EFFECT OF ELECTRICAL-STIMULATION ON KILLING SALMONELLA-TYPHIMURIUM INVARIOUS SALT-SOLUTIONS

Electrical stimulation was evaluated as a method to kill Salmonella ty phimurium in various salt solutions at different concentration. Salmon ella typhimurium at 2 X 10(5) CFU/ml was treated at 22-24C for 60 min in each salt solution using electricity at 10 mA/cm(2) current, 1 kHz frequency, and 50% duty cycle. Samples taken at various times were ser ially diluted, plated on tryptic soy agar and xylose lysine desoxychol ate agar, and incubated at 37C for 18-24 h. To detect injured cells, s amples were also pre-enriched in buffered peptone water at 37C for 4-5 h before being plated. Results indicated all salmonellae were electri cally killed at 5 min in NaCl, at 30 min in NaNO3, and at 45 min in Na C2H3O2 at 0.15 and 0.015 M concentrations. Salmonellae were also kille d at 45 min in Na3PO4 and at 60 min in Na2CO3 at 0.0015 M concentratio n by electricity in combination with high pH.