Susceptibility of biofilm Escherichia coli, Salmonella Enteritidis and Staphylococcus aureus to detergents and sanitizers.

This study was conducted to investigate the susceptibility of the biofilm cells of Escherichia coli O157, Salmonella Enteritidis, and Staphylococcus aureus to some cleaning detergents and sanitizers. No weakly acidic, neutral, and weakly alkaline detergent could remove the biofilm bacteria from stainless steel chips at commonly used concentrations recommended by manufacturers. Among sanitizers, sodium hypochlorite did not completely inactivate any biofilm bacteria at active chlorine concentrations of 25 to 200 microg/ml. Benzalkonium chloride, alkyldiaminoethyl glycine hydrochloride, chlorhexidine digluconate, and polyhexamethylenebiganide inactivated the great majority of E. coli and S. Enteritidis at commonly used concentrations, but did not inactivate S. aureus effectively enough. The biofilm S. aureus population was shown to be more tolerant than the E. coli and/or S. Enteritidis populations to the sanitizers.