肠道定植和血流感染肠杆菌科细菌的流行病学分析

发布时间：2018-05-27 01:01

本文选题：血流感染 + 养老院　；参考：《上海交通大学》2015年硕士论文

【摘要】：目的:了解养老院居住者肠道定植产超广谱β-内酰胺酶(Extended-spectrumβ-lactamase,ESBLs)肠杆菌科细菌的发生率和耐药性,并从居住者个人、医护人员和养老院机构三个层面确定定植危险因素;了解瑞金医院2012年住院患者血培养分离病原体种类和耐药性,在此基础上对2011-2013年该院分离的引起血流感染(Bloodstream infections,BSI)大肠埃希菌的耐药性和分子流行病学特征进行分析,进而为临床合理使用抗菌药物、防控医院获得性血流感染和耐药菌的播散提供科学依据。方法:1)以VITEK 2Compact全自动微生物分析系统鉴定细菌作为参考方法,建立联合应用科玛嘉定位显色培养基、吲哚试验、鸟氨酸脱羧酶试验、赖氨酸脱羧酶试验鉴定常见氧化酶阴性革兰阴性杆菌的方法并进行评估;2)收集上海市7家养老机构居住者的肛拭标本和临床病历资料,对分离出的肠杆菌科细菌菌株采用上述方法进行鉴定,纸片扩散法进行药敏试验,聚合酶链式反应(Polymerase chain reaction,PCR)扩增编码ESBLs和碳青霉烯酶的基因,应用统计学软件从居住者个人、医护人员、机构水平三个层面对所有可能的变量进行分析并确定产ESBLs菌株定植的危险因素;3)收集瑞金医院2012年1月1日-12月31日住院患者送检所有血培养标本的菌株信息和患者信息以分析阳性检出率、病原体分布、科室分布、患者特征和耐药性;4)收集瑞金医院2011年6月-2013年6月引起血流感染最常见的大肠埃希菌菌株,纸片扩散法进行药敏试验,pcr扩增编码esbls和碳青霉烯酶的基因、系统发生群基因和多位点序列分型(multi-locussequencetyping,mlst)基因,并采用软件eburst对序列型(sequencetype,st)进行分析以探究菌株间的同源性。结果:1)采用本次研究所建立的以显色培养基联合简单生化反应的鉴定方案对8个属10个种共318株菌的鉴定结果表明,与vitek2compact全自动微生物分析系统鉴定结果相比,这10个菌种鉴定的特异性均大于90%,灵敏度为75%~100%;一致性分析表明除弗劳地枸橼酸杆菌的kappa值为0.5947外,其余均大于0.85;mcnemar检验p值均大于0.05;该鉴定法成本只有参考方法的10%;2)390位养老院居住者共分离到457株肠杆菌科细菌,其中183(46.92%)株产esbls;大肠埃希菌(365,79.87%)、奇异变形杆菌(40,8.75%)和肺炎克雷伯杆菌(24,5.25%)是最常见的菌种;ctx-m是最常见的β-内酰胺酶(198,99.00%),其中ctx-m-14(84,42.00%)的比例最高;两株产碳青霉烯酶的肺炎克雷伯杆菌分离自同一家养老院,均携带blakpc-2且均为st11;分离菌对碳青霉烯类、tzp,ak,fos,cl和tgc的耐药率低;侵入性医疗操作(or=3.112,95%ci1.725-5.615,p=0.000)、喹诺酮使用史(or=1.808,95%ci1.047-3.121,p=0.034)和每周洗澡次数(or=1.959,95%ci1.163-3.302,p=0.012)是肠道定植产esbls肠杆菌科细菌的独立相关变量;3)2012年瑞金医院5546例住院患者送检血培养标本16428份,血培养阳性者384例,阳性率为6.92%;检出病原体398株,其中革兰阴性(g-)菌272株(68.34%),革兰阳性(g+)菌94株(23.62%),真菌32株(8.04%);61~80岁患者阳性率(8.26%)最高,送检阳性率居前5位的科室分别是灼伤整形科、中医科、心外监护病区、移植病区和创伤外科;g+球菌对va、tec、lzd保持高敏感率,发现1株耐万古霉素屎肠球菌;g-杆菌中肠杆菌科细菌对ak和碳青霉烯类药物敏感率高,肠杆菌科细菌、鲍曼不动杆菌、铜绿假单胞菌对碳青霉烯类药物的耐药率分别为7.51%、70.97%、35.90%;4)2011年6月至2013年6月共连续收集到引起血流感染大肠埃希菌128株,其中80株产esbls,未发现产碳青霉烯酶菌株;分离株对ak,tzp和碳青霉烯类抗生素保持高敏感率;ctx-m-14(40/80)是最常见的β-内酰胺酶,其次是ctx-m-55(17/80)和ctx-m-15(14/80);b2群是最常见的系统发生群,但是在产esbls菌株中d群的比例最高;共检测到49个序列型,分为6个非重复的进化组或克隆复合物以及33个单体,其中st131(17/128)是最常见的序列型,其次是st69(12/128)和st648(10/128)。结论:1)显色培养基联合简单生化试验可快速经济有效地鉴定数种常见氧化酶阴性革兰阴性杆菌;2)养老院居住者每周的洗澡次数、侵入性医疗操作史和喹诺酮类抗生素使用史是产ESBLs肠杆菌科细菌肠道定植的独立相关变量,抗生素的合理使用、遵循无菌操作和护理原则、注意养老院居住者的个人卫生是控制耐药菌在养老机构播散的重要措施;3)瑞金医院血流感染病原体以G-菌为主,老年患者血培养阳性率高,引起血流感染大肠埃希菌的同源性低,不存在产ESBLs菌株的院内克隆传播;4)养老院居住者肠道产ESBLs肠杆菌科细菌的定植率和瑞金医院血流感染产ESBLs大肠埃希菌的发生率均较高(45%),但是后者高于前者,而且后者对大多数临床常用抗生素的耐药率也高于前者,TZP、AK、FOS、CL、TGC和碳青霉烯类可作为治疗的良好选择,ESBL表型均以CTX-M-14、CTX-M-15和CTX-M-55为主。
[Abstract]:Objective: to understand the incidence and resistance of Extended-spectrum beta lactamase (Extended-spectrum beta -lactamase, ESBLs) Enterobacteriaceae in the enteric colonization of the elderly in the nursing home, and to determine the risk factors of colonization from the three levels of the inhabited individual, the medical staff and the nursing home institution, and to understand the pathogen of the blood culture separation of the hospitalized patients in Ruijin hospital in 2012. On the basis of the species and drug resistance, the drug resistance and molecular epidemiology of the Bloodstream infections (Bloodstream infections, BSI) Escherichia coli isolated from the hospital were analyzed on this basis, and the scientific basis for the rational use of antibiotics and prevention and control of the hospital acquired blood flow infection and the spread of drug resistant bacteria was provided. 