猪源粪肠球菌的基因型及耐药性分析

Analysis of Genotype and Antimicrobial Resistance in Enterococcus faecalis Isolated from Pigs

关键词:  粪肠球菌  耐药性  基因型  抗菌药物

Key words:  Enterococcus faecalis  antimicrobial resistance  genotype  antimicrobial agents

摘要:

为了解上海地区规模化猪场中粪肠球菌的耐药性和基因型， 2013年3月-2014年5月从上海地区10个规模化养猪场收集到分离鉴定的粪肠球菌133株，采用微量肉汤稀释法对12种抗菌药物进行药敏试验，采用PCR技术分别检测分离株中β-内酰胺类抗生素耐药相关基因（TEM）、氨基糖苷类抗生素耐药相关基因［aac(6’)/aph(2”)和aph(3’)-Ⅲ和ant(6)-Ⅰ］、四环素耐药相关基因（tetM）、红霉素耐药相关基因（ermB和mefA）和万古霉素耐药相关基因（vanA和vanB）。结果显示，在133株粪肠球菌中，耐药基因ermB、tetM、TEM、ant(6)-Ⅰ、aac(6’)/aph2”、aph(3’)-Ⅲ、vanA的检出率分别为：95.5%（127/133）、91.0%（121/133）、63.2%（84/133）、45.9%（61/133）、42.1%（56/133）、24.1%（32/133）、3.0%（4/133）；未检出mefA和vanB基因的菌株。分离菌株对12种抗菌药物的耐药性较为严重，且以6~9耐为主要耐药株，占81.2%。试验表明，上海地区猪源粪肠球菌多重耐药现象严重，携带抗菌药物相关耐药基因是导致分离株耐药的主要原因。

Abstract:

This study was conducted to investigate the antibiotic susceptibility and resistance genotypes in Enterococcus faecalis strains isolated from ten Large-scale pig farms in Shanghai. 133 strains of E. faecalis were collected between March 2013 and May 2014. The susceptibility testing was performed by broth microdilution, and the genotypes of β-lactam antibiotics resistance-associated gene(TEM), aminoglycoside genes［aac(6’)/aph(2”), aph(3’)-Ⅲ and ant(6)-Ⅰ］, tetracycline gene(tetM), erythromycin genes(ermB and mefA) and vancomycin genes(vanA and vanB ) were analyzed by PCR. The positive rate of the resistance genes ermB, tetM, TEM, ant(6)-Ⅰ, aac(6’)/aph2”, aph(3’)-Ⅲ, vanA in the 133 strains of E. faecalis tested were 95.5%(127/133), 91.0%(121/133), 63.2%(84/133), 45.9%(61/133), 42.1%(56/133), 24.1%(32/133), and 3.0%(4/133), respectively. No mefA and vanB gene strains were detected. 12 kinds of antibacterial drug resistance were relatively serious and 6~9 resistance as the main drug resistant strains were detected，accounting for 81.2%. This study shows that multidrug resistance of E. faecalis was a serious issue, and resistance genes harbored were the very important reasons for resistance to antibiotics in E. faecalis.