Effectiveness of radiation processing in elimination of Aeromonas from food

Abstract

Genus Aeromonas has emerged as an important human pathogen because it causes a variety of diseases including gastroenteritis and extra-intestinal infections. Contaminated water, sprouts, vegetables, seafood and food of animal origin have been considered to be the important sources of Aeromonas infection. In the present study, radiation sensitivity of indigenous strains of Aeromonas spp. from different food samples was evaluated. The decimal reduction dose (D10) values of different Aeromonas isolates in saline at 0–4°C were in the range of 0.031–0.046kGy. The mixed sprouts, chicken and fish samples were inoculated with a cocktail of five most resistant isolates (A. salmonicida Y567, A. caviae A85, A. jandaei A514A, A. hydrophila CECT 839T and A. veronii Y47) and exposed to γ radiation to study the effectiveness of radiation treatment in elimination of Aeromonas. D10 values of Aeromonas cocktail in mixed sprouts, chicken and fish samples were found to be 0.081±0.001, 0.089±0.003 and 0.091±0.003kGy, respectively. Radiation treatment with a 1.5kGy dose resulted in complete elimination of 105CFU/g of Aeromonas spp. from mixed sprouts, chicken and fish samples. No recovery of Aeromonas was observed in the 1.5kGy treated samples stored at 4°C up to 12 (mixed sprouts) and 7 days (chicken and fish samples), even after enrichment and selective plating. This study demonstrates that a 1.5kGy dose of irradiation treatment could result in complete elimination of 105CFU/g of Aeromonas spp. from mixed sprouts, chicken and fish samples.