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1.
根据荚膜多糖和脂多糖抗原表位的不同,猪胸膜肺炎放线杆菌分为15个血清型,某些血清型问存在交叉反应,不同血清型甚至同一血清型不同菌株间的毒力大小不一样,致病性也有强弱之别。该菌的致病性与多种毒力因子密切相关,主要有外毒素、外膜蛋白、脂多糖、英膜多糖、转铁蛋白、脲酶等。本文综述了国内外对胸膜肺炎放线杆菌的几种主要毒力因子及血清型的研究进展。  相似文献   

2.
胸膜肺炎放线杆菌(Actinobacillus pleuropneum oniae,APP)的毒力因子有很多,其中主要包括外毒素、脂多糖、荚膜多糖、外膜蛋白、转铁结合蛋白、黏附素等,这些毒力因子都能引起胸膜肺炎的发生。1 APP的主要毒力因子及致病性1.1外毒素目前为止已经发现胸膜肺炎放线杆菌可以产生4种毒素。这些毒素都属于RTX(R epeat in structure Toxin)毒素家族,且不同血清型的APP所分泌的毒素种类不同,毒素的溶血性及细胞毒性也不同,因此可以作为分型的依据[1]。ApxⅠ和ApxⅡ具有溶血活性和细胞毒性作用,而ApxⅢ只有细胞毒性作用。ApxⅠ溶血活性强于…  相似文献   

3.
猪传染性胸膜肺炎(Porcine infectious pleuropneumonia)是由胸膜肺炎放线杆菌( Actinobacillus pleuropneumoniae, APP)引起的猪的呼吸道疾病.为了有效地控制本病,长期以来人们一直致力于研究高效、能提供强大保护力的疫苗,其中研究较多的是亚单位疫苗.人们发现把去除细胞的培养物上清液接种猪也可提供一定的保护力,于是对其中可能的毒力因子及具免疫原性的成分分别进行了分析.包括荚膜多糖、脂多糖内毒素、外膜蛋白、溶血素、转铁结合蛋白、蛋白酶以及所谓的渗透因子等.  相似文献   

4.
从分子质量、基因结构及致病机理等方面概述了猪传染性胸膜肺炎放线杆菌溶血外毒素ApxⅠ,ApxⅡ,ApxⅢ和ApxⅣ的基本特点和研究进展.比较并归纳了这4种溶血外毒素的异同点及在15种血清型中存在的特点.  相似文献   

5.
猪传染性胸膜肺炎(PCP)是猪的一种严重的呼吸系统疾病。目前,对该病的预防主要使用几个致病血清型的胸膜肺炎放线杆菌(App)全菌体灭活苗,交叉保护力差。亚单位疫苗采用多个血清型共有的免疫保护性抗原外毒素(Apx)及外膜蛋白,具有很强的交叉免疫保护效果,使用前不必检测病原血清型,全世界通用,大大降低免疫副反应,应用空间广阔。论文阐述了猪传染性胸膜肺炎亚单位疫苗的研究进展,为猪传染性胸膜肺炎的预防和控制提供参考。  相似文献   

6.
猪传染性胸膜肺炎是世界公认的危害养猪业的5个主要传染病之一,该病病原为猪胸膜肺炎放线杆菌(APP)。由于各国流行的血清型不尽相同,各型之间及同一血清型的不同菌株之间的毒力和致病力有差异嘲,几乎无交叉保护;此外,多杀性巴氏杆菌和链球菌都会引起继发性猪急性胸膜肺炎。随着我国养猪业的迅速发展,猪的引进与跨省区运输加速了APP的广泛流行,给该病的诊治带来极大困难。  相似文献   

7.
猪传染性胸膜肺炎是由胸膜肺炎放线杆菌(Actinobacillus pleuropneumoniae,APP)引起的细菌性呼吸道传染病。Apx毒素(actinbacillus pleuropneumoniae toxin)是由胸膜肺炎放线杆菌分泌的一类溶血毒素,在胸膜肺炎放线杆菌致病过程中,Apx毒素起了重要的作用。  相似文献   

