Scientists a step closer to making vaccine against biological weapons

Washington, July 28 : Experts at the Society for General Microbiology have made a significant advance towards making a vaccine against an organism that may be used to produce biological weapons.

Writing about their achievement in the Journal of Medical Microbiology, the researchers have revealed that they have made a rapid progress in understanding how the pathogen Francisella tularensis causes disease.

"Only very few bacteria are needed to cause serious disease," said Prof Petra Oyston from Dstl, Porton Down.

"Because of this and the fact that tularemia can be contracted by inhalation, Francisella tularensis has been designated a potential biological weapon. Since the events of September 2001 and the subsequent anthrax attacks on the USA, concern about the potential misuse of dangerous pathogens including F. tularensis has increased. As a result, more funding has been made available for research on these organisms and has accelerated progress on developing medical countermeasures," the researchers added.

Tularemia circulates in rodents and animals like rabbits and hares, and outbreaks in humans often happen at the same time as outbreaks in these animals.

The disease is probably transmitted by insects like mosquitoes, ticks, and deer flies.

People can also become infected by contact with contaminated food or water and by breathing in particles containing the bacteria.

Farmers, hunters, walkers and forest workers are most at risk of contracting tularemia.

The researchers say that research into F. tularensis's pathogenesis attains significance in view of the fact that various nations have developed it as a biological weapon, and also because some are said to have produced antibiotic-resistant strains.

"Progress is being made. Since the genome of F. tularensis was sequenced, researchers have taken great strides in understanding the molecular basis for its pathogenesis. This is essential information for developing a vaccine and getting it licensed," said Prof. Oyston.

The researchers, however, concede that they are still unsure about the function of most F. tularensis genes.

"Recently genes needed by F. tularensis for growth and survival have been identified. These could be targets for novel antimicrobial development or could be used in the production of a vaccine," said Prof. Oyston.

"Although we are getting closer to addressing key issues such as the need for an effective vaccine, it appears we are still some way from understanding the pathogenesis of F. tularensis. More research is needed in this area," Prof. Oyston added.

ANI