ICU与非ICU鲍氏不动杆菌耐药性和耐药基因比较分析

Drug resistance and drug resistance genes in Acinetobacter baumannii strains form ICU and non-ICU patients:a comparative study

目的回顾性分析重症监护病房(ICU)与非ICU鲍氏不动杆菌分离株的耐药性、耐药基因及外排泵基因表达差异,为临床合理使用抗菌药物和多药耐药菌的防控提供科学依据。方法对来自于2009年1月-2014年3月中山大学附属第三医院住院患者下呼吸道感染的鲍氏不动杆菌分离株213株按照来源分为ICU组(82株)和非ICU组(131株),对上述分离株进行耐药性检测,同时检测耐药基因(OXA-23、OXA-24、OXA-48、OXA-51、OXA-58、OXA-143、OXA-235、NDM-1、KPC、IMP、VIM、GIM-1、SPM-1、SIM-1、FIM-1、ISAba1和ISAba4)和外排泵基因(adeB、adeJ、adeG、craA、abeM和amvA)、外膜蛋白基因(omp25、omp33-36、carO)的表达。结果与非ICU组鲍氏不动杆菌分离株比较,ICU分离株对亚胺培南有更高的耐药率(达到90.2%),差异具有统计学意义(χ^(2)=7.117,P=0.008);耐药基因OXA-51检出率在ICU组和非ICU均超过95%,OXA-23、VIM在ICU组和非ICU组检出率分别是80.0%vs.60.3%(P=0.007),50.0%vs.29.0%(P=0.002);未检出OXA-48、OXA-143、OXA-235、KPC、NDM-1及SIM-1基因;ICU组和非ICU组相比,adeB相对表达量比较有统计学差异(P<0.05)。结论ICU和非ICU组来源的鲍氏不动杆菌对亚胺培南耐药性、耐药基因(OXA-23、VIM)和外排泵基因adeB表达存在统计学差异,提示ICU鲍氏不动杆菌耐药性高可能是上述多种耐药机制的结果。

OBJECTIVE To retrospectively analyze the differences in drug resistance and expressions of drug resistance genes and efflux pump genes in Acinetobacter baumannii isolates between the intensive care unit(ICU)patients and the non-ICU patients so as to provide scientific bases for reasonable clinical use of antibiotics and control of multidrug-resistant organisms(MDROs).METHODS Totally 213 strains of A.baumannii that were isolated from the patients with lower respiratory tract infection who were hospitalized in the Third Affiliated Hospital of Sun Yat-sen University from Jan 2009 to Mar 2014 were divided into the ICU group with 82 strains and the non-ICU group with 131 strains according to the source of the strains.The drug resistance of the strains was detected.The expressions of drug resistance genes(OXA-23,OXA-24,OXA-48,OXA-51,OXA-58,OXA-143,OXA-235,NDM-1,KPC,IMP,VIM,GIM-1,SPM-1,SIM-1,FIM-1,ISAba1 and ISAba4),efflux pump genes(adeB,adeJ,adeG,craA,abeM and amvA)and outer membrane protein genes(omp25,omp33-36,carO)were detected.RESULTS The drug resistance rate of the A.baumannii strains of the ICU group was 90.2%to imipenem,significantiy higher than that of the strains of the non-ICU group(χ^(2)=7.117,P=0.008).The detection rate of the drug resistance gene OXA-51 was more than 95%in the ICU group and the non-ICU group;the detection rate of OXA-23 was 80.0%in the ICU group,60.3%in the non-ICU group(P=0.007);the detection rate of VIM was 50.0%in the ICU group,29.0%in the non-ICU group(P=0.002).OXA-48,OXA-143,OXA-235,KPC,NDM-1 and SIM-1 genes were not detected.There was significant difference in the relative expression level of adeB between the ICU group and the non-ICU group(P<0.05).CONCLUSION There are significant differences in the drug resistance rate to imipenem,expressions of drug resistance genes(OXA-23,VIM)and efflux pump gene adeB between the A.baumannii strains isolated from the ICU group and the strains isolated from the non-ICU group.It is suggested that the above drug resistance mechanisms may be the causes of high drug resistance rates of the A.baumannii strains isolated from the ICU patients.