Detection of Listeria monocytogenes in Raw and Imported UHT Milk in Baghdad

Abstract

In order to investigate the presence of Listeria monocytogenes in raw and imported Ultra Heat Treatment (UHT) milk, this study was done by random collection of samples from different areas in Baghdad province and its surroundings from different animals (small and large ruminants) as 68 total samples (53 raw milk samples and 15 imported UHT samples)collected weekly from October 2007 till January 2008, and processed according to standard protocols of Listeria monocytogenes . The results showed reisolation of 10 isolates from 68 samples (14.7%) as 6 isolated from raw milk samples (11.3%) and 4 isolated from UHT milk samples (26.7%) ,these revealed significant differences (P≤0.05) in isolated percentage of Listeria monocytogenes from raw milk of Cows, Buffalos , Ewes and Does especially from Al-Fadhyllea region , the highest isolation percentage was in November (2007) as 16.7%(3 isolates from 18 samples ) especially from ewes as 1 isolate from 3 samples (33.4%) followed by cows and buffaloes with nonisolates from Does . The percentage of isolation from UHT milk samples was 26.7% as 2 isolates from white UHT milk samples (40%) and 2 isolates from 10 chocolate UHT milk samples (20%). We concluded from this study by contamination of raw and imported UHT milk samples by Listeria monocytogenes in Baghdad.