16S rRNA基因及外膜蛋白基因分析在鸭疫里默氏菌鉴定中的应用

本实验对鸭疫里默氏菌（包括6个血清型）、大肠杆菌、鼠伤寒沙门氏菌和多杀性巴氏杆菌进行了16S rRNA基因片段的扩增和测序，并将测序结果进行了同源性比较和酶切分析；同时根据标准血清2型鸭疫里默氏菌外膜蛋白的基因序列设计一对引物进行扩增。根据16S rRNA的测序结果及EcoRⅠ和HaeⅢ酶切片段分析，可将鸭疫里默氏菌与其它临床症状易混淆的细菌感染相区别，而外膜蛋白基因序列的特异性也为鸭疫里默氏菌的鉴别诊断提供了一种快速、准确的PCR鉴定方法。     

鸭疫里默氏菌的分离鉴定

采集福州郊区某番鸭场病死鸭的肝、脾、脑、心血,从中分离到1株细菌,经对分离菌进行培养特性、形态观察、生化鉴定及荧光抗体试验,确定为鸭疫里默氏菌。经人工感染试验,表明该菌对雏鸭有较强的致病力,致死率高达47%。     

鸭疫里默氏菌一个可能新型的鉴定

用玻片凝集试验、试管凝集试验和琼脂扩散沉淀试验，对13个鸭疫里默氏菌分离株进行了血清型鉴定。玻片凝集试验中，这些菌株只与8型抗血清发生强凝集反应，试管凝集试验中，其代表菌株C882与8型参考菌株之间仅存在单向低度交叉凝集反应，且与1～19型中的其他18个血清型参考菌株无可见的交叉凝集反应；用C882吸收可消除8型抗血清与C882等菌株之间的交叉凝集反应，但不影响8型抗血清的同源凝集反应和沉淀反应能力。琼扩试验中，C882与1～19型参考菌株之间不产生可见的交叉沉淀反应。沉淀反应模式表明，以C882为代表的13株细菌的热稳定抗原具有同一性。结果表明，13株待检菌株可能属于一个新的血清型。     

鸭疫里默氏菌的分离鉴定

本研究经过菌落形态、染色形态、生化实验以及PCR实验,从来自湖北4个鸭场的81份病料中,分离到11株鸭疫里默氏茵。以5.0×10~8CFU/mL剂量感染健康昆明鼠和健康樱桃谷鸭,鼠和鸭分别在感染后7 h和12 h出现症状,直到感染后1周,实验动物均死亡,而对照组则未出现任何症状,表明该菌株为有毒力菌株,药物敏感实验结果显示部分细菌对某些药物已经产生耐药性。     

四种血清型鸭疫里默氏杆菌外膜蛋白免疫原性分析

采用超声波裂解和超速离心法提取1型、2型、10型与11型鸭疫里默氏杆菌(Ra)的外膜蛋白(Omp),经SDS-PAGE分析,以上4个血清型Ra的Omp均由13～17个蛋白多肽组成,其分子质量大小为20～120 ku,相同血清型的电泳图谱相似,不同血清型的电泳图谱差异较大.交叉免疫印记试验结果表明,4种血清型在44～69 ku有交叉反应的蛋白多肽.     

鸭疫里默氏菌的分离鉴定及免疫原性

自西安某鸭场病鸭中分离到 1株菌 ,经染色镜检、分离培养、生化试验、动物回归试验 ,鉴定为鸭疫里默氏菌 ;用分离菌株制作成油佐剂灭活疫苗 ,免疫 10日龄雏鸭 ,于免疫后 30 d用同源菌攻击 ,保护率为 83%(5 / 6 ) ,结果表明 ,本菌具有良好的免疫原性。     

鸭疫里默氏菌研究进展

鸭传染性浆膜炎是由鸭疫里默氏菌引起的一种重要的鸭细菌病。由于该病分布的广泛性以及引起鸭的高死亡率、发育迟缓和淘汰率增加,给养鸭业造成巨大的经济损失。所以,对鸭疫里默氏菌进行深入研究,以便预防和控制、乃至最终消灭本病,有着重要的经济意义。论文从血清型、诊断方法、疫苗等方面概述了近年来鸭疫里默氏菌研究进展。     

