transmission to both butchery personnel and consumers, the meat of animals infected by Brucella spp. should be analysed before being marketed. In this respect, PCR technique performed on swabs proved to be more useful, practical and faster than the traditional bacteriological method.