Identification and detection of Salmonella strains isolated from chicken carcasses and environmental sources in Dourados, MS, Brazil

The application of methodologies that can rapidly and precisely identify Salmonella in both foods and water samples is of great interest to public health. Salmonella sp. was isolated from chicken carcasses and water samples from aquaculture tanks using both traditional culture methods and bacteriological analyses. DNAs from these isolates were extracted and Multiplex Polymerase Chain Reactions (mPCR) were performed using primers forinvA, fliC and sefA genes to detect the genus Salmonella and to differentiate the serovars Typhimurium and Enteritidis respectively. The results of these bacteriological analyses indicated that 94% of the chicken carcass samples were contaminated by 46 Salmonellasp. strains. mPCR analyses indicated that 43 of these strains belonged to the genusSalmonella. Among these isolates, 32% were genotyped as Salmonella enteritidis while none were identified as Salmonella typhimurium. Bacteriological analyses of the aquaculture tank water samples indicated that 73% were contaminated, and 11Salmonella sp. strains were isolated; mPCR analyses indicated that all of them belonged to the genus Salmonella, but no S. enteritidis and S. typhimurium serovars were identified. Multiplex PCR was found to be a very sensitive test that allowed rapid and reliable identification of these bacteria.   Key words: Salmonella enteritidis, Salmonella typhimurium, bacteriological analyses, multiplex polymerase chain reactions, aquaculture.