Bacteriological quality of ice cream in Tripoli-Libya

Objective: To determine the bacteriological quality of ice cream sold in Tripoli city and susceptibility of the isolated bacterial agents to the commonly used antibiotics. Materials and methods: One hundred and sixty ice cream samples were collected from six different small and two large manufactures in Tripoli. Standard bacteriological techniques were used to determine the total bacterial count (TBC) and coliforms, isolate the pathogenic organisms and determine their susceptibilities to antibiotics. Results. TBC of samples examined ranged between 3 x 10(1) and 5 x 10(8) cfu/ml (mean = 6.9 x 10(7)) and the MPN values of coliforms between 0.0 and 11/ml (mean = 8). Of the samples studied Escherichia coli was isolated from 10 [including 2 serogroup O157] (6%), Salmonella spp. from 8 (5%), Aeromonas spp. from 30 (19%). Staphylococcus aureus from 60 (38%) and Listeria monocytogenes from 7 (4%). Nearly 80% of the samples examined did not conform to the Libyan Standards for Ice Cream (LSIC). Resistance to one antibiotic was detected in more than 80% of the isolated bacterial pathogens and multiple-drug resistance (resistance to three antibiotics) in 25%. Conclusion. Antibiotic-resistant pathogenic bacteria is not uncommon in ice cream sold in Tripoli particularly from small manufactures. Application of the HACCP system should be introduced into the ice cream industry to improve the quality of such products manufactured in Libya. (c) 2005 Elsevier Ltd. All rights reserved.