鸭疫里默氏菌病的诊治

鸭疫里默氏菌病(鸭传染性浆膜炎),是由鸭疫里默氏菌感染引起的一种接触性、急性或慢性传染性疾病,是鸭、鹅、火鸡等多种禽类的常见的传染性疾病之一,规模养殖的禽群一旦染疫发病常以高死亡率给养鸭生产者造成巨大的经济损失;该病已经成为很多地区养鸭业的头号杀手.笔者长期从事养殖生产技术推广,对于规模场鸭疫里氏杆菌病的预防与控制,进行了一些有益的探索与实践.     

鸭疫里默杆菌通过外膜蛋白Omp45结合鸭补体调节因子Vitronectin

旨在筛选和鉴定与鸭补体调节因子Vitronectin(Vn)结合的鸭疫里默杆菌(Riemerella anatipestifer,R.anatipestifer)外膜蛋白。在酵母表达鸭Vn及间接免疫荧光和免疫斑点杂交试验检测鸭疫里默杆菌结合Vn的基础上,以重组Vn为诱饵蛋白进行His pull-down及LC-MS/MS质谱鉴定,筛选外膜蛋白并进行生物信息学分析;原核表达候选外膜蛋白及截短片段,制备多克隆抗体,利用Far-Western blot验证与鸭Vn结合,并用间接ELISA测定肝素和氯化钠对结合的影响;测定Vn及抗外膜蛋白抗体对血清杀菌活性的影响。结果显示,鸭疫里默杆菌能在体外结合鸭Vn,经His-pull down、质谱鉴定及蛋白质结构分析,筛选出的外膜蛋白Omp45具有β桶状结构及7个暴露于细胞膜外的多肽环;成功原核表达Omp45及截短片段,制备的抗Omp45多克隆抗体间接ELISA效价超过1∶12 800,Western blot检测多克隆抗体可以与重组蛋白发生特异性反应;Far-Western blot及间接ELISA结果显示,Omp45、包含2个及以上细胞膜外多肽环的...     

13型鸭疫里默氏菌的分离与鉴定

无菌采集鸭疫里默氏菌病病鸭肝脏分别接种到含血清改良马丁琼脂平板、麦康凯琼脂平板和马丁肉汤中,并将分离菌作生化试验。结果：分离菌的纯培养物能分解葡萄糖、棉子糖、尿素酶和过氧化氢酶。该分离菌株只与13型RA标准阳性血清发生凝集反应。     

Screening and Identification of Outer Membrane Proteins of Riemerella anatipestifer Recruited Duck C4b-binding Protein

The purpose of this experiment was to screen and identify the outer membrane proteins of Riemerella anatipestifer (R. anatipestifer) interacting with duck C4b-binding protein (C4BP). The preserved R. anatipestifer was resuscitated, then the outer membrane proteins of R. anatipestifer were extracted and His pull-down and LC-MS/MS were conducted by using duck C4BPα as the bait protein, and the candidate outer membrane proteins that might interact with duck C4BP were screened out. The candidate proteins were cloned, prokaryotic expression was conducted and the polyclonal antibodies were prepared by immunizing the mice. Far-western blot was conducted to verify the outer membrane proteins of R. anatipestifer interacting with duck C4BP. The clone and prokaryotic expression of functional domains of candidate proteins and C4BPα were conducted, and Far-western blot was used to identify the interaction sites between candidate proteins and C4BP. The deposition of complement C3b, C4b and C4BP on the surface of R. anatipestifer were detected by ELISA to verify the function of the candidate proteins. The results showed that a total of 3 outer membrane proteins of R.anatipestifer interacting with duck C4BP were screened out by His pull-down and LC-MS/MS, namely ECE-1, SODs and Omp62. The polyclonal antibodies of 3 outer membrane proteins were successfully prepared, the titers of 3 polyclonal antibodies were more than 1∶6 400 by ELISA, and the result of Western blot showed that 3 polyclonal antibodies could specifically react with corresponding recombinant proteins. The results of Far-western blot showed that only ECE-1 could interact with C4BP, and only the full length of ECE-1 could interact with duck C4BP, and the interaction region between duck C4BP and ECE-1 was located in SCR 2 and SCR 3 of C4BPα. Anti-ECE-1 antibody could significantly increase the C3b and C4b deposition on the surface of R. anatipestifer using 3.125% normal duck serum (NDS, P<0.05), while anti-ECE-1 antibody could significantly decrease the deposition of C4BP on the surface of R. anatipestifer using 6.25% NDS (P<0.05). The study successfully screened out and identified one outer membrane protein (ECE-1) of R. anatipestifer interacting with duck C4BP, which provide a basis to further study the mechanism of R. anatipestifer immune escape.     

