多药耐药性阴沟肠杆菌院内垂直传播分析

Vertical Transmission of Multidrug-resistant Enterobacter cloacae Clinical Isolates

目的了解昆明市级医院阴沟肠杆菌多药耐药菌株的院内垂直传播现状。方法采用美国临床实验室标准化研究所（CLSI）推荐的K-B法药敏试验检测昆明市第一人民医院2002年7月-2004年6月临床分离阴沟肠杆菌的耐药表型;脉冲场凝胶电泳（PFGE）分析耐药菌株的克隆传播状况。结果第一、二代头孢菌素的耐药率〉80.0%;三代头孢菌素除头孢他啶外,耐药率均〉70.0%;头孢吡肟的耐药率为31.5%;头霉素类的耐药率〉65.0%;亚胺培南100.0%敏感;β-内酰胺酶抑制剂复合制剂耐药率为50.0%～90.0%;庆大霉素耐药率高达66.7%,而阿米卡星耐药率只有14.1%;环丙沙星耐药率为48.4%;复方新诺明耐药率为64.8%;ICU分离的14株阴沟肠杆菌中7株具有相同PFGE指纹。结论昆明市第一人民医院临床分离阴沟肠杆菌多药耐药严重,存在耐药菌株的垂直传播。

OBJECTIVE To investigate vertical transmission of multidrug-resistant Enterobacter cloacae clinical isolates from a hospital in Kunming. METHODS The phenotypes of resistant to 23 antimicrobial agents E. cloacace strains isolated from our hospital during Jul 2002 to Jun 2004 were determined by K-B disc agar diffusion method according to the Clinical Laboratory Standards Institute （CLSI）. The clone transmission of the antibioticsresistant strains was determined by pulsed field gel electrophoresis（PFGE）. RESULTS The percentage of the isolates resisting to penicillin, and the first and the second generation cephalosporins among the E. cloacace clinical isolates was more than 80.0%. To the third generation, it was more than 70.0 % excluding ceftazidime. 31.5% Of the isolates resisted to eefepime. The percentage of isolates resisted to cephamycin was more than 65.0%. All of the isolates were sensitive to imipenem. To the combinational agents of penicillin and β-laetamase inhibitor, the percentage of resistant isolates was 50.0-90.0%. 66.7% Of isolates resisted to gentamicin, but to amikacin, the percentage was not so high （14.1%）. 48.4% Of the isolates resisted to ciprofloxacin and 64.8% to trimethoprim/sulfamethoxazole. PFGE revealed that there were clone transmissions of the drug-resistant E. cloacace in ICU. CONCLUSIONS The multidrug-resistance is critical among the E. cloacae clinical isolates. The vertical transmission of antibiotics-resistant strains is existing.