Minimum bacteriostatic and bactericidal concentrations of household sanitizers for Escherichia coli strains in tryptic soy broth Original Research Article

The minimum bacteriostatic and bactericidal concentrations of various household sanitizers were determined for four different strains of Escherichia coli grown in tryptic soy broth. The sanitizers included apple cider vinegar, white vinegar, bleach, hydrogen peroxide, and lemon and lime juices. The strains included American Type Culture Collection (ATCC) 8739 (a strain used for the assay of antimicrobial preservatives), Center for Disease Control (CDC) 1932 (a nalidixic acid-resistant strain), National Veterinary Services Laboratory (NVSL) A940-1-5 (an animal isolate of O157:H7) and NVSL H8302 (human isolate of O157:H7). The minimum bacteriostatic concentrations for the strains tested ranged from 1·2–2·0% for bleach, 0·3–0·4% for commercial hydrogen peroxide solution, and 11·7–15% for white vinegar. The minimum bactericidal concentrations were 1·7–2·5% for bleach; 0·4% for commercial hydrogen peroxide solution, 16·7–20% for white vinegar, 2·7% for apple cider vinegar, and 6·7% for both lemon and lime juices. The various sanitizers tested differed significantly (P<0·05) in their inhibitory action. The only significant differences (P<0·05) among the E. coli strains tested were for ATCC 8739, which was more resistant to bleach, and CDC 1932, which was more sensitive to white vinegar.