Determination of the Principal Sources of Listeria spp. Contamination in Poultry Meat and a Poultry Processing Plant

Abstract

The presence of Listeria spp. in chicken drumsticks, wings, breasts, and livers taken from a poultry processing plant was investigated. The poultry pieces found to be most contaminated were drumstick meat and skin, with 96% of samples shown to contain Listeria spp. Drumsticks contained the highest number of Listeria spp., with counts in many cases exceeding 3 log CFU/g for skin and muscle. Samples were also taken from various surfaces in the processing plant, where the most contaminated areas were found to be in the final stages of meat processing. Three samples were positive for Listeria spp. immediately after washing and disinfection had taken place. The results suggest that drumsticks are responsible for a large amount of the contamination of chicken carcasses, and that the surfaces that come into contact with these pieces of meat play an important role in spreading Listeria spp. Disinfection procedures used by this processing plant do not effectively control Listeria spp.