Oral vaccination of brushtail possums with BCG: Investigation into factors that may influence vaccine efficacy and determination of duration of protection     

BM Buddle  FE Aldwell  DL Keen  NA Parlane  KL Hamel  GW de Lisle 《New Zealand veterinary journal》2013,61(5):224-230

AIMS: To determine factors that may influence the efficacy of an oral pelleted vaccine containing Mycobacterium bovis bacille Calmette-Guérin (BCG) to induce protection of brushtail possums against tuberculosis. To determine the duration of protective immunity following oral administration of BCG.

METHODS: In Study 1, a group of possums (n=7) was immunised by feeding 10 pellets containing dead Pasteur BCG, followed 15 weeks later with a single pellet of live Pasteur BCG. At that time, four other groups of possums (n=7 per group) were given a single pellet of live Pasteur BCG orally, a single pellet of live Danish BCG orally, 10 pellets of live Pasteur BCG orally, or a subcutaneous injection of live Pasteur BCG. For the oral pelleted vaccines, BCG was formulated into a lipid matrix, and each pellet contained approximately 10⁷ colony forming units (cfu) of BCG, while the vaccine injected subcutaneously contained 10⁶ cfu of BCG. A sixth, non-vaccinated, group (n=7) served as a control. All possums were challenged by the aerosol route with a low dose of virulent M. bovis 7 weeks after vaccination, and killed 7–8 weeks after challenge. Protection against challenge with M. bovis was assessed from pathological and bacteriological findings.

In Study 2, lipid-formulated live Danish BCG was administered orally to three groups of possums (10–11 per group), and these possums were challenged with virulent M. bovis 8, 29 or 54 weeks later. The possums were killed 7 weeks after challenge, to assess protection in comparison to a non-vaccinated group.

RESULTS: The results from Study 1 showed that vaccine efficacy was not adversely affected by feeding dead BCG prior to live BCG. Feeding 10 vaccine pellets induced a level of protection similar to feeding a single pellet. Protection was similar when feeding possums a single pellet containing the Pasteur or Danish strains of BCG. All vaccinated groups had significantly reduced pathological changes or bacterial counts when compared to the non-vaccinated group. In Study 2, oral administration of Danish BCG induced protection against challenge with M. bovis, which persisted for at least 54 weeks after vaccination. Some protection was observed in possums challenged 54 weeks after vaccination, but this protection was significantly less than that observed in groups vaccinated 29 or 8 weeks prior to challenge. There was a strong relationship between the proportion of animals producing positive lymphocyte proliferation responses to M. bovis antigens and protection against challenge with M. bovis.

CONCLUSIONS: Factors considered potentially capable of interfering with vaccination, including feeding dead BCG to possums prior to feeding live BCG, feeding multiple doses of BCG at one time, and changing strains of BCG, were shown not to interfere with the acquisition of protective immune responses in possums. Protection against tuberculosis was undiminished up to 29 weeks after vaccination with BCG administered orally. It is concluded that vaccination of possums by feeding pellets containing BCG is a robust and efficient approach to enhance the resistance of these animals to tuberculosis.  相似文献   

Creationist questions JAVMA News statement     

Hagerman VB 《Journal of the American Veterinary Medical Association》2008,232(6):834

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Associations between sole ulcer, white line disease and digital dermatitis and the milk yield of 1824 dairy cows on 30 dairy cow farms in England and Wales from February 2003-November 2004     

Amory JR  Barker ZE  Wright JL  Mason SA  Blowey RW  Green LE 《Preventive veterinary medicine》2008,83(3-4):381-391

The milk yields of 1824 cows were used to investigate the effect of lesion-specific causes of lameness, based on farmer treatment and diagnosis of lame cows, on milk yield. A three-level hierarchical model of repeated test day yields within cows within herds was used to investigate the impact of lesion-specific causes of lameness (sole ulcer, white line disease, digital dermatitis and other causes) on milk yield before and after treatment compared with unaffected cows. Cattle which developed sole ulcer (SU) and white line disease (WLD) were higher yielding cattle before they were diagnosed. Their milk production fell to below that of the mean of unaffected cows before diagnosis and remained low after diagnosis. In cattle which developed digital dermatitis (DD) there was no significant difference in milk yield before treatment and a slightly raised milk yield immediately after treatment. The estimated milk loss attributable to SU and WLD was approximately 570 and 370 kg, respectively. These results highlight that specific types of lameness vary by herds and within herds they are associated with higher yielding cattle. Consequently lesion-specific lameness reduction programmes targeting the cow and farm specific causes of lameness might be more effective than generic recommendations. They also highlight the importance of milk loss when estimating the economic impact of SU and WLD on the farms profitability.  相似文献   

Intradermal Test for Pregnancy     

C. A. Barker 《Canadian journal of veterinary research》1941,5(11):324-325

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Surgical Repair of Incised Teat Wound     

C. A. V. Barker 《Canadian journal of veterinary research》1946,10(7):191-194

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Characterisation of resistance to potato leafroll virus accumulation in Solanum phureja     

Liliana Franco-Lara  Hugh Barker 《Euphytica》1999,108(2):137-144

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Food security in sub‐Saharan Africa,edited by S. Devereux and S. Maxwell. Intermediate Technology Development Group (ITDG), London, 2001. ISBN 1 85339 523 4 (paperback), xviii+350 pp     

David Barker 《Land Degradation \u0026amp; Development》2004,15(2):197-199

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A geospatial variable rate irrigation control scenario evaluation methodology based on mining root zone available water capacity     

K. A. Miller  J. D. Luck  D. M. Heeren  T. Lo  D. L. Martin  J. B. Barker 《Precision Agriculture》2018,19(4):666-683

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Renal tubular-cell neoplasms in black-footed ferrets (Mustela nigripes)--38 cases     

Lair S  Barker IK  Mehren KG  Williams ES 《Veterinary pathology》2006,43(3):276-280

Thirty-eight cases of renal tubular cell neoplasms were diagnosed in 184 captive, adult (>1-year-old), black-footed ferrets (Mustela nigripes) examined from 1985 to 1996. This prevalence (20.7%) is one of the highest reported for this neoplasm in a population of animals. These tumors rarely metastasized (1/38), and usually were incidental postmortem findings, associated clinical disease being present in only 3 (8%) of the 38 cases. The prevalence of renal tubular cell neoplasms found at postmortem examination increased linearly with age, up to 67% in ferrets >8 years old. Both males (prevalence = 19%) and females (prevalence = 24%) were affected. Multiple renal tumors were common, and seven ferrets (18.4% of affected animals) had bilateral tumors. The cause of this neoplastic syndrome could not be determined. Since most of the animals affected by this condition were in their postreproductive years of life, the impact of this neoplastic syndrome on the captive propagation of this species is negligible.  相似文献   

E7 (1057ΔTA) mutation of the acidic α‐glucosidase gene causes Pompe's disease in Droughtmaster cattle          下载免费PDF全文

RE Lyons  DJ Johnston  MR McGowan  A Laing  B Robinson  H Owen  BD Hill  BM Burns 《Australian veterinary journal》2017,95(5):138-142

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