气管环中和试验对2株IBV定型研究

本试验将二个 Ｉ Ｂ Ｖ 地方分离株宜毒和１１８ 毒连同 Ｉ Ｂ Ｖ 呼吸型代表株 Ｍ４１和肾型代表株 Ｔ 株制备免疫血清后在气管环上作交叉中和试验，结果显示宜株与 Ｔ 株（ Ｒ＝ ０．１８）， Ｍ 株（ Ｒ＝ ０１３５）抗原性上相差甚远，可能是一株不同于 Ｔ 和 Ｍ株的独立血清型或变异株，而１１８ 株与 Ｔ株相差较远，与 Ｍ 株（ Ｒ＝ ０．７１）比较接近，可能是马萨诸塞血清型中的一个亚型或变异型，这结果对疫苗的研制有一定指导意义。     

鸭疫里默氏杆菌二价灭活疫苗株筛选及免疫原性研究

通过对山东省鸭疫里默氏杆菌病流行病学调查,发现山东省主要流行鸭疫里默氏杆菌的血清型为Ⅰ、Ⅱ型.将临床分离鉴定的两种血清型致病菌株进行毒力测定和抗原性分析,筛选出适合制成鸭疫里默氏杆茵二价灭活苗的种子菌株,并对其免疫原性进行了研究.     

山东地区鸡传染性支气管炎病毒抗原相关性和血清分型

为进一步明确山东地区鸡传染性支气管炎病毒(IBV)的流行病学,对IBV分离株之间以及与疫苗株之间的抗原相关性进行了分析。分别制备了3个疫苗株(4/91、H120和Ma5)和18个分离株的单因子阳性血清,通过鸡胚交叉中和试验测定了阳性血清对同源病毒和异源病毒的中和效价,计算了不同毒株之间的抗原相关系数(R值),并根据R值进行血清分型。结果显示,3个疫苗株和18个分离株可分为5个血清型。疫苗株4/91属于血清Ⅰ型,H120、Ma5与2个分离株(SDWF0608和SDLY0701)属于同一血清型,分离株SDZB0808与SDLY0702、CK/CH/SD08/007和CK/CH/SD09/001等15个毒株为同一血清型,CK/CH/SD09/006和CK/CH/SD10/001分别与其他3和6个分离株组成两个血清型。进一步分析发现,部分IBV毒株之间表现单向中和反应性,属于同一血清型的IBV毒株之间抗原相关性可能存在明显差异。本研究结果一方面表明IBV毒株之间复杂的抗原相关性,另一方面显示IBV流行株与3个疫苗株之间抗原性存在明显差异。     

不同地区101个禽源性大肠杆菌分离株的致病性试验

从国内１８个省、市、自治区大肠杆菌病疑似病禽中分离并鉴定出大肠杆菌５９５株,鉴定出其中４４０个分离株的血清型。采用Ｒｏｓｅｎｂｅｒｇ氏报道的方法,测定了来自不同地区的６０个优势血清型分离株对ＳＰＦ鸡、３０个其他常见血清型及１１个国内少见血清型分离株对普通易感鸡的致病性。结果表明：所测定的１０１个分离株均为致病株,且９０％以上属高、中度致病株。     

