Isolation of Bacteria from Raw Milk Collected at Milk Super Markets in Tripoli City

Globally, billions of people consume milk and dairy products every day. Milk samples were collected at 15 milk collection centers (milk super market). According to stratified random sampling design. Samples were analyzed for Total Plate Count (TPC). The prevalence of selected pathogens such as Listeria monocytogenes, E. coli and Salmonella was determined. The mean counts per ml for TPC, psychrotrophs and thermophiles were 12×106, 7.5×103 and 9.1×103, respectively. A TPC less than 106 cfu ml−1 was used as a basic standard by MCC in the Price Incentive Programme. From the 150 milk samples tested, approximately 90% were contaminated by coliform bacteria and 65% were E. coli positive, with mean counts ranged from 103 to 104 cfu ml−1. S. aureus was isolated from more than 60% of the samples and the mean count per ml was 12×103. Meanwhile, E. coli was also detected in20 (33.5%) samples. However, Salmonella was only detected in 1.4% of the samples, with the Central region having the highest frequency of isolation. Thirteen Salmonella serotypes were identified, including S. muenchen, S. anatum and S. agona. A total of 47 strains of Listeria were isolated from 4.4% Listeria-positive samples including L. monocytogenes (1.9%), L. innocua (2.1%) and L. welshimeri (0.6%). The presence of pathogenic bacteria such as E. coli, Salmonella and Listeria spp. in raw milk is of public health concern since drinking raw milk is still considered good for health in rural population.