title: The effects of some halogen-containing compounds on Bacillus subtilis endospores.
abstract: Sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) were more active against Bacillus subtilis 8236 spores in both viability and in germination and outgrowth studies than were polyvinylpyrrolidone-iodine (PVP-I) and Lugol's solution. Of the two chlorine compounds studied NaOCl proved to be the more active. The two iodine-containing compounds gave contrasting results with the Lugol's solution demonstrating increased antibacterial activity with increasing available iodine concentration. The antibacterial behaviour of PVP-I, however, reflected the more complex nature of aqueous iodine-surfactant mixtures. Initially, non-complexed iodine concentration (the active species) increased with increasing total available iodine concentration, resulting in increasing antibacterial activity. However, due to changes in the physical properties of the mixture, a maximum concentration of non-complexed iodine was reached so that a further increase in total available iodine resulted in a decrease in non-complexed iodine concentration and consequently a decrease in the antibacterial activity of the solution was observed. A greater inhibitory effect was observed in subsequent germination and outgrowth studies when spores were pre-treated with respective biocide than when untreated spores were added to germination media containing biocide at t = 0. This may reflect a combination of different contact times plus the neutralizing effect of the germination media on such halogen compounds.
authors.affiliation: Pharmaceutical Microbiology Research Laboratory, Welsh School of Pharmacy, University of Wales College of Cardiff, UK.
authors.forename: N D
authors.initials: ND
authors.lastname: Williams
authors.forename: A D
authors.initials: AD
authors.lastname: Russell
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects*; D004202:Disinfectants / Q000494:pharmacology*; D007454:Iodides / Q000494:pharmacology; D011206:Povidone-Iodine / Q000494:pharmacology; D012973:Sodium Hypochlorite / Q000494:pharmacology*; D012996:Solutions; D013171:Spores, Bacterial / Q000187:drug effects; D014227:Triazines / Q000494:pharmacology*
chemical_list: D004202:Disinfectants; D007454:Iodides; D012996:Solutions; D014227:Triazines; D011206:Povidone-Iodine; D012973:Sodium Hypochlorite; C011765:troclosene; C010389:Lugol's solution