猪源屎肠球菌 tetM 基因的检测

摘要

The susceptibilities of pig-derived Enterococcus faecium to tetracycline and other antibiotics were detected by using broth microdilution method, and the prevalence of tetracyclines-tolerant genes ( tet genes) in Enterococcus faecium was investigated by using PCR and DNA sequencing.The aim of this study is to analyze the tolerant mechanisms of tested Enterococcus faecium strains to tetracyclines.The results showed that all 14 strains of Enterococcus faecium isolated from pigs were tolerant to tetracycline, doxycycline, ciprofloxacin and erythromycin, and 4 strains were tolerant to ceftiofur.Among the above 14 strains, 13 strains con-tained tetL gene, 9 strains contained tetM gene, and 9 strains carried both tetL and tetM.The tolerance of pig-derived Enterococcus faecium to tetracyclines was mediated mainly by two mechanisms: drug initiative excretion and ribosomal protection, and it was closely related to carrying tetM and tetL genes.%用微量肉汤倍比稀释法测定了猪源屎肠球菌对四环素等抗生素的敏感性，用PCR和DNA测序方法检测了屎肠球菌中四环素类耐药基因（ tet基因），并分析了试验菌对四环素类的耐药机制。结果表明：14株猪源屎肠球菌对四环素、多西环素、环丙沙星、红霉素全部耐药，4株对头孢噻呋耐药；在14株屎肠球菌中，分别有13株和9株含tetL和tetM基因，其中有9株同时携带tetL和tetM基因；猪源屎肠球菌主要存在主动外排和核糖体保护两种耐药机制，其对四环素类的耐药性主要与携带tetM和tetL有关。