10日龄肉鸭混合感染新型鸭肝炎病毒和多杀性巴氏杆菌的病原学研究

对1例疑似鸭肝炎病毒和多杀性巴氏杆菌混合感染的10日龄肉鸭采用常规的病毒、细菌鉴定方法和RT-PCR、PCR方法分别进行病毒、细菌的分离与鉴定。病毒鉴定为新型鸭肝炎病毒,细菌鉴定为荚膜血清A型多杀性巴氏杆菌多杀亚种。细菌对SPF鸡的毒力试验结果显示,分离的巴氏杆菌与强毒标准株C48-1毒力相近,为强毒株。细菌对10日龄肉鸭的致病性回归试验结果表明,一定数量的该株巴氏杆菌可导致10日龄雏鸭的感染死亡。结果表明,该批肉鸭为新型鸭肝炎病毒和A型多杀性巴氏杆菌混合感染。这是国内首例从感染鸭肝炎病毒10日龄雏鸭肝脏中分离到多杀性巴氏杆菌。     

西藏牛源多杀性巴氏杆菌分离鉴定及耐药性分析研究

多杀性巴氏杆菌是一种能感染多种动物甚至人的重要的病原菌。研究对西藏某地临床症状疑似出败病死亡的牛进行了巴氏杆菌的分离鉴定、致病性、荚膜分型及耐药性分析,掌握西藏牛源多杀性巴氏杆菌的生物学特性为临床合理用药提供科学依据。采集死亡牛肺脏、肝脏、脾脏、肾脏等脏器及淋巴结,分离细菌并进行培养,研究其形态学特征及其生理生化分析。随后对分离菌株进行荚膜分型、动物实验和药敏实验。结果表明,从肺脏组织中成功分离鉴定出1株牛源巴氏杆菌且分离菌株为A型巴氏杆菌,且动物致病性试验证明该细菌具有致病作用且病例变化较明显,说明分离菌株为致病菌;该菌株对苯唑西林、万古霉素和克林霉素不敏感;庆大霉素、多粘菌素B和氯霉素中敏;对哌拉西林、头孢呋辛、氧氟沙星等其他大多数抗菌药物均敏感。     

奶牛荚膜血清A型巴氏杆菌的分离鉴定及致病性

山东省某规模化奶牛场10~30日龄的犊牛出现发热、咳嗽和关节肿大的临床症状,并造成部分犊牛死亡。为查明死亡原因并制定相应的防控方案,在流行病学调查和现场剖检的基础上,对采集的病料进行病理组织学检查、细菌分离鉴定、生化试验,并对鉴定的病原菌进行动物感染试验和药敏试验,对分离菌的PCR产物进行多杀性巴氏杆菌特异性基因和荚膜血清型特异性基因序列的测定。结果表明,该场犊牛主要死于以纤维素性肺炎为特征的败血症,死亡原因为多杀性巴氏杆菌感染所致,且分离的多杀性巴氏杆菌为荚膜血清A型高致病性菌株,对小鼠呈高致死性;该分离菌株对林可霉素、头孢噻呋、多西环素耐药,对恩诺沙星、氟苯尼考高度敏感。     

一株鸡源多杀性巴氏杆菌的分离鉴定

为了确定引起湖北省荆州市某养鸡场鸡群发生疑似禽霍乱死亡的原因,试验从该养鸡场采集病死鸡的肝脏病原,通过细菌分离鉴定、16S rDNA克隆测序分析、荚膜和脂多糖PCR分型、药敏试验及致病性试验对病原进行了研究。结果表明：分离菌株呈革兰氏染色阴性,瑞氏染色为两极浓染的球杆菌;分离菌经荚膜和脂多糖PCR分型鉴定为荚膜B型、脂多糖L2型,将其命名为JZ-B-1;JZ-B-1菌株与巴氏杆菌的同源性高达99%以上,在系统进化树中分别与多杀性巴氏杆菌属和多杀性巴氏杆菌败血亚种处于同一分支上,属多杀性巴氏杆菌败血亚种;菌株JZ-B-1对哌拉西林、羧苄西林和青霉素有耐药性,对头孢他啶、头孢呋辛、头孢拉定、头孢唑林、头孢哌酮、头孢曲松、氨苄西林、四环素、新霉素、卡那霉素、庆大霉素、丁胺卡那、氯霉素、呋喃唑酮、万古霉素、氧氟沙星、诺氧沙星、麦迪霉素高度敏感。说明从病死鸡中分离的菌株为荚膜B型多杀性巴氏杆菌属败血亚种,丰富了鸡源多杀性巴氏杆菌的生物学亚型,对湖北地区巴氏杆菌病的防控和细菌耐药性研究具有一定的指导意义。     

