Germination and Characterization of Bacillus anthracis and Bacillus cereus in Nematodes

Bacillus anthracis is a Gram‐positive, spore‐forming, rod‐shaped bacterium known to cause anthrax. B. cereus is a related soil dwelling, beta hemolytic bacterium that can cause two food poisoning syndromes characterized by nausea and vomiting. Both species are typically present in soil as spores, yet they do not germinate in soil. We hypothesize that B. cereus and B. anthracis spores germinate in the gut of nematodes. Synchronized cultures of C. elegans were used to determine the effect of B. anthracis and B. cereus on the lifespan of nematodes: these results were inconclusive. Next, co‐plating of C. elegans with: 1) B. anthracis and B. cereus; 2) B. cereus and E. coli; and 3) B. anthracis and E. coli showed no preference as food sorces for C. elegans. B. anthracis spore germination was monitored in real time by co‐plating C. elegans with a B. anthracis strain containing the Pps12 plasmid. Insertion of this plasmid was expected to facilitate the fluorescence of B. anthracis in the gut of C. elegans upon germination. B. anthracis spores fluoresced in germination buffer supplemented with inosine and alanine; however, florescence was not detectable when ingested by C. elegans. Understanding the mechanism of B. anthracis and B. cereus germination is fundamental to preventing infection by each organism. Supported by NIH R25GM063775