猪源肠球菌明胶液化表型与5种毒力基因的检测分析  

Detection and analysis of gelatin liquefaction phenotypes and five virulence genes of Enterococcus isolated from swine

作　　者：李岱霞 朱娜[1] 蒋逸凡 任杰 黎满香[1] LI Dai-xia;ZHU Na;JIANG Yi-fan;REN Jie;LI Man-xiang(College of Veterinary Medicine,Hunan Agricultural University,Changsha 410128,China)

机构地区：[1]湖南农业大学动物医学院

出　　处：《中国预防兽医学报》2019年第4期361-365,共5页Chinese Journal of Preventive Veterinary Medicine

基　　金：湖南省科技计划项目(2015NK3017)

摘　　要：为探究明胶液化的表型与其5种毒力基因在不同来源和不同种属猪肠球菌中的分布差异,本研究采用PCR方法以及明胶液化试验对湖南分离的375株肠球菌携带的明胶酶基因(gelE)、调控gelE表达的毒力基因反应调节子基因(fsrA)、前肽加工蛋白基因(fsrB)、组氨酸激酶基因(fsrC)、丝氨酸蛋白酶基因(sprE)共5种毒力基因的分布情况以及液化明胶现象进行检测。结果显示,共263株肠球菌检测到了毒力基因,检出率分别为41.3%(gelE)、45.9%(fsrA)、50.9%(fsrB)、48.8%(fsrC)、48.8%(sprE)。能够同时检测到5种毒力基因的菌株共有110株,其中粪肠球菌106株,且该5种毒力基因在106株粪肠球菌中的检出率均为最高,另外4株为其它肠球菌。在明胶液化试验中,共有155株肠球菌检测到gelE基因,但只有106株能够发生明胶液化现象,且这些菌株正是能够同时检测到5种毒力基因的106株粪肠球菌,而另外4株能够同时检测到5种毒力基因的其它肠球菌却不能发生明胶液化现象。结果表明,粪肠球菌是肠球菌中主要携带毒力基因的菌属,与屎肠球菌以及其它肠球菌相比,更容易出现液化明胶的表型,这可能与粪肠球菌中某些明胶液化的机制有关,且除gelE外,参与gelE表达的几种毒力基因对该表型的出现也具有一定的影响。In order to explore the distribution of gelatin liquefaction phenotypes and five virulence genes in the Enterococcus isolated from different sources and different breeds of swine,five virulence genes and gelatin liquefaction reaction were detected and examined among 375 Enterococcus isolated from swine in Hunan province by PCR and gelatin liquefaction tests.The results showed that virulence genes were detected in 263 Enterococcus isolates and the detection rates were 41.3%for gelE(gelatinase gene),45.9%for fsrA(esponse regulator gene),50.9%for fsrB(propeptide processing protein gene),48.8%for fsrC(histidine kinase gene),and 48.8%for sprE(serine protease gene),respectively.E.faecalis possessed the highest detection rate of all five kinds of virulence genes among all tested Enterococcuse.A total of 110 isolates of Enterococcus was found carrying all five kinds of virulence genes,106 of which were E.faecalis,the rest of other 4 isolates were other Enterococci.There were 155 isolates of Enterococcus were detected to carry gelE by PCR,but only 106 of which were able to liquify gelatin according to the result of gelatin liquification test,and these 106 isolates were exactly the same 106 isolates of E.faecalis which carried all of the five kinds of virulence genes.Meanwhile,the other 4 isolates of other Enterococci with all five kinds of virulence genes were not capable of liquifying gelatin.To conclude,E.faecalis is the main virulence gene carrier among all kinds of the tested Enterococcus and the phenotype which owns the ability to liquify gelatin occurs more frequently in E.faecalis,compared with E.faecium and other Enterococci.This study may be relevant to some mechanisms concerning gelatin liquefaction in Enterococcus faecalis,and expect for gelE,the other virulence genes involved in gelE's expression must contribute to this phenotype.

关 键 词：肠球菌 粪肠球菌 群体感应系统 毒力基因 明胶分解 

分 类 号：S852.61[农业科学—基础兽医学]