1) 1) using the VITEK 2Compact automatic microbiological analysis system to identify the bacteria as a reference method, the combined application of Colma color culture medium, indole test, ornithine decarboxylase test, lysine decarboxylase test and evaluation of common oxidase negative gram-negative bacilli were evaluated. 2) 7 pension institutions in Shanghai were collected. The resident's anal swab specimens and clinical records were used to identify the isolated bacterial strains of Enterobacteriaceae, drug sensitivity test, polymerase chain reaction (Polymerase chain reaction, PCR) to amplify the genes encoding ESBLs and carbapenem, using statistical software from the inhabited individual and the medical staff. The three levels of the institutional level were analyzed for all possible variables and the risk factors for ESBLs producing strain were determined. (3) the strain information and patient information of all the blood culture specimens in Ruijin hospital on January 1, 2012 -12 month were collected to analyze the positive rate, the distribution of the disease, the distribution of the Department, the characteristics of the patients and the drug resistance. 4) collect the most common Escherichia coli strains that caused the blood flow infection in Ruijin hospital in June -2013 June 2011, the paper diffusion method for drug sensitivity test, PCR amplification of ESBLs and carbapenem gene, systematic gene and multipoint sequence typing (multi-locussequencetyping, MLST) gene, and eburst sequence type (sequ). Encetype, st) analysis to explore the homology between strains. Results: 1) the identification results of 8 genera and 10 species were identified by the identification scheme of color culture medium combined with simple biochemical reaction established by this study. Compared with the vitek2compact automatic microbiological analysis system identification results, the identification of the 10 strains was specific. The sex was more than 90% and the sensitivity was 75%~100%; the consistency analysis showed that the kappa value of citric acid bacilli was 0.5947, the rest was more than 0.85; the p value of McNemar test was more than 0.05; the cost of the identification method was only 10% of the reference method; 2) 390 elderly residents were separated into 457 Enterobacteriaceae, of which 183 (46.92%) plants produced ESBLs; 365,79.87%, 40,8.75% and Klebsiella pneumoniae (24,5.25%) are the most common strains; ctx-m is the most common beta lactamase (198,99.00%), of which the proportion of ctx-m-14 (84,42.00%) is the highest; two Klebsiella pneumoniae producing carbapenenes from the same nursing home, all carrying blakpc-2 and all For st11, the resistance rates of isolated bacteria to carbapenems, TZP, AK, FOS, Cl and TGC were low; invasive medical operations (or=3.112,95%ci1.725-5.615, p=0.000), the history of the use of quinolone (or=1.808,95%ci1.047-3.121, p=0.034) and weekly bath times (or=1.959,95% ci1.163-3.302) were independent variables of Enterobacteriaceae. 