多重耐药鲍曼不动杆菌耐药基因及分子流行病学研究

发布时间：2018-02-24 08:49

本文关键词： 多重耐药鲍曼不动杆菌耐药基因聚合酶链反应脉冲场凝胶电泳　出处：《四川医科大学》2015年硕士论文　论文类型：学位论文

【摘要】：鲍曼不动杆菌是一类非发酵的革兰阴性杆菌,为条件致病菌。广泛存在于水、土壤、医院环境和人体皮肤表面,是医院感染的重要致病菌之一,主要引起获得性肺炎特别是呼吸机相关性肺炎、菌血症、尿路感染、继发性脑膜炎等。随着广谱抗菌药物和免疫抑制剂大量使用,对常用的β-内酰胺类、氨基糖苷类、氟喹诺酮类等抗菌药物同时耐药的多重耐药鲍曼不动杆菌分离率明显增多,并在医院内广泛流行,给临床抗感染治疗带来极大的麻烦,同时对医院感染控制提出了新的挑战。对多重耐药鲍曼不动杆菌(Multi-drug resistant Acinetobacter baumannii,MDRAB)的药敏试验和医院科室分布情况进行统计和分析,并检测相关耐药基因和对菌株进行同源性分析,从而指导医生合理使用抗菌药物,探讨我院多重耐药鲍曼不动杆菌产生的耐药机制,为我院预防与控制院内感染提供理论依据,给流行病学研究奠定基础。本研究收集四川医科大学附属第一医院2013年9月至2014年9月临床分离的62株非重复多重耐药鲍曼不动杆菌。利用MicroScan WalkAway96 Plus全自动微生物鉴定/药敏测试系统进行鉴定、验证,琼脂稀释法检测菌株对23种抗生素的最低抑菌浓度(MIC),利用聚合酶链反应(Polymerase Chain Reaction,PCR)检测菌株的6种相关耐药基因(TEM、SHV、VIM、IMP、OXA-23、OXA-24)的携带情况,将扩增所得的阳性产物送上海铂尚生物技术有限公司测序,将测序所得序列和GenBank数据库进行对比分析,并采用脉冲场凝胶电泳(Pulsed Field Gel Electrophoresis,PFGE)对62株多重耐药鲍曼不动杆菌进行分子分型并分析其同源性。结果显示:62株多重耐药鲍曼不动杆菌主要分离于痰液,其中40株分离于痰液标本,11株分离于分泌物,其余为分离于血液标本4株、中段尿标本3株、脑脊液标本2株和胸水标本2株。临床科室分布分别是重症监护室24株,呼吸内科10株,神经外科8株,余下菌株来源于其他临床科室。62株多重耐药鲍曼不动杆菌对青霉素类的耐药率均为100%;对头孢菌素中头孢曲松钠耐药率为96.8%,其余均为100%。对氨苄西林/舒巴坦的耐药率为80.6%,对碳青霉烯类抗生素中亚胺培南和美罗培南的耐药率为90.3%和88.7%,对氨基糖苷类抗生素中庆大霉素、阿米卡星、妥布霉素的耐药率分别为93.5%、80.6%和53.2%,对喹诺酮类抗生素中环丙沙星、左氧氟沙星、加替沙星的耐药率分别为100%、85.5%和64.5%,对多粘菌素和多粘菌素b的耐药率为12.9%和11.3%。对四环素、米诺环素、替加环素的耐药率分别为90.3%、17.7%、3.2%。对磺胺甲恶唑和利福平的耐药率为69.4%和92%。6种耐药基因共检出4种,其中tem阳性有52株,阳性率为83.9%,vim阳性有53株,阳性率为85.5%,imp阳性有41株,阳性率为66.1%,oxa-23阳性有58株,阳性率为93.5%。4种耐药基因阳性扩增产物经测序后与genbank中已提交的相应基因序列的同源性为98%-100%。pfge将62株多重耐药鲍曼不动杆菌分为4型,a型和b型为主要克隆株。a型包括4个亚型共32株,b型有2个亚型共19株,c克隆有8株。d克隆有3株。以上研究表明我院分离的多重耐药鲍曼不动杆菌主要分布在呼吸内科、重症监护室、神经外科,呼吸道感染在感染病例中为主,与接受各种侵袭性操作有关。多重耐药鲍曼不动杆菌的耐药情况十分严峻,62株耐药菌株对23种抗生素的耐药水平高于全国细菌耐药监测网的水平。oxa-23在62株多重耐药鲍曼不动杆菌中的携带率最高,为93.5%。并且携带vim、tem、imp菌株也高达85.5%、83.9%、66.1%,说明携带多种耐药基因是在多重耐药鲍曼不动杆菌的中十分普遍。我院鲍曼不动杆菌pfge分型分为4型,以a型为主,共有32株占51.6%,主要在重症监护室、呼吸内科、神经外科、骨科、血液科5个病区流行,其次为B型,主要集中在呼吸内科、重症监护室和儿科。多重耐药鲍曼不动杆菌在我院各临床科室广泛分布并流行传播,克隆株在医院内部和医院之间克隆蔓延已成为全球性的问题,成为耐药菌株逐年增加的一个重要因素。因此,应对医院感染控制加大力度,制定更加严格的院感制度,慎重合理使用抗菌药物,防止多重耐药鲍曼不动杆菌的爆发流行。
[Abstract]:Bauman Acinetobacter is a kind of non fermentative gram negative bacteria are opportunistic bacteria. Widely exist in water, soil, hospital environment and human skin is an important pathogen of nosocomial infection, the main cause of pneumonia especially ventilator-associated pneumonia, bacteremia, urinary tract infection, secondary meningitis etc. with the use of antibacterial drugs and immunosuppressive agents of common broad-spectrum beta lactams, aminoglycosides, multi drug resistant Bauman fluoroquinolones and other antimicrobial agents and drug resistance of Acinetobacter isolated rate increased significantly, and widely popular in the hospital for clinical anti infection treatment brought great trouble to the hospital at the same time the infection control has brought new challenges. For multi drug resistant Acinetobacter Bauman (Multi-drug resistant Acinetobacter baumannii, MDRAB) of the drug sensitivity test and the distribution of hospital departments of statistics and Analysis and detection of drug resistance related genes and to analyze the homology of the strains, so as to guide the rational use of antimicrobial drugs doctors in our hospital, to explore multidrug resistance mechanisms of Bauman, provide a theoretical basis for the prevention and control of hospital infection in our hospital, to lay the foundation for epidemiological research. This study collects the Sichuan Medical University the first hospital from September 2013 to September 2014 a total of 62 strains of non repetitive multi drug resistant Acinetobacter Bauman. Confirmed by MicroScan WalkAway96 Plus automatic microorganism identification / drug sensitivity test system were identified, the minimum inhibitory concentration of agar dilution method to detect strains to 23 antibiotics (MIC), using polymerase chain reaction (Polymerase Chain Reaction. PCR) 6 kinds of drug resistance related gene detection strains (TEM, SHV, VIM, IMP, OXA-23, OXA-24) the carrying status of positive products of the amplified platinum