鸭霍乱的诊断和防治

对某鸭场采样进行细菌分离鉴定、荧光PCR检测、药敏试验。发现鸭群感染多杀性巴氏杆菌,该分离菌对恩诺沙星、新霉素高度敏感,而对庆大霉素、氟苯尼考不敏感。     

三株鸭源荚膜A型多杀性巴氏杆菌的分离与鉴定

从疑似禽霍乱死亡鸭分离到3株细菌,经PCR法鉴定为荚膜A型多杀性巴氏杆菌,纸片法进行药物敏感试验,发现3株细菌同时敏感的药物有恩诺沙星、多黏菌素B、复方新诺明和头孢唑啉,3株细菌同时耐受的药物有链霉素、四环素、克林霉素和青霉素。本研究结果可为禽源多杀性巴氏杆菌的血清流行病学和禽霍乱的临床治疗提供参考。     

新疆石河子规模化牛场多杀性巴氏杆菌的分离鉴定及药敏试验

为了确定石河子地区某规模化牛场出现呼吸困难、咳嗽、病牛消瘦甚至死亡的病因,本研究以病牛病变组织为研究对象,采用常规细菌分离鉴定和细菌16SrRNA序列分析来鉴定菌种,以及多杀性巴氏杆菌种特异性基因Kmt-1和各个荚膜血清型特异性基因(hyaD-hyaC、bcbD、dcbF、ecbJ、fcbD)PCR扩增来确定细菌的血清型,同时应用纸片扩散法对分离细菌进行药物敏感性试验和小鼠感染试验。结果表明,从病变的肺组织中分离到1株菌落为灰白色、露珠状、不溶血,染色为革兰阴性球杆状细菌,生化鉴定结果符合巴氏杆菌特征,同时16SrRNA序列分析与NCBI上已公布的多杀性巴氏杆菌16SrRNA序列同源性在99%以上;对多杀性巴氏杆菌特异性基因Kmt-1以及各血清型特异性基因PCR扩增只扩增到Kmt-1和hyaD-hyaC特异性基因片段;分离菌株对链霉素、庆大霉素、卡那霉素耐药,对其他30种药物敏感,同时感染小鼠全部死亡。结果显示从病牛体内分离到1株毒力较强的血清A型多杀性巴氏杆菌。     

鸡源巴氏杆菌GZ-TZ2017株的分离及其16S rRNA序列分析

为了探明贵州某肉鸡养殖场突发疾病病因,试验通过解剖、细菌分离、染色镜检、药敏试验、生化试验、16S rRNA的PCR扩增及序列分析等方法对病原进行分析。结果表明:从病鸡内脏中分离得到1株革兰氏阴性、两极浓染的球杆菌,将其命名为GZ-TZ2017;该菌株的培养特性、菌体形态、生化试验特征均与已报道的巴氏杆菌相似;GZ-TZ2017菌株对米诺环素、氧氟沙星和诺氟沙星等抗生素较为敏感,对头孢拉啶、苯唑西林、卡那霉素、青霉素等抗生素耐药;16S rRNA PCR扩增得到大小为1 400 bp左右的目的片段,分离菌GZ-TZ2017与各地分离的多杀性巴氏杆菌的同源性极高,均在99.0%以上;GZ-TZ2017与多杀性巴氏杆菌属细菌属于一个分支,和重庆分离株PM-LK(GenBank登录号为KX579746)、安徽滁州分离株CZ-6(GenBank登录号为KY673151)在同一小分支上,属于禽巴氏杆菌。说明该肉鸡场鸡群感染了禽巴氏杆菌。     

荚膜D型多杀性巴氏杆菌引起兔化脓性肺炎的诊断及病原生物学特性研究

本研究对河南某兔场发生呼吸道感染病死兔的组织样本进行病原核酸检测、分离鉴定和生物学特性研究.病原核酸荧光定量PCR结果显示,多杀性巴氏杆菌呈现阳性;细菌分离获得多杀性巴氏杆菌,命名为HN0604株;特异性和荚膜血清型PCR鉴定结果显示,该细菌为荚膜D型多杀性巴氏杆菌;将分离株HN0604人工感染兔后,复制出纤维素性化脓...     

