A Study On The New Molecular Typing Method Detecting Strong Pathogenic Serotypes Of Salmonella Enterica

Salmonella are commen fooboune pathogens. According to the principle of classification and nomenclature recognized internationally, the genus Salmonella consists of only two species, Salmonella enterica and Salmonella bongori. The serotypes of Salmonella enterica is the most abundant in Salmonella genus, most of them are pathogen strains. The serotypes such as S. Enteritidis, S. Typhimurium,S.Typhi and S. Gallinarum are more serious pathogenicity. Currently, the detection of Salmonella enterica relies on the traditional culture method, which requires 5-7 days to obtain the test results. This is not conducive to the timely diagnosis and control of the disease spreading. Therefore, it is necessary to establish a rapid, accuracy and efficient method for the detection of Salmonella enterica and its serotypes.This study has designed primers and probes based on the commen gene sequences of Salmonella enterica and the specific sequence of S. Enteritidis, S. Typhimurium, S. Typhi and S. Gallinarum. Salmonella enterica can be detected at genus level, and S. Enteritidis, S. Typhimurium, S. Typhi and S. Gallinarum can also be determined at serotypes level by real-time PCR.The primers and probe designed for Salmonella enterica can detect 25 kinds of serotypes of Salmonella enterica (49 strains in all), while 11 strains of negetive control strains are negative; The primers and probe designed for S. Enteritidis can detect 15 strains of S. Enteritidis, while 34 strains of non-S. Enteritidis and 11 strains of negetive control are negative; The primers and probe designed for S. Typhimurium can detect 11 strains of S. Typhimurium, while 38 strains of non-S. Typhimurium and 11 strains of negetive control are negative; The primers and probe designed for S. Typhi can detect 31 strains of S. Typhi, while 110 strains of non-S. Typhi and 22 strains of negetive control are negative; The primers and probe designed for S. Gallinarum can detect 34 strains of S. Gallinarum, while 107 strains of non-S. Gallinarum and 22 strains of negetive control are negative. In addition, the detection of inoculated sample has demonstrated that the results from real-time multiplex PCR method are consistent with those from the traditional method.This study has established rapid real-time PCR methods for the detection of Salmonella enterica, S. Enteritidis, S. Typhimurium, S. Typhi and S. Gallinarum by TaqMan probe. This is a high specificity, user-friendly and standardized easily method, which could be applied in the industry of disease control and prevention or the field of food safety and inspection.