血流感染碳青霉烯耐药肺炎克雷伯菌的耐药特征及机制研究  

Resistance Characteristics and Mechanism of Carbapenem-Resistant Klebsiella Pneumoniae in Bloodstream Infection

作　　者：董国伟[1] 张省委 郭洁[1] 钟英成[1] 谢宇端 朝浩鹏[1] 韩志城 唐新宁[1] DONG Guowei;ZHANG Shengwei;GUO Jie;ZHONG Yingcheng;XIE Yuduan;CHAO Haopeng;HAN Zhicheng;TANG Xinning(Department of Clinical Laboratory,Wangjing Hospital,China Academy of Traditional Chinese Medicine,Beijing 100102,China;Department of Clinical Laboratory,Dongfang Hospital of Beijing TCM Hospital,Beijing 100078,China)

机构地区：[1]中国中医科学院望京医院检验科,北京100102 [2]北京中医药大学东方医院检验科,北京100078

出　　处：《标记免疫分析与临床》2022年第2期211-215,共5页Labeled Immunoassays and Clinical Medicine

基　　金：中国中医科学院望京医院院级课题(青蒿琥酯对碳青霉烯类耐药大肠杆菌抗菌增敏作用研究)(编号:WJYY2020-32)。

摘　　要：目的探讨无菌血标本分离碳青霉烯耐药肺炎克雷伯菌(CRKP)的耐药机制及分子分型。方法测定32株CRKP最低抑菌浓度(MIC),mCIM和eCIM法检测碳青霉烯酶;PCR法检测耐药基因;多位点序列分型(MLST)进行分子分型;RT-PCR检测膜孔蛋白OMPK35/36基因相对表达情况。结果药敏试验显示32株CRKP对所有β-内酰胺类、喹诺酮类抗生素耐药,对阿米卡星耐药率87.5%、对复方新诺明耐药率56.3%、替加环素耐药率6.2%。mCIM阳性30例,eCIM阳性1例。基因测序检出30例产碳青霉烯酶菌株;菌株携带blaKPC-2基因占90.6%(29/32)、检出1株产金属酶NDM-5菌株;超广谱β-内酰胺酶SHV、CTX及AmpC酶DHA基因检出率分别为62.5%、46.9%、37.5%。MLST分型结果显示ST11型29株,占90.6%,ST524两株;ST716一株。膜孔蛋白表达水平,12株OMPK35表达水平降低,4株OMPK35与OMPK36表达同时降低。结论血流感染分离的CRKP存在高度耐药性,耐药菌主要携带碳青霉烯耐药基因KPC-2;非产碳青霉烯酶菌株耐药与产ESBLs合并膜孔蛋白表达降低相关。MLST分型表明,ST11型是我院CRKP主要类型。Objective To study the resistance characteristics,resistance mechanism and molecular classification of carbapenem-resistant Klebsiella pneumoniae(CRKP)isolated from sterile specimens.Methods The minimum inhibitory concentration(MIC)of 32 strains of CRKP was determined,and carbapenase was detected by modified carbapenem inactivation method(mCIM)and EDTA-modified carbapenem inactivation method(eCIM).The resistance genes were detected by polymerase chain reaction(PCR);Multilocus sequence typing(MLST)was used to classify strains.The relative expression of OMPK35/36 gene was detected by RT-PCR.Results Antimicrobial susceptibility test showed that 32 strains of CRKP were resistant to allβ-lactam and quinolone antibiotics.The resistance rate to amikacin was 87.5%.The resistance rate to cotrimoxazole was 56.3%.The resistance rate to tigecycline was 6.2%.There were 30 mCIM positive cases and 1 eCIM positive case.30 carbapenemase-producing strains were detected by gene sequencing.90.6%(29/32)of the strains carried blaKPC-2,and one NDM-5 metalloenzyme producing strain was detected.The detection rates of extended-spectrum beta-lactamase SHV,CTX were 62.5%and 46.9%,respectively,and DHA-1 AmpC beta-lactamase 37.5%.MLST was classified into ST11 type(29 strains),accounting for 90.6%,ST524 type(2 strains),ST716(1 strain).For the expression level of outer membrane protein:the expression level of 12 OMPK35 strains decreased,and the expression level of OMPK35 and OMPK36 strains(4 strains)decreased simultaneously.Conclusion CRKP isolated from bloodstream infection in our hospital has high resistance,and the resistant bacteria mainly carry carbapenem resistance gene KPC-2.Resistance of non-carbapenemase-producing strains is associated with ESBLs production and reduced expression of outer membrane proteins.MLST shows that ST11 is the main type of CRKP in our hospital.

关 键 词：血流感染 碳青霉烯类耐药肺炎克雷伯菌 耐药基因 多位点序列分型 

分 类 号：R378.996[医药卫生—病原生物学]