猪源多杀性巴氏杆菌的分离鉴定及其荚膜血清型鉴定

从病死母猪肺脏中分离到一株革兰氏阴性小杆菌,用生理生化鉴定、药敏试验、致病性试验和PCR鉴定方法对分离菌株进行鉴定,并用多杀性巴氏杆菌荚膜分型引物对分离株的荚膜血清型进行鉴定。结果表明:本菌为猪多杀性巴氏杆菌,对多种抗生素高度敏感,对小白鼠有强致病性;PCR扩增16SrDNA基因获得1415bp片段,分离株的16SrDNA核苷酸序列与多杀性巴氏杆菌(AY078999)的同源性为99%,因此该分离菌株被鉴定为致病性巴氏杆菌,命名为YN20110122株;本菌分离株为荚膜A型血清型多杀性巴氏杆菌。     

The immunogenicity and pathogenicity of Pasteurella multocida isolated from poultry in Indonesia

Of 13 field isolates of Pasteurella from chickens and ducks in Indonesia, 10 were confirmed as P. multocida subspecies multocida, one as P. multocida subspecies gallicida and one as P. multocida subspecies septica. Nine were capsular Type A four were Serotype 1, one was Serotype 4, one was Serotype 11, one was Serotypes 4,12, and the remaining six were untypable. Five isolates were pathogenic for mice and two were pathogenic for chickens. Both a trivalent vaccine which included local field isolates and an imported commercial vaccine, were efficacious in layer chickens against challenge with virulent reference and local field strains. Though not statistically significant, the protection provided by the trivalent vaccine against virulent field isolate challenge was slightly better and could provide an improvement over the currently used imported vaccine although further field trials are required. A bacterin vaccine produced from a Serotype 1 field isolate grown in the allantoic sac of embryonated chicken eggs provided chickens with good cross protection against heterologous serotype challenge.     

鸭源巴氏杆菌的分离鉴定及药敏试验

本试验为确定江西新余地区鸭发病的病原,对3个鸭场的病死鸭进行细菌分离,并通过形态特征、培养特性和生化试验对分离菌进行鉴定。从病死鸭的肝脏和心脏中分离到5株鸭多杀性巴氏杆菌,且分离菌对试验鸭和小白鼠有较强的致病性。药敏试验结果表明,分离的5株菌对左氧氟沙星、卡那霉素、头孢西丁、先锋必和大观霉素较为敏感。     

鸭巴氏杆菌病灭活疫苗的研制与应用初报

鸭巴氏杆菌病发病急、死亡快，用禽霍乱疫苗免疫，效果欠佳，为此，我们从发病鸭中分离一株鸭巴氏杆菌强毒株，制成氢氧化铝甲醛灭活疫苗，试用１００多万羽份，表明对该病具有良好的保护作用。     

Occurrence of Pasteurella multocida and related species in village free ranging chickens and their animal contacts in Tanzania

Investigation was done to determine the presence of Pasteurella multocida and related species in free ranging chickens and ducks, dogs, cats and pigs in three climatic zones (cool, warm and hot) of rural Morogoro, Tanzania. A total of 153 isolates of P. multocida ssp. multocida and related species were obtained by direct culture on blood agar, selective medium and mouse inoculation. P. multocida ssp. multocida was isolated from 0.7% of chickens and 7% of ducks. In dogs and cats, P. multocida ssp. multocida was isolated from 1 and 68%, respectively. One isolate of Pasteurella gallinarum was isolated from a duck. Other species obtained were; P. multocida ssp. septica, Pasteurella stomatis and taxon 16 from dogs and cats, while Pasteurella dagmatis and Pasteurella canis were found in dogs only. Prevalence of P. multocida ssp. multocida was significantly higher (P<0.01) in ducks of the warm zone (22%) than in ducks of other zones (0%). No significant difference was observed between the prevalence of P. multocida ssp. multocida in chickens of the warm zone (2%) and chickens of the cool and hot zones (0%). Extended phenotypic characterization revealed phenotypic similarities between two isolates from chickens and the duck strains. Mouse inoculation appeared to be more sensitive in detecting P. multocida ssp. multocida than blood agar and selective medium. Direct culture on blood agar recovered most of the isolates from dogs. This study has demonstrated for the first time the presence of P. multocida and related species in the village free ranging chickens, ducks, dogs and cats in Tanzania. Other non-classified Pasteurella spp. were also observed in the study, but further characterization is required before the final classification can be made. This paper reports for the first time the isolation of unclassified Pasteurella from dogs and cats in Africa. The results implies that fowl cholera might be occurring in free ranging poultry, and dogs and cats kept in contact might serve as sources of P. multocida to chickens and ducks. Subsequent applications of molecular techniques to analyse the epidemiological relatedness of clones isolated from different host species is indicated.     

Turkey macrophage and heterophil bactericidal activity against Pasteurella multocida.

Bactericidal activity of turkey macrophages and heterophils was demonstrated in an in vitro colorimetric bactericidal assay. Two vaccine strains and one field isolate of Pasteurella multocida A:3,4 and a single isolate each of Escherichia coli and Staphylococcus aureus were compared for susceptibility to the bactericidal activity of turkey macrophages and heterophils. Only P. multocida A:3,4-strain M-9 (the least virulent strain) was susceptible to macrophage bactericidal activity in the absence of specific immune serum, whereas all three P. multocida A:3,4 organisms were killed when opsonized with specific immune serum. E. coli was susceptible to the bactericidal activity of macrophages, and S. aureus was resistant. All bacteria tested were highly sensitive to the bactericidal activity of intact turkey heterophils, regardless of the opsonin treatment. Electron microscopic findings suggested that heterophils may kill extracellular P. multocida. Only S. aureus and E. coli were killed by lysed heterophils.     

