当前位置:主页 > 医学论文 > 护理论文 >

弯曲菌抗生素敏感性及遗传特征分析

发布时间:2019-05-20 04:18
【摘要】:弯曲菌主要导致食源性疾病,弯曲菌病的常见症状为腹泻性肠炎,通常为自限性无需抗生素的治疗,但对于免疫力低下、病程迁延的患者以及重症患者而言,抗生素的治疗是必要的。喹诺酮类和大环内酯类为临床治疗弯曲菌病的常用药物,然而弯曲菌对于重要的临床常用抗生素的耐药性逐渐增加,尤其是对喹诺酮类的耐药率已几乎达到100%,严重影响了临床治疗的有效性,加重了疾病负担。弯曲菌为人兽共患病原菌,其耐药的产生和传播机制相对复杂,畜禽养殖中抗生素作为饲料添加剂的使用以及临床不合理用药均会在一定程度上增加弯曲菌的耐药性。为获得我国菌株的耐药特征及变化趋势,本研究对实验室收集保存的858株我国不同来源的空、结肠弯曲菌进行了抗生素敏感性分析,结果显示我国菌株对于喹诺酮类为接近95%的高耐药率。对空、结肠弯曲菌分别比较12种抗生素的耐药率,发现结肠弯曲菌对红霉素、链霉素等的耐药率显著高于空肠弯曲菌。对1994~2013年分离的空肠弯曲菌分四个时期的耐药率结果表明,随着时间的推进,我国空肠弯曲菌的整体耐药率逐渐升高,耐药趋势严峻。本研究为我国耐药弯曲菌的监测及指导临床用药提供了数据支持。目前已经从分子水平明确了弯曲菌对多种抗生素的耐药机制,基因水平的研究对弯曲菌疾病的预防控制具有重要意义。目前已发现的大环内酯类耐药机制有:靶向突变(23S rRNA及核糖体蛋白L4和L22)、CmeABC主动外排系统以及2013年最新报道的核糖体RNA甲基化酶基因ermB介导的水平转移机制。临床上除大环内酯类和喹诺酮类之外,在菌血症及全身感染、重度感染中氨基糖苷类常作为备选药物,因此对氨基糖苷类的耐药机制研究也是必要的。本研究对158株红霉素耐药菌株进行大环内酯类耐药相关23S rRNA点突变、核糖体RNA甲基化酶基因ermB筛查,82.91%(131/158)筛查到23S rRNA基因上A2075G位点突变,18.99%(30/158)筛查到ermB基因,30株ermB阳性菌株中9株已知ermB相关耐药基因岛的型别,3株已完成全基因组测序及耐药岛分析,8株分析进行中,10株测序进行中。ermB相关耐药基因岛及耐药基因的出现表明弯曲菌可能是肠道中耐药基因及基团传播的储存库。菌株耐药基因筛查结果显示,23 S rRNA基因A2075G突变以及ermB基因的检测可获得我国近100%菌株的耐药特征,据此可设计Real-time PCR对临床病人粪便标本进行检验,在鉴定菌株的同时确定菌株的耐药性,从而迅速有效的指导临床用药。对221株链霉素耐药菌株进行了氨基糖苷类耐药相关aadE-sat4-aphA-3耐药基因簇的分布分析,阳性率为10.86%(24/221)。本研究为我国空、结肠弯曲菌耐药机理的研究提供了理论依据,同时为我国重要耐药弯曲菌菌株的监测提供依据。基因分型具有高分辨率、重复性好、易于标准化及自动化等优点,近年来分子生物学不断发展,细菌的分型技术已不再局限于传统的表型分型,PFGE、 MLST等分子分型技术广泛应用于食源性病原微生物的暴发识别以及溯源分析等。弯曲菌的MLST分析技术具有高分辨率、较好的重复性、数据标准化、可与国际数据库比较及共享且操作过程快速简便等优点,本研究的目的在于了解我国不同来源的耐药弯曲菌有无显著的克隆群,耐药菌株间是否具有遗传相关性以及家禽、家畜等储存宿主来源的菌株有无与人感染菌株密切相关的特殊ST型别,因此使用该技术对158株不同来源红霉素耐药弯曲菌、100株链霉素耐药弯曲菌进行分子分型,分型结果显示,大部分腹泻患者来源的结肠弯曲菌与鸡来源的弯曲菌有着相似的基因型及耐药性,耐药菌株在弯曲菌中没有形成显著的克隆群分布。158株红霉素耐药弯曲菌中ST6322与ST1145均含有ermB基因,提示ermB基因可能与这两种ST型别存在一定关联,需要增加菌株数量分析。本研究得到的结果将完善我国的弯曲菌监测并对我国的食品安全有着重要意义。
[Abstract]:Campylobacter is the main cause of food-borne diseases. The common symptoms of Campylobacter are diarrhotic enteritis, usually self-care without the treatment of antibiotics, but the treatment of antibiotics is necessary for patients with low immunity, long course of disease and severe patients. The noonone and macrolides are commonly used drugs for clinical treatment of the bending diseases, however, the resistance of the bending bacteria to the important clinical common antibiotics is gradually increased, especially the drug resistance rate of the noonone is almost 100%, and the effectiveness of the clinical treatment is seriously affected, And the burden of the disease is increased. Campylobacter is a common pathogen of human, and its drug resistance is relatively complex. The use of antibiotics as feed additive in livestock and poultry culture and the irrational use of antibiotics will increase the drug resistance of the Campylobacter to some extent. In order to obtain the drug-resistant character and the changing trend of the strains in China, this study conducted the antibiotic sensitivity analysis of 858 strains of the Chinese strain which were stored in the laboratory, and the results showed that the strains of the Chinese strains were close to 95% of the high-resistance rate. The resistance rate of 12 kinds of antibiotics was compared with that of Campylobacter jejuni, and the resistance rate of Campylobacter coli to erythromycin and streptomycin was significantly higher than that of Campylobacter jejuni. The drug resistance rate of Campylobacter jejuni isolated from 1994 to 2013 showed that the resistance rate of Campylobacter jejuni in China increased with time, and the drug resistance trend was serious. This study provides data support for monitoring and guiding the clinical application of drug-resistant bending bacteria in China. At present, the resistance mechanism and gene level of Campylobacter jejuni have been identified from the molecular level, which is of great significance