title: Emergence and development of resistance to antimicrobial chemicals and heat in spores of Bacillus subtilis.
abstract: The emergence and development of chemical and thermal resistance in spores of Bacillus subtilis was examined. The chemicals studied were of the disinfectant type: glutaraldehyde, hypochlorite, hypochlorite-methanol and povidone-iodine. Growth and sporulation were followed by electron microscopy and resistance assigned to specific stages in relation to 45Ca and DPA accumulation. A sequential development of resistance was observed with thermal resistance appearing first at early Stage V corresponding to maturation of cortex and deposition of rudimentary spore coat material. Chemical resistance coincided with middle to late Stage V dependent on the chemical concerned. A progressive development of resistance was observed on prolonged incubation in sporulation medium and was affected by inclusion of lysozyme in the spore washing sequence.
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects / Q000254:growth & development*; D004202:Disinfectants / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D006358:Hot Temperature; D013171:Spores, Bacterial / Q000187:drug effects
chemical_list: D004202:Disinfectants