Virulence of raptor-origin Pasteurella multocida in domestic chickens.

Pasteurella multocida belonging to somatic serotype 1 and capsular type A has been known to cause avian cholera in domestic poultry. Pasteurella multocida serotype 1 has also been isolated from raptorial birds. However, the capsular type for these raptorial isolates remains unknown. Moreover, the virulence of these raptorial isolates for domestic poultry has not been determined. The objectives of this study were to determine the capsular type of raptorial P. multocida serotype 1 isolates and to determine if these isolates were virulent for domestic chickens. Study chickens were inoculated with one of three P. multocida isolates. Isolate WESO-1 was obtained from a western screech owl (Otus kennicottii) and isolates RTHA-2 and RTHA-4 were isolated from two red-tailed hawks (Buteo jamaicensis). These isolates were given by either the oral, intravenous, or intraocular route. Control birds were given brain-heart infusion broth. The capsular serotypes of three isolates were also determined. The RTHA-2 and RTHA-4 isolates belonged to P. multocida capsular type A. The WESO-1 isolate belonged to capsular type F. Results also demonstrated that, for the isolates examined, the intraocular route did not cause mortality in chickens. There was mortality in all groups for the intravenous route. However, various mortality patterns were observed when P. multocida was given orally for the three different isolates. The RTHA-4 isolate (serotype 1:A) was the most virulent for domestic chickens. The WESO-1 isolate (serotype 1:F) was the least virulent for chickens among the raptorial isolates examined.     

Pasteurella multocida-associated sinusitis in khaki Campbell ducks (Anas platyrhynchos)

Pasteurella multocida group B, serotype 3, was isolated from sinusitis-affected khaki Campbell ducks. To study the role of P. multocida in sinusitis, commercial khaki Campbell ducks were experimentally infected with P. multocida alone or combined with Escherichia coli. In Expt. 1, experimental ducks were infected with P. multocida intranasally or ocularly. A comparison was done by intranasal inoculation with pooled nasal discharge from the affected ducks or phosphate-buffered saline. The ducks intranasally inoculated with the nasal discharge or P. multocida showed sinusitis. In Expt. 2, E. coli alone or a combination of P. multocida and E. coli was intranasally inoculated into experimental ducks. The ducks intranasally inoculated with the combination of P. multocida and E. coli had sinusitis, the same as found in the field but less severe than that of the field cases. Pasteurella multocida was already present in litter/floor of duck farms. We concluded that P. multocida played a role in induction of sinusitis. However, the sinusitis in ducks may be initiated by poor management, especially in the brooding period of ducks.     

Outbreak of Fowl cholera in Baikal teals in Korea

Fowl cholera (FC) caused by Pasteurella multocida was diagnosed in waterfowl, Baikal teals (Anas formosa), submitted to the National Veterinary Research and Quarantine in Korea. The total number of mortalities was 13,228 out of approximately 100,000 birds that wintered in Cheonsoo Bay, the most important habitat area of Baikal teals in the world. Clinical signs were detected in only a few birds because of sudden death. Grossly, the dead Baikal teals had lesions consistent with FC, including multifocal necrotic foci in the liver with enlargement, petechial or ecchymotic hemorrhages on the heart, and mucoid exudates in the duodenal mucosa. Microscopically, there were hepatocytic necrosis with bacterial colonization, hemorrhage and necrosis in the myocardium, and hemorrhagic enteritis. Pasteurella multocida was isolated from the liver and the heart of all birds examined, and the isolate (P-627) was the serotype 1 X 12 X 13 by the agar gel immunodiffusion test. In order to estimate the virulence of P-627, 5-wk-old commercial ducks were exposed intramuscularly or intratracheally to the bacterium. On the basis of mortality rate, the isolate, P-627, was found to be highly virulent. This is the first report of an outbreak of FC in Baikal teals in Korea.     

Resistance of Pasteurella multocida A:3,4 to phagocytosis by turkey macrophages and heterophils

A virulent field isolate and 2 vaccine strains of Pasteurella multocida A:3,4 were compared for resistance to phagocytosis by turkey macrophages and heterophils, using in vitro assays. The least virulent vaccine strain (M-9) was phagocytosed to a greater degree than was the field isolate or the other vaccine strain (Clemson University). All 3 bacteria differed significantly from each other in the amount of capsular material present as measured by polycationic ferritin labeling and electron microscopy. Removal of the capsule with hyaluronidase resulted in a significant increase in phagocytosis of the field isolate.