Effect of gamma radiation cobalt-60 on the growth of selected gram negative pathogenic bacteria

Abstract

Foodbome infections still remain as an important cause of preventable morbidity and mortality in the world. Escherichia coli and Salmonella are the most potentially dangerous foodbome pathogens in ready-to-eat foods. In this study, Cobalt-60 is a type of Gamma-ray radiation, 3.7 Mbq strength with dose 140 milliroentgen(mR) performed on two selected Gram-negative foodbome pathogenic bacteria and the effectiveness of reducing microbial population of these pathogens in saline water was investigated. Two parameters which were investigates in the study were the distance of the sample to the Cobalt-60 source and the time exposure with gamma radiation. According to percentage of reduction by gamma radiation Cobalt-60, E.coli was higher reduction than Salmonella. Distance at O cm between sample and gamma radiation source and 180 second time exposure of both cultures to gamma radiation Cobalt-60 showed the greatest microbial destruction. Cobalt-60 is effective to inactivate bacterial population in saline.