Different pathologies but equal levels of responsiveness to the recombinant F1 and V antigen vaccine and ciprofloxacin in a murine model of plague caused by small- and large-particle aerosols.

Presently there is a significant effort to develop and evaluate vaccines and antibiotics against the potential bioterrorism agent Yersinia pestis. The animal models used to test these countermeasures involve the deposition of small particles within the lung. However, deliberate aerosol release of Y.

Characterization and deposition of respirable large- and small-particle bioaerosols.

The deposition patterns of large-particle microbiological aerosols within the respiratory tract are not well characterized. A novel system (the flow-focusing aerosol generator [FFAG]) which enables the generation of large (>10-microm) aerosol particles containing microorganisms under laboratory conditions was characterized to permit determination of deposition profiles within the murine respiratory tract. Unlike other systems for generating large aerosol particles, the FFAG is compatible with microbiological containment and the inhalational challenge of animals.

The identification and evaluation of ATP binding cassette systems in the intracellular bacterium Francisella tularensis.

Francisella tularensis is a facultative intracellular bacterium responsible for the disease tularemia. Analysis of the fully sequenced genome of the virulent F. tularensis strain SCHU S4 has led to the identification of twenty ATP binding cassette (ABC) systems, of which five appear to be non-functional.

Antibiotic-free plasmid stabilization by operator-repressor titration for vaccine delivery by using live Salmonella enterica Serovar typhimurium.

Live, attenuated bacteria are effective vectors for heterologous antigen delivery. However, loss of heterologous gene-bearing plasmids is problematic, and antibiotics and their resistance genes are not desirable for in vivo DNA vaccine delivery due to biosafety and regulatory concerns. To solve this problem, we engineered the first vaccine delivery strain that has no requirement for antibiotics or other selectable marker genes to maintain the recombinant plasmid.