Publications by authors named "Gareth A Williams"

Bovine tuberculosis (bTB), caused by infection, is a zoonotic disease in cattle that represents a significant ongoing challenge to cattle farming productivity and the livelihoods of livestock farmers in the UK. Vaccination of cattle with BCG could directly target the ability of to proliferate within vaccinates, restricting bTB pathogenesis and onward disease transmission, and represent a step change in the tools available to help control bTB in farmed cattle. A Marketing Authorisation (MA) is required before a cattle BCG vaccine could be sold and supplied as a veterinary medicine within the UK and this requires comprehensive data supporting vaccine quality, efficacy and, most importantly, its safety.

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Article Synopsis
  • Bovine tuberculosis, caused by Mycobacterium bovis, is a significant infectious disease affecting cattle globally, with varying responses to infection that are not fully understood.
  • A study using advanced assays revealed that cell-mediated immune responses (CMI) appeared as early as two weeks after infection, while antibody responses were also detectable in some cattle within four weeks.
  • The findings suggest a need for better biomarkers to predict infection outcomes, especially in low-and-middle income countries where traditional control methods, like test-and-slaughter, are impractical.
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Bovine tuberculosis (bTB) is a global disease of livestock that has damaging economic, animal health and public health consequences. Conventional bTB disease control strategies, based around the testing and slaughter of cattle infected with bTB, are typically used to help limit or reduce the transmission of this disease but in many low- and middle-income countries such strategies may often be economically unviable, culturally unacceptable or logistically impracticable. The use of vaccination to protect cattle against bTB could provide a potentially more affordable, ethically acceptable and practical additional disease control measure.

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Aims: To assess the prevalence of Mycobacterium bovis bacilli in faecal samples of tuberculous cattle, and to better understand the risk of environmental dissemination of bovine tuberculosis (TB) through the spreading of manure or slurry.

Methods And Results: Faecal samples were collected from 72 naturally infected cattle with visible lesions of TB that had reacted to the tuberculin skin test and 12 cattle experimentally infected with M. bovis.

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Bacillus Calmette-Guérin ( BCG) was generated over a century ago for protection against (Mtb) and is one the oldest vaccines still in use. The BCG vaccine is currently produced using a pellicle growth method, which is a complex and lengthy process that has been challenging to standardise. Fermentation for BCG vaccine production would reduce the complexity associated with pellicle growth and increase batch to batch reproducibility.

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Bovine tuberculosis (TB) in Great Britain adversely affects animal health and welfare and is a cause of considerable economic loss. The situation is exacerbated by European badgers () acting as a wildlife source of recurrent infection to cattle. Vaccination of badgers against TB is a possible means to reduce and control bovine TB.

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Article Synopsis
  • Oral vaccination with Mycobacterium bovis BCG has been effective in protecting badgers from tuberculosis (TB), with evidence showing that live BCG needs to persist in the host for sustained protection.
  • The study found that live BCG remained in vaccinated badgers for at least 8 weeks after oral administration, especially in the oropharyngeal area, while lower levels were detected in the small intestine.
  • The findings indicate that badgers may have an unfavorable gut environment for keeping BCG viable, which is crucial information for developing effective oral vaccines for this species.*
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In developing an oral bait BCG vaccine against tuberculosis in badgers we wanted to understand the conditions of the gastrointestinal tract and their impact on vaccine viability. Conditions mimicking stomach and small-intestine caused substantial reduction in BCG viability. We performed in vivo experiments using a telemetric pH monitoring system and used the data to parameterise a dynamic in vitro system (TIM-1) of the stomach and small intestine.

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European badgers (Meles meles) are a wildlife reservoir for Mycobacterium bovis (M. bovis) in parts of England, Wales and Ireland, constituting a potential source of tuberculosis (TB) infection for cattle. Vaccination of badgers against TB is one of the tools available for helping reduce the prevalence of bovine TB in badgers, made possible by the licensing in 2010 of Bacillus Calmette-Guérin (BCG) vaccine for intramuscular administration to badgers (BadgerBCG).

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The control of tuberculosis (TB) in cattle in the UK and Ireland is compromised by transmission of Mycobacterium bovis to cattle from the European badger (Meles meles), which acts as a wildlife reservoir. Vaccination of badgers could potentially contribute to TB control but the only licensed vaccine is injectable BadgerBCG which requires the live-capture of badgers. Current research is aimed at developing an oral TB vaccine (where vaccine is contained within bait) that is intended to be more cost-effective to deploy over large areas.

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The European badger () is a reservoir host of and responsible for a proportion of the tuberculosis (TB) cases seen in cattle in the United Kingdom and Republic of Ireland. An injectable preparation of the (BCG) vaccine is licensed for use in badgers in the UK and its use forms part of the bovine TB eradication plans of England and Wales. However, there are practical limitations to the widespread application of an injectable vaccine for badgers and a research priority is the development of an oral vaccine deliverable to badgers in bait.

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The oral vaccination of wild badgers (Meles meles) with live Bacillus Calmette-Guérin (BCG) is one of the tools being considered for the control of bovine tuberculosis (caused by Mycobacterium bovis) in the UK. The design of a product for oral vaccination requires that numerous, and often competing, conditions are met. These include the need for a highly palatable, but physically stable bait that will meet regulatory requirements, and one which is also compatible with the vaccine formulation; in this case live BCG.

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Saturn's narrow F ring exhibits several unusual features that vary on timescales of hours to years. These include transient clumps, a central core surrounded by a multistranded structure and a regular series of longitudinal channels associated with Prometheus, one of the ring's two 'shepherding' satellites. Several smaller moonlets and clumps have been detected in the ring's immediate vicinity, and a population of embedded objects has been inferred.

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