肺炎克雷伯菌的喹诺酮外排基因qepA的检测及菌株同源性分析

目的 检测质粒介导的喹诺酮类外排基因qepA在临床分离的产超广谱β-内酰胺酶(ESBLs)的肺炎克雷伯菌中的分布情况,并对阳性菌株进行同源性分析.方法 41株细菌的鉴定和药敏采用Vitek-2 Compact系统;采用PCR法检测qepA并进行序列测定、比对.应用Rep-PCR法采用Diversilab系统对qepA阳性菌株进行同源性分析;同时了解阳性株上的rmtB分布情况.结果 5株肺炎克雷伯菌上检测到qepA基因,检出率为12.2%.Diversilab分析结果表明其中两株的qepA阳性菌同源性超过99%.包含qepA的肺炎克雷伯菌中2株(40%)检出rmtB.结论 在肺炎克雷伯菌临床菌株上检出质粒介导的喹诺酮类外排基因qepA.

Abstract：

Objective To investigate the prevalence of qepA, quinolone efflux protein, among 41 unique clinical strains of K. pneumoniae producing ESBLs and to study the qepA-bearing isolates using the Diversilab system. Methods Identification and antimicrobial susceptibility were performed by Vitek-2 Compact System. Screening of qepA was carried out by PCR amplification. The NCBI BLAST program was utilized for sequence comparisons. qnr-bearing strains was evaluated by the Repetitive-sequence-based PCR(Rep-PCR) employing the Diversilab system. And the existence of rmtB was detected among these qepA contained isolates. Results qepA were detected in 5 isolates( 12.2% ). The Rep-PCR profiles produced by the Diversilab system showed that 2/5 of isolates were indistinguishable. And 60% of qepA-positive isolates were detected to harbor rmtB gene. Conclusion The data suggest the emergence of qepA-borne K. pneumoniae.

Study of qepA among clinical isolates of Klebsialla pneumoniae

Objective To investigate the prevalence of qepA, quinolone efflux protein, among 41 unique clinical strains of K. pneumoniae producing ESBLs and to study the qepA-bearing isolates using the Diversilab system. Methods Identification and antimicrobial susceptibility were performed by Vitek-2 Compact System. Screening of qepA was carried out by PCR amplification. The NCBI BLAST program was utilized for sequence comparisons. qnr-bearing strains was evaluated by the Repetitive-sequence-based PCR(Rep-PCR) employing the Diversilab system. And the existence of rmtB was detected among these qepA contained isolates. Results qepA were detected in 5 isolates( 12.2% ). The Rep-PCR profiles produced by the Diversilab system showed that 2/5 of isolates were indistinguishable. And 60% of qepA-positive isolates were detected to harbor rmtB gene. Conclusion The data suggest the emergence of qepA-borne K. pneumoniae.