Studies have confirmed the key role of Bacillus anthracis protective antigen (PA) in the US and UK human anthrax vaccines. However, given the tripartite nature of the toxin, other components, including lethal factor (LF), are also likely to contribute to protection. We examined the antibody and T cell responses to PA and LF in human volunteers immunized with the UK anthrax vaccine (AVP).
View Article and Find Full Text PDFLive attenuated bacteria provide the potential to replace traditional needle-based vaccination with an orally administered vaccine. The heterologous antigen gene is usually transformed as a multi-copy plasmid into the bacterial cell, but plasmids in live bacterial vaccine strains are often unstable, so an alternative approach is to integrate the single-copy antigen gene into the bacterial chromosome. We report a comparison between the chromosomally integrated and the plasmid-borne Bacillus anthracis protective antigen gene in live Salmonella enterica serovar Typhimurium, using the Operator-Repressor Titration (ORT) system to ensure stable plasmid maintenance.
View Article and Find Full Text PDFThe major virulence determinant in clostridial myonecrosis caused by Clostridium perfringens is a phospholipase C (PLC), the alpha-toxin. Previously, mice have been protected against challenge with heterologous alpha-toxin or Clostridium perfringens spores by immunisation with the C-domain (known as Cpa(247-370) or alpha-toxoid) of the alpha-toxin. In this study, we have determined the ability of the alpha-toxoid to protect against the lethal effects of a divergent C.
View Article and Find Full Text PDFBacillus anthracis is the causative agent of anthrax, a disease that affects wildlife, livestock, and humans. Protection against anthrax is primarily afforded by immunity to the B. anthracis protective antigen (PA), particularly PA domains 4 and 1.
View Article and Find Full Text PDFWe describe the use of two insertion sequence elements (ISFtu1 and ISFtu2) in Francisella tularensis to type strains by restriction fragment length polymorphism (RFLP). The RFLP profiles of 17 epidemiologically unrelated isolates were determined and compared. Our results showed that RFLP profiles can be used to assign F.
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