Effects of Water Chiller on Listeria Monocytogenes Contamination of Poultry Carcasses in Industrial Slaughterhouses of Western Azerbaijan Province

Listeria spp. has been isolated from poultry، red meat and meat products and fish in many countries around the world. According to the reports of isolation of Literia monocytogenes in water and ice used for retaining freshness of food products and possibility of the increasing of bacterial contamination of poultry carcass after cooling in water chiller in poultry slaughter house، the effects of water chiller on Listeria monocytogenes contamination of poultry carcasses before and after chilling process in four industrial slaughter houses of western Azerbaijan province was investigated. Ninety poultry carcasses from 4 industrial slaughter houses in western Azerbaijan was investigated for Listeria monocytogenes before and after chilling process using the modified Canadian version of U. S. Food and Drug Administration (FDA) Listeria isolation method. Listeria monocytogenes contamination was 4. 9 MPN g-1 in one sample before chilling process in water chiller. The result of Listeria monocytogenes contamination in the same positive sample and 6 other samples which did not show positive result before chilling process were 18، 43، 28، 21، 14، and 92، respectively. All of the isolated belongs to the serogroup 1. Paired-samples T test indicated significant difference (P<0. 05) between the contamination levels before and after chilling process. Free available chlorine content of water in water chiller of these slaughter houses was not measurable.