2012-2014年辽宁省大连市某医院分离粪肠球菌耐药性及多位点序列分析

Antibiotic susceptibility and multi locus sequence type of Enterococcus faecalis strains isolated from patients of a hospital in Dalian

目的了解大连市某医院2012-2014年住院患者分离粪肠球菌耐药性、携带毒力基因情况和多位点序列分型(MLST)的型别。方法使用自动化仪器法对分离菌株的耐药性进行鉴定。应用聚合酶链式反应(PCR)方法检测4种常见毒力基因的携带情况。应用MLST对分离菌株进行分型。结果分离的55株粪肠球菌中耐药菌株比例为92.72%,其中多重耐药菌的比例为65.45%。分离的粪肠球菌对四环素的耐药率最高,对红霉素、高浓度庆大霉素和利福平也有较高的耐药率。对青霉素耐药率为7.27%,未发现对糖肽类和脂肽类抗生素耐药的菌株。55株粪肠球菌共有28个MLST型别,其中CC(Clonal complex)16为优势克隆群,占菌株总数的43.64%。有多株同一克隆群的粪肠球菌具有相似的耐药谱和毒力携带情况。结论大连市某医院分离到多株属于同一克隆、多重耐药且携带多种毒力基因的粪肠球菌,需要针对优势克隆菌株的特点指导临床用药和院内感染的预防控制。

Objective To investigate antibiotic resistance,virulence genes,and sequence types of Enterococcus faecalisstrains isolated from patients in a hospital in Dalian,Liaoning province.Methods The antibiotic resistance of the E. faecalisisolated were detected with auto device. Polymerase chain reaction（PCR）was conducted for the four virulence genes of thestrains,and multi locus sequence typing（MLST）were performed to identify the sequence types of the E. faecals strains.Results A total of 55 E. faecalis strains isolated from the patients. Up to 92.72% of the strains were antibiotic resistant,and65.45% of the stains were multi drug resistant. The strains＇ resistances to 14 antibiotics were tested,the resistance totetracycline was highest,followed by that to erythromycin,high-concentration gentamicin and rifampicin. The resistant rate topenicillin was 7.27%,and no E. faecalis strains resistant to glycopeptide and lipopeptide antibiotics were detected. Twenty eightsequence types（STs）were detected in 55 E. faecalis strains,and CC16 was the major clonal complex including 43.64% of theE. faecalis strains. The characteristics of antibiotic resistance and virulence genes were similar in the E. faecalis isolates withsame STs.Conclusion The same clonal complex E. faecalis strains isolated from the patients of a hospital in Dalian sharedsimilar virulence genes and multi drug resistant pattern. The result can be used to guide clinical antibiotic use and nosocomialinfection control targeting predominant clonal complex of E. faecalis.