Phenotypes and Genotypes of Clinical Isolates of ESBLs-producing Klebsiella pneumoniae / 中华医院感染学杂志

ABSTRACT

OBJECTIVE To investigate the relationship between phenotypes and genotypes of clinical isolates of ESBLs-producing Klebsiella pneumoniae.METHODS Agar dilution method was used to test the MICs of 11 antibiotics against 67 ESBLs-producing K.pneumoniae strains.PCR was performed for amplifying ?-lactamase-encoding genes of SHV-,TEM-,and CTX-M-type,and the PCR products of some strains were cloned and sequenced to identify their gene serotypes.RESULTS With no imipenem-resistant strains among 67 strains,their resistant rates to 10 kinds of antibiotics were 10.45-89.55% The cross-resistant rates to aminoglycosides of 60 strains and to ?-lactams of 44 strains were 88.33% and 40.91%,respectively.The positive rates of SHV-,TEM-,and CTX-M-type for 67 strains were 91.04%,56.72% and 28.36%,respectively,and SHV-12,TEM-1 and CTX-M-3 genotypes were found in 7 strains by cloning and sequencing.CONCLUSIONS Sixty seven strains of ESBLs-producing K.pneumoniae present a clear feature of multi-resistance and cross-resistance to most of antibiotics except imipenem,among them there are 7 strains producing SHV-12 and CTX-M-3 extended-spectrum ?-lactamase coexistent with TEM-1 broad-spectrum ?-lactamase.