副猪嗜血杆菌病原检测及aroA基因PCR-RFLP分型

本试验应用PCR方法及PCR-RFLP技术对aroA基因在副猪嗜血杆菌病原检测及基因分型中的作用进行探讨。以针对aroA基因的PCR引物成功检测出18株来自广西各地区猪场的副猪嗜血杆菌,敏感性检测结果表明,该PCR方法可检测的最低菌数为10²个。对该18株副猪嗜血杆菌进行aroA基因的序列测定,并进行aroA基因的酶切位点分析,筛选出Hind Ⅲ和FokⅠ两种限制性内切酶,利用PCR-RFLP技术对1株血清5型参考菌株与本研究中18株广西菌株aroA基因的完整编码序列进行Hind Ⅲ和FokⅠ限制酶谱分析,结果显示可分为与毒力相关的3种谱型。本研究结果表明,应用PCR方法及PCR-RFLP技术对副猪嗜血杆菌进行检测分析有助于更好地研究副猪嗜血杆菌的生物学特性及aroA基因的功能。     

Typing of Haemophilus parasuis strains by PCR-RFLP analysis of the tbpA gene

On the basis of a species-specific PCR assay, a RFLP analysis for typing of Haemophilus parasuis strains was developed and evaluated. Amplification was based on the gene tbpA, encoding a transferrin-binding protein. RFLP analysis of the 1.9-kb tbpA-amplicon using TaqI, AvaI and RsaI endonucleases produced 12 different patterns for the reference strains of the 15 known H. parasuis serovars, and showed a high heterogeneity (33 RFLP groups) for 101 H. parasuis clinical isolates tested. The sensitivity, typeability (100% versus 65% for immunodiffusion), high degree of discrimination (0.93 versus 0.84 for immunodiffusion), simplicity and low cost per test make this PCR-RFLP assay a useful method for typing H. parasuis and, therefore, for studying the epidemiology of outbreaks of Gl?sser's disease.     

aroA gene PCR-RFLP diversity patterns in Haemophilus parasuis and Actinobacillus species

The Haemophilus parasuis aroA gene encodes 5-enolpyruvylshikimate-3-phosphate synthase and participates in the aromatic amino acids and the folic acid universal metabolic pathway of bacteria. The application of aroA-based PCR-RFLP methodology yields a significant degree of diversity in H. parasuis and Actinobacillus species. PCR amplification of the aroA gene rendered a 1,067-bp fragment in all 15 H. parasuis serovars, and also in Actinobacillus pleuropneumoniae serotypes 1-12, Actinobacillus lignieresii, Actinobacillus equuli, Actinobacillus porcinus, Actinobacillus rossii, Actinobacillus suis, Actinobacillus ureae, Actinobacillus minor and Actinobacillus indolicus. Sau3AI and RsaI digestions of the aroA PCR products rendered seven different restriction fragment length polymorphism (RFLP) patterns: group I (H. parasuis serovars 1, 2, 4-6, and 8-15, A. porcinus and A. ureae), group II (H. parasuis serovars 3 and 7, and A. pleuropneumoniae serotypes 1, 4, 5, 9, 11 and 12), group III (A. lignieresii), group IV (A. pleuropneumoniae serotype 7), group V (A. pleuropneumoniae serotypes 2, 3, 6 and 8, A. equuli, A. rossii, A. minor and A. indolicus), group VI (A. suis) and group VII (A. pleuropneumoniae serotype 10). This is the first report describing the presence of aroA gene in H. parasuis, A. lignieresii, A. porcinus, A. rossii, A. suis, A. ureae, A. minor and A. indolicus and the data presented here demonstrates a significant degree of aroA genetic diversity in H. parasuis and species of the genus Actinobacillus.     