3) in 2012, there were 16428 samples of blood culture specimens from 5546 hospitalized patients in Ruijin hospital and 384 positive blood culture cases, the positive rate was 6.92%, 398 strains of pathogens were detected, including 272 gram-negative (g-) strains (68.34%), 94 (23.62%) and 32 (8.04%) strains of gram-positive (23.62%) bacteria (23.62%); the positive rate of 61~80 years old (8.26%) was the highest, and the positive rate of inspection was in the former laboratories. They were burn plastic department, Department of traditional Chinese medicine, external heart monitoring area, transplant area and trauma surgery; g+ Staphylococcus maintained Gao Min susceptibility to VA, TEC, LZD, found 1 strains of vancomycin resistant Enterococcus; g- bacilli had high sensitivity to AK and carbapenems, Enterobacteriaceae, Acinetobacter Bauman, Pseudomonas aeruginosa The drug resistance rates of alkenes were 7.51%, 70.97%, 35.90%, 4) from June 2011 to June 2013. 128 strains of Escherichia coli causing blood flow infection were collected continuously. 80 of them produced ESBLs, and no carbapenem producing strains were found; the isolates kept the Gao Min susceptibility to AK, TZP and carbapenems; ctx-m-14 (40/80) was the most common beta lactam. Enzyme, followed by ctx-m-55 (17/80) and ctx-m-15 (14/80); B2 group is the most common phylogenetic group, but the proportion of D groups in ESBLs producing strains is the highest; 49 sequences are detected, divided into 6 non repetitive evolutionary groups or cloned complexes and 33 monomers. ST131 (17/128) is the most common sequence type, followed by st69 (12/128) and st648 (10) /128) conclusion: 1) the color culture medium combined with simple biochemical test can quickly and efficiently identify several common oxidase negative gram-negative bacilli; 2) the weekly bath times, the history of invasive medical operation and the history of the use of quinolones are independent variables of intestinal colonization of ESBLs Enterobacteriaceae. The rational use of the elements, following the principle of aseptic operation and nursing, and paying attention to the personal hygiene of the residents in the nursing home is an important measure to control the spread of drug resistant bacteria in the pension institution. 3) the main pathogens of the blood flow infection in Ruijin hospital are G- bacteria, the positive rate of blood culture in the elderly patients is high, the homology of the Escherichia coli in the blood flow infection is low, and the ESBLs production does not exist. 4) the rate of colonization of Enterobacteriaceae ESBLs and ESBLs Escherichia coli in Ruijin hospital were higher (45%), but the latter was higher than the former, and the latter was also higher than the former, TZP, AK, FOS, CL, TGC and carbapenems. The class ESBL can be used as a good choice for treatment. The phenotype of CTX-M-14 is mainly CTX-M-15, CTX-M-55.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R446.5

【相似文献】