2008-2012年上海市肠炎沙门氏菌分离株毒力基因筛查与ERIC-PCR分型

Screening of Virulence Genes and ERIC-PCR Sub-typing for Salmonella Enteritidis Isolates in Shanghai during 2008—2012

采集上海地区2008—2012年来自临床病人和市售食品的肠炎沙门氏菌分离株90株;采用聚合酶链式反应(polymerase chain reaction,PCR)方法,对存在于毒力岛SPI和毒力质粒上的9种常见毒力基因携带情况进行了调查;并采用本实验优化的肠杆菌基因间保守重复序列-聚合酶链式反应(enterobacterial repetitive intergenic consensus-PCR,ERIC-PCR)方法对这些分离株进行亚分型。结果显示:毒力基因inv H、sop E、sug R的携带率为100.0%(90/90),iac P、avr A、rhu M、prg K均为98.9%(89/90),而spv B、spv C分别为85.6%(77/90)和78.9%(71/90)。优化的ERIC-PCR体系能够较好地区分8种主要沙门氏菌血清型,共17株菌,辛普森指数(D值)为0.970 6。然而,90株肠炎沙门氏菌分离株却具有一致的ERIC-PCR指纹图谱。在所调查分离株中,毒力基因的携带率较高,尤其是inv H、sop E和sug R,对人类健康存在较大威胁;ERIC-PCR虽然可用于区分沙门氏菌不同血清型,但对肠炎沙门氏菌的分型效果不佳。

In this study, a total of 90 isolates of Salmonella Enteritidis, including clinical and foodbome isolates, were collected from different areas of Shanghai during 2008 to 2012. Polymerase chain reaction （PCR） was used to investigate the carrying rates of 9 common virulence genes not only in SPIs （SPI-I and SPI-3） but also in virulence plasmid. In addition, an optimized enterobacterial repetitive intergenic consensus （ERIC）-PCR was applied to subtype these isolates. The PCR results of 90 isolates showed that the carrying rate was 100.0% for virulence genes invH, sopE and sugR, and 98.9% for iacP, avrA, prgK and rhuM, while the carrying rate of spvB and spvC was 85.6% and 78.9% respectively. Seventeen strains belonging to eight different Salmonella serovars were clearly differentiated by ERIC-PCR, with the Simpson＇s Diversity Index up to 0.970 6. However, the ERIC-PCR profiles of 90 Salmonella Enteritidis isolates showed no difference. In conclusion, the carrying of these virulence genes, especially sugR, invH and sopE, is very common among these isolates, demonstrating that they pose a potential threat to human health and that ERIC-PCR can be applied to the molecular classification of different Salmonella serovars, but not for Salmonella Enteritidis.