Cytotoxin CctA, a major virulence factor of Clostridium chauvoei conferring protective immunity against myonecrosis.

Objective: The purpose of this study was to determine the identity of the major toxin of Clostridium chauvoei, an important pathogen of cattle causing black leg and to determine its value as a protective antigen in vaccines against myonecrosis.

Methods: Genomic sequence analysis was used to determine potential virulence genes of C. chauvoei.

Eimeria species parasites as novel vaccine delivery vectors: anti-Campylobacter jejuni protective immunity induced by Eimeria tenella-delivered CjaA.

Vaccination of poultry against coccidiosis caused by the Eimeria species is almost entirely based upon varied formulations of live parasites. The recent development of a series of protocols that support genetic complementation by transfection in Eimeria now provides an opportunity to utilise live anticoccidial vaccines to deliver additional vaccinal antigens. The capacity of Eimeria tenella to express an exogenous antigen and induce an immune response during in vivo infection which is protective against subsequent bacterial challenge has been tested here using the anti-Campylobacter jejuni vaccine candidate CjaA.

Genetic and functional characterization of the NanA sialidase from Clostridium chauvoei.

Clostridium chauvoei is the causative agent of blackleg, a wide spread serious infection of cattle and sheep with high mortality. In this study we have analyzed the sialidase activity of the NanA protein of C. chauvoei and cloned the sialidase gene nanA.

The consistency approach for quality control of vaccines - a strategy to improve quality control and implement 3Rs.

Current batch release testing of established vaccines emphasizes quality control of the final product and is often characterized by extensive use of animals. This report summarises the discussions of a joint ECVAM/EPAA workshop on the applicability of the consistency approach for routine release of human and veterinary vaccines and its potential to reduce animal use. The consistency approach is based upon thorough characterization of the vaccine during development and the principle that the quality of subsequent batches is the consequence of the strict application of a quality system and of a consistent production of batches.

Application of the Three Rs to challenge assays used in vaccine testing: tenth report of the BVAAWF/FRAME/RSPCA/UFAW Joint Working Group on Refinement.

This report aims to facilitate the implementation of the Three Rs (reduction, refinement and replacement) in the testing of vaccines for regulatory and other purposes. The focus is predominantly on identification of reduction and refinement opportunities in batch potency testing but the principles described are widely applicable to other situations that involve experimental infections of animals. The report should also help to interpret the requirements of the European Pharmacopoeia with regard to the use of alternative tests, humane endpoints and other refinements.

The consistency approach for the quality control of vaccines.

Current lot release testing of conventional vaccines emphasizes quality control of the final product and is characterized by its extensive use of laboratory animals. This report, which is based on the outcome of an ECVAM (European Centre for Validation of Alternative Methods, Institute for Health and Consumer Protection, European Commission Joint Research Centre, Ispra, Italy) workshop, discusses the concept of consistency testing as an alternative approach for lot release testing. The consistency approach for the routine release of vaccines is based upon the principle that the quality of vaccines is a consequence of a quality system and of consistent production of lots with similar characteristics to those lots that have been shown to be safe and effective in humans or the target species.

Maternal vaccination against subclinical necrotic enteritis in broilers.

The inclusion of antibacterial feed additives has until now been the major strategy for controlling Clostridium perfringens-associated necrotic enteritis in broilers. In the present study, the effect of maternal immunization against the disease was examined. Broiler breeder hens were injected intramuscularly with candidate vaccines based on C.

Perspectives from a developed nation.

Epilepsy is the most common serious neurologic disorder, affecting 350,000 people in the United Kingdom. There are five neurologists per 1,000,000 population, which is better than in India but much lower than in other developed nations. Thus, a patient's day-to-day prescribing, supervision, and support depends on primary care.