Detection of extended-spectrum ?-lactamases in Klebsiellae pneumoniae isolates with qnr gene / 中国药理学通报

ABSTRACT

Aim To identify the extended-spectrum ?-lactamases(ESBLs) gene in Klebsiellae pneumoniae isolates with qnr gene.Methods Antimicrobial agents susceptibilities were determined with standard agar dilution procedure on Mueller-Hintonagar and 3 isolates with qnr gene were confirmed as ESBLs producing strains by NCCLS Confirmatory Test.The partial blagene of ESBLs producing isolates were detected by PCR using universal primers for TEM,SHV,CTX-M-1group,CTX-M-2 group,CTX-M-13group,OXA-1group,OXA-2 group,OXA-10 group,PER-1 and VEB-1,respectively.At the same time,Class 1 integrase gene was also detected by PCR.The entire blaCTX-M-13group,blaTEM,blaOXA-1group were amplified by PCR using the primers outside the Open Reading Frame(ORF) of these ?-lactamases.The PCR products were also directly sequenced and analyzed;the clinical isolates of ESBLs producers were detected by PFGE. Results 3 Klebsiellae pneumoniae isolates with qnr gene were ESBLs producers and they produced CTX-M-14 ESBLs and TEM-1 ?-lactamases.1 isolate simultaneously produced OXA-1?-lactamases,and 3 isolates carried class 1 integron.Besides quinolones,ESBL producers were also resistant to most ?-lactams,and PFGE patterns of two isolates were same.Conclusion 3 Klebsiellae pneumoniae isolates with qnr gene produced CTX-M-14 ESBLs,which caused their multi-resistance,and clone spread was found in them.More attention should be paid to detect those strains.