副猪嗜血杆菌tbpB基因的PCR-RFLP分型

本研究应用生物学软件Vector NTI对副猪嗜血杆菌(Haemophilus parasuis,Hps)的转铁结合蛋白tbpB进行基因分型研究,通过选择AluⅠ、AvaⅡ和RsaⅠ3种限制性内切酶对15株Hps标准株和12株分离株的tbpB基因进行RFLP分析。经过生物学软件Vector NTI精确分型,标准株得到了11个基因型,其中基因型Ⅰ(AAA)包括血清型1、3和15,Ⅱ(BBB)包括血清型2、9和11;分离株的分型产生了10种基因型,其中6种为新的基因型。这一结果证实了Hps流行株的多样性,说明该方法对于猪革拉泽氏病流行病学规律的研究具有实用意义,同时,需要对更多的分离株做进一步的研究。     

Serological characterization of Haemophilus parasuis isolates from China

From September 2002 to December 2004, a total of 281 strains of Haemophilus parasuis were isolated from 17 provinces of China. All these isolates were serotyped by both the gel diffusion (GD) and the indirect haemagglutination (IHA) tests. By combining the GD and IHA results, serovar 4 (24.2%) and serovar 5 (19.2%) were the most prevalent serovars, followed by serovars 13 (12.5%), 14 (7.1%) and 12 (6.8%), while 12.1% of the isolates could not be assigned to a serovar (nontypable). A comparison of the number of isolates obtained from the respiratory tract of swine without polyserositis with those obtained from swine with polyserositis revealed an increased frequency of serovar 4 and a significantly decreased frequency of serovar 13 among isolates from the respiratory tract of swine without polyserositis, whereas the frequency of isolation of serovars 5, 12, 14 and nontypable from swine with or without polyserositis were similar. Co-infection of H. parasuis and other bacterial agents was studied in 183 cases examined from June 2003 to December 2004. Streptococcus suis (30.6%; 56), Escherichia coli (21.9%; 40), Bordetella bronchiseptica (21.3%; 39) and Pasteurella multocida (14.2%; 26) were the bacterial agents frequently co-isolated with H. parasuis in China.     

浙江地区副猪嗜血杆菌分离株的生物学特性

为明确浙江地区副猪嗜血杆菌(HPS)病的流行特点,提高对该病的免疫防控能力,本研究对HPS分离株进行生物学鉴定。结果表明,HPS在含有2%小牛血清和16μg/mL NAD的TSB培养基中生长良好,在TSB液体培养基中培养16 h～18 h后,活菌数达到峰值;6个分离株对小鼠的LD50分别为2.03×109、5.3×109、1.34×1010、7.0×109、1.17×1010和1.62×109;可在感染HPS豚鼠的心血中分离到该菌;ERIC-PCR指纹图谱分析结果表明,4个分离株与4型、5型和9型标准菌株图谱一致,但有2个分离株与15个血清型标准菌株图谱不吻合。研究提示浙江地区内HPS的散发、流行的原因可能是由于该细菌血清型复杂性造成的。     

2009～2010年华南地区副猪嗜血杆菌分离株ERIC-PCR指纹图谱的鉴定和分析

本试验采用肠杆菌基因间重复一致序列多态性聚合酶链式反应(ERIC-PCR)对2009~2010年分离自华南地区的41株副猪嗜血杆菌野生菌株及15株参考菌株进行了指纹图谱的鉴定。利用BioNumerics 5.1软件对所有菌株的ERIC-PCR指纹图谱进行分析,结果显示,15株具有不同血清型的参考菌株均具有不同的指纹图谱;41株华南地区副猪嗜血杆菌野生分离株则具有26个不同的指纹图谱,该方法对所有56株副猪嗜血杆菌的鉴别率为0.984。由此可见,ERIC-PCR分型方法具有较好种间的鉴别能力,可作为副猪嗜血杆菌病流行病学研究中的一种有效的辅助分子手段。     

Prevalence of Haemophilus parasuis serovars isolated in Spain from 1993 to 1997

From 1993 to 1997, 327 strains of Haemophilus parasuis were isolated from spanish swine in our Diagnostic Laboratory and 174 strains (53.2%) were serotyped. Four serotypes, sv. 5 (18.4%), sv 4 (16%), sv. 2 (9.2%) and sv. 13 (8%) were the most frequently isolated and 29.3% of the studied strains were classified as non typable. The results obtained indicate that the distribution of the serotypes in Spain is very similar to that found by other researchers in Germany, Australia, Canada and alike to that found in the United States.     

