对碳青霉烯类抗生素不敏感肠杆菌科细菌NDM-1基因分析

发布时间：2018-03-29 03:06

本文选题：肠杆菌科　切入点：碳青霉烯酶　出处：《华北理工大学》2015年硕士论文

【摘要】：目的了解我院临床分离的对碳青霉烯类抗生素不敏感的肠杆菌科细菌感染患者的临床特征,对常用抗菌药物的耐药性,明确产碳青霉烯酶表型和NDM-1基因型检出情况。方法收集我院2013年4月到2014年3月临床分离的对碳青霉烯类抗生素不敏感的肠杆菌科细菌作为研究对象。采用改良Hodge试验检测细菌是否产碳青霉烯酶,双纸片协同试验筛查金属β-内酰胺酶。对高度耐药的肠杆菌科细菌利用特异性引物进行NDM-1基因PCR扩增,采用双脱氧末端终止法进行DNA测序,所测序列与Gen Bank基因库中的已知序列进行BLAST比对,以明确所测细菌的基因型。结果1菌株分布情况:我院2013年4月到2014年3月临床标本中分离出30株对碳青霉烯类抗生素不敏感的肠杆菌科细菌,其中肺炎克雷伯菌16株,占53.3%;阴沟肠杆菌12株,占40.0%;弗劳地枸橼酸杆菌和布氏枸橼酸杆菌各1株。这些细菌来自不同的科室,但主要分布在重症医学科15株(50.0%),神经内科重症病房8株(26.7%),其次为普通外科4株(13.3%),神经内科、呼吸内科和康复科各1株。标本主要来源于痰20株,占66.7%,其次为尿液5株(16.7%),血液4株(13.3%),引流液1株(3.3%)。2药物敏感性试验结果:30株细菌对氨苄西林、头孢菌素类、含β-内酰胺酶抑制剂的复合制剂和单环β-内酰胺类抗生素的耐药率最高,均为100%;对碳青霉烯类抗生素亚胺培南和美洛培南的耐药率分别为100%和86.7%;对四环素、氯霉素、庆大霉素、左氧氟沙星、环丙沙星的耐药率在66.7%~93.3%之间;对多粘菌素最敏感,敏感率高达100%,其次为复方新诺明和阿米卡星,敏感率分别为66.7%和46.7%。3表型确认结果:30株细菌中,26株改良Hodge试验阳性,即检出产碳青霉烯酶细菌26株,阳性率为86.7%(26/30);18株双纸片协同试验阳性,即检出产金属β-内酰胺酶细菌18株,阳性率为60.0%(18/30)。4 NDM-1基因确证结果:对高度耐药的肠杆菌科细菌进行NDM-1基因确证,共有5株为产NDM-1菌株。5株菌包括肺炎克雷伯菌2株,阴沟肠杆菌2株,布氏枸橼酸杆菌1株;其中分布在重症医学科3株,神经内科重症病房2株;3株分离自患者尿液,2株分离自患者痰。5株细菌对多粘菌素均敏感,3株对复方新诺明敏感,2株对阿米卡星敏感;而对常见的β-内酰胺类抗生素以及喹诺酮类、四环素类、氯霉素类等非β-内酰胺类抗生素均耐药。5株产NDM-1菌株改良Hodge试验以及双纸片协同试验结果均为阳性。5感染患者临床特征:30株肠杆菌科细菌分离自28例患者。28例细菌感染患者平均年龄约为74岁,多有较严重的呼吸道疾病,心脑血管疾病,严重外伤,重症感染等基础疾病,平均住院时间8个月。其中5株产NDM-1菌株分离自4例患者,感染患者平均年龄为73岁,2例脑梗死,1例肾功能不全,1例感染性休克,平均住院时间10个月。4例细菌感染患者最终2例存活,2例死亡。结论1我院临床分离的对碳青霉烯类抗生素不敏感的肠杆菌科细菌主要以肺炎克雷伯菌和阴沟肠杆菌为主,在临床主要引起病人下呼吸道感染,对临床常用抗菌药物表现为多重耐药。2我院肠杆菌科细菌已出现产NDM-1菌株,其主要引起病人泌尿系统感染和下呼吸道感染。年老体弱,严重的基础疾病,长期住院,侵入性治疗,这些都是产NDM-1菌株产生的诱发因素。感染产NDM-1菌株患者的死亡是由严重的基础疾病引起的,而与感染产NDM-1细菌并无直接的关系。3产NDM-1菌株除了对多粘菌素全部敏感,对复方新诺明和阿米卡星部分敏感外,对其他类抗生素全部耐药,临床在治疗此类细菌引起的感染时可进行参考。
[Abstract]:Objective to investigate the clinical isolates in our hospital of carbapenem sensitive of bacteria of Enterobacteriaceae infections in patients with clinical features, of antibiotic resistance, clear carbapenemase producing phenotype and NDM-1 genotype detection. Methods collected in our hospital from April 2013 to March 2014 the clinical separation is not sensitive to carbapenems antibiotics of the Enterobacteriaceae bacteria as the research object. By detecting the modified Hodge test whether carbapenemases, double disk synergy test screening of metallo beta lactamase. Specific primers of Enterobacteriaceae based on highly drug-resistant NDM-1 gene was amplified by PCR, using the dideoxy method for DNA sequencing, the measuring the known sequence Gen sequence and Bank gene library of BLAST in comparison, clear genotype measured by bacteria. Results 1 strains distribution: in our hospital from April 2013 to March 2014 Pro Isolation of 30 strains is not sensitive to carbapenems in Enterobacteriaceae clinical specimens, including 16 strains of Klebsiella pneumoniae, accounting for 53.3%; 12 strains of Enterobacter cloacae, accounted for 40%; Citrobacter freundii and Citrobacter freundii 1 strains. These bacteria from different departments, but mainly in the ICU of 15 strains (50%), Department of Neurology ICU 8 strains (26.7%), followed by general surgery, 4 strains (13.3%), Department of Neurology, Department of respiratory medicine and Rehabilitation Department of the 1 strains. 