to the prevention and control of Campylobacter disease. The macrolide-resistant mechanisms that have been found are: targeted mutations (23S rRNA and ribosomal proteins L4 and L22), CmeC active efflux systems, and the latest reported ribosomal RNA methylase gene erB-mediated level transfer mechanism in 2013. In addition to macrolides and other types of macrolides, in the case of bacteremia and systemic infection, the amino-glycosides are often used as alternative drugs in severe infections, and therefore, the study of the drug-resistant mechanism of the amino-glycosides is also necessary. In this study, the 23S rRNA point mutation, the ribosomal RNA methylase gene erB screen and the 82.91% (131/158) of the 158 erythromycin resistant strains were screened to the A2075G site mutation of the 23S rRNA gene. 18.99% (30/158) were screened to the mB gene,9 of the 30 mB positive strains were known to be the type of the mB-related drug-resistant gene island,3 of the 3 strains had completed the whole genome sequencing and the drug-resistant island analysis, and the 8 strains were analyzed and the 10 strains were sequenced. The emergence of mB-associated drug-resistant gene and drug-resistant genes indicates that the Campylobacter may be a repository of drug-resistant genes and groups in the gut. The screening results of the drug-resistant gene of the strain show that the 23S rRNA gene A2075G mutation and the detection of the mB gene can obtain the drug resistance characteristic of the nearly 100% strain in China, so that the real-time PCR can be designed to test the stool sample of the clinical patient, and the drug resistance of the strain can be determined at the same time of the identification strain, So as to rapidly and effectively guide the clinical medication. The distribution of resistance-related aadE-sat4-apA-3-resistant gene cluster of 221 streptomycin-resistant strains was analyzed, and the positive rate was 10.86% (24/221). This study provides a theoretical basis for the study of the mechanism of drug resistance in the air and colon of our country, and provides the basis for the monitoring of the strain of the major drug-resistant strains in China. The gene typing has the advantages of high resolution, good repeatability, easy standardization and automation, and the like, MLST and other molecular typing techniques are widely used in the outbreak identification and trace analysis of food-borne pathogenic microorganisms. the MLST analysis technology of the bending bacteria has the advantages of high resolution, good repeatability, standardization of data, comparison and sharing with an international database, rapid and convenient operation, and the like, and the purpose of the research is to understand the presence or absence of a significant clone group of drug-resistant bending bacteria of different sources in China, if there is a genetic correlation between the resistant strains and the presence or absence of a special ST-type strain which is closely related to the human infection strain, The results showed that most of the diarrhea patients had similar genotype and drug resistance to the Campylobacter from the source of the chicken, and the drug-resistant strains did not form a significant colony distribution in the Campylobacter, and both ST6322 and ST1145 in the 158 strains of erythromycin-resistant strains contain the mB gene. It is suggested that the mB gene may be associated with the two ST types, and it is necessary to increase the number of the strains. The results obtained in this study will improve the monitoring of Campylobacter in China and have important significance for food safety in China.
【学位授予单位】:中国疾病预防控制中心
【学位级别】:硕士
【学位授予年份】:2015
【分类号】:R446.5

