菌落多重PCR鉴定不同荚膜血清型的多杀性巴氏杆菌

参照文献报道的多杀性巴氏杆菌KMT1基因和荚膜生物合成位点hyaD-hyaC、bcbD、dcbF、ecbJf、cbD基因的序列合成了6对特异性引物,建立了多杀性巴氏杆菌种和型的菌落多重PCR方法。结果表明,本所保藏的A、B、D、E、F各型多杀性巴氏杆菌均扩增出了相应的预期片段,PCR结果与Biolog鉴定结果和Carter氏间接血球凝集试验结果相一致;而支气管败血波氏杆菌、胸膜肺炎放线杆菌、大肠埃希菌、猪链球菌和粪肠球菌的扩增均为阴性。     

天津地区禽多杀性巴氏杆菌分离株血清型鉴定

通过Ｃａｒｔｅｒ氏荚膜型鉴定方法和琼脂扩散试验,对天津地区禽多杀性巴氏杆菌血清型进行鉴定。结果１６株分离菌中１１株为Ａ：１（４）,４株为Ａ：１（３,４）,１株为－：１（４）表明引起天津地区禽霍乱的致病菌与国内报道的以Ａ：１型为主有一定的差异。     

用多重PCR方法快速鉴定多杀巴氏杆菌毒力型

革兰氏阴性细菌多杀巴氏杆菌组成的异型物种与多种动物疾病有关。根据荚膜抗原(capA、B、D、E、F)把分离株分成5群。最近,一种新型PCR方法被用来确定多杀巴氏杆菌感染和毒力基因(tbpA、pfhA、toxA、hgbB)之间存在的流行病学相关性。然而,这种方法既繁琐又费力。因此,本试验设计了可靠的多重PCR方法来快速检测多杀巴氏杆菌的毒力基因。用多重PCR方法检测分离自临床上各种健康和患病宿主的87株多杀巴氏杆菌中的每种毒力相关基因。用本试验改进和简化的多重PCR方法即可完成4种毒力基因的快速检测,而且该方法也可用于流行病学调查的快速检测。     

猪多杀性巴氏杆菌PCR检测方法的建立及其应用

设计了1对用以检测猪多杀性巴氏杆菌的引物。对临床送检的有肺炎症状或萎缩性鼻炎症状的发病猪的病料进行细菌培养．然后挑菌做PCR，同时对可疑菌落纯化培养后做生化鉴定。结果，从不同省(市)的送检病料中分离鉴定出66株多杀性巴氏杆菌，PCR检测结果与生化鉴定结果完全符合；该引物对其他6种猪的常见呼吸道病原菌的扩增结果均为阴性；该PCR检测方法能检出CFU为10^3／mL的巴氏杆菌模板。     

猪多杀性巴氏杆菌PCR检测方法的建立及应用

设计了一对用以检测猪多杀性巴氏杆菌的引物。对临床送检的有肺炎症状或萎缩性鼻炎症状的发病猪的病料进行细菌培养，然后挑菌做PCR，同时对可疑菌落纯化培养后做生化鉴定。结果，从不同省(市)送检的病料中分离鉴定出66株多杀性巴氏杆菌，PCR检测结果与生化鉴定结果完全符合；该引物对其他6种猪的常见呼吸道病原菌扩增均为阴性；该PCR检测方法能检测出cfu为10^3的巴氏杆菌模板。     

