Genus-specific detection of salmonellae in equine feces by use of the polymerase chain reaction.

Members of the genus Salmonella were identified in feces from horses, using the polymerase chain reaction (PCR) and genus-specific oligonucleotide primers. Feces from healthy horses were determined to be culture-negative for Salmonella spp. Fecal samples were inoculated with known numbers of colony-forming units (CFU) of S anatum, S derby, S enteritidis, S heidelberg, S newport, and S typhimurium. The DNA was extracted from fecal samples and amplified by PCR, using genus-specific primers. Sensitivity of the assay extended to 10(3) CFU of Salmonella sp/g of feces; sensitivity of microbiologic culture with enrichment extended to 10(2) CFU of Salmonella sp/g of feces. Feces that were not inoculated with Salmonella spp were negative by the PCR. Detection of Salmonellae in feces was possible, using the PCR, within 10 to 12 hours from the time of submission of samples.