辽西猪产业链主要环节链球菌耐药性及其传递的研究

发布时间：2018-01-21 17:59

本文关键词： 辽西猪产业链链球菌耐药性传递　出处：《锦州医科大学》2017年硕士论文　论文类型：学位论文

【摘要】：目的为明确链球菌耐药性产生的原因及发展趋势,探究辽西地区猪产业链链球菌耐药性之间的联系,研究链球菌耐药性在同属异种及异属异种细菌之间的传递,对降低因细菌耐药性的产生而对动物疾病防治及公共卫生安全所带来的危害有重要意义,为指导临床合理用药、提高疗效及制定有针对性的控制措施提供依据。方法对从辽西地区某重点养殖猪场、对应下游屠宰场及其覆盖的肉品销售市场分离获得的163株猪源链球菌和8株人源链球菌,用链球菌培养基分离培养,应用形态观察、生化实验、16Sr RNA基因检测方法鉴定,对鉴定的链球菌采用微量稀释法进行多种兽用和人用抗菌药物敏感性检测,并参照CLSI制定的肠球菌判定标准进行判定。对辽西猪链不同环节分离的链球菌的耐药种类、耐药比例等方面比较分析。选择共同耐药率较高的药物进行主要耐药基因的检测,比较分析各环节链球菌耐药基因种类及其耐药基因检出率,对其共同携带的耐药基因进行同源性比对分析。通过对猪产业链主要环节猪链球菌耐药普、耐药基因普、耐药基因同源性比对、分析,说明链球菌耐药性是否在猪产业链中发生了传递。为进一步验证链球菌耐药性是否可以发生水平传播,以分离获得的耐药菌株作为供体菌,叠氮化钠耐药大肠埃希杆菌J53、链球菌ATCC 29212作为受体菌进行质粒接合转移试验,将实验获得的接合子进行耐药性及耐药基因检测和序列同源性分析,验证耐药性及耐药基因是否可以在不同菌株间传递,初步分析链球菌耐药性的传递方式。结果药物敏感性检测结果显示:产业链各环节中分离的猪源和人源链球菌同时对9种兽用抗菌药物(泰乐菌素、链霉素、环丙沙星、四环素、林可霉素、庆大霉素、青霉素、红霉素、多黏菌素E)和10种人用抗菌药物(青霉素、阿莫西林、奎奴普汀、四环素、复方新诺明、头孢噻肟、红霉素、克林霉素、左氧氟沙星、万古霉素)产生表观耐药性。选取共同耐药率较高的3类(大环内酯类、四环素类、多黏菌素E类)抗菌药物的9种主要相关基因进行检测,结果显示分离菌株携带的共同耐药基因有6种,分别是:tet L、Mcr-1、Erm B、tet O、tet M、Mef A/E,其中分离自养猪场、屠宰场和销售市场的猪源链球菌对四环素类耐药基因tet L的检出率最高,分别为91.89%、82.35%和90.48%,对多黏菌素E类耐药基因Mcr-1、大环内酯类耐药基因Erm B和Erm A的检出率也较高,均达50%以上。人源链球菌对四环素类耐药基因tet L和大环内酯类耐药基因Erm B的检出率最高达100%,对多黏菌素E类耐药基因Mcr-1和大环内酯类耐药基因Mef A/E的检出率分别为50%和62.5%。对检出率较高的耐药基因tet L、Erm B和Mcr-1进行同源性比对分析,结果显示,分离自养猪场、屠宰场、销售市场的猪源链球菌和分离自养猪场的人源链球菌耐药基因tet L和Erm B同源性较高,均达到97%以上,其中tet L耐药基因同源性达到了100%,上述结果显示,在辽西猪产业链三个主要环节分离到的链球菌对多种常用兽用及人用抗菌药物产生共同表观耐药,并检出多种同类耐药基因,其中检出率较高的同类耐药基因具有高度同源性,该结果提示细菌耐药性及其耐药基因在猪产业链各环节以及猪和人之间发生了传递。质粒接合转移实验结果表明:接合子中检出四环素类耐药基因tet L和大环内酯类耐药基因Erm B,接合子的耐药性检测证明,接合子对上述耐药基因所对应的药物:泰乐菌素、链霉素、四环素、林可霉素、红霉素产生了耐药,说明链球菌耐药基因可通过质粒在不同来源的链球菌之间传播,也可以通过质粒在不同种属细菌之间传播,从而导致耐药性的传递。结论1、辽西猪产业链主要环节所分离的猪源链球菌对多种兽用和人用抗菌药物产生了共同耐药性,并携带具有高度同源性的共同耐药基因。在猪和人之间也发生了链球菌耐药性的传递。2、辽西猪产业链中主要环节链球菌共同携带的tet L和Erm B耐药基因,可通过质粒介导在同属异种及异属异种细菌之间传播。链球菌耐药性在猪产业链各环节和猪与人间可发生传递。
[Abstract]:Objective to produce a clear reason and developing trend of antimicrobial resistance of Streptococcus, western Liaoning pig industry chain between the study of antimicrobial resistance of Streptococcus contact on antimicrobial resistance of Streptococcus in heterogeneous and belong to different genus of dissimilar transfer between bacteria, to reduce the emergence of drug resistance of bacteria and harmful to animal disease prevention and public health safety brought has important significance to guide clinical rational drug use and improve the curative effect and provide basis for control measures. Methods from the farm a key culture in western Liaoning, the corresponding downstream slaughterhouse and covering the meat market isolated 163 strains of Streptococcus suis and obtained 8 strains of Streptococcus, Streptococcus pneumoniae isolated and cultured with medium, using morphological observation biochemical experiments, identification, detection of 16Sr RNA gene of Streptococcus, identified by microdilution method for a variety of antimicrobial drug use and the beast The sensitivity of detection, and the judgment standard for judging according to the CLSI formulation of Enterococcus. Type of resistance to separate the link chain in swine streptococcus, comparative analysis and so on. The proportion of drug resistance detection of drug selection common drug resistance rate is higher for the main resistance genes, resistance genes detection rate of Streptococcus species and resistance genes in each link of the analysis. The common resistance genes carried by homology analysis. The main part of the industrial chain of Pig Streptococcus suis resistant Pu, Pu resistant gene, resistance gene homology analysis, description of drug resistance bacteria in pig industry chain transfer occurred. To verify whether the level of antimicrobial resistance of Streptococcus can spread, resistant strains to isolate as a donor, sodium azide resistant Escherichia coli J53, Streptococcus ATCC 29212 as the receptor