Prevalence of enterotoxin gene (stn) among different serovars of Salmonella

The prevalence of Salmonella enterotoxin (stn) gene among different Salmonella serovars by using polymerase chain reaction (PCR) and its status of expression on the Chinese hamster ovary (CHO) cells were investigated. All the 26 strains of Salmonella enterica such as serovars Typhimurium, Enteritidis, Dublin, Typhi, Newport, Weltevreden, Gallinarum, etc. investigated in this study were found to carry stn gene as examined by the PCR and gene probe. However, only a limited number of stn positive strains (34.6%) were found to express phenotypically the Salmonella enterotoxin (Stn) as tested by the CHO cell assay. The strains of S. bongori were found to be negative for Stn production both genotypically and phenotypically.