Bactericidal effect of chlorine on attached salmonellae with and without sonification

Broiler breast skin was immersed in a Salmonella typhimurium cell suspension for 0.25, 30, or 60 min, then i) shaken for 1 min or stirred for 30 min in a Cl2 solution with 0.5 ppm free residual Cl2 and ii) sonified for 15 or 30 min with or without chlorine (0.5 ppm free residual). Data showed that attached/entrapped salmonellae are not readily accessible to chlorine. Salmonellae were reduced by 1 log10 by chlorine. Sonification seemed to detach attached/entrapped cells thus reducing counts by 1 to 1.5 logs. Sonification of skin in a chlorine solution was the most effective treatment which reduced Salmonella counts by 2.44 to 3.93 logs