ICU耐亚胺培南铜绿假单胞菌产金属β-内酰胺酶的研究

Study of metallo-β-lactamase producing of imipenem resistant Pseudomonas aeruginosa in ICU

目的研究ICU耐亚胺培南铜绿假单胞菌（IRPA）的耐药性、产金属β-酰胺酶（MBLs）情况及其编码的基因亚型。方法对ICU住院患者连续分离的86株IRPA进行回顾性分析。经VITEK-32型全自动微生物分析仪对分离的IRPA进行菌种确证及药敏检测，双纸片增效法检测其产MBLs的情况。PCR法检测MBLs表型筛选阳性菌株的基因型。结果IRPA除对多黏菌素B敏感率达100．0％，对阿米卡星敏感率略高外，对其他抗生素的耐药率均超过46％。86株IRPA中MBLs表型筛选检出率达48．8％（42／86），阳性菌株经PCR扩增后检出41株带有MBLs基因，其中IMP-1最多，占26．7％（23／86），携带多耐药基因的IRPA有13株，占15．1％（13／86）。结论产MBLs是ICUIRPA耐药的主要机制之一，其基因型以IMP-1为主，多耐药基因携带情况严重，加强MBLs的监测可帮助临床合理选用抗生素并抑制细菌耐药基因的传播。

Objective To investigate the resistance of imipenem resistant Pseudomonas aeruginosa （IRPA）,metallo-β-lactamase （MBLs） producing and prevalences of the coding genes of IRPA in ICU. Methods Eighty-six clinical strains of Pseudomonas aeruginosa in ICU continuously collected were analyzed retrospectively. Pseudomonas aeruginosa and its drug susceptibility was identified by BioMerieux VITEK-32 system,and double disk synergy test was used to screen the MBLs producing IRPA. Then, the MBI.s phenotype positive IRPA were confirmed by PCR to explore the genotype of them. Results Except polymyxin B with 100.0% sensitivity and amikacin with higher sensitivity, the percentage of drug resistance for other antibiotics was more than 46%. MBLs phenotype positive IRPA accounted for 48.8% （42/86） by double disk synergy test and genotype positive accounted for 47.7% （41/86） by PCR in MBLs phenotype positive IRPA. Among these,the most common was IMP-1 which constituted for 26.7% （23/86）. What＇s more, there were 15.1% （13/86） strains IRPA which carried multidrug resistant genes. Conclusions The main mechanism of drug resistance of IRPA in ICU is MBLs producing and IMP-1 is the most prevalent genotype,and IRPA with multidrug resistant genes is serious. Thus,monitoring of MBLs should be strengthened to help to use antibiotics rationally and prevent transmission of these genes.