Isolation,Identification and Drug Resistance Analysis of Riemerella anatipestifer from Muscovy Duck

In order to understand the drug resistance of Riemerella anatipestifer from Muscovy duck,this study carried out bacterial isolation and culture,Gram staining microscopy,pathogen detection,biochemical test,16S rRNA sequence analysis,PCR identification,drug sensitivity test and drug resistance gene detection for Muscovy duck suspected of Riemerella anatipestifer infection.The results of bacterial isolation showed that on the blood agar medium,the isolated bacteria grew creamy needle tip size colonies with smooth surface,neat edge,luster and translucency.The Gram-negative bacillus brevis was detected by Gram-negative staining microscopy,and it was named GZQN201907.In the biochemical test of GZQN201907,urea reaction was positive,but glucose,maltose,lactose and other biochemical reactions were negative.The 16S rRNA phylogenetic tree was in the same branch as Riemerella anatipestifer.And the OmpA gene of PCR identification results of the isolated strain were positive.The drug sensitivity test was sensitive to 18 antibiotics including cefuroxime,erythromycin and ceftazidime,moderately sensitive to carboxypicillin and ciprofloxacin,and sensitive to neomycin and cotrimoxazole.And the resistance genes could detect the β-lactam resistance genes VIM and TEM,tetracycline resistance genes tetB,macrolide resistance genes ermB and ermF.The results of drug sensitivity test and drug resistance gene detection indicated that GZQN201907 showed the same resistance phenotype and gene detection results for β-lactam,tetracycline and macrolide.In the animal regression test,all the ducklings inoculated with GZQN201907 died within 72 h,while the control group showed no symptoms,indicating that GZQN201907 was virulent to the ducklings.One strain of Riemerella anatipestifer from Muscovy duck was successfully isolated,which laid a foundation for the prevention and treatment of Riemerella anatipestifer from muscovich.     

番鸭源鸭疫里默氏杆菌的分离鉴定及其耐药性分析

为了解番鸭源鸭疫里默氏杆菌的耐药性,本研究对疑似鸭疫里默氏杆菌感染的发病番鸭进行细菌分离培养、革兰氏染色镜检、病鸭病原检测、生化试验、16S rRNA序列分析、PCR鉴定、药敏试验和耐药基因检测。细菌分离结果显示,分离菌在鲜血琼脂培养基上长出表面光滑、边缘整齐、有光泽、半透明的奶油状针尖大小菌落;革兰氏染色镜检呈革兰氏阴性短小杆菌,命名为GZQN201907。GZQN201907生化试验中尿素反应阳性,葡萄糖、麦芽糖、乳糖等生化反应呈阴性。其16S rRNA系统进化树与鸭疫里默氏杆菌处于同一分支;并且分离菌鸭疫里默氏杆菌OmpA基因PCR鉴定结果为阳性。其对头孢呋辛、红霉素、头孢他啶等18种抗菌药耐药,对羧苄西林和环丙沙星中度敏感,对新霉素和复方新诺明敏感。而耐药基因能检测出β-内酰胺类耐药基因VIM、TEM,四环素类耐药基因tetB,大环内酯类耐药基因ermB和ermF。药敏试验与耐药基因检测结果说明,GZQN201907对β-内酰胺类、四环素类、大环内酯类3类药物的耐药表型和耐药基因检测结果一致。动物回归试验中接种GZQN201907的雏鸭在72 h内全部死亡,而对照组雏鸭未出现任何症状,说明GZQN201907对雏鸭有致病力。试验成功分离到1株番鸭源鸭疫里默氏杆菌,为鸭疫里默氏杆菌病的防治奠定基础。     