bacteria plasmid conjugation Transfer test, the experiment of the transconjugants were detected and the sequence of drug resistance and resistance gene homology analysis, whether drug resistance and drug resistance genes can be transferred between different strains of verification, preliminary analysis of transmission of antimicrobial resistance of Streptococcus. The results of drug sensitivity test results show that: the separation of each link in the chain of swine streptococcus and at the same time 9 kinds of antibacterial drugs on animal (tylosin, streptomycin, ciprofloxacin, tetracycline, clindamycin, gentamicin, penicillin, erythromycin, polymyxin E) and 10 with antibiotics (penicillin, amoxicillin, quinupristin, tetracycline, cotrimoxazole, erythromycin, cefotaxime. Clindamycin, levofloxacin, vancomycin) have apparent resistance. Select 3 kinds of common drug resistance rate is higher (macrolides, tetracyclines, polymyxin E) examined 9 major genes related to antibacterial drugs Test results show the common resistance genes in isolates carrying 6 kinds, respectively is: Tet L, Mcr-1, Erm B, Tet O, Tet M, Mef A/E, of which the highest detection rate of autotrophic separation farms, slaughterhouses and sales of swine streptococcus of the tetracycline resistance gene tet and L, respectively 91.89%, 82.35% and 90.48%, the polymyxin E resistance gene Mcr-1, macrolide resistant gene Erm B and Erm A detection rate is higher, reached more than 50%. The detection rate of up to 100% of the tetracycline resistance gene of Streptococcus Tet L and macrolide resistance gene Erm B that of polymyxin E resistance gene Mcr-1 and macrolide resistance gene Mef A/E detection rates were 50% and 62.5%. on the high detection rate of drug resistance gene tet L, Erm B and Mcr-1 homology comparison analysis, results showed that the separation of autotrophic farms, slaughterhouses, sales market of swine streptococcus and Isolated from pig people Streptococcus resistant gene tet L and Erm B homology, reached more than 97%, of which Tet L resistance gene homology reached 100%, the results showed that the isolated in three major aspects of the industry chain of pig streptococcus to a variety of commonly used veterinary and human use of Antibacterials in common the apparent drug resistance, and found many similar resistance genes, resistance genes and similar high detection rate with a high degree of homology, the results suggest that the bacterial resistance and resistance gene transfer in the pig industry chain, each link between pig and human. Plasmid conjugation experiment results show that the tetracycline resistance gene tet L and macrolides the Erm B class of resistance genes detected in the zygote zygote, the detection of drug resistance, drug transconjugants corresponding to the resistance gene, tylosin, tetracycline, streptomycin, lincomycin, erythromycin Hormone resistance, resistance genes that Streptococcus by plasmids between different sources of Streptococcus transmission, also can through the plasmid in different species of bacteria spread, resulting in drug resistance transfer. Conclusion 1 swine streptococcus mainly in pig industry chain link from a variety of animal and people have a common resistance use of antibiotics, and carry a high similarity common resistance genes. Between pig and human also happened to pass.2 Tet L and the antimicrobial resistance of Streptococcus, Streptococcus Erm B resistance gene in the pig industry chain in the main link together to carry, through plasmid mediated communication between heterogeneous and dissimilar bacteria belong to different. Transfer of antimicrobial resistance of Streptococcus can occur in the pig industry chain and pig and human.

【学位授予单位】：锦州医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S852.611

【相似文献】