医院ICU分离株肺炎克雷伯菌基因进化分析和耐药性研究  

Evolutionary analysis of Klebsiella pneumoniae genes and study of the drug resistance of K. pneumoniae isolated from the ICU

作　　者：徐陶[1] 胡丽蓉[1] 薛钰婷[1] 

机构地区：[1]泸州医学院附属医院ICU,四川泸州646000

出　　处：《中国病原生物学杂志》2014年第10期941-945,共5页Journal of Pathogen Biology

摘　　要：目的研究医院ICU分离株肺炎克雷伯菌耐药和基因关键位点突变情况,为肺炎克雷伯菌感染治疗提供依据。方法对分离株肺炎克雷伯菌采用琼脂扩散法做15种常见抗生素的药敏试验,方法及标准参照2013版美国临床实验室标准化委员会药敏试验标准（CLSI）;按照CLSI对超广谱β酰胺酶进行检测和验证,采用改良Hodge试验检测碳青霉烯酶;PCR扩增I类整合酶基因;对QRDR（喹诺酮耐药决定区）耐药株基因gyrA和parC进行检测并与疫苗株比对。结果药敏试验显示,ICU分离株肺炎克雷伯菌对亚胺培南,美罗培南,阿米卡星的耐药率分别为1.4%、2.7%和4.0%。对复方新诺明和庆大霉素耐药率分别为68.0%和62.7%,对其他抗生素耐药率在10%-60%之间。采用琼脂扩散法检出23株产ESBLs,占30.7%;采用改良Hodge试验检测碳青霉烯酶6株阳性,占8.0%;PCR检测I类整合子21株阳性,占28.0%。耐药株QRDR基因检测和序列分析显示,gyrA基因编码产物第83位由丝氨酸（Ser）变异为苯丙氨酸（Phe）S83F,第87位天冬氨酸（Asp）变异为谷氨酸（Asn）D87N,parC基因编码产物第80位由丝氨酸（Ser）变异为异亮氨酸（Ile）S80I。结论本组分离菌中带有I类整合子和产碳青霉烯酶检出率较低,分离株肺炎克雷伯菌对亚胺培南、美罗培南和阿米卡星耐药率低于10%,上述药物可作为一线药物用于肺炎克雷伯菌的感染治疗。对QRDR基因检测发现gyrA和parC基因突变引起细菌对环丙沙星和左氧氟沙星耐药,因此氟喹诺酮类药物应慎用。Objectives To study the drug resistance of Klebsiella pneumoniae isolated from the ICU and to study genetic mutations at key sites in order to provide a basis for clinical treatment of K.pneumonia. Method Drug sensitivity to15 antibiotics was tested using the agar diffusion method.The testing method and standards were based on the 2013 standards for antimicrobial susceptibility testing of the CLSI.Extended-spectrumβ-lactamases（ESBLs）were detected and verified using CLSI standards.Carbapenemases were verified with a modified Hodge test.Detection of Class I integrons in K.pneumonia：Integrons were amplified with PCR using F：5＇-GCATCCTCGGTTTTCTGG-3＇and R：5＇-GGTGTGGCGGGCCTTCGTG-3＇as primers. Result Drug sensitivity testing revealed that K.pneumoniaresistance to imipenem was 1.4%,its resistance to meropenem was 2.7%,and its resistance to amikacin was 4%.Its resistance to cotrimoxazole was 68%and its resistance and gentamicin was 62.7%.Its resistance to other antibiotics was between 10%and60%.The agar diffusion method indicated that 23strains（30.67%）were ESBL-producing strains.Six strains of K.pneumonia（8%）tested positive for carbapenemases.Twenty-one strains of K.pneumonia（28%）had class I integrons.Detection of QRDR genes in drug-resistant strains：Two mutations in gyrA（S83Fand D87N）and a single mutation in parC（S80I）. Discussion In the current testing,K.pneumoniaresistance to imipenem,meropenem,and amikacin was less than 10%,which means that these antibiotics can be used as first-line drugs to treat K.pneumonia.Mutations in the genes gyrA and parC were evident.These mutations can cause resistance to ciprofloxacin and levofloxacin,so fluoroquinolones should be used prudently.

关 键 词：肺炎克雷伯菌 耐药性 超广谱β酰胺酶 碳青霉烯酶 喹诺酮耐药决定区 

分 类 号：R996[医药卫生—毒理学]