我院重症医学科鲍曼不动杆菌耐药性及分子流行病学研究

Study on Drug Resistance and Molecular Epidemiology of Acinetobacter baumannii in Intensive Care Unit of Our Hospital

目的:明确我院重症医学科鲍曼不动杆菌的耐药规律及主要机制,为临床合理用药提供参考。方法:选择2015年1月-2016年12月我院重症医学科检出的鲍曼不动杆菌90株,采用二倍稀释法检测其对10种常用β-内酰胺类抗菌药物的耐药性,采用聚合酶链反应法检测其β-内酰胺酶基因。结果:90株鲍曼不动杆菌来自于痰液(46株,占51.11%)、脓液(13株,占14.44%)、血液(12株,占13.33%)等标本;对青霉素类及第三、四代头孢菌素类抗菌药物的耐药率较高(≥50%),对碳青霉烯类抗菌药物的耐药率相对较低(<30%),对含酶抑制剂复合制剂头孢哌酮/舒巴坦的耐药率最低(11.11%)。有68.89%的菌株检出了β-内酰胺酶基因,其中检出Amp C、CTX-M2、TEM-1、SHV-5、PER-1、OXA-23基因的菌株分别有42、8、30、20、48、12株,检出率分别为46.67%、8.89%、33.33%、22.22%、53.33%、13.33%。未检出上述基因菌株的半数抑菌浓度(MIC50)为1~256μg/m L;检出上述基因菌株的MIC50为2~1 024μg/m L。其中,检出1、2、3种上述基因的菌株分别有19、15、26株,其MIC50分别为2~512、2~1 024、4~1 024μg/m L。结论:我院重症医学科检出的鲍曼不动杆菌主要来自于痰液标本,对常用β-内酰胺类抗菌药物的耐药率普遍较高;检出的β-内酰胺酶基因以PER-1、Amp C为主,且检出的基因种类越多,菌株对β-内酰胺类抗菌药物的耐药率越高。临床应进一步检测鲍曼不动杆菌的同源性,做好院内环境消毒,加强该菌耐药性监测,加大抗菌药物临床使用管理力度,并根据药敏试验结果合理选用抗菌药物,以减少耐药鲍曼不动杆菌的产生。

OBJECTIVE:To confirm the regularity of drug resistance and main mechanism of Acinetobacter baumannii in ICU of our hospital,and to provide reference for rational drug use in clinic.METHODS:Ninety strains of A.baumannii were collected from ICU of our hospital during Jan.2015-Dec.2016.Drug resistance of A.baumannii to 10 kinds of commonly usedβ-lactam antibiotics was determined by two-fold dilution method.The presence ofβ-lactamase genes was detected by PCR.RESULTS:Totally 90 strains of A.baumannii were separated from sputum specimen(46 strains,51.11%),purulent fluid specimen(13 strains,14.44%)and blood specimen(12 strains,13.33%),etc.The resistance rates of A.baumannii to penicillins,three or four-generation cephalosporins were in high level(≥50%),while that of it to carbapenems was in low level relatively(<30%),that of it to inhibitor compound preparation containing enzyme as cefoperazone/sulbactam was the lowest(11.11%).β-lactamase genes were detected in 68.89%of strains,and there were 42 strains of AmpC,8 strains of CTX-M2,30 strains of TEM-1,20 strains of SHV-5,48 strains of PER-1,12 strains of OXA-23 genes;detection rates of them were 46.67%,8.89%,33.33%,22.22%,53.33%,13.33%,respectively.MIC50 of strains without above genes were 1-256μg/mL,and MIC50 of strains with above genes were 2-1 024μg/mL.There were 19 strains with 1 kind of above genes,15 strains with 2 kinds of above genes,26 strains with 3 kinds of above genes;MIC50 of them were 2-512,2-1 024,4-1 024μg/mL,respectively.CONCLUSIONS:A.baumannii were mainly from sputum specimen in ICU of our hospital,and resistant rate of commonly usedβ-lactam antibiotics is in high level generally.β-lactamase genes were mainly PER-1 and AmpC;the more gene types,the higher resistant rate of strains toβ-lactam antibiotics.It is necessary to further detect the homlolgy of A.baumannii,conduct hospital environment disinfection,strengthen drug resistance monitoring,enhance clinical application management of antibiotics,and select antibiotics rationally according to drug sensitivity test so as to reduce the occurrence of drug-resistant A.baumannii.