猪源多杀性巴氏杆菌的生物学鉴定与荚膜PCR分型

从表现猪萎缩性鼻炎临床症状的猪群中分离出13株多杀性巴氏杆菌(Pasteurella multocida,Pm),采用Pm种特异性的KMT1-KMT2引物进行PCR扩增,结果与传统的生化反应鉴定完全一致。基于对甘露醇、卫茅醇、山梨醇、海藻糖的发酵能力和产生鸟氨酸脱羧酶的特性,Q_1、Q_3、Q_6、Q_7、Q_(10)、Q_(13)和C_(48-1)鉴定为Pm多杀亚种(Pm subsp.multocida);Q_2、Q_4、Q_5、Q_8、Q_9、Q_(11)、Q_(12)鉴定为Pm败血亚种(Pm subsp.septica)。对13株Pm分离物采用A型、B型和D型引物进行PCR扩增,8株鉴定为A血清型(61.5%);5株鉴定为D血清型(38.5%);没有发现B血清型的菌株。同时对金黄色葡萄球菌抑制试验、中性吖啶黄沉淀试验与荚膜PCR分型的相关性进行了讨论。     

多杀性巴氏杆菌PCR检测方法的建立

为了研究多杀性巴氏杆菌的PCR检测方法,试验采用特异性引物对32个经鉴定为巴氏杆菌的菌株以及其他5种常见的病原菌进行了扩增。结果表明:该引物对巴氏杆菌的检出率达到91%,对其他5种病原菌的检测结果均为阴性。说明试验所设计的引物可用于巴氏杆菌感染的诊断。     

牛源荚膜血清A型多杀性巴氏杆菌的分离鉴定

从采集于黑龙江、天津的病牛肺组织中分离到2株病原菌,经菌落形态学观察、培养特性、生化反应和小鼠毒力试验,初步鉴定为多杀性巴氏杆菌,分别命名为Pm-HLJ和Pm-TJ.参考多杀性巴氏杆菌种特异性基因kmt1和荚膜血清型特异性基因hyaD-hyaC、bcbD、dcbF、ecbJ和fcbD,合成引物,通过多重PCR扩增2株菌的种特异性基因和荚膜血清型特异性基因.选取Pm-HLJ的目标PCR产物进行克隆、序列测定、Blast搜索同源序列并且比较分析.结果显示,Pm-HLJ的kmt1基因片段全长460 bp,与GenBank中各血清型kmt1基因同源性均在96.6%以上;荚膜血清型A菌株特异性基因同源性为99.9%;而与其他荚膜血清型B、D、E、F的型特异性基因的同源性均低于50%.由此确认,分离的2株多杀性巴氏杆菌均为荚膜血清A型,这是我国A型多杀性巴氏杆菌引发牛出血性败血症的首例报道.     

羔羊多杀性巴氏杆菌的分离鉴定

应用实验室细菌学分离技术，从以咳嗽、呼吸等临床症状为主要特征的，死亡羔羊的肺、肝、脾、肾等组织中分离到一株病原菌。经细菌形态和培养特性观察，染色镜检，生化实验，结合临床症状及流行病学特点，确定该病原分离株为多杀性巴氏杆菌。     

野生草食动物源多杀性巴氏杆菌荚膜分型的研究

采用Carter荚膜群鉴定法对分离于我国黑鹿、白唇鹿、斑马和赤大袋鼠的56株多杀巴氏杆菌进行荚膜血清型鉴定,结果表明：B型占78．6％（44／56）,h型占14．3％（8／56）,D型占3．6％（2／56）,另有2株未能确定型,占3．6％（2／56）。其中荚膜B型是斑马、黑鹿和白唇鹿源多杀性巴氏杆菌的主要血清群,荚膜A型是赤大袋鼠源多杀性巴氏杆菌的主要血清群。黑鹿和白唇鹿源多杀性巴氏杆菌均存在2个血清群。     

Rapid virulence typing of Pasteurella multocida by multiplex PCR

The gram-negative bacterium Pasteurella multocida constitutes a heterogeneous species associated with wide range of disease in many animals. Isolates are classified into five groups based on capsular antigen (capA, B, D, E and F). Recently, a new valuable PCR-based method was introduced to determine the epidemiological correlation between P. multocida infection and existence of virulence genes including tbpA, pfhA, toxA and hgbB. However, this method is tedious and laborious. Thus, in the current study, we designed a reliable multiplex PCR method for rapid detection of virulence genes in P. multocida. Eighty seven strains of P. multocida isolated from various clinically healthy and infected hosts were examined by uniplex PCR method for each virulence associated genes. Based on our improved and simplified multiplex PCR method, rapid detection of four virulence genes was accomplished. It is proposed that its implementation may benefit the epidemiological investigations.     