【相似文献】

相关期刊论文 前10条

1 ;关于举办“临床抗生素敏感性系列试验讲习班”的预备通知[J];临床检验杂志;1994年02期

2 侯凤琴,沈宝铨,孙新婷;200株空肠弯曲菌对30种抗生素敏感性研究[J];医师进修杂志;2001年03期

3 高业栋,陈昌菊,苏辉;临床常见病原菌对常用抗生素敏感性变迁的研究[J];预防医学情报杂志;2001年03期

4 王璐;泌尿生殖道支原体对10种抗生素敏感性分析[J];社区医学杂志;2004年03期

5 尹军,刘海梅,李珍大,杨毓华;耐甲氧西林表皮葡萄球菌胞外粘质测定及其对抗生素敏感性研究[J];临床检验杂志;1994年03期

6 张素华,,陆玲娣;45例肺部绿脓杆菌感染对5种常用抗生素敏感性的比较[J];安徽医科大学学报;1994年02期

7 ;外科ICU抗生素敏感性与全院性抗菌谱的比较[J];国外医学.外科学分册;1999年03期

8 凌志强;快速测定细菌生物膜的抗生素敏感性筛选新技术[J];国外医学(流行病学传染病学分册);1999年06期

9 Cellini L.;Grande R.;Di Campli E. ;成虹;;意大利中部地区幽门螺杆菌的遗传变异性、抗生素敏感性及其毒力标记物分析[J];世界核心医学期刊文摘(胃肠病学分册);2006年08期

10 张学杰;王欣俞;;支原体对9种抗生素敏感性测定[J];黑龙江医学;2008年05期

相关会议论文 前4条

1 王继华;张娣;王宇鹏;李振鹏;李秀园;姚艳;;10种大肠杆菌对47种抗生素敏感性测试的研究[A];第十次全国环境微生物学术研讨会论文摘要集[C];2007年

2 陈慧红;沈伟伟;沈波;余素飞;周华;何小帆;;对碳青霉稀类抗生素敏感性下降的肠杆菌科细菌耐药机制的研究及流行病学调查[A];2011年浙江省检验医学学术年会论文汇编[C];2011年

3 张玉惠;张伟忠;梁金荣;;舟山海岛地区胆道感染细菌谱及抗生素敏感性研究[A];2009年浙江省外科学学术年会论文汇编[C];2009年

4 赵素蕊;王占伟;王贺;闫薇;刘文云;彭秋生;姜森;郭宇;张正;;5种革兰阳性菌对抗生素敏感性7年变化趋势的分析[A];中华医学会第七次全国检验医学学术会议资料汇编[C];2008年

相关硕士学位论文 前4条

1 张艾煜;弯曲菌抗生素敏感性及遗传特征分析[D];中国疾病预防控制中心;2015年

2 朱明;海洋硅藻海链藻(Thalassiosira sp.)培养条件及其对抗生素敏感性的研究[D];中国海洋大学;2002年

3 李姗姗;潜在益生乳杆菌的抗生素敏感性研究[D];河北农业大学;2012年

4 张孝平;阿司匹林增加幽门螺杆菌对抗生素敏感性的机制[D];北京大学;2008年



本文编号:2481345

资料下载
论文发表

本文链接:https://www.wllwen.com/huliyixuelunwen/2481345.html


Copyright(c)文论论文网All Rights Reserved | 网站地图 |

版权申明:资料由用户904f7***提供,本站仅收录摘要或目录,作者需要删除请E-mail邮箱bigeng88@qq.com