珠三角及邻地鸭疫里默氏杆菌主要生物学特性的研究

为明确珠三角地区鸭疫里默氏杆菌(RA)的药物敏感性、血清型类型及其同源性,本研究对100株鸭源及鹅源RA进行分离与鉴定,并采用琼脂扩散试验进行血清型分类及其对12种药物的敏感性试验;选取10个代表株测定其对7日龄雏鸭的致病性及ompA基因序列,比较相互间的同源性以及其它生物特性的关系。结果表明:分离株的生化特性基本一致,代表株对雏鸭具有强的致病性;所有菌株具有一重以上的耐药性,63株细菌具有双重或多重耐药性,97%的菌株对奥格门丁敏感,其它药物敏感度依次为壮观霉素、青霉素、环丙沙星、氨苄西林、链霉素、诺氟沙星、罗红霉素、磺胺甲噁唑、利福平和卡那霉素;93%的菌株对庆大霉素耐药,表明该地区RA对大部分常用药物产生一重或多重耐药;100株菌株分属于4种血清型,其中83株属于血清1型,属于其它3个血清型的菌株分别有10株、5株和2株,以第4种血清型致病性最强;10个代表株中9株的外膜蛋白基因序列同源性达96%以上,5株为100%,1株与其它株的同源性为90.1%～90.4%,表明10株菌的外膜蛋白基因序列的同源性较高,外膜蛋白基因与血清型和菌株的致病性无直接关系。     

石河子几个鸡场大肠杆菌自家苗的研制及应用效果观察

禽大肠杆菌病的病原为大肠埃希氏杆菌(Escherichiacoli),其血清型极多,其中菌体抗原(O)171种,荚膜抗原(K)103种,鞭毛抗原(H)56种,这些抗原可组合成大量抗原性不同的血清型。刘秀梵等〔1〕从我国18个省、市、自治区分离出440株禽源性大肠杆菌,经鉴定有60个血清型之多,而且不同地     

鸡源致病性大肠杆菌1型菌毛pilA基因的PCR扩增、克隆及序列分析

研究选择从四川规模化鸡场分离鉴定的5株优势血清型鸡源致病性大肠杆菌代表株(O89,O119,O141,O127)的1型菌毛pilA基因的PCR扩增片段分别定向克隆到pUC18质粒的多克隆位点,并转化到DH5 α株大肠杆菌载体菌中,对目的基因的序列测定结果表明：5个克隆片段均含有1型菌毛pilA基因的全序列,全长459bp,编码信号肽和结构蛋白。用生物软件(DNASTAR)对9株大肠杆菌1型菌毛pilA基因序列、氨基酸序列、菌毛蛋白质二级结构预测及抗原性进行了分析比较,结果显示：鸡源致病性大肠杆菌1型菌毛间具有同源性,1型菌毛间存在一定的相同抗原位点。     

鸭肝炎病毒的分离与鉴定

1999-2008年从山东、河南、浙江、江苏、广西、山西、江西、广东、福建和辽宁等地有典型鸭病毒性肝炎症状的病死雏鸭中共分离得到22株病毒。用鸭肝炎病毒（DHV）Ⅰ型（DHV-1）抗血清和新型DHV （N-DHV）抗血清对分离的22株病毒进行血清中和试验;对22株病毒的抗原相关VP1基因进行RT-PCR扩增和测序,然后对VP1基因的核苷酸与推导的氨基酸序列进行分析。结果表明,目前我国存在DHV-1和N-DHV两种血清型。其中分离到的12株为DHV-1,10株为N-DHV。依据VP1基因序列同源性进行的血清型分型结果与根据抗原性鉴定进行的血清型分型结果一致。12株DHV-1的氨基酸序列同源性为95%左右,10株N-DHV的氨基酸同源性为98%左右;DHV-1分离株与N-DHV分离株间氨基酸同源性为72%-77%。同血清型病毒株间的VP1基因变异很小,表明DHV的抗原性稳定。     

