Antimicrobial resistance and gene typing of extendedspectrum βlactamasesproducing Klebsiella pneumoniaeLIU Xiaochun,WANG Guoqing,WANG Rong, LIU Yunde (Department of Laboratory Medicine, Tianjin Medical University, Tianjin 300203, China)［Abstract］ObjectiveTo investigate antimicrobial resistance and genotypes of extendedspectrum βlactamases(ESBLs)producing Klebsiella pneumoniae(K. pneumoniae) isolated from clinic in a hospital . MethodsK. pneumoniae were collected, ESBLs preliminary screen and phenotype confirmatory tests were carried out according to the NCCLS guidelines; antimicrobial susceptibility tests were determined by KirbyBauer test; gene types of βlactamases were performed with PCR . ResultsThe detection rate of ESBLsproducing K. pneumoniae was 62.22%(56/90). ESBLsproducing strains were only sensitive to the combination of the third generation cephalosporins with βlactamases inhibitor and carbapenems. The detection rate of genes of SHV, CTXM1, TEM and CTXM9 was 69.64%, 51.79%, 37.50% and 0.00% respectively. 35.71% and 14.28% of ESBLproducing K. pneumoniae carried two or three genes respectively. ConclusionAntimicrobial resistance of K. pneumoniae is serious, the main gene types are SHV and CTXM1