產(chǎn)碳青霉烯酶革蘭陰性桿菌的耐藥及傳播機(jī)制研究
[Abstract]:Background with the extensive use of various antibiotics, multidrug-resistant and even pan resistant bacteria are increasing, which poses a great challenge to clinical diagnosis and treatment. It has become a worldwide problem. Carbapenems are the last line of defense for the severe infection of multiresistant gram-negative bacilli, carbapenem resistant gram-negative bacilli Carbon penicenase is the main cause of resistance to carbapenems. Carbapenenems include A, B, and D three enzymes in the classification of Ambler molecules, which are a class of beta lactamases, which can obviously hydrolyze imipenem or meropenem and other carbapenems. Most carbon green Mycophenase genes are located in transferable gene elements such as plasmids and integrons. Bacteria in the same genus and different species can obtain resistance genes through conjugation, conduction, transformation, transposing and so on, causing more bacteria to produce carbapenem. The carbapenems resistant bacteria are resistant to beta lactam antibiotics and most of them are also resistant to beta lactam antibiotics. The resistance to quinolone, aminoglycoside and other antibiotics, thus showing the characteristics of multidrug-resistant and even pan resistance. Therefore, the rapid detection of carbapenems by bacteria is of great significance in controlling the spread and infection of these bacteria. The main methods for the detection of carbapenems are the modified Hodge test (the m). Odified Hodge test) this is a phenotypic experiment. This is the phenotypic confirmatory test recommended by the American clinical laboratory standardization association (CLSI). There are also the imipenem -EDTA double paper synergistic test and the Etest MBL commercialization test, specifically for the test of carbopenicolenes in the B Group [1]. but with a group of resistant genes containing the resistant strain. The more complex and more complex, the specificity and sensitivity of the methods are challenged, and the detection methods for carbapenems are urgently needed to be innovated. The Clinical and Laboratory Standards Institute (CLSI) introduced the Carba NP test [2] in 2015 as the Enterobacteriaceae, Pseudomonas aeruginosa and the genus acomonas. The confirmatory test of the phenotypic phenotypic detection of carbapenenenes produced by bacteria was first reported in 2012 by the research team of Professor Patrice Nordmann of the French Academy of Southern forensic medicine (Prof Patrice Nordmann). Since then, the Carba NP test for the detection of carbapenem producing Pseudomonas sp. and the Carba NP test indicating the type of carbapenenenes has been reported. The test can be directly judged. The type of enzyme producing enzyme producing carbapenenenase is more simple and faster than the modified Hodge test. With the rapid development of molecular biology and bioinformatics, the whole genome sequencing technology is widely used. Whole genome sequencing is the whole sequence of unknown species of species. With more than second generation sequencing technology (NGS) and third generation sequencing technology, second generation sequencing technology can be quickly and low cost for whole genome sequencing. Its equipment suppliers are mainly 454 (Roche), SOLi D (AB) and Solexa. third generation sequencing technology began to be popularized in 2011, and their single molecule real time sequencing technology (SMRT) Different from the second generation sequencing, it was developed by Pacific Biosciences, and its sequence read long up to 3kb. high throughput sequencing technology has made human genome form a major change, especially in the field of microorganism with small genome information, which has become an identification of pathogenic microorganism, a study of pathogenic mechanism and so on. In this study, the Carba NP test recommended by CLSI was used to screen the multidrug-resistant gram-negative bacilli of suspected carbapenem production in our hospital. The multiple PCR method was used to detect the resistance genes of the screening positive results, so as to understand the prevalence of carbapenem production in Gram-negative bacilli in our hospital and to explore the Carba NP test. 4 strains of Klebsiella pneumoniae producing carbon penicylenzyme from the same patient were conjugation / conversion tests, and the differences in drug sensitivity of conjugation / transformed bacteria and parent strains were compared and the homology of 4 strains was analyzed. 