Effect of potassium sorbate and pH on the survival of Staphylococcus aureus in saturated sugar solutions

Addition of 0.3% (w/w) of potassium sorbate (a permitted food additive) coupled with a reduction of pH from 7 to 6 or 5.5, resulted in a dramatic decrease in the survival of two S. aureus strains inoculated (10(8) c.f.u./ml) in laboratory media supplemented with sugar (227 g sugar/100 g water) and incubated at 35 degrees C. These in vitro results may be of potential value to improve the efficacy of sugar therapy for the treatment of certain infected wounds; however, clinical trials are needed to confirm these findings.