Antibiotic resistance and genotypes of extended spectrum β-lactamases producing Klebsiella pneumoniae isolates

Objective To investigate the profiles of genotype and antibiotic resistance of extended spectrum β-lactamases(ESBLs)-producing Klebsiella pneumoniae isolates from Chongqing area.Methods Antimicrobial susceptibility testing for 10 antibiotics against the ESBLs-producing isolates were determined by the Kirby-Bauer method.TEM,SHV and CTX-M genes in the isolates were detected by PCR.Results The 35 strains of ESBLs-producing K.pneumoniae were all susceptible to imipenem,and their resistance rate to cefepime was 22.9%.But the resistance rates of isolates to other antimicrobial agents were up to 50%,and to cefotaxime,ceftazidime and ceftriaxone were 82.9%,68.5% and 65.7%,respectively.Of all the isolates,26 strains were detected to harbor CTX-M gene,24 strains were detected to harbor TEM genes and 15 strains were detected to harbor SHV gene.Conclusion The ESBLs-producing K.pneumoniae are highly-resistant to antimicrobial agents.CTX-M type is the most common ESBLs genotype in Chongqing area.