中国部分食品中肠炎沙门菌分离株的PFGE分子型别分析研究

Study on Molecular Type of Salmonella enteritidis Strains Isolated from Foods in China

目的研究中国食品中肠炎沙门菌分离株的分子谱别。方法用脉冲场凝胶电泳分型技术对从中国11个省市食品中分离的51株肠炎沙门菌进行分子分型。结果肠炎沙门菌经2种内切酶XbaⅠ、SpeⅠ处理后,均分为11个不同的带型。两种内切酶的分型结果不相同,但其中有部分交叉。2种内切酶的PFGE分型都有2个主要的带型,分别涵盖了分离株的70%,并在两型之间有部分兼容性。通过双酶系统的双重分型,还可以将其中的型别进一步区分为亚型。在各地区之间菌株的型别分布无明显规律,在各种食品之间菌株的型别分布,SpeⅠ酶切后的结果更有规律。分离自羊肉中的4株菌经XbaⅠ、SpeⅠ酶切表现为同一PFGE型别,在XbaⅠ分型结果中为XF型,在SpeⅠ分型结果中为SE型,揭示了一定的亲缘关系。结论脉冲场凝胶电泳分型技术是肠炎沙门菌分子分型的有效手段。

Objective To research the molecular type of Salmonella enteritidis strains isolated from foods in China.Method 51 strains of Salmonella enteritidis which were isolated from foods in 11 provinces were identified by pulsed field gel electrophoresis. Results 11 distinct DNA fragment profiles,PFGE types A to K,were observed by 2 kinds of enzyme digestion（XbaⅠ、SpeⅠ）,respectively.Between 2 kinds of enzyme system,the results were not the same,but there were some intercrossed.There were 2 dominant patterns in 2 kinds of restricted enzyme system occupying 70% of all isolates,respectively.The pattern type XF and XK of the XbaⅠ profile could be further subtyped by SpeⅠ profile.There was no correlation between the strain profiles and the isolated regions.However,4 strains isolated from the mutton were the same molecular type in 2 kinds of restricted enzyme systems,showing certain epidemiological trend.Conclusion PFGE could be a effective method for determining the molecular epidemiological relationship among the different Salmonella enteritidis strains.