20 strains from sputum specimens, accounting for 66.7%, followed by the urine of 5 strains (16.7%). The blood of 4 strains (13.3%), 1 strains (3.3%) drainage.2 drug sensitivity test results: 30 strains of bacteria to ampicillin, cephalosporins, drug containing beta lactamase inhibitor compound and monobactam antibiotic. The highest rate was 100%; resistant to carbapenems imipenem and meropenem Rates were 100% and 86.7%; tetracycline, chloramphenicol, gentamicin, levofloxacin, ciprofloxacin resistance rate was 66.7%~93.3%; the most sensitive to polymyxin, sensitive rate as high as 100%, followed by cotrimoxazole and Amikacin, the sensitive rates were 66.7% and 46.7%.3 confirmed phenotypic results: 30 strains of bacteria. 26 strains of modified Hodge test positive detection of carbapenemase produced 26 bacterial strains, the positive rate was 86.7% (26/30); 18 strains of double disk synergy test is positive, i.e. producers of metallo beta lactamase 18 bacterial strains, the positive rate was 60% (18/30).4 NDM-1 gene confirmed: NDM-1 gene was confirmed Enterobacteriaceae of highly resistant, a total of 5 strains of NDM-1 producing strains.5 strains including 2 strains of Klebsiella pneumoniae, 2 strains of Enterobacter cloacae, Citrobacter freundii 1 strains; the distribution in ICU of 3 strains, 2 strains of the ICU Department of Neurology; 3 strains isolated from patients Urine, 2 strains isolated from sputum bacterial strains in.5 were sensitive to polymyxin, 3 strains of cotrimoxazol-sensitive, 2 strains were sensitive to Amikacin; and tetracycline on common beta lactam antibiotics such as chloramphenicol, quinolones, and non beta lactam antibiotic resistant.5 strains strain NDM-1 modified Hodge test and double disc synergy test results for clinical characteristics of patients with positive.5 infection: 30 strains of Enterobacteriaceae isolated from 28 patients with.28 cases of bacterial infection in patients with an average age of about 74 years, there are more severe respiratory disease, cardiovascular disease, severe trauma, severe infection and other diseases and the average hospitalization time was 8 months. Among the 5 strains of NDM-1 producing strains were isolated from 4 patients, infection in patients with an average age of 73 years, 2 cases of cerebral infarction, 1 cases of renal insufficiency, 1 cases of septic shock, the average hospitalization time was 10 months.4 cases of bacterial infection in patients with the final 2 The patients survived, 2 cases died. Conclusion: 1 our hospital clinical isolates of carbapenem sensitive Enterobacteriaceae in Klebsiella pneumoniae and Enterobacter cloacae, in clinical patients mainly caused lower respiratory tract infections, to antibiotics showed multiple drug resistant Escherichia coli.2 in our hospital there has been NDM-1 producing strains of bacteria, the main cause of patients with urinary system infection and lower respiratory tract infection. The frail elderly, basic diseases, serious long-term hospitalization, invasive treatment, these are the inducing factors of NDM-1 producing strains. NDM-1 producing strains infection is caused by the death of patients with severe underlying diseases, and with the infection of NDM-1 producing bacteria have no direct relationship between.3 in addition to NDM-1 producing strains were completely sensitive to polymyxin, to cotrimoxazole and Amikacin some sensitive to other antibiotics, all clinical in the treatment of such resistance. A bacterial infection can be used for reference.

【学位授予单位】：华北理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R446.5

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