Impact of Expression of DHA AmpC ?-Lactamases Mediated by Plasmid on Antibiotics Susceptibility of Clinical Isolates of Klebsiella pneumoniae / 中华医院感染学杂志

ABSTRACT

OBJECTIVE To investigate the prevalence of DHA AmpC ?-lactamases mediated by plasmid in Klebsiella pneumoniae in China.METHODS Antimicrobial susceptibility test was conducted by the methods of double agar dilution and ESBLs confirmatory in K-B method according to the criteria of guidelines of CLSI.AmpC ?-lactamases were detected on the basis that AmpC ?-lactamases could be inhibited by 3-aminophenylboronic acid(APB).Gene chip technology and PCR were used to detect ESBLs and AmpC gene.RESULTS Among total 34 isolates of K.pneumoniae 32(94.1%) produced AmpC ?-lactamases and ESBLs.The most common(38.3%) were types DHA and TEM and SHV.MIC50 and MIC90 of all strains to all tested antimicrobial agents were lower than 34 strains tested 0.25?g/ml and 0.5?g/ml.Fourteen strains AmpC and ESBLs were conjugated successfully.CONCLUSIONS DHA AmpC ?-lactamases mediated by plasmid are the most common in K.pneumoniae in General Hospital of PLA of China.The most common(38.3%) are types DHA and TEM and SHV.Fourteen(41.2%) strains can be spreaded by plasmid.