华东地区部分猪场关节炎主要病原菌流行状况调查及致病基因变异分析

发布时间：2018-03-24 05:10

本文选题：猪关节炎　切入点：猪链球菌　出处：《上海交通大学》2015年硕士论文

【摘要】：猪关节炎(porcine arthritis)是指由一种或多种因素造成的关节组织炎症,通常由细菌性病原引起。据研究,我国大部分猪场关节炎主要由猪链球菌(streptococcus suis,S.suis),副猪嗜血杆菌(haemophilus parasuis,HPS)和葡萄球菌(Staphylococcus)等病原菌引起,给猪养殖业带来了极大损失。S.suis和HPS还能引起猪其他的临床症状,且由于长期应用抗生素,导致病原菌表现出多重耐药性,给猪场疾病防治造成了很大困难。为了解我国华东地区部分猪场猪关节炎主要病原体的流行状况,本文根据链球菌2型(streptococcus suis type 2,S.suis2)的荚膜多糖基因cps2J和HPS的16s rRNA基因建立了检测猪链球菌2型和副猪嗜血杆菌的二重PCR检测方法,利用该方法,对2013-2014年期间华东地区部分猪场疑似猪关节炎的120份细菌样品进行检测鉴定,获得14株S.suis2和12株HPS。在120份细菌样品中检测到21株S suis,表明S.suis2是链球菌中主要流行菌株,并通过进一步建立的系列多重PCR方法证明S.suis分离株的毒力因子分布型为低毒力型:+cps2J-/+mrp-ef-sly-gdh-/+gadph-/+orf2。将14株S.suis2的荚膜多糖基因cps2J与四株国内株和两株国外株进行序列比对,结果显示同源性为94%—99%,说明S.suis2分离株的cps2J基因发生了变异,基因进化树分析表明华东地区S.suis2具有广域性;对4株HPS分离株进行tbpA基因的限制性片段多态性(restriction fragment length polymorphism,RFLP)分型分析,结果表明4株HPS都为副猪嗜血杆菌杆菌最流行的DBE型。对S.suis和HPS分离株进行药敏试验,发现两种菌表现多重耐药性,并且青霉素类类和头孢菌素类药物对两者均有较好的敏感性,提示青霉素类药物和头孢菌素类药物可作为猪关节炎的治疗药物。本研究首先为检测猪场关节病主要病原提供了快速准确的检测方法,检测结果为华东地区猪关节病病原学研究积累了有益资料,对病原菌主要毒力因子的初步分析可为未来疫苗的研制提供参考,药敏试验也可为制定猪关节病防治措施提供一定的指导。
[Abstract]:Porcine arthritis is an inflammation of the articular tissue caused by one or more factors, usually caused by bacterial pathogens. Most of the arthritis in pig farms in China is mainly caused by pathogenic bacteria such as streptococcus suis S.suis, Haemophilus parahaemophilus parasuisus HPSs and Staphylococcus staphylococcus, which have brought great losses to pig breeding. S. suis and HPS can also cause other clinical symptoms in pigs. As a result of long-term application of antibiotics, the pathogens showed multidrug resistance, which caused great difficulties in the prevention and treatment of pig farm diseases, in order to understand the prevalence of the main pathogens of pig arthritis in some pig farms in East China. Based on the capsule polysaccharide gene cps2J of Streptococcus suis type 2 and 16s rRNA gene of HPS, a double PCR method for detection of Haemophilus suis and Streptococcus suis 2 was established. From 2013 to 2014, 120 samples of suspected porcine arthritis from pig farms in East China were detected and identified, 14 strains of S.suis2 and 12 strains of HPSS were obtained. 21 strains of S suis were detected in 120 samples of bacteria, indicating that S.suis2 is the main prevalent strain of streptococcus. A series of multiplex PCR methods were established to prove that the virulence factor distribution of S.suis isolates was low virulence type: cps2J-/ mrp-ef-sly-gdh-/ gadph-/ orf2.The sequence of cps2J gene of 14 S.suis2 isolates was compared with four domestic and two foreign strains. The results showed that the homology was 94-99, which indicated that the cps2J gene of S.suis2 isolates had been mutated, and the phylogenetic tree analysis of S.suis2 in East China showed that S.suis2 was widespread, and four HPS isolates were analyzed by restriction fragment length polymorphism (RFLP). The results showed that the four strains of HPS were the most popular DBE type of Haemophilus parasuis. The drug sensitivity test of S.suis and HPS isolates showed that the two strains showed multidrug resistance. Penicillin and cephalosporins have good sensitivity to both. It is suggested that penicillin and cephalosporins can be used as therapeutic drugs for porcine arthritis. The results provided useful data for the etiological study of swine arthropathy in East China, and the preliminary analysis of the main virulence factors of pathogenic bacteria could provide a reference for the development of vaccine in the future. The drug sensitivity test can also provide some guidance for the prevention and treatment of pig arthropathy.
【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】：S858.28

【共引文献】