Inhibition of Listeria monocytogenes in chicken meat by pediocin AcH/PA-1 produced by Pediococcus pentosaceus OZF
Pediococcus pentosaceus OZF isolated from human breast milk, possessed anti-listerial activity. The purpose of this study was to evaluate the use of pediocin AcH/PA-1, produced by OZF strain, for inhibition the Listeria monocytogenes growth in raw chicken meat products. The meat products were irradiated, inoculated with L. monocytogenes (about 5 log10 cfu/g) and purified pediocin AcH/PA-1 in a minimal effective concentration, packed and stored at 4°C for 4 weeks. A significant decrease (3.8 log10 cycles, p<0.05) was observed on pediocin AcH/PA-1 treated samples, following the end of 14 days of storage when compared with the controls. However, re-growth of L. monocytogenes after prolonged incubation time points (3-4 weeks) was detected. This undesirable situation might be due to the degradation of pediocin AcH/PA-1 by proteases derived from raw meat product or its interactions with various meat ingredients. Although the antimicrobial action of bacteriocins as meat preservatives may be quite limited, more effective protection systems can be provided with multi-hurdle preservation methods.
Listeria monocytogenes is an important pathogenic bacterium that is commonly present in unfavorable environmental conditions and food systems since it survives at refrigeration temperatures (1). Contamination of L. monocytogenes is still considered as a major safety concern. This pathogen has caused several outbreaks of food borne infections, particularly in neonates or immunocompromised patients (2). Many reports describing outbreaks of listeriosis associated with the consumption of either raw or ready to eat meat products led to increased attention to this problematic pathogen (3, 4). Therefore, in order to prevent contaminations from farm to store and to enhance the microbial safety of the food products, it is necessary to develop novel improved food preservation methods.
Although the hygienic rules and sanitation applications have been used for controlling L. monocytogenes contamination in food products, safety is still an issue of concern (5). Currently, there has been an increased attention in use of various generally recognized as safe (GRAS) metabolites to satisfy the consumer demands. Therefore the ...