Characterization of Pasteurella multocida strains isolated from human infections

Isolates of Pasteurella multocida recovered from infected humans (n = 15) were characterized by traditional and molecular microbiological methods and were compared with cat-derived strains (n = 5). The most prevalent subspecies among strains from human infections was P. multocida subsp. septica (80%), and nearly all isolates showed a similar combination of virulence-associated genes. MLST analysis classified the 20 P. multocida strains into 16 different sequence types, and we assigned 11 new sequence types (ST), however, only one of those (ST 334) was shared by two human and one cat isolates. P. multocida subsp. septica strains formed a distinct phylogenetic group within the species. The strains showed resistance to erythromycin, clindamycin and sulfamethoxazole, and with two exceptions, resistance to tilmicosin was also detected. Each strain was susceptible to ampicillin, streptomycin, gentamycin, tetracycline, doxycycline, cefazolin, cefpodoxime, chloramphenicol, florfenicol and enrofloxacin. Common characteristics (virulence profile and antibiotic sensitivity pattern) shared by strains isolated from humans and cats support the view that domestic cats may serve as a potential reservoir for P. multocida.     

Identification of avian strains of Pasteurella multocida in India by conventional and PCR assays

The prevalence of capsular and somatic serotypes were studied among 123 Pasteurella multocida strains isolated from chickens (n = 94), ducks (22), quails (4), turkeys (2) and geese (1) from different geographical regions of India. All strains exhibited similar cultural and morphological characteristics. Ninety-two of the isolates belonged to serotype A:1, the most prevalent serotype, with serotypes A:3, A:1,3, D:3 and F:3 having two isolates each. Only one isolate was positive for serotypes A:4 and D:1. Twenty isolates were untyped. A multiplex capsular PCR assay generated amplicons of sizes 460, 1044, 657 and 854 bp in 106 isolates identified as capsular serotype-A, 15 in serotype D and two in serotype F. Capsular types B and E were not detected in any of the avian isolates studied. The present findings suggest that a multiplex capsular PCR assay may be suitable for the rapid initial identification serotypes P. multocida during epidemiological studies of fowl cholera.     

Capsular serogroups of Pasteurella multocida isolated from animals in Zimbabwe

Pasteurella multocida is isolated from a variety of disease conditions from different animal species in our diagnostic laboratory. In order to determine serogroup distribution among the isolates, an indirect haemagglutination test using glutaraldehyde-fixed sheep red blood cells was employed. A serological examination of 79 isolates revealed that 47/79 were of capsular serogroup A, 11/79 capsular serogroup D, 4/79 capsular serogroup B and 17/79 were untypable strains. None of the isolates belonged to either serogroup E or F. All those from cases of classical pasteurellosis could be grouped, but a significantly high proportion of those which originated from companion animals were untypable. The significance of these results is discussed. This report appears to be the first detailed information on the prevalence of various serogroups of P. multocida in animals in southern Africa.     

Virulence genotype of Pasteurella multocida strains isolated from different hosts with various disease status