1 strains of multiple resistant strains carrying bla KPC-2 were sequenced by high throughput sequencing. Through bioinformatics analysis, the drug resistance mechanism and drug resistance gene environment of Klebsiella pneumoniae were investigated. Objective 1. to understand the prevalence and molecular mechanism of multi resistant gram-negative bacilli of carbapenem production in the First Affiliated Hospital of Guangzhou Medical University and to understand the carbon production of gram-negative bacilli by Carba NP test. The effect of penicilenes on the resistance and homology of 4 strains of klebber strains from the same patient.3..4. high flux sequencing method was used to analyze the genetic environment of 1 strains of KPC positive klebber strain. Method 1. collected 59 strains of multiple tolerance of clinical isolation in the first hospital of Guangzhou Medical University, the first hospital microorganism room, October January 2010. Gram-negative bacilli of the drug, all strains were identified by VITEK2 microorganism automatic identification instrument and drug sensitivity test, screening the gram-negative bacilli resistant to more than three kinds of antimicrobial agents, and resistant to at least one carbapenene antibiotic, that is, suspected carbapenems, and the type of carbapenems, and the sensitivity of carbapenems. The epidemiological characteristics of.2. were analyzed by Carba NP test for the detection of carbapenem producing strains, and multiple PCR techniques were used to detect the related resistance genes of the positive strains of carbapenem test, to understand the main genotypes of carbapenems of gram-negative bacilli in our hospital and to explore the test of Carba NP test. The effect of gram-negative bacilli carbapenem.3. obtained 4 strains of Klebsiella pneumoniae zygote or transformant through conjugation test and electrical transformation test. The receptor bacteria carried the resistance gene bla NDM-1 or bla KPC-2 to extract plasmid DNA. The multiple resistant strain LJ1, LJ2, LJ3, LJ4 DNA were extracted by the enzyme cutting technique and analyzed the plasmid type.4. respectively. Methods the homologous and plasmid incompatible groups were analyzed, and 7 Klebsiella pneumoniae housekeeping genes were detected by PCR method. The ST typing was carried out by MLST online tools. The homologous.5. extracted transformants LJ4C total DNA was further analyzed. Illumina Miseq and Pac Bio RS II platform were used for high flux sequencing. In its PBc R pipeline, using the data of Illumina Mi Seq Reads (two generation sequencing) to carry on the error correction.RAST online tools to carry on the gene annotation, Res Finder and NCBI BLAST network tools to carry on the resistance gene analysis. Results the epidemiological and drug susceptibility results of 1.59 strains of gram-negative bacilli were analyzed. The resistance rates of.59 strains to imipenem, meropenem, and eopenem were 62.71% and 61.02% respectively. The strains of 64.41%. were mainly from 35.6% (21/59) bile 5.1% (3/59), 8.5% (5/59), ascites 5.1% (3/59), and 1 in urine. 3.6% (8/59), hydrothorax 3.4% (2/59), blood 23.7% (14/59), and drainage 5.1% (3/59). Multidrug-resistant gram-negative bacilli were mainly carried with NDM-1 gene and KPC-2 genotype strains, and carbapenem producing bacteria with citrate, Pseudomonas aeruginosa and Klebsiella pneumoniae were more common in.2.Carba NP test and multiple PCR. Analysis and comparison of the results of.Carba NP test to determine 33 strains of carbapenenenase producing carbapenenenase, respectively a class a enzyme 12, 21 B enzymes, and PCR method to detect a variety of carbapenems, including KPC (12 strains), IMP (7 strains), NDM (12 strains), VIM (3). The sensitivity and specificity of Carba