Decontamination of fluid milk containing Bacillus spores using commercial household products.

Although commercial sanitizers can inactivate bacterial spores in food processing environments, relatively little data exist as to the decontamination of products and surfaces by consumers using commercial household products. Should a large scale bioterrorism incident occur in which consumer food products were contaminated with a pathogenic sporeformer such as Bacillus anthracis, there may be a need to decontaminate these products before disposal as liquid or solid waste. Studies were conducted to test the efficacy of commercial household products for inactivating spores of Bacillus cereus (used as a surrogate for B. anthracis) in vitro and in fluid milk. Validation of the resistance of the B. cereus spores was confirmed with B. anthracis spores. Fifteen commercial products, designed as either disinfectants or sanitizers or as potential sanitizers, were purchased from retail markets. Products selected had one of the following active compounds: NaOCl, HCl, H2O2, acetic acid, quaternary ammonium compounds, ammonium hydroxide, citric acid, isopropanol, NaOH, or pine oil. Compounds were diluted in water (in vitro) or in 2% fat fluid milk, and spores were exposed for up to 6 h. Products containing hypochlorite were most effective against B. cereus spores. Products containing HCl or H2O2 also reduced significant numbers of spores but at a slower rate. The resistance of spores of surrogate B. cereus strains to chlorine-containing compounds was similar to that of B. anthracis spores. Therefore, several household products on the market may be used to decontaminate fluid milk or similar food products contaminated by spores of B. anthracis.

alpha-Bungarotoxin binding to the nicotinic acetylcholine receptor is inhibited by two distinct subpopulations of anti-receptor antibodies.

Affinity-purified antibodies to the nicotinic acetylcholine receptor of Torpedo marmorata were fractionated into two populations using a covalently cross-linked receptor-toxin immunosorbent lacking free toxin-binding sites. The population of antibodies which bound to and were subsequently eluted from this resin, and which cannot possibly contain antibodies directed to the toxin-binding site itself, was effective in inhibiting the binding of toxin to receptor in solution. This unequivocally demonstrates that inhibition of toxin binding can be mediated by antibodies which are not directed against the toxin-binding site. A second minor population of antibodies which did not bind to the affinity resin but which did inhibit the binding of toxin to receptor in solution was detected. Two subpopulations of toxin-binding inhibitory antibodies can therefore be distinguished. A clear differentiation should be made in future work describing "anti-toxin site" antibodies between antibodies directly binding to the toxin-binding site and the pseudo-anti-toxin-binding site antibodies described in this report.