8.
猪传染性胸膜肺炎(Porcine infectious pleuropneumonia)是由胸膜肺炎放线杆菌(Actinobacillus pleuropneumonicae,APP)引起的猪的呼吸道疾病,为了有效地控制本病,长期以来人们一直致力于研究高效,能提供强大保护力的疫苗,其中研究较多的是亚单位疫苗,人们发现把去除细胞的培养物上清液接种猪也可提供一定的保护力,于是对其中可能的毒力因子及具免疫原性的成分分别进行了分析,包括荚膜多糖,脂多糖内毒素,外膜蛋白,溶血素,转铁结合蛋白,蛋白酶以及所谓的渗透因子等。  相似文献   

9.
溶血外毒素(Apx)是胸膜肺炎放线杆菌(APP)最主要的毒力因子及保护性抗原。利用PCR技术扩增APP血清5型编码APXⅠN-端具有保护性抗原表位的APXⅠA部分基因,扩增片段长度为1 149 bp。将其插入原核表达载体PET-32a中,转化至E.coilBL21中诱导表达。SDS-PAGE分析结果表明APXⅠA基因能在大肠杆菌中高效表达,融合蛋白的分子量约为40 ku。Western-blot结果表明该融合蛋白能被APP阳性猪血清所识别,指示表达的蛋白具有良好的免疫活性,为建立猪传染性胸膜肺炎的诊治及高效亚单位疫苗的研制奠定了基础。  相似文献   

10.
胸膜肺炎放线杆菌毒力因子研究进展   总被引:2,自引:1,他引:1  
胸膜肺炎放线杆菌是引起猪传染性胸膜肺炎的重要病原。在APP致病过程中各种毒力因子发挥着决定性的作用,且致病机理较为复杂。目前,疫苗免疫是预防和控制该病的有效措施。研制亚单位疫苗及基因工程苗具有良好的应用价值,而了解和认识APP的毒力因子的特性是开展这一工作的基础。  相似文献   

11.
In the present study, the characterization of 3 atypical isolates of Actinobacillus pleuropneumoniae is presented. Two isolates (1B and 27E) showed positive reactions in coagglutination, immunodiffusion, and indirect hemagglutination tests for serotypes 1 and 7, whereas the third isolate (26B) reacted with antisera to serotypes 1, 4, and 7. These atypical isolates of A. pleuropneumoniae possessed a capsular polysaccharide (CPS) antigenically related to serotype 1 as well as an O-chain lipopolysaccharide antigenically related to serotype 7 or to serotypes 4 and 7, as shown by the use of monoclonal antibodies. Results of toxin profile and virulence assays for mice and pigs showed them to be more related to A. pleuropneumoniae serotype 7 field isolates. All 3 isolates induced antibodies mainly against serotype 7/4 O-long-chain lipopolysaccharide (LC-LPS) and, to a lesser extent, to the CPS of serotype 1, in experimentally infected pigs. Diagnostic laboratories that use a LC-LPS-based enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of A. pleuropneumoniae infection in swine would probably diagnose herds infected with these atypical isolates as being infected by A. pleuropneumoniae serotypes 7 or 4, whereas those that use a CPS-based ELISA would probably consider them as infected by A. pleuropneumoniae serotype 1.  相似文献   

12.
Active and passive immunization studies in mice were undertaken to examine the protective efficiency of vaccines prepared from different components of Actinobacillus pleuropneumoniae, or combinations thereof. Subcutaneous immunization using either washed formalinized whole cells, capsular polysaccharide, lipopolysaccharide or purified hemolysin I (105 kDa protein) partially protected mice against intranasal challenge with a lethal dose of homologous or heterologous A. pleuropneumoniae serotypes. However, full protection was obtained if the formalinized whole cells were supplemented with purified hemolysin. Similar protection was obtained when mice were immunized simultaneously with a sublethal dose of live cells by the intranasal route and with formalinized whole cells subcutaneously. Passive immunization using rabbit hyperimmune serum against formalinized whole cells provided almost total protection whereas hyperimmune serum against capsular polysaccharide, lipopolysaccharide or hemolysin alone provided only a partial protection. Cell mediated immunity as detected by the foot pad test may not be implicated significantly in the protein against acute A. pleuropneumoniae infection. However, humoral immune response seems to play an important role in protection. All the antigenic components examined may contribute to the protection to some extent. However, heat-labile components such as hemolysin and outer membrane proteins may play a crucial role in protection against acute challenge infection.  相似文献   

