Efficacy of sodium chlorite in inactivating <i>Vibrio parahaemolyticus</i> attached to polyethylene terephthalate surfaces

Abstract

The inactivation of Vibrio parahaemolyticus cells attached to a polyethylene terephthalate (PET) disc in a sodium chlorite (NaClO 2 ) solution was kinetically studied in a weakly acidic pH range of 4.0 -6.5. The logarithmic reduction in the survival ratio depended on the concentration-time product. All inactivation curves showed a linear reduction phase, and the reduction in viable cells was greater than 4-log. No significant desorption of attached cells was observed during the inactivation treatment. The first-order inactivation rate constant (k) increased by approximately 4.5-fold for every 1.0 unit fall in pH. At all pH values, the k values calculated for the attached cells were approximately half of those for the unattached cells. These findings indicate that a weakly acidic NaClO 2 solution is effective in inactivating bacteria attached to hard surfaces.Keywords ： sodium chlorite / inactivation efficacy / Vibrio parahaemolyticus / polyethylene terephthalate / microbial calorimetry.