表皮葡萄球菌生物膜形成与细菌耐药性的相关性分析

目的探讨表皮葡萄球菌临床分离株生物膜的形成情况,分析其生物膜形成与细菌耐药性的相关性。方法收集2014年1月至2015年2月住院患者血标本分离出的表皮葡萄球菌62株,采用生物膜形成试验和聚合酶链式反应(PCR)扩增试验检测细菌生物膜,并采用纸片扩散法(K-B法)进行细菌药物敏感性试验。结果利用生物膜形成试验检出生物膜阳性菌株23株,检出率为37.1%;PCR扩增试验检出icaA基因27株,检出率为43.5%,差异无统计学意义(P0.05);两种方法同时阳性的菌株为14株。生物膜阳性菌株对所测抗菌药物的耐药率普遍高于生物膜阴性菌株,其中对庆大霉素、青霉素G、苯唑西林、左旋氧氟沙星、头孢西丁的耐药率比较差异有统计学意义(P0.05),所有菌株对万古霉素、利奈唑胺、奎奴普丁/达福普汀均敏感。结论两种方法对表皮葡萄球菌生物膜的检出率无明显差异,生物膜阳性菌株耐药率普遍高于生物膜阴性菌株。

Analysis on correlation between biofilm formation and bacterial resistance in Staphylococcus epidermidis

Objective To investigate the formation of biofilm in clinical isolates of Staphylococcus epidermidis ,and to analyse the correlation between biofilm formation and antibacterial resistance of Staphylococcus epidermidis .Methods A total of 62 strains of Staphylococcus epidermidis isolated from blood specimens of inpatients with bloodstream infection ,from January 2014 to February 2015 ,were collected .The biofilm formation of Staphylococcus epidermidis was detected by using the semi‐quantitative adherence as‐say and polymerase chain reaction(PCR) amplification experiment .The antibacterial susceptibility test was carried out according to K‐B method .Results The positive rate of biofilm formation detected by using the semi‐quantitative adherence assay and PCR for icaA gene were 37 .1% (23 strains) and 43 .5% (27 strains) respectively ,and there was no statistically significant difference(P>0 .05) .There were 14 positive strains detected by both methods .The resistance rates of strains producing biofilm to antibacterial a‐gents were generally higher than those of non‐producing biofilm strains ,and there were statistically significant differences in resist‐ance rates of strains to gentamicin ,penicillin ,oxacillin ,levofloxacin and cefoxitin(P<0 .05) .All bacteria were sensitive to vancomy‐cin ,linezolid and quinupristin/dalfopristin .Conclusion There is no significant difference between the two methods in detecing bio‐film formation .The resistance rates of strains producing biofilm to antibacterial agents were generally higher than those of non‐pro‐ducing biofilm strains .