13.
本试验用分离纯化的猪胸膜肺炎放线杆菌(APP)3型荚膜多糖(CPS),致敏双醛化处理的绵羊血红细胞,建立了APP的血清学诊断方法,结果表明,该方法特异性强,仅与APP 3型阳性血清反应,可以用其进行APP疫苗免疫后抗体检测,该诊断方法简单、快速,适用于临床疾病的诊断。  相似文献   

14.
Atypical Actinobacillus pleuropneumoniae serotype 13 strains present in North America are described here for the first time. Different from serotype 13 strains described in Europe, North America strains are biotype I and antigenically related to both, serotypes 13 and 10. Chemical and structural analysis of the capsular polysaccharide (CPS) and lipopolysaccharide (LPS) of a representative strain revealed that the CPS is almost identical to that of the reference strain of serotype 13, having a slightly higher degree of glycose O-acetylation. However, it produces an O-PS within the LPS antigenically and structurally identical with that of the reference strain of A. pleuropneumoniae serotype 10. The O-PS was characterized as a homopolymer of 1,2 linked β-D-galactofuranosyl residues, a structure unrelated to that of the O-PS produced by the reference strain of serotype 13. Strains from Canada and United States are antigenically, phenotypically and genotypically similar. Animals infected by one of these strains induced antibodies that were detected by a LPS-based ELISA diagnostic test using either the homologous antigen or that of serotype 10. Based on the LPS and toxin profile, these strains might be misidentified as A. pleuropneumoniae serotype 10.  相似文献   

15.
对猪胸膜肺炎放线杆菌(Actinobacillus pleuropneumon iae,App)生物I型ZY(App-1)株TfbA基因进行克隆和序列测定,结果表明:ZY株TfbA基因全长1 782 bp,编码594个氨基酸残基组成的多肽;对App ZY株与AP37(App-1)株、AP213(App-5)株和AP205(App-7)株的TfbA基因进行分析比较,结果表明三型TfbA的核苷酸的同源性分别为99.8%、74.4%和72.2%;氨基酸的同源性分别为99.7%、64.1%和58.6%。系统发育进化树分析结果表明,ZY株与AP37株的亲缘关系最近。分析组成TfbA蛋白N-端重叠的16聚体多肽发现了3个有转铁蛋白结合活性的区域,长度为13或14个氨基酸。第1和第3个区域在App-1、App-5、App-7型间变异较大,同源性很低,第2个区域在App-1型和App-5型两者之间同源性高,几乎相同。  相似文献   

16.
Monoclonal antibodies (Mabs) against Actinobacillus pleuropneumoniae serotype 7 were produced and characterized. Three Mabs directed against surface polysaccharides were selected. One of the Mabs was directed against a capsular polysaccharide epitope (CPS) of A. pleuropneumoniae serotype 7 whereas two other Mabs reacted with different epitopes of the LPS O-chain. One of the latter reacted with the reference strain of serotype 7 and the other one with serotypes 7 and 4. These three Mabs were used to test, by Dot-ELISA, 508 field strains of A. pleuropneumoniae. None of the strains belonging to other serotypes different from serotypes 4 and 7 were positive with the Mabs. Used in combination, the CPS and one of the LPS O-chain directed Mabs were shown to be suitable for serotyping since they detected 100% of serotype 7 strains. In this study, we confirm for the first time that A. pleuropneumoniae serotype 4 is present in North America. Finally, both O-chain specific Mabs also reacted with the O-chain of Actinobacillus lignieresii. The cross-reactivity between the two species was confirmed using sera from pigs experimentally infected with A. pleuropneumoniae serotype 7 and A. lignieresii, using immunoblotting and ELISA. This is the first report of a specific cross-reactivity between the LPS of these bacterial species.  相似文献   

