ICU患者耐碳青霉烯类肺炎克雷伯菌的耐药及传播机制的分析

Antibiotic resistance and transmission mechanism of carbapenem-resistant Klebsiella pneumoniae in ICU patient

目的 探讨ICU患者耐碳青霉烯类肺炎克雷伯菌的耐药机制,并分析其传播特征。方法 收集2017年4月-2021年4月分离自ICU患者的59株碳青霉烯类耐药肺炎克雷伯菌(CRKP),K-B法进行药敏试验;改良Hodge试验和改良碳青霉烯灭活试验(m CIM)检测碳青霉烯酶表型;EDTA协同试验检测金属β-内酰胺酶;qPCR法检测碳青霉烯酶、超广谱β内酰胺酶(ESBL)、Amp C酶基因;接合试验初步探讨其传播机制。结果 59株CRKP对米诺环素、复方新诺明、阿米卡星、庆大霉素的耐药率较低(均<32.20%),对其他抗生素具有较高的耐药率。改良Hodge试验和mCIM试验结果均表明,有58株(98.31%)CRKP产碳青酶烯酶。EDTA协同试验检出5株(8.47%)CRKP产金属酶。qPCR检测结果显示,碳青霉烯酶基因检出58株(98.31%),ESBL基因检出59株(100%),Amp C酶基因检出5株(8.47%)。58株CRKP发生接合转移的有32株,转移发生率为55.17%,KPC-2亚型为主。结论 本院CRKP呈多重耐药性,其耐药机制以产KPC-2酶为主,且易通过质粒在菌株间相互传递。

Objective To analysis of antibiotic resistance and transmission mechanism of carbapenem-resistant Klebsiella pneumonia in the intensive care unit(ICU) in our hospital.Methods Collect 59 carbapenem-resistant Klebsiella pneumonia(CRKP) strains isolated from ICU patients from April 2017 to April 2021.Drug susceptibility was detected by K-B method;Modified Hodge test and modified carbapenem inactivation(m CIM) test were carried out to detect carbapenemase phenotype.Imipenem-EDTA disk method was used to detect whether the strain produced metallo-β-lactamase.PCR method was used to detect the genes encoding carbapenemases,ESBLs,Amp C enzyme genes.The joint experiment explores the propagation mechanism.Results All 59 CRKP strains had low resistance rates to minocycline,compound trimethoprim,amikacin,and gentamicin(all <32.20%),and high resistance rates to other antibiotics.Among them,the resistance rate of piperacillin,aztreonam,and cephalosporin antibiotics was 100%.Both the modified Hodge test and the mCIM test showed that 58 strains(98.31%) of CRKP produced carbapenase.Imipenem-EDTA disk method results showed that 5 strains(8.47%) of CRKP produced metalloenzymes.The qPCR test results showed that 58 strains(98.31%) of carbapenemase gene were detected,5 strains(8.47%) of the metal β-lactamase gene were detected.In addition,59 strains(100%) of ESBL gene were detected,and 5 strains(8.47%) of Amp C enzyme gene were detected.There were 32 of 58 CRKP strains undergoing conjugative metastasis,with a metastasis rate of 55.17%.Among them,one strain obtained the NDM-1 enzyme gene,and 31 strains obtained the KPC-2 enzyme gene.Conclusion CRKP in our hospital is multi-drug resistant,and its resistance mechanism is mainly KPC-2 enzyme production,and it is easily transmitted between strains through plasmids.