副猪嗜血杆菌Plp4蛋白的原核表达及免疫原性分析

为原核表达副猪嗜血杆菌P1p4蛋白,本研究通过PCR方法扩增P1p4全长基因并克隆于pET-28a(+)载体中,将重组质粒转化BL21(DE3)感受态中,采用0.4 mM IPTG经22℃诱导表达了35 ku的重组蛋白.经western blot试验证明Plp4蛋白具有良好的反应原性,免疫6周龄昆明小鼠制备免疫血清,ELISA检测表明制备的抗血清效价在1∶15000以上,表明P1p4蛋白具有良好的免疫原性.     

2012～2014年江西地区副猪嗜血杆菌分离株ERIC-PCR指纹图谱分析

在对15种副猪嗜血杆菌血清型参考株鉴定获得15种不同ERIC-PCR指纹的基础上,对2012~2014年分离自江西地区41株副猪嗜血杆菌临床分离菌株进行指纹鉴定。结果表明,41株副猪嗜血杆菌产生20种不同的指纹图谱,相同血清型的菌株表现出不同的指纹图谱,无法进行血清分型的副猪嗜血杆菌应用该方法可得到充分区分。该方法证实副猪嗜血杆菌ERIC-PCR指纹图谱存在丰富的多样性,可适用于副猪嗜血杆菌的快速基因分型及分子流行病学调查。     

副猪嗜血杆菌冻干保护剂的研究

采用冻存实验筛选出一种冻存存活率为100％的副猪嗜血杆菌保护剂(HPS-d),通过冷冻干燥实验测定HPS-d冻干存活率为25.94％.利用单因素分析实验优化保护剂HPS-d基质,在HPS-d中添加3种保护剂基质,结果显示:当海藻糖比例为1％、L-精氨酸盐酸盐比例为3％、BHI培养基/保护剂比例为1∶2时,冻干存活率达73.65％ ～77.61％.Plackett-Burman实验设计考察了保护剂8种组分的保护效果,结果显示:D-山梨醇、L-精氨酸盐酸盐和D-海藻糖是影响冻干存活率的显著因素.冷冻干燥验证实验证明优化后保护剂HPS-d平均冻干存活率达74.77％.     

副猪嗜血杆菌ompP2基因的克隆鉴定及序列分析

用PCR技术对华南地区分离的17株不同血清型副猪嗜血杆菌菌株ompP2基因进行克隆鉴定,并以CLUSTALS1和PHYLIP-3.68软件将ompP2基因序列进行比对和遗传进化分析.17株副猪嗜血杆菌茵株中均能扩出ompP2基因,克隆测序结果发现ompP2基因大小有所不同,与参考序列ABKM01000007的同源性在92％～99％之间.序列比较结果显示,ompP2基因与GenBank公布的副猪嗜血杆茵全基因组测序中的ompP2基因序列具有较高的同源性,不同菌株ompP2基因序列大小存在差异,为进一步验证ompP2蛋白的功能及相关研究奠定了基础.     

副猪嗜血杆菌病疫苗研究进展

副猪嗜血杆菌病又称猪革拉泽氏病,副猪嗜血杆菌主要引起猪的多发性浆膜炎、纤维素性心包炎、关节炎和脑膜炎。目前预防该病主要是灭活疫苗,但不同血清型之间交叉保护性不强或无交叉保护作用。因此,发展新的广谱疫苗是未来的趋势。文章对副猪嗜血杆菌病的疫苗及其研究现状进行了分析综述。     

Characterization of Haemophilus parasuis isolated from Brazilian swine through serotyping, AFLP and PFGE

Haemophilus parasuis infection in pigs is characterized by fibrinous polyserositis, arthritis and meningitis. Despite the fact that traditional diagnosis is based on herd history, clinical signs, bacterial isolation and serotyping, molecular-based methods are alternatives for species-specific tests and epidemiological studies. The aim of this study was to characterize H. parasuis field strains from different states of Brazil, employing serotyping and genotyping methods. Serotyping revealed that serovar 4 was the most prevalent (26.1%), followed by serovars 5 (17.4%), 14 (8.7%), 13 (4.4%) and 2 (4.4%), whereas 39% of the strains were considered as untypeable. AFLP with a single enzyme and PFGE were able to type all isolates tested, generating 34 and 20 different profiles, respectively, including untypeable strains. Besides the slightly higher discrimination index presented by AFLP, PFGE with Not I restriction enzyme showed a better correlation with epidemiological data, grouping strains of the same serovar, animal or farm origin. The results indicated AFLP and PFGE as valuable tools for typing H. parasuis isolates collected in Brazil.     

