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Author(s): Timothy D. Read (corresponding author) [1, 2]; Scott N. Peterson [1, 3]; Nicolas Tourasse [4, 7]; Les W. Baillie [1, 2, 5]; Ian T. Paulsen [1, 6]; Karen E. [...]

The degree to which teichoic acids in the cell wall of Bacillus subtilis are alanylated determines the secretion of recombinant protective antigen of Bacillus anthracis. Protective antigen is used to create the anthrax vaccine so researchers are interested in creating a recombinant form in Bacillus subtilis. This will eliminate trace amounts of other proteins that can cause an adverse reaction to the vaccine.

The high intrinsic decontamination resistance of Firmicutes spores, is important medically (disease) and commercially (food spoilage). Effective methods of spore eradication would be of considerable interest in the health care and medical products industries; particularly if the decontamination method effectively killed spores while remaining benign to both humans and sensitive equipment. Intense blue light at ~ 400 nm is one such treatment that has drawn significant interest. This work has determined the resistance of spores to blue light in an extensive panel of Bacillus subtilis strains, including wild-type strains and mutants that: i) lack protective components such as the spore coat and its pigment (s) or the DNA protective α/β-type small acid-soluble spore proteins (SASP); ii) have an elevated spore core water content; or iii) lack enzymes involved in DNA repair, including homologous recombination and non-homologous end joining (HR and NHEJ), apurinic/apyrimidinic endonucleases, nucleotide- and base excision repair (NER & BER), translesion synthesis (TLS) by Y-family DNA polymerases and spore photoproduct (SP) removal by SP lyase (SPL). The most important factors in spore blue light resistance were determined to be: spore coats/pigmentation, α/β-type SASP, NER, BER TLS and SP repair. A major conclusion from this work is that blue light kills spores by DNA- damage, and the results in this work indicate at least some of the specific DNA-damage. It appears that high-intensity blue light could be a significant addition to the agents used to kill bacterial spores in applied settings. [ABSTRACT FROM AUTHOR]

Melioidosis is a disease that is difficult to treat due to the causative organism, Burkholderia pseudomallei being inherently antibiotic resistant and it having the ability to invade, survive, and replicate in an intracellular environment. Combination therapy approaches are routinely being evaluated in animal models with the aim of improving the level of protection and clearance of colonizing bacteria detected. In this study, a subunit vaccine layered with the antibiotic finafloxacin was evaluated in vivo against an inhalational infection with B. pseudomallei in Balb/c mice. Groups of mice vaccinated, infected, and euthanized at antibiotic initiation had a reduced bacterial load compared to those that had not been immunized. In addition, the subunit vaccine provided a synergistic effect when it was delivered with a CpG ODN and finafloxacin was initiated at 48 h post-challenge. Vaccination was also shown to improve the outcome, in a composite measure of survival and clearance. In summary, layering a subunit vaccine with the antibiotic finafloxacin is a promising therapeutic alternative for use in the treatment of B. pseudomallei infections., Competing Interests: The authors declare no conflict of interest.