Four Portraits of the Plague Organism

Yersinia pestis organisms have infective and self-protective features that are expressed or suppressed to fit different conditions. The Y. pestis bacteria respond selectively to a variety of signals (which occur inside or outside of diverse hosts and cells) by expressing products that ultimately promote the multiplication and survival of the organisms. This paper briefly outlines the dynamics and time courses of the warfare between invading bacteria and susceptible hosts. At least four different sets of products and mechanisms are described as characteristic of natural life cycles of wild-type Y. pestis in non-human hosts. This information is used to project likely hazards for human beings, design of effective vaccines, and selection of other countermeasures. See also ADA409494, Proceedings of the 2001 ECBC Scientific Conference on Chemical and Biological Defense Research, held in Hunt Valley, MD on 6-8 Mar 2001.