To learn more about the molecular biology of Pasteurella multocida 289 strains isolated from various clinically healthy and diseased hosts were examined for capsule biosynthesis genes (capA, B, D, E, and F) and 14 virulence associated genes by PCR and DNA-DNA-hybridization. As expected, capsule type A strains were highly adapted to bovines (92.3%) and poultry (85.7%) while we mainly found capA (34.9%)- and capD (58.1%)-positive strains in swine. A noticeable amount of capD-positive strains also originated from small ruminants (34.9%) and capF was detected in wild type strains from diseased cattle (2.2%) and cats (7.4%). None of the isolates harboured capE, while capB was exclusively found in all strains from buffaloes. Nearly all isolates showed a combination of genes encoding outer membrane proteins, colonization factors, iron aquisition factors and superoxid-dismutases without any clue for host specificity. In contrast, the transferrin binding protein encoding gene tbpA (31.5%) was limited to ruminant strains and only 37.0% of all P. multocida strains harboured pfhA, coding for a filamentous hemagglutinin, supposed to be a putative adhesion- und serum resistance factor. PfhA revealed a strong positive association to the outcome of disease in bovine hosts and in combination with toxA to that in swine. The dermonecrotoxin encoding toxA, present in 12.5% of all strains, was detected in isolates from swine, small ruminants, cattle, and poultry. A significant association to the disease status, however, was only existent in swine, although with 66.7% we found a notably high prevalence of the toxin gene among strains from small ruminants. The genes toxA, tbpA and pfhA as well as capsule biosynthesis genes are supposed to be important epidemiological marker genes for characterizing P. multocida field strains.     

猪源多杀性巴氏杆菌PCR鉴定方法的建立

为建立一种灵敏、特异的猪源多杀性巴氏杆菌PCR检测方法,根据GenBank已公布的多杀性巴氏杆菌plpE基因序列的保守片段设计合成引物,经plpE基因阳性质粒构建、反应条件的优化、特异性试验和敏感性试验,对猪源多杀性巴氏杆菌特异性PCR检测方法进行了研究;并将该PCR方法用于检测来自四川省6个规模化猪场的64份疑似多杀性巴氏杆菌肺部组织样品。结果显示,建立的PCR方法具有良好的特异性和敏感性,检测的敏感性为5×101拷贝的目的基因;多杀性巴氏杆菌(A、B、D血清型)PCR均为阳性、APP和HPS等病原均为阴性;64份临床疑似样品中检出36份样品阳性,阳性检出率为56.2%。以plpE基因初步建立的多杀性巴氏杆菌PCR检测方法具有较好的特异性、重复性、敏感性和可靠性,可用于多杀性巴氏杆菌的检测鉴定。     

PCR检测方法在多杀性巴氏杆菌定种中的应用

为修订行业标准《猪巴氏杆菌病诊断技术》（NY/T 564-2002）,改进多杀性巴氏杆菌定种方法,采用16S rDNA基因序列分析法对中国兽医微生 物菌种保藏管理中心（CVCC）保藏的63株猪源多杀性巴氏杆菌进行复核鉴定。63株猪源多杀性巴氏杆菌中有60株菌种与原鉴定结果一致。建立多杀性巴 氏杆菌基于kmtΙ基因的PCR定种方法,对经16S rDNA PCR方法确认为多杀性巴氏杆菌的60株菌进行定种。结果表明,60株菌均扩增出了预期片段,基于 kmtΙ基因的PCR定种方法与16S rDNA PCR方法试验结果相一致。研究结果显示,可将基于kmtΙ基因的PCR定种方法增添至行业标准中,作为原有生化鉴 定方法的补充进行多杀性巴氏杆菌的定种。     

产毒素多杀性巴氏杆菌菌落双重PCR检测方法的建立

为建立快速特异的PCR方法以及同时检测并区分产毒素与非产毒素多杀性巴氏杆菌,本研究根据GenBank登录的多杀性巴氏杆菌KMT1基因和toxA毒素基因序列,设计合成了2对特异引物。特异性试验表明产毒素多杀性巴氏杆菌C51-6扩增出了460bp和1854bp的2条目的片段,而不产毒素多杀性巴氏杆菌、大肠埃希菌、胸膜肺炎放线杆菌、猪链球菌、支气管败血波氏杆菌、副猪嗜血杆菌和鸡白痢沙门菌的扩增均为阴性;敏感性试验表明该PCR方法能从含450CFU的菌液中扩增出相应的目的片段。同时用豚鼠皮肤坏死试验和小鼠致死试验对该PCR方法进行了验证。