A novel surfactant nanoemulsion with broad-spectrum sporicidal activity against Bacillus species

Two nontoxic, antimicrobial nanoemulsions, BCTP and BCTP 401, have been dev eloped. These emulsions are composed of detergents and oils in 80% water. B CTP diluted up to 1 : 1000 inactivated >90% of Bacillus anthracis spores in 4 h and was also sporicidal against three other Bacillus species. This spo ricidal activity is due to disruption of the spore coat after initiation of germination without complete outgrowth. BCTP 401 diluted 1 : 1000 had grea ter activity than BCTP against Bacillus spores and had an onset of action o f <30 min. Mixing BCTP or BCTP 401 with Bacillus cel eus prior to subcutane ous injection in mice reduced the resulting skin lesion by 99%, Wound irrig ation with BCTP 1 h after spore inoculation yielded a 98% reduction in skin lesion size, and mortality was reduced 3-fold. These nanoemulsion formulas are stable, easily dispersed, nonirritant, and nontoxic compared with othe r available sporicidal agents.