Salmonella prevalence on eggs and prevention strategy by bacteriophage

Koç, Emre
Today, eggs and egg products are one of the biggest food sources in the World and Turkey is one of the biggest hen’s egg producers in the world. In Turkey, there are 4 different poultry cultivation methods which are organic egg, free-range egg, cage free egg and cage egg. Salmonella is one of the most common pathogen bacteria found in egg industry. Thus, protection of food sources from Salmonella like pathogen is very crucial for food safety requirements. In this study, Salmonella prevalence in eggs from cultivation methods of hen’s were investigated and bacteriophage application, an alternative prevention method, was used to eliminate presence of Salmonella.For this purpose, 250 different eggs were collected according to their cultivation methods (organic, free-range, cage-free-cage-village) and 17 Salmonella strains (6.8%) were isolated in this study. Prevalence of Salmonella in free-range egg was 12%, cage-free egg was 10% and cage egg was 12%. However, no Salmonella was found in commercial organic eggs and village eggs. From those 17 Salmonella strains, 3 different serotypes Salmonella Infantis (88.2%), Salmonella Kentucky (5.88%) and Salmonella Telaviv (5.88%) were determined. In the bacteriophage application study, 10^8 PFU/mL bacteriophage solution was used for egg samples which were initially contaminated with 2 different Salmonella solutions (10^7cfu/mL & 10^5cfu/mL) to test the ratio of the numbers of virus particles to the numbers of the host cells in a given infection medium which is known as multiplication of infection (MOI). After incubation of contaminated eggs at 4 °C for 7 days, Salmonella was counted. Respectively, 2.24 log reduction and 3.64 log reduction of Salmonella was obtained by 10 MOI and 10^3 MOI. Further studies should be conducted to increase the efficiency of bacteriophage treatment on commercial eggs and different food sources.


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Citation Formats
E. Koç, “Salmonella prevalence on eggs and prevention strategy by bacteriophage,” M.S. - Master of Science, Middle East Technical University, 2022.