摘要
目的 了解北京朝阳医院临床分离的多重耐药阴沟肠杆菌的 β-内酰胺酶编码基因。方法 对 12株临床分离的多重耐药的阴沟肠杆菌进行琼脂稀释法药敏试验、改良三维试验法和聚合酶链反应克隆测序。结果 12株阴沟肠杆菌对多种抗生素耐药 ,改良三维试验法证实同时产生 Am p C酶和 ESBL s;其中 ,9株 ESBL s编码基因PCR结果阳性 ,分别为 SHV- 2、SHV- 12、CTX- M- 3和 CTX- M- 14型 ESBL s;对另外 3株进行粗酶等电点测定发现 ,存在 7.89和 8.0等电点条带 ,并被克拉维酸抑制 ;12株细菌 am p D和 amp C基因 PCR扩增均呈阳性 ,将 6株耐药菌进行 amp D基因的克隆测序发现均存在羧基端可疑的突变位点。结论 12株多重耐药的阴沟肠杆菌同时产生≥ 1种的 ESBL s及高产 Am p C酶。
OBJECTIVE To investigate the β-lactamase-encoding genes of Enterobacter cloacae isolated in Beijing Chaoyang Hospital. METHODS Standard agar dilution method,improved three-dimensional tests,PCR amplification,gene cloning and DNA sequencings were performed in the 12 strains of E. cloacae resistant to many antibiotics. RESULTS Twelve strains of E. cloacae were multiple-drug-resistant and proved to produce AmpC β-lactamase and ESBLs by improved three-dimensional tests. DNA sequences of 9 strains of E. cloacae revealed ESBLs of SHV-2,SHV-12,CTX-M-3,CTX-M-14 and β-lactamase of TEM-1 and SHV-11. The other three strains produced unidentified enzymes with pI 7.89 and 8.0 which were inhibited by cloxacillin. The ampD gene sequencing results of 6 strains showed that there were amino acid substitutions in the carboxy-terminal of AmpD. CONCLUSIONS Twelve strains of E. cloacae produced AmpC β-lactamase and one or more types of ESBLs.
出处
《中华医院感染学杂志》
CAS
CSCD
2004年第5期481-484,共4页
Chinese Journal of Nosocomiology
基金
国家自然科学基金 (30 2 70 0 74 )
关键词
阴沟肠杆菌
AMPC酶
ESBLS
聚合酶链反应
基因
Enterobacter cloacae
AmpC beta-lactamase
Extended-spectrum β-lactamases (ESBLs)
Polymerase chain reaction
Gene