鸭肝炎病毒分子流行病学分析

为了解我国鸭病毒性肝炎(DH)的流行情况,本研究用标准DH病毒(DHV)Ⅰ型(DHV-1)抗血清和新型DHV(N-DHV)抗血清对国内分离的7株DHV进行了血清中和试验。结果表明,PLK株和YB3株为DHV-1;YB1、YB2、YB5、HY2和HY3株为N-DHV。同时,对国内分离的9株病毒的抗原相关VP1基因进行RT-PCR扩增和测序,对VP1基因的核苷酸与推导的氨基酸序列分析的结果表明,3株DHV-1的氨基酸序列同源性为95%左右,6株N-DHV的氨基酸同源性为98%左右;DHV-1分离株与N-DHV分离株间氨基酸同源性为72%～77%。参照同属微RNA病毒的人肠病毒的血清型分型标准,通过对DHV VP1基因序列同源性比较,判定9株病毒的血清型。依据VP1基因序列同源性进行的血清型分型结果与根据抗原性鉴定进行的血清型分型结果一致。同血清型病毒株间的VP1基因变异很小,表明DHV的抗原性稳定。同型不同毒株间VP1基因的差异可以导致病毒在致病力、细胞感染能力等方面的差异。研究结果表明,目前我国存在DHV-1和N-DHV两种独立的血清型,但尚未见血清亚型的流行。     

新疆北疆地区致犊牛腹泻大肠杆菌的分离鉴定及部分生物学特性

为研究确定新疆北疆地区规模化奶牛场犊牛腹泻病原性大肠杆菌的优势血清型、致病性及毒力因子特征。采用细菌学、免疫学及分子生物学的方法对从新疆呼图壁、石河子、奎屯3个主要奶牛生产基地14个规模化奶牛场10日龄内腹泻犊牛直肠棉拭子样品进行了大肠杆菌的分离与鉴定、O血清群、黏附素及肠毒素的测定。结果从302份样品中分离并经生化鉴定获得180株呈β溶血的大肠埃希菌,其中94株对小鼠有致病性;对其中53株代表菌株的O血清型、黏附素及肠毒素测定,结果为8株携带K99菌毛及STa毒素基因,6株携带F41茵毛基因,6株产生LT毒素;28株分离株分布于16个O血清型,其中O101,O6,O114,O78为优势血清型,占被测菌株的50％。结果表明,新疆北疆主要奶牛养殖区致犊牛腹泻大肠杆菌是以携带K99、F41和产ST的溶血性大肠杆菌为主,其研究结果为犊牛大肠杆菌性腹泻的免疫防治提供病原学依据。     

东北地区猪群链球菌分离鉴定及流行病学调查分析

为了解猪链球菌在东北地区正常猪群中的流行情况,对黑龙江、吉林、辽宁省等地无菌采集的2 204份鼻拭子接入含有1‰抗生素的链球菌液体选择培养基中,37℃静止培养24 h,挑取细菌培养物涂片,革兰氏染色后镜检,将镜检为革兰氏阳性的链球菌利用PCR方法进行猪链球菌种的鉴定,在此基础上再利用PCR方法进行猪链球菌1、2、7、9血清型的分型鉴定.结果显示,黑龙江、吉林、辽宁3省猪群链球菌的携带率分别为29%、27%、34%,东北地区分离得到猪链球菌共155株,其中1型猪链球菌7株,2型猪链球菌39株,7型猪链球菌4株,9型猪链球菌11株,其他型猪链球菌94株.     

Antigenic diversity of infectious bursal disease viruses

Statistically significant antigenic differences were detected among serotype I infectious bursal disease viruses (IBDV) using the virus-neutralization test. Eight serotype I commercial vaccine strains, five serotype I field strains, and two serotype II field strains were tested. Hyperimmune guinea pig antisera against heterologous and homologous IBDV strains were used in cross-neutralization tests. Relatedness values were calculated from geometric mean antibody titers based on a minimum of three tests. Six subtypes were distinguished among the 13 serotype I strains tested.     

Serotype and apx genotype profiles of Actinobacillus pleuropneumoniae field isolates in Korea.

A total of 100 field isolates of Actinobacillus pleuropneumoniae isolated from lung tissues of pigs with severe pleuropneumonia were serotyped by slide agglutination and precipitation tests. Polymerase chain reactions for apxICA, apxIICA, apxIIICA, apxIBD and apxIIIBD genes were used to determine their genotype prevalence. Serotypes 2 (56 isolates), 5 (28 isolates) and 6 (11 isolates) were the most common; only two isolates belonged to serotype 7, and three were untyped. Among the 97 isolates identified by serotype, 70 had the same apx genes as their respective serotype reference strains, but 27 did not have any of the apx genes present in the corresponding serotype reference strain. Among these 27 isolates, 10 were serotype 2, 12 were serotype 5, three were serotype 6 and two were serotype 7.     

