Author/Authors :
Afshordi، Reyhaneh نويسنده Department of Medical Laboratory Sciences, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, IR Iran , , Zare Jeddi، Maryam نويسنده Center for Air Pollution Research(CAPR), Institute for Environmental Research(IER), University of Medical Sciences, Tehran, Iran Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran , , Salehi، Ali نويسنده , , Pourmand، Mohammad Reza نويسنده Department of Medical Biotechnology, School of Advanced Technology, Tehran University of Medical sciences, Tehran, IR Iran , , Saboor-Yaraghi، Ali Akbar نويسنده Department of Nutrition and Biochemistry, School of Public Health, Tehran University of Medical Sciences,Tehran, Iran , , Amin Harati، Farzaneh نويسنده Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, IR Iran , , Sadighara، Parisa نويسنده Department of Environmental Health, Food Safety Division, Faculty of Public Health, Tehran University of Medical Sciences, Tehran, I. R. Iran ,
Abstract :
Bacteria in foodstuff are the most important agent of foodborne disease. Aside from their infectious effects, obligate aerobes have a respiratory metabolism with oxygen as the terminal electron acceptor. Therefore, they can produce reactive oxygen species and free radicals in contaminated food. Malondialdehyde (MDA) is a product of lipid peroxidation used as an indicator of oxidative stress. This study aimed to evaluate the oxidative damage produced by two common food pathogenic bacteria in foodstuff. The egg yolks were incubated with different dilutions (105,106, and 107) of Staphylococcus aureus and Salmonella enteritidis at 37°C for 20 hours. The level of MDA in egg yolk was measured by fast and simple enzymatic or colorimetric methods, such as the thiobarbituric acid reactive species method. The high group (107) had a higher MDA level of 1.97 ± 0.11 (µg MDA/g) in S. aureus and 1.65 ± 0.27 (mg MDA/L) in S. enteritidis than the control (0.90 ± 0.13 mg MDA/L). We concluded that common food pathogenic bacteria can induce oxidative damage in foodstuff aside from other common problems. Heating or sterilization methods cannot protect foodstuff from the damage caused by the presence of pathogenic bacteria.
