耐碳青霉烯类抗菌药物的耐药性及其相关影响因素

Analysis of drug resistance of carbapenem-resistant antibiotics and its related influencing factors discussion

目的对耐碳青霉烯类肠杆菌科产碳青霉烯酶、整合子分布及外膜孔蛋白的缺失情况进行分析和特征讨论。方法收集宜宾市第三人民医院患者的痰液、尿液、分泌物、血液等标本,临床分离的87株对碳青霉烯类抗菌药物耐药的肠杆菌科细菌(CRE)菌株进行分析。结果对87株CRE菌株进行聚合酶链反应扩增碳青霉烯酶基因,检出碳青霉烯酶基因74株,占85.06%。包括肺炎克雷伯菌65株(87.84%),大肠埃希菌6株(8.11%),阴沟肠杆菌、产酸克雷伯菌、产气肠杆菌各1株,分别占1.35%。整合酶基因检测结果显示,Ⅰ类整合子检出52株,检出率为59.77%(52/87),其中47株来自产碳青霉烯酶菌株,5株为非产碳青霉烯酶菌株,同时均以肺炎克雷伯菌检出的比例最高(分别为39株和3株);Ⅱ类整合子检出8株,检出率为9.20%(8/87),其中4株来自产碳青霉烯酶菌株,4株为非产碳青霉烯酶菌株;未检出Ⅲ类整合子。Ⅰ类和Ⅱ类整合子检出3株,2株来自产碳青霉烯酶的肺炎克雷伯菌株,1株为非产碳青霉烯酶的肺炎克雷伯菌株。肺炎克雷伯菌菌株外膜孔蛋白缺失情况表明,70株对碳青霉烯类抗菌药物耐药的肺炎克雷伯菌株中,膜蛋白无异常达18.57%,其中产碳青霉烯酶菌株中膜蛋白无异常为16.92%;OmpK35表达下调的菌株占24.29%,OmpK35缺失的占10.00%;OmpK36表达下调和缺失的比例分别为4.23%和57.14%;产碳青霉烯酶菌株中OmpK35表达下调的菌株占50.77%,OmpK35缺失的占9.23%;OmpK36表达下调和缺失的比例分别为3.08%和55.38%。结论对碳青霉烯类抗菌药物耐药的CRE的耐药情况非常严重,且肺炎克雷伯菌碳青霉烯酶基因检出最高,耐药最严重;耐药性的发生还与整合酶基因Ⅰ类整合子,以及孔膜蛋白表达减低与缺失密切相关。

Objective To analyze and characterize the carbapenemase,integron distribution and the loss of outer membrane pore protein of carbapenem-resistant Enterobacteriaceae.Methods A total of 87 carbapenemresistant strains isolated from clinical specimens of sputum,urine,secretions and blood were collected.A total of 87 isolates of carbapenem-resistant Enterobacteriaceae（CRE）strains were analyzed to discuss the production of carbapenemase,integrin distribution and the outer membrane pore protein in the absence of analysis and characteristics.Results A total of 87 carbapenem antibiotics resistant strains of Enterobacteriaceae（CRE）were amplified by PCR for carbapenemase gene.The results showed that 74 strains of carbapenemase genes were detected,accounting for 85.06%,including Klebsiella pneumoniae 65 strains（87.84%）,the highest proportion of detection;In addition,Escherichia coli detected in 6 cases（8.11%）,Enterobacter cloacae,Klebsiella oxytoca and Enterobacter aerogenes were detected in 1 patient,accounting for 1.35%.Fifty-two ClassⅠintegrons were detected in the integrase gene,and the detection rate was 59.77%（52/87）.47 strains were from carbapenemase-producing strains,5 strains were from non-producing carbapenems,and the highest proportion was detected by Klebsiella pneumoniae（39 cases and 3 cases,respectively）.The detection rate of class Ⅱ integrons was 9.20%（8/87）,and the positive rate of Klebsiella pneumoniae was the highest,Of which 4 strains were from carbapenemase-producing strains and 4 strains were from non-carbapenemase-producing strains.In this study,class Ⅲ integrons were not detected.Three isolates of classⅠ and class Ⅱ integrons were identified,two were Klebsiella pneumoniae-producing Klebsiella pneumoniae strains and 1 Klebsiella pneumoniae isolates from non-carbapenemase-producing strains.Klebsiella pneumoniae outer membrane pore protein loss analysis results suggest that a total of 70 strains of carbapenem antibiotic-resistant Klebsiella pneumoniae strains,the membrane protein is no abnormal ratio of 18.57%,of which carbapenem producing strain accounting for16.92%;The proportion of down regulated OmpK35 expression was 24.29%,and OmpK35 deletion was 10.00%;The proportion of down regulated OmpK36 was 4.23% and OmpK36 deletion 57.14%,respectively.Among the carbapenem producing strains,the percentage of down regulated OmpK35 was 50.77%,OmpK35 deletion was 9.23%,and the ratio of OmpK36 expression down and deletion was 3.08% and 55.38%,respectively.Conclusion The resistance of carbapenem-resistant Enterobacteriaceae to carbapenemresistant bacteria is severe,and the Klebsiella pneumoniae carbapenemase gene is the most sensitive and the drug-resistant is the most serious.The occurrence of drug resistance is also related to the integrase Gene classⅠintegrons and decreased expression of porcine membrane protein are closely related to the deletion.