Prevalence of various phenotypes of Streptococcus suis isolated from swine in the U.S.A. based on the presence of muraminidase-released protein and extracellular factor.

The present study describes the prevalence of muraminidase-released protein (MRP) and extracellular factor (EF) proteins associated with virulence of Streptococcus suis serotype 2 from a collection of USA strains. Sixty-six strains belonging to serotypes 1, 2, 3, 4, 7, and 10, were analyzed with a set of double antibody sandwich ELISAs and Western blots. Nineteen of 34 serotype 2 strains from cases of swine meningitis had the MRP+EF+ phenotype. Five of 7 serotype 2 strains isolated from lungs had an MRP*EF- phenotype. An MRP-EF+ phenotype was found in 4/34 strains isolated from swine meningitis. The MRP*EF- and MRP-EF+ phenotypes have not been reported previously. All strains of serotypes other than 2, including isolates from cases of meningitis, had the MRP-EF- phenotype, suggesting that these strains must have other, as yet undetected, virulence factors.     

Restriction endonuclease analysis of Marek's disease virus DNA: differentiation of viral strains and determination of passage history.

The restriction endonuclease (RE) patterns of DNA from serotype 1 Marek's disease viruses (MDVs) are unique to serotype 1 viruses and can also be used to differentiate between low and high cell-culture-passaged viruses. We compared the RE patterns of DNA from seven serotype 2 and 3 MDVs before and after serial in vitro passage. Passage of four serotype 2 strains resulted in a variety of changes in the RE pattern. Individual strains within a serotype exhibited unique restriction patterns that allowed individual isolates to be differentiated. In a similar manner, the serotype 3 virus strains displayed RE pattern variations that were unique to each strain, as well as differences between low and high cell-culture passage. Our findings, together with earlier reports, suggest that the RE patterns of MDV DNA provide a simple and accurate method to: 1) differentiate between the three MDV serotypes, 2) differentiate between virus strains within a serotype, and 3) determine whether the viruses have been passaged extensively in cell culture.     

西南地区鸭疫里默氏菌血清型调查和三价灭活油乳剂疫苗的研制

本文对2006～2009年从四川、重庆、云南等主要养鸭区分离鉴定的261株鸭疫里默氏菌（RA）的血清型进行鉴定，结果显示血清Ⅰ、Ⅱ、Ⅳ型RA占总分离株的68．20％。筛选出免疫原性好的Ⅰ、Ⅱ、Ⅳ型RA分离株各1株，制备三价灭活油乳剂疫苗，安全性和效力检验结果显示该三价苗安全，接种后无不良反应，3日龄雏鸭首免后14～31d对Ⅰ、Ⅱ、Ⅳ的攻毒保护率均在83．33％以上。     

Biochemical and serological properties of Actinobacillus pleuropneumoniae biotype 2 strains isolated from swine

The biochemical and serological properties of 21 strains of Actinobacillus pleuropneumoniae biotype 2 isolated from haemorrhagic necrotic pleuropneumonia of swine were examined. For serologic typing, the indirect haemagglutination (IHA) and the double gel-diffusion tests were used. On the basis of their soluble surface antigens, our A. pleuropneumoniae biotype 2 isolates could be assigned to two proposed serotypes. Serotype 1 comprised 11 strains and serotype 2 comprised 10 strains. All strains contained two surface antigen components. In the strains belonging to serotype 1, one of the antigens was identical with the serotype-specific antigen of Pasteurella haemolytica T4. Both antigens of serotype 2 strains proved to be type-specific. Four strains received from Switzerland, including the holotype strain of A. pleuropneumoniae biotype 2, and three strains isolated from swine in the G.D.R. belonged to serotype 2. Both the double gel diffusion and the IHA tests detected a 2-way cross-reaction between biotype 1, serotype 2 and biotype 2, serotype 2 strains of A. pleuropneumoniae, which could be eliminated using cross-absorbed sera.     

