耐碳青霉烯类肠杆菌目细菌的碳青霉烯酶基因检测和临床分析

Detection and clinical analysis of carbapenemase gene of carbapenem-resistant Enterobacterales

目的了解医院耐碳青霉烯类肠杆菌目细菌(CRE)的临床分布、耐药性分析、携带的碳青霉烯酶耐药基因及患者临床情况。方法收集从临床样本中分离非重复128株CRE菌株,对所有CRE菌株用VITEK2 Compact鉴定仪和基质辅助激光解吸电离-飞行时间质谱仪进行鉴定与复核,进行mCIM和eCIM表型试验、碳青霉烯酶免疫层析法检测酶型和PCR技术检测基因型,用WHONET 5.6软件统计分析CRE临床分布和耐药率。查阅CRE菌株来源患者病历资料。结果mCIM阳性、eCIM阴性82株,mCIM阳性、eCIM阳性22株,m CIM阴性、eCIM不解释24株。免疫层析法检测酶型与PCR检测结果为产KPC菌株82株(78.8%),NDM菌株21株(20.2%),IMP菌株1株(1.0%),未检出VIM和OXA耐药基因。肺炎克雷伯菌主要携带耐药基因KPC(92.8%),大肠埃希菌主要携带耐药基因NDM(91.7%)。主要耐药菌株为肺炎克雷伯菌(72.7%),其次为大肠埃希菌(16.4%),CRE主要分布于神经外科(27.3%),其次为ICU(23.4%),标本类型以痰液标本为主(66.4%),其次为尿液标本(16.4%);对厄他培南、亚胺培南、美罗培南的耐药率分别为100.0%、83.6%和80.5%,头孢他啶/阿维巴坦的耐药率为17.2%,耐药菌株见于产NDM、IMP菌株,但对替加环素耐药率较低(2.5%)。男性70例,女性51例,年龄主要为老年患者,>60岁占53.7%;基础疾病主要见于颅脑疾病,其次为恶性肿瘤、2型糖尿病;抗菌药物使用2种或以上占88.4%;住院天数>14 d占76.9%,抗菌药物使用>14 d占70.2%,患者死亡或自动出院占39.7%。结论CRE菌株主要携带KPC耐药基因,大多分布于神经外科,肺炎克雷伯菌占比最高,以痰标本为主,CRE感染主要见于颅脑疾病,住院时间长,使用抗生素种类多的老年患者,这些结果对于临床加强耐药监测、合理选用抗生素具有重要参考价值。

Objective To observe the clinical distribution,drug resistance and carbapenem-resistant genes and clinical situation of carbapenem-resistant Enterobacterales(CRE)in the hospital.Methods A total of 128 non-duplicate CRE strains were isolated from clinical samples,which were identified and rechecked using VITEK 2 Compact and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.All the strains were analyzed with carbapenemase phenotypic screening test(mCIM and eCIM),the enzyme type were detected using the rapid detection method of carbapenemase(colloidal gold immunochromatography)and PCR was used to detect the genotype.WHONET 5.6 was used to analyze the clinical distribution and drug resistance.Review the patient case data for CRE strains.Results A total of 82 strains were mCIM positive and eCIM negative;22 strains were mCIM positive and eCIM positive;24 strains were mCIM negative and eCIM uninterpreted.The results of immunochromatography and PCR detection were 82 KPC-producing strains(78.8%),21 NDM-producing strains(20.2%),and 1 IMP-producing strain(1.0%).;no VIM and OXA resistance genes were detected.Klebsiella pneumoniae mainly carried KPC(92.8%),and Escherichia coli mainly carried NDM(91.7%).Klebsiella pneumoniae accounted for the highest proportion of CRE strains(72.7%),followed by Escherichia coli(16.4%);CRE mainly distributed in neurosurgery(27.3%),followed by ICU(23.4%).Sputum samples were the main type(66.4%),followed by urine samples(16.4%).The resistance rate to Ertapenem,Imipenem and Meropenem were 100.0%,83.6%and 80.5%respectively,and that to Ceftazidime/Avibactam was 17.2%.The drug-resistant strains were found in NDM-and IMP-producing strains respectively,but the resistance rate to Tigecycline was lower(2.5%).There were 70 males and 51 females,mainly elderly patients,53.7%of whom were over 60 years old.The main underlying diseases were craniocerebral diseases,followed by malignant tumors and type 2 diabetes mellitus.88.4%of the patients used two or more kinds of antibiotics;duration of hospitalization>14 days accounted for 76.9%,use of antibiotics>14 days accounted for 70.2%;death and/or voluntary discharge accounted for 39.7%.Conclusion CRE strains mainly carry KPC resistance genes,and most of them are distributed in the neurosurgery department,with Klebsiella pneumoniae accounting for the highest proportion,mainly in sputum specimens.CRE infection is mainly found in elderly patients with craniocerebral diseases,long hospital stay and use of multiple antibiotics.These results have important reference value for strengthening clinical drug resistance monitoring and rational selection of antibiotics.