Detection of extendedª²spectrum betaª²lactamases and analysis of antibiotic resistance in clinical isolates of Klebsiella pneumoniae

    CHENG Xunª²Min, ZHANG Qi, XU Yuanª²Hong£¬ LI Min, ZHU Suª²Zhen£¬SHEN Jiª²Lu

    1Department of Clinical Laboratories, Huaibei People¬ðs Hospital, Huaibei 235000, China, 2Department of Clinical Laboratories, First Affiliated Hospital of Anhui Medical University, Hefei 230022, China

    ¡¾Abstract¡¿ AIM: To study the phenotype and genotype distribution of extendedª²spectrum betaª²lactamases (ESBLs)ª²producing Klebsiella pneumoniae(K. pneumoniae)and its drug resistance. METHODS: Seventyª²seven strains of K. pneumoniae were determined by 1999 NCCLs methods and the genotype of ESBLs was amplified by polymerase chain reaction (PCR). The antibiotic susceptibility of bacteria was determined by microdilution. RESULTS: In the 77 positive K. pneumoniae isolates of the initial screen test, 45 strains (58.1%) were confirmed by cefotaxime and cefotaximeª²clavulanic acid but only 27 strains were confirmed by ceftazidime and ceftazidimeª²clavulanic acid. PCR showed that TEM, SHV, CTXª²M or OXAª²type ESBLs in the clinical strains were 19, 8, 36, 11 strains respectively. CONCLUSION: K. pneumoniae is one of the most common ESBLsª²producing strains. The rates of ESBLsª²producing K. pneumoniae significantly increase in recent years and CTXª²M is most common genotype. Some strains carry two or more genotypes. Imipenem is the most susceptible antibiotic. ......