Experimental field trial with an immunostimulating complex (ISCOM) vaccine against contagious bovine pleuropneumonia

The experimental field trial with an immunostimulating complex (ISCOM) vaccine has been an occasion to explore the role of a Th1 response in the pathogenesis caused by Mycoplasma mycoides subsp. mycoides small colony (MmmSC) and in immune protection. The ISCOM complex is known to promote Th1 response. Antibodies to MmmSC were detected by indirect enzyme-linked immunosorbent assay (ELISA) in the vaccinated cattle, although the levels were lower than in a previous study. No antibodies were detected by complement fixation test (CF). After the challenge infection, vaccinated animals developed CF antibody response. They showed significantly reduced mortality compared with controls. However, gross pathological and histopathological score for vaccinated animals was as high as for the non-vaccinated, characterized by a high inflammatory reaction with histopathology dominated by interlobular pneumonia with vasculitis.     

Efficacy of two vaccine formulations against contagious bovine pleuropneumonia (CBPP) in Kenyan indigenous cattle

A live, attenuated vaccine is currently the only viable option to control of CBPP in Africa. It has been suggested that simple modifications to current vaccines and protocols might improve efficacy in the field. In this report we compared the current vaccine formulation with a buffered preparation that maintains Mycoplasma viability at ambient temperature for a longer time. Groups of animals were vaccinated with the two formulations and compared with non vaccinated groups. Half of the animals in each group were challenged 3 months post vaccination, the other half after 16 months. Protection levels were measured using the pathology index, calculated from post mortem scores of lesions from animals killed during the course of clinical disease. In the challenge at 3 months post vaccination, the protection levels were 52% and 77% for the modified and current vaccine preparations, respectively. At 16 months post vaccination, the protection levels were 56% and 62% for the modified and current vaccine preparations, respectively. These findings indicate that there are no differences in protection levels between the two vaccines. Because of its longer half life after reconstitution, the modified vaccine might be preferred in field situations where the reconstituted vaccine is likely not to be administered immediately.     

Experimences with a lyophilised contagious bovine pleuropneumonia vaccine in the ivory coast

Summary Trials on a lyophilised vaccine prepared fromM. mycoides var.mycoides strain T1, were carried out on humpless N'dama and Baoulé cattle and on zebu cattle. Post-vaccinal complications in some animals made the vaccine unsuitable under prevailing conditions for widespread field use on the humpless cattle in Ivory Coast. However the post-vaccinal lesions can be controlled and the proven immunological effectiveness of this lyophilised product have convinced the author that its use should be gradually extended as staff training and improved facilities permit. The product was acceptable for field vaccination of the zebu herds. The number and extent of local lesions were much reduced in herds revaccinated after one year. Serological findings based on the complement fixation test are discussed.

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Sumario Se realizaron vacunaciónes con una vacuna preparada deM. mycoides var.mycoides cepa T1, en ganado bovino N'dama sin joroba, ganado Baoulé y en ganado cebú. Las complicaciones post-vaccinales en algunos animales hizo que la vacuna no sea la adecuada considerando las condiciones prevalentes para su uso en el campo en el ganado sin joroba ne la Costa de Marfil. Sin embargo, las lesions post-vacunales pueden ser controladas y la probada efectividad inmunológica de este producto liofilizado han convencido al autor de que su uso debería de extenderse gradualmente tanto como el adiestramiento del personal y la mejora de facilidales lo permitan. El producto fue aceptable para la vacunación de campo del ganado cebú. El número y extensión de las lesions locales fue mucho mas reducido en hatos revacunados despues de un a?o. Se discuten hallazgos serológicos basados en la prueba de fijación de complemento.

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Résumé Des essais avec un vaccin lyophilisé préparé avec la souche T1 deM. myco?des var.myco?des ont été effectués sur du bétail zébu et sur du bétail sans bosse des races N'dama et Baoulé. Des réactions post-vaccinales observées chez certains animaux font que ce vaccin n'est pas recommandable pour son emploi à large échelle chez le bétail taurin de la C?te d'Ivoire dans les circonstances actuelles. Cependant ces complications vaccinales peuvent être combattues et l'efficacité immunologique indubitable de ce vaccin lyophilisé a convaincu l'auteur que son emploi devrait être progressivement étendu dans la mesure oú l'entra?nement du personnel et des facilités améliorées le permettraient. Ce vaccin est satisfaisant pour la vaccination de masse dans les troupeaux de zébus. Le nombre et l'importance des réactions locales sont réduites de beaucoup chez les animaux revaccinés après un an. Des données sérologiques obtenues par la méthode de fixation du complément sont discutées.

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Serving on a United Nations Development Programme/Technical Assistance assignment on the control of contagious bovine pleuropneumonia with the Ministry of Animal Production, Republic of the Ivory Coast     

疑似肉牛传染性胸膜肺炎防治研究

近年来,有肉牛发生一种顽固性呼吸道病,以高热、咳嗽、气喘、病死率高为特征,给养殖户造成一定经济损失,为了解决这一问题,笔者对疑似传染性胸膜肺炎病牛采用流行病学调查、临床症状、病理剖检、实验室诊断等方法进行系统研究,以期尽早控制该病。     

The immunizing dose of T1 strainMycoplasma mycoides against contagious bovine pleuropneumonia

Summary Cattle vaccinated against Contagious Bovine Pleuropneumonia with the T₁ strain ofMycoplasma mycoides with doses of 10⁹, 10⁷ and 10⁵ colony forming units were challenged six months later by the ‘in contact’ method, namely mixing with vrtificially infected ‘donor’ animals. The results of the experiment suggest that the vaccinating dose of this strain should not contain less than 10⁷ colony forming units.