NP test are 97.06% and 100%.3.3 strains Klebsiella pneumoniae respectively. Carrying resistance gene bla NDM-1, these strains can transfer drug-resistant genes through conjugation, carrying drug resistant gene bla KPC-2 strain LJ4 unsuccessfully, and use electrical transformation to obtain transformant.S1 nucleic acid endonuclease analysis of 4 strains of plasmid type.4. with ERIC-PCR method to analyze LJ1, LJ2, LJ3, LJ4 strain homology LJ4 bacteria have different band type.LJ3, LJ4 does not belong to any one of the 18 found plasmid incompatible groups, LJ1 and LJ2 belong to the incompatible group Inc F II group. The carbapenem strain LJ4 carries the BLA KPC-2 type carbapenem gene, which is sequenced high flux and obtained the plasmid P CT-KPC from the LJ4 strain. It is a 151466bp ring molecule, including the plasmid skeleton of 120783bp, which encodes, replicating, transferring, maintaining and stabilizing the coding region, as well as the coding region containing two segment resistant genes. (MRR) the.P CT-KPC plasmid contains 53.81% GC content, a total of 233 identified open reading frame ORFs, and 138 encoding genes are highly similar to the known functional proteins. Plasmid LJ4C is constructed from a partial plasmid structure of P HN7A8, P KPC-LK30 and an additional tra region to form a chimerism, joining the transfer gene cluster tra and bacterial connection. The plasmid structure study found that the transformants of LJ4 strain also carried bla CTX-M-65, blafos A3, blarmt B, BLA SHV, BLA TEM1b and multiple resistant genes to spread widely between poultry and pets. The results of this study showed that the plasmid isolated from the patient was with the strain of the pet source. The plasmid structure is highly homologous, which does not exclude the possibility of homologous recombination between the sick pets and the poultry and the human source bacteria. Conclusion 1. the carbapenem bacteria producing carbapenem in our hospital are more common, such as citric acid bacilli Freund, Pseudomonas aeruginosa and Klebsiella pneumoniae. It is suggested that the multiple drug resistant strains have been detected in the clinic and should be screened out. To find out the status of carbapenem production in order to apply the.2.Carba NP test to the screening of carbapenems of multi resistant gram-negative bacilli, it is easy, fast, accurate, and can be used in clinical laboratory to promote the use of.3. with ESBLs, Fos A, RMT B, KPC plasmid and Bla ND. M-1 and Bla KPC-2 genes can be transmitted in the same type of bacteria by conjugation or transformation. It indicates that the possible.4. high throughput sequencing of these multidrug resistant genes in bacteria is rapid, comprehensive and accurate in the analysis of drug resistance genes, genetic environment and bacterial genotyping, so as to facilitate the study of the mechanism of bacterial resistance.
【學(xué)位授予單位】:廣州醫(yī)科大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2017
【分類(lèi)號(hào)】:R446.5
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 杜娜;杜艷;;耐碳青霉烯類(lèi)腸桿菌科細(xì)菌耐藥基因傳播機(jī)制研究現(xiàn)狀[J];微生物學(xué)免疫學(xué)進(jìn)展;2015年05期
2 柳延虎;王璐;于黎;;單分子實(shí)時(shí)測(cè)序技術(shù)的原理與應(yīng)用[J];遺傳;2015年03期
3 杜玲;劉剛;陸健;劉丑生;哈福;;高通量測(cè)序技術(shù)的發(fā)展及其在生命科學(xué)中的應(yīng)用[J];中國(guó)畜牧獸醫(yī);2014年12期
4 周華;周建英;俞云松;;多重耐藥革蘭陰性桿菌感染診治專(zhuān)家共識(shí)解讀[J];中華內(nèi)科雜志;2014年12期
5 曾章銳;邵海楓;;革蘭陰性桿菌對(duì)碳青霉烯類(lèi)抗生素耐藥機(jī)制的研究進(jìn)展[J];醫(yī)學(xué)研究生學(xué)報(bào);2014年05期
6 孫晶;常軍霞;劉巍;;ERIC-PCR與PFGE檢測(cè)銅綠假單胞菌同源性的方法學(xué)比較[J];中國(guó)抗生素雜志;2013年04期
7 谷秀梅;楊敏;劉文恩;;產(chǎn)碳青霉烯酶菌株實(shí)驗(yàn)室檢測(cè)研究進(jìn)展[J];國(guó)際檢驗(yàn)醫(yī)學(xué)雜志;2013年01期
8 安軍;蔡挺;張順;;耐碳青霉烯類(lèi)大腸埃希菌和肺炎克雷伯桿菌多重耐藥研究進(jìn)展[J];現(xiàn)代實(shí)用醫(yī)學(xué);2011年03期
9 湯瑾;李卿;蔣燕群;;對(duì)肺炎克雷伯菌碳青霉烯酶的研究進(jìn)展[J];檢驗(yàn)醫(yī)學(xué);2010年01期
10 周曉光;任魯風(fēng);李運(yùn)濤;張猛;俞育德;于軍;;下一代測(cè)序技術(shù):技術(shù)回顧與展望[J];中國(guó)科學(xué):生命科學(xué);2010年01期
相關(guān)博士學(xué)位論文 前1條
1 齊艷;產(chǎn)KPC型碳青霉烯酶肺炎克雷伯菌分子分型及傳播機(jī)制研究[D];浙江大學(xué);2012年
相關(guān)碩士學(xué)位論文 前1條
1 馮群嶺;革蘭陰性桿菌β-內(nèi)酰胺類(lèi)耐藥機(jī)制研究[D];西北大學(xué);2008年
,本文編號(hào):2126854
本文鏈接:http://sikaile.net/linchuangyixuelunwen/2126854.html