Microbial quality and safety of ready to eat vegetable salads vended in Kawempe Division, Kampala District, Uganda

Abstract

Raw vegetable salads are regularly implicated in foodborne illnesses globally. There is wide consumption of vegetable salads, mainly comprised of onions, tomatoes and cabbages, along with street vended foods in Uganda. However, there is limited information about their microbial quality and safety. This cross-sectional study aimed at generating baseline information about the safety and quality of vegetable salads served with street -vended foods in Kawempe division, Kampala district. The objectives of the study were to determine the mesophilic aerobic bacterial load and the prevalence of selected common foodborne pathogens in the ready-to-eat vegetable salads. A total of 60 samples were collected from selected areas of Kawempe division, that is, Kikoni, Wandegeya, Mulago, Bwaise and Kikumi Kikumi. The vegetable salad samples were randomly and aseptically collected from different street food vendors and transported under cold chain to the Microbiology laboratory at the College of Veterinary Medicine Animal Resources and Biosecurity, Makerere University. The microbial load was determined using total viable plate counts, while selected common food pathogens were detected using singleplex Polymerase Chain Reaction. The mean mesophilic aerobic count in the different zones ranged from 5.359±0.72 log10 cfu/g to 7.009±1.97 log10 cfu/g with the minimum aerobic count in the samples being 3 log10 cfu/g and maximum being 9.46 log10 cfu/g. Among the 60 samples collected, the prevalence of the selected food borne pathogens, that is, Staphylococcus aureus, Bacillus cereus, Salmonella spp and Listeria monocytogenes was 85%, 26.7%, 13.3%, and 35% respectively. Surprisingly, Escherichia coli was not detected in any of the samples. These results indicate that the vegetables are notably contaminated, and have poor microbiological quality that could potentially result in outbreak of foodborne illnesses. These findings call for the attention of relevant authorities to ensure that adequate hygienic standards and regular monitoring of the quality of RTE vegetable salads are improved and practiced to avoid possible foodborne infections.