RESUMEN
Anthrax is a zoonosis caused by Bacillus anthracis, which seriously affects human health. In recent years, a special phenomenon is found that the metabolic active of a bacterium remains after it is killed. To development of a KBMA (killed but metabolically active) Bacillus anthracis vaccine candidate strain, a plasmid pMAD and a recombinase system Cre-loxP were used to knockout the uvrAB gene of B. anthracis AP422 which lacks both of two plasmids pXO1 and pXO2. The results of PCR and RT-PCR shows that uvrAB genes were deleted from B. anthracis AP422 chromosome successfully. The constructed B. anthracis AP422deltauvrAB was inactivated by photochemical treatment (PCT) including an exposure in a long-wave-length ultraviolet (UVA) light and a treatment of 8-Methoxypsoralen (8-MOP), then the metabolic activity were detected by the method of MTS. The results showed that the killed B. anthracis AP422deltauvrAB maintained a highly metabolic activity for at least 4 hours, showing a state of KBMA. The KBMA strain of B. anthracis AP422deltauvrAB provides the prospective vaccine candidate strain for anthrax.
Asunto(s)
Vacunas contra el Carbunco/genética , Vacunas contra el Carbunco/inmunología , Carbunco/prevención & control , Bacillus anthracis , Vacunas de Productos Inactivados/inmunología , Carbunco/inmunología , Carbunco/microbiología , Vacunas contra el Carbunco/efectos de la radiación , Bacillus anthracis/genética , Bacillus anthracis/inmunología , Técnicas de Inactivación de Genes , Metoxaleno/farmacología , Rayos Ultravioleta , Vacunas de Productos Inactivados/genéticaRESUMEN
We report that a toxin neutralization assay (TNA) can detect a decrease in the immunogenicity of anthrax vaccines as a consequence of brief exposure to elevated temperature. This attribute of TNA may help in adopting immunogenicity as a replacement of the current potency test, which involves protection from lethal challenge.