17.
A genetic typing method utilizing PCR for the identification of Actinobacillus pleuropneumoniae serotype 2 isolates has been developed based on the in vitro amplification of a 1.4 kb DNA segment of the serotype 2 capsular polysaccharide genes cps2AB. The assay was tested with all serotype reference strains and a collection of 92 different A. pleuropneumoniae strains of all 15 serotypes of both biovars I and II, originating from 18 different countries worldwide. The cps2 based PCR identified the serotype 2 reference strain and all 12 serotype 2 collection strains contained in this set. DNA was not amplified from the remaining A. pleuropneumoniae reference and collection strains, indicating the PCR assay was highly specific. Furthermore, the PCR method detected all 31 A. pleuropneumoniae serotype 2 field isolates from diseased pigs that were identified in parallel as serotype 2 by agar gel diffusion. The serotype 2 PCR assay proved to be highly specific and reliable for the identification of serotype 2 isolates of A. pleuropneumoniae.  相似文献   

18.
Two monoclonal antibodies (MAbs), lMAb-1 and lMAb-5, against Actinobacillus pleuropneumoniae serotype 1 were obtained. In enzyme-linked immunosorbent assay-inhibition tests with whole cell antigens obtained from serotype 1 to 12 strains of A. pleuropneumoniae, lMAb-1 reacted to only a serotype 1, strain 4074. The epitope recognized by lMAb-1 was a carbohydrate sensitive to periodate oxidation and resided on capsular polysaccharide (CP) of A. pleuropneumoniae serotype 1. On the other hand, lMAb-5 reacted with serotype 1, 9 and 11 strains at the same degree and its epitope was found to be located on O-polysaccharide of serotype 1, 9 or 11 lipopolysaccharide (LPS). These results showed that CP was one of the serotype-specific antigens of A. pleuropneumoniae, and that O-polysaccharide of LPS obtained from serotype 1, 9 or 11 strain was the cross-reacting antigen among these strains.  相似文献   

19.
Actinobacillus pleuropneumoniae is the etiological agent of porcine pleuropneumonia, which causes worldwide severe losses in pig farming. The virulence of the 15 serotypes of A. pleuropneumoniae is mainly determined by the three major RTX toxins ApxI, ApxII and ApxIII, which are secreted by the different serotypes in various combinations. A fourth RTX toxin, ApxIV, is produced by all 15 serotypes only during infection of pigs, but not under in vitro conditions. Pigs infected with A. pleuropneumoniae show specific antibodies directed against ApxIV. In contrast, antibodies against the other three toxins ApxI, ApxII and ApxIII are also found in pigs free of A. pleuropneumoniae. The antibodies to the three latter might result from other, less pathogenic Actinobacillus species such as A. rossii and A. suis. We used a recombinant protein based on the N'-terminal part of ApxIV to serologically detect A. pleuropneumoniae infections in pigs by immunoblot analysis. The analysis of sera of experimentally infected pigs revealed that ApxIV-immunoblots detected A. pleuropneumoniae infections in the second to third week post infection. We developed an indirect ELISA based on the purified recombinant N'-terminal moiety of ApxIV. The analysis of sera from pigs that were experimentally or naturally infected by A. pleuropneumoniae, and of sera of pigs that were free of A. pleuropneumoniae, revealed that the ELISA had a specificity of 100% and a sensitivity of 93.8%. The pre-validation study of the ApxIV-ELISA revealed that the latter was able to detect A. pleuropneumoniae-positive herds, even when clinical and pathological signs of porcine pleuropneumonia were not evident. Pigs vaccinated with a subunit vaccine Porcilis App were serologically negative in the ApxIV-ELISA.  相似文献   

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