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Sumario Ganado bovino vacunado contra la pleuro neumonía contagiosa con la cepa T₁ deMycoplasma mycoides, con dosis de 10⁹, 10⁷, y 10⁵ unidades formadoras de colonias, fueron desafiados 6 meses despues por el método de ‘contacto directo’ mezclandolos con animales ‘dadores’ artificialm nte infectados. Los resultados del experimento sugieren que la dosis vacunal de esta cepa no debería de contener menos de 10⁷ unidades formadoras de colonias.

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Résumé Du bétail vacciné contre la péripneumonie contagieuse bovine avec la souche T₁ deMycoplasma myco?des, à des doses respectives de 10⁵, 10⁷ et 10⁹ unités viables (donnant naissance à des colonies) fut éprouvé 6 mois plus tard par la méthode de contact, en mélangeant les animaux vaccinés à des animaux ‘donneurs’ artificiellement infectés. Les résultats de cette expérience suggèrent que la dose vaccinante de cette souche ne doit pas contenir moins de 10⁷ unités formatrices de colonies.

     

Effect of some cultural factors on T1 broth vaccine for contagious bovine pleuropneumonia

The effect of some aspects of buffering capacity, glucose concentration, length of incubation and extent of exposure to air during the preparation of live Mycoplasma mycoides var. mycoides strain T1 broth culture vaccine was investigated. A consistently good vaccine was obtained using 0.07 M phosphate buffered medium containing 0.1% glucose and incubating in stoppered bottles. The shelf-life of this vaccine stored at 4 degrees C was up to 12 weeks. The effect of other storage temperatures on the viability of the vaccine is given.     

Assessing the effectiveness of intubation as a challenge model in contagious bovine pleuropneumonia vaccine experiments

A study was carried out to assess the effectiveness of a bronchoscope in administering a pathogenic field strain of Mycoplasma mycoides subsp. mycoides (MmmSC) in cattle challenge experiments. Out of 16 animals inoculated using the bronchoscope, 10 (62.2%) showed clinical disease as evidenced by fever and 15 (93.8%) displayed typical lesions of CBPP from which MmmSC was isolated. Serum samples collected weekly were tested by Complement Fixation Test (CFT) and competitive enzyme-linked immunosorbent assay (c-ELISA). Antibodies to MmmSC were detected in 10 out of the 16 animals by the CFT and 11 out of the 16 animals by c-ELISA. The onset of clinical disease was as early as 2 days post-inoculation, and most of the animals developed clinical disease 2 to 3 weeks post-infection. These results clearly demonstrate that nasotracheal inoculation of pathogenic strain of MmmSC with the aid of a bronchoscope can lead to early onset of clinical disease; similar to previous studies but with higher numbers of animals showing clinical disease. This is in contrast with previous studies where early clinical disease was observed in as little as 15% of inoculated animals. This nasotracheal inoculation method using a bronchoscope can, therefore, be adopted for use in experimental challenge infections of cattle. This method is found to be a better replacement to the contact transmission method whose drawback includes extra cost of donor animals and unpredictable rate and timing of transmission from intubated to challenge animals.     

猪传染性胸膜肺炎疫苗的研究进展

综述了近年来国内外在猪传染性胸膜肺炎的灭活疫苗、亚单位疫苗和基因工程疫苗(重组亚单位疫苗、重组核酸疫苗、活载体疫苗、基因缺失疫苗等)方面取得的研究进展,论述了不同疫苗的优缺点,旨在为猪传染性胸膜肺炎的防控和疫苗的研制提供思路。     

A history of the prevalence and control of contagious bovine pleuropneumonia in China

Atrial natriuretic peptide (ANP) is a cardiovascular biomarker that might be useful in assessing the severity of cardiac disease in horses. Plasma ANP concentrations (Cp(ANP)) were compared between horses with heart disease but normal chamber size and function (Group A; n=6), horses with heart disease associated with left atrial (LA) enlargement, LA dysfunction, and/or left ventricular (LV) enlargement (Group B; n=5), and horses with no clinically apparent cardiovascular disease (Group C; n=13). The median (min-max) for Cp(ANP) was significantly higher in Group B (53.5 (36.0-70.7) pg/mL), compared to Group A (12.5 (6.3-19.8) pg/mL) and Group C (13.4 (7.2-34.0) pg/mL). Backwards stepwise multiple linear regression showed that Cp(ANP) in horses with heart disease was related to LA dimensions, but not to LV size, LA function, and LV function. The results indicated that Cp(ANP) in horses might be useful in detecting LA enlargement and that Cp(ANP) could be related to the severity of cardiac disease. Larger prospective studies are necessary to confirm these results.