血清2型鸭疫里默氏杆菌外膜蛋白多肽的组成及免疫原性

采用超声波裂解和超速离心法提取血清 2型鸭疫里默氏杆菌 (RA)的外膜蛋白 ,在透射电镜下观察 ,外膜蛋白呈典型的双层泡状结构 ,形态主要呈 O型或牙齿状或不规则的小碎片。SDS- PAGE电泳分析 ,血清 2型 RA的外膜蛋白由 11条多肽组成 ,相对分子质量 (Mr)在 2 6 0 0 0～ 135 0 0之间 ,主要蛋白为 310 0 0、330 0 0、75 0 0 0、10 10 0 0和 116 0 0 0 ,其相对百分含量分别为 16 .97%、15 .14 %、13.97%、19.83%和 12 .6 9%。经免疫印迹证实 ,血清 2型 RA的 4 0 0 0 0外膜蛋白与免疫鸭血清呈较强的阳性反应 ,是主要免疫原蛋白。用分离的外膜蛋白加上弗氏佐剂制备的亚单位疫苗免疫雏鸭后 ,可诱导产生较强的抗体 ,免疫鸭对同源 RA菌株的攻击可产生 10 0 %的免疫保护     

鸭疫里氏杆菌病病原的分离鉴定

鸭疫里氏杆菌(Riemerella anatipestifer,RA)病,是造成养鸭业严重经济损失的传染病之一。作者对某鸭场的病死鸭进行临床症状观察、病理剖检,通过细菌的分离培养及鉴定,确诊病死鸭病原为鸭疫里氏杆菌。鉴于养殖场中该病的存在及对养鸭业的危害,建议加强对鸭疫里氏杆菌病的诊断及监控。     

鸭疫里默氏菌的分离培养和PCR鉴定

对某鸭场送检的发病雏番鸭进行临床症状、病理变化观察、病原的分离和纯化,同时以外膜蛋白(OMPA)保守区设计一对特异性引物,PCR扩增,回收目的条带,进行测序与序列分析.结果表明,该菌为革兰氏阴性、无芽孢小杆菌,在TSA培养基上形成光滑圆形透明菌落,有荧光,不发酵糖,初步怀疑为鸭疫里默氏菌;PCR扩增,琼脂糖凝胶电泳,在600 bp处扩增出了一条清晰的条带,回收目的条带,测序,并与genebank中序列比对,确诊该菌为鸭疫里默氏菌.     

鸭疫里默氏菌一个可能新型的鉴定

用常规表型指标、RA种特异性PCR扩增以及16S rRNA序列分析,将来自广东和浙江的5个待检菌株鉴定为鸭疫里默氏菌。随后用玻片凝集试验、试管凝集试验和琼脂扩散沉淀试验进行了血清型鉴定。结果表明,这5株鸭疫里默氏菌为同一个血清型,但其代表菌株C2006与1～19型参考菌株和以往分离到的可能新型菌株C882均不发生可见的交叉凝集反应和交叉沉淀反应,说明这5个分离株可能属于另一个新的血清型。     

2型鸭疫里默氏杆菌的分离

从北京地区两个发病的鸭场中分离到两株细菌,经过染色,生化鉴定,凝集试验和琼扩试验,鉴定为２型鸭设里默氏杆菌,经过致病性试验,其中一株有很强烈致病性,另一株在实验室条件下,人工感染小鸭未能引起小鸭发病。