Analysis of virulence factors in Salmonella speces

根据已报道的序列设计特异性的沙门氏菌肠毒素基因寡核苷酸引物（stn 101和stn 111），用于临床和食品分离沙门氏菌的聚合酶链反应（PCR）检测。采用不同菌株作为对照，包括肠道细菌。所有沙门氏菌（567株，58个血清型）的PCR结果均为阳性。另一方面，其他细菌属（30个不同种的224株）对这些特异性引物没有产生和PCR产物。PCR系统检测限为每克粪便和肉糜样品1个细菌细胞，分别采用胰酶豆汤或沙门氏菌富集肉汤进行富集。结果表明，该PCR系统在公共卫生领域具有实际应用价值。

The specific oligonucleotide primers for Salmonella enerotoxin gene (stn 101 and stn 111) were designed according to the reported sequences for polymerase chain reaction (PCR) method to examine various strains of Salmonella isolated from clinical specimens and food samples. As the control, different bacterial strains including enteric bacteria were used. All of the Salmonella strains (567 strains with 58 serovar) showed positive results for the expected PCR. On the other hand, the other bacterial genera (224 strains of 30 different species) did not yield and PCR product for these specific primers.The detection limit of the PCR system was one bacterial cell per one gram of fecal and minced-meat samples using enrichment procedure by Trypticase soy broth or Salmonella enrichment broth, respectively. We concluded that this PCR system is useful for the practical application in the field of the public health.