Molecular Detection of Brucella spp. in Ruminant Herds in Greece

Abstract

Brucellosis is a worldwide distributed infectious disease. Ruminants and other animal species (swine, dogs, equids etc), as well as wild mammals can be affected. The disease can be transmitted to humans through the food chain or by direct contact with infected animals. Because of the relatively high economic burden due to abortions within a herd, significant efforts have been employed and hence the disease in most European countries has been eradicated. Accordingly, Greece applies both control and eradication programs concerning small ruminants (sheep and goats) and bovines depending on the geographical area. Current challenges in the standard antibody-based laboratory methods used for Brucella detection are the failure to differentiate antibodies against the wild strain from the ones against the vaccine strain Rev1 and antibodies against B. melitensis from those against B. abortus. The aim of the study was to modify previously published protocols based on PCR analysis and to generate a new diagnostic tool able to confirm the doubtful results delivered from serology and mainly to do easier and more reliable the detection of Brucella. For this reason, 264 samples derived from 191 ruminants of the farm and divided in 2 groups (male/female) were examined with a modified DNA extraction and PCR protocol. Molecular examination revealed the presence of Brucella spp. in 39 out of 264 samples (derived from 30 animals). In addition, Brucella spp. was detected in infected tissues derived from testicles, inguinal lymph nodes, fetal liver and fetal stomach content molecular detection of than other infected tissues.