肠球菌β-内酰胺酶的测定及耐药性分析

Detection of β-lactamase and analysis of drug resistance in Enterococci spp.

目的 研究肠球菌 β-内酰胺酶与耐药性的关系。方法 采用纸片扩散法 (K- B法 )检测 32株肠球菌对 8种抗生素的耐药性 ,采用 nitrocefin法测定 β-内酰胺酶。结果 药敏测定结果显示肠球菌对链霉素、红霉素、庆大霉素的耐药率分别达到 96 .9%、93.8%、84.4%,对万古霉素、替考拉宁的耐药率都为 0。对青霉素类抗生素的耐药性 ,屎肠球菌对氨苄西林、青霉素 G、氨苄西林 /舒巴坦耐药率分别为 71.4%、85 .7%、5 7.1%,粪肠球菌则分别为 8.7%、13.0 %、0 ;屎肠球菌产 β-内酰胺酶阳性率为 71.4%,粪肠球菌为 31.1%。结论 肠球菌对氨基糖苷类抗生素、红霉素具有高度耐药性 ,对万古霉素、替考拉宁全部敏感 ,屎肠球菌对青霉素类抗生素的耐药性与产 β-内酰胺酶率明显高于粪肠球菌 ,且屎肠球菌、粪肠球菌对青霉素类抗生素的耐药性与 β-内酰胺酶的产生呈正相关系。

Objective To study the relationship between β-lactamase and drug resistance in Enterococci. Methods Eight antibiotic drug resistance of 32 strains of Enterococcus were detected by using disk agar diffusion method (K-B method), and nitrocefin-based test were used to detected the β-lactamase. Results The resistant rates of Enterococci to streptomycin and erythromycin, gentamycin were 96.9%, 93.8%, 84.4%, respectively , to vancomycin, teicoplanin were zero. Drug resistant rate of E.faceium to ampicillin, penicillin G, ampicillin-sulbuctam were 71.4%, 85.7%, 57.1%; E.faecalis to these drugs were 8.7%, 13.0%, 0, respectively . β-lactamase producing positive rates in E.faeciam and in E.faecalis were 71.4%, 31.1%, respectively . Conclusion Enterococci has high drug resistance to aminoglycosides antibiotics and erythromycin, while to vancomycin and teicoplanin was all susceptible. For drug resistance to penicillins antibiotics and the β-lactamase producing rate, E.fecium was higher than E.faecalis. And there were positive relationships among penicillin resistance of E.faecium or E.faecalis and their β-lactamase productivity.