is sent to Shanghai students Material Technology Co. Ltd. will be sequenced, sequence and GenBank database were analyzed by pulsed field gel electrophoresis (Pulsed Field Gel Electrophoresis, PFGE) of 62 strains of multidrug-resistant Acinetobacter Bauman for molecular typing and homology analysis. The results showed that 62 strains of multidrug-resistant Acinetobacter isolated from major Bauman in the sputum, 40 of which were isolated from sputum specimens, 11 strains were isolated from the rest of secretions, is separated from the blood samples of 4 strains, 3 strains of urine, cerebrospinal fluid specimens of 2 strains and 2 strains of pleural effusion specimens. The distribution of clinical departments were ICU 24 strains, 10 strains of respiratory medicine, Department of Neurosurgery, 8 strains. The remaining strains from other clinical departments.62 strains of multi resistant Acinetobacter Bauman resistant to penicillin rate was 100%; the cephalosporin ceftriaxone resistance rate was 96.8%, the rest are 100%. to ampicillin / sulbactam The resistant rate was 80.6%, the resistance to imipenem in carbapenems imipenem and meropenem were 90.3% and 88.7%, the aminoglycoside antibiotic gentamicin, Amikacin, tobramycin resistance rates were 93.5%, 80.6% and 53.2% of the quinolones antibiotics ciprofloxacin, levofloxacin, gatifloxacin resistance rates were 100%, 85.5% and 64.5% of polymyxin B and polymyxin resistance rate of 12.9% and 11.3%. of tetracycline, minocycline, tigecycline resistance rates were 90.3%, 17.7%, 3.2%. resistant to sulfamethoxazole and rifampin were 69.4% and 92%.6 resistant genes were detected in 4, among them there are 52 TEM positive strains, the positive rate was 83.9%, VIM positive 53 strains, the positive rate was 85.5%, imp positive 41 strains, the positive rate was 66.1%, OXA-23 positive 58 strains, the positive rate of 93.5%.4 gene positive PCR products were sequenced and Gen The homology of the corresponding gene sequence has been submitted to the bank in the 98%-100%.pfge of 62 strains of multi resistant Acinetobacter Bauman is divided into 4 types, type A and B as the main clone. Type A includes 4 subtypes of 32 strains, 2 B subtype 19 strains, 8 strains of C clone.D clone 3 the study indicated that multi drug resistant strains. Bauman in our hospital isolates of Acinetobacter are mainly distributed in the Department of respiratory medicine, Department of Neurosurgery, ICU, mainly in case of infection of respiratory tract infection, and accept a variety of invasive operation. Multidrug resistant Bauman real drug resistance bacteria is very serious, the level of resistance of 62 strains of resistant strains to 23 antibiotics is higher than that of mohnarin level.Oxa-23 in 62 strains of multidrug-resistant Acinetobacter Bauman in carrying the highest rate, carrying VIM, 93.5%. and TEM, imp was as high as 85.5%, 83.9%, 66.1%, that carry multiple resistance genes in multiple Bauman resistant Acinetobacter is common in our hospital. Bauman Acinetobacter PFGE divided into 4 types, with a total of 32 strains, accounting for 51.6%, mainly in the ICU, respiratory medicine, Department of Neurosurgery, Department of orthopedics, Department of Hematology, 5 wards pop, followed by B, mainly concentrated in the Department of respiratory medicine ICU, and pediatrics. Multi drug resistant Acinetobacter Bauman in all clinical departments in our hospital are widely distributed and spreading, clones between the hospital and hospital internal clone spread has become a global problem, become drug resistant strains increased year by year one of the most important factors. Therefore, to deal with the hospital infection control efforts to develop more strict hospital system, carefully rational use of antimicrobial drugs to prevent multidrug resistant Bauman real epidemic coli outbreak.

【学位授予单位】：四川医科大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R446.5

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