Antibacterial effects of some fermented commercial and homemade dairy products and 0.9% lactic acid against selected foodborne pathogens

Abstract

In this study, the antibacterial effects of homemade yoghurt, commercial yoghurt, commercial kefir and probiotic yoghurt on viability of Salmonella typhimurium (ATCC 14028), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and Staphylococcus aureus (ATCC 25923) was investigated by using disc diffusion method. Antibaterial effects of the samples were tested at 24, 48 h and the 7 day intervals. Homemade yoghurt showed the maximum antibacterial effect against the pathogens. It was determined that the most sensitive pathogenic bacteria to dairy products were Salmonella typhimurium whereas the least sensitive pathogen was Pseudomonas aeruginosa. Comparing to the antimicrobial effect of 0.9% lactic acid which was used as positive control, our results concluded that the bacteria found in fermented dairy products have an antibacterial activity and this activity is not caused by only lactic acid. © 2011 Academic Journals Inc.