Severe pleuritis associated with certain strains of Pasteurella multocida in swine

Pasteurella multocida was isolated from 2 farms on which grower or finisher pigs had problems of severe emaciation and high death loss (greater than 5%). At necropsy, the pigs had extensive suppurative pleuritis and pericarditis, with adhesions over the lung surface. On one farm, the pigs also had multiple lung abscesses. Histologic findings included polymorphonuclear cell infiltration in bronchial and alveolar spaces, thickening of alveolar walls, pleuritis, and in some cases, abscesses. From all pigs, P multocida was isolated. The strains (A52, A59) were serotype A and were nontoxigenic. Experimental reproduction of the disease was achieved by sequentially infecting conventionally weaned pigs intranasally with pseudorabies virus; 7 days later, infection with selected P multocida laboratory strains (A50 and D82, A52 and A59) was achieved. At necropsy, pigs inoculated with strains A59 and A52 (serotype A, pleurotropic) had more severe lesions (P less than 0.05) than those inoculated with strain A50 (serotype A, pneumotropic). Also, pigs infected with strains A59 and A52 had extensive pleuritis and abscessation, which were not observed in the other groups. Strain D82 (serotype D) was not capable of producing pneumonia or pleuritis. Pleuritis and abscessation may be associated with certain P multocida strains that are serotype A, but not with others. These pleurotropic strains seem to be more virulent than pneumotropic strains, and infection with the former may result in extensive pleuritis and abscess formation.     

Biochemical typing of Actinobacillus pleuropneumoniae

A study was conducted to evaluate the possibility of using biochemical differences among strains of a given serotype of Actinobacillus pleuropneumoniae as epidemiological markers, to rapidly identify the source of infection in herds affected with swine pleuropneumonia. Out of 38 different biochemical and physiological tests performed on a total of 67 strains belonging to serotypes 1 and 5 of A. pleuropneumoniae, three fermentation tests, glycerol, lactose and raffinose, allowed the classification of serotype 1 strains into 6 phenotypic groups and serotype 5 strains into 4 of these groups. Groups II and III were exclusively composed of serotype 1 strains, whereas the majority of strains in groups I and IV belonged to serotypes 1 and 5 respectively, the latter comprising almost all the serotype 5 studied.     

Serotype 2 reoviruses from the feces of cats with and without diarrhea.

During a virus survey carried out in the period 1989-90 with 148 fecal samples collected from cats in Japan, three reovirus strains were isolated in feline cell cultures. Two strains (Nos. 114 and 140) were from 48 diarrheal fecal samples and another strain (No. 32/41) was from 100 normal fecal samples. The strains grew in feline and simian cell cultures with producing typical intracytoplasmic inclusion bodies in which virus particles were densely packed. All strains, especially Nos. 32/41 and 140 strains, showed trypsin-dependent growth in vitro. Their ultrastructural and genomic properties were characteristic of genus reovirus in the Reoviridae. All strains agglutinated erythrocytes of human type O but not of bovine. Although they were identified as serotype 2 by hemagglutination-inhibition test with the hyperimmune sera against human reovirus prototype strains, No. 114 strain was typical and the other two strains were atypical serotype 2 reoviruses. Furthermore, from the reason that Nos. 32/41 and 140 strains possessed some common properties though derived from cats in distant locations, they were considered to be reoviruses having been maintained in the cat population. Seroepizootiologic survey revealed that the prevalence of serotype 3 infection was most widespread and serotype 2 was least among three serotypes of reovirus in a cat population.