副猪嗜血杆菌黏附基因的表达和免疫原性鉴定

为获得副猪嗜血杆菌(HPS)黏附素基因的表达产物并对其进行免疫原性鉴定,本研究采用PCR技术扩增了HPS黏附素基因序列,将扩增产物与表达载体pET-32a(+)连接,得到表达重组质粒。通过EcoRⅤ和HindⅢ双酶切鉴定和测序确认正确后,将重组质粒转化大肠杆菌BL21(DE3)中进行表达。经SDS-PAGE电泳分析,获得了59.5ku的表达产物,与预期大小的黏附素蛋白分子量一致。经western blot检测,表达产物与HPS阳性血清反应,证明表达产物具有一定的免疫活性。提示本研究所表达的蛋白将有助于HPS的血清学诊断和疫苗的研发。     

中国东南部地区副猪嗜血杆菌分离株ERIC-PCR指纹图谱分析

采用肠杆菌基因间重复一致序列PCR方法,在对15种副猪嗜血杆菌血清型参考株鉴定获得15种不同ERIC-PCR指纹的基础上,对分离自中国东南部发生Glasser's病的不同猪场的111株副猪嗜血杆茵进行了指纹鉴定.结果显示:111株分离株显示出23种指纹图谱,前3种最流行的指纹图谱为ERIC-PCR X X(20/111),X X ⅢⅠ(9/111)和Ⅳ(8/111).且在111株分离株中,来自不同地区的分离株分别表现出不同种类的指纹图谱.该试验表明,ERIC-PCR方法可适用于对某一地区的副猪嗜血杆菌进行分子流行病学的研究和基因型的鉴定;试验结果还揭示了副猪嗜血杆茵在中国东南部地区已广泛存在并具有多样的基因型.     

副猪嗜血杆菌血清5型TbpA蛋白的表达及其免疫原性分析

为原核表达副猪嗜血杆菌血清5型TbpA蛋白,本研究利用特异性引物扩增tbpA基因,并将其克隆到pMD 18-T载体中进行序列测定.再将其亚克隆于pET-28a中构建重组表达质粒pET-tbpA.将其转化受体菌E.coli BL21 (DE3),经IPTG诱导后,SDS-PAGE电泳和western blot分析表明,表达的重组蛋白约106 ku,并以包涵体形式存在.表达的重组蛋白经纯化后,免疫6周龄昆明小鼠制备免疫血清,ELISA分析表明制备的血清抗体效价在1∶3 200以上,表明TbpA具有良好的免疫原性.     

Prevalence and characterization of genotypic diversity of Haemophilus parasuis isolates from southern China

From September 2008 to December 2010, 112 Haemophilus parasuis strains were isolated from 536 pigs with clinical signs of Glässer’s disease in South China, for a frequency of 21%. The 112 strains were subjected to serovar analysis by gel diffusion (GD) and indirect hemagglutination (IHA) tests and to genotype analysis by means of pulsed-field gel electrophoresis (PFGE). With a combination of the GD and IHA results, serovars 5 and 4 were found to be the most prevalent, at 23% and 17%, respectively, followed by serovars 2 (8%), 15 (7%), 13 (6%), and 12 (5%); 20% of the strains were nontypeable. The 112 strains were genetically diverse, with 85 genotypes identified (discriminatory index 0.992). The 89 typeable isolates belonged to 15 H. parasuis serovars displaying 63 different PFGE profiles. The 23 nontypeable strains displayed 22 different PFGE profiles. These findings confirmed that 15 serovars and diverse genotypes of H. parasuis were widely distributed in southern China.     

副猪嗜血杆菌研究进展

近年来 ,国内外许多猪场出现了一种以多发性浆膜炎和关节炎及高死亡率为特征 ,严重危害仔猪和青年猪的传染病。经细菌分离培养、生化鉴定和分子生物学试验证明 ,该传染病主要是由副猪嗜血杆菌所引起。为了更加全面地认识该病原体 ,文章对其流性病学、理化特性、分子生物学、诊断及防制作了较为全面的概述。