PREVALENCE OF ENTEROBACTERIACEAE IN READY-TO-EAT VEGETABLE SALAD SOLD

ABSTRACT

Salads have always been an important food item for human consumption, and a good source of vitamins, dietary fiber and minerals. Salads are normally not subjected to any step that eliminates pathogens before consumption. Thus, while being important for human health , they must be considered potential health risks. The aim of this research work was to determine the prevalence of enterobacteriaceae in ready-to-eat salads sold in Benin city, Edo state. A total of ten samples were obtained from five restaurants and five local food vendors in five locations in Benin city. All samples were serially diluted and inoculated on Nutrient Agar and Eosin Methylene Blue Agar. Bacterial isolates were identified based on cultural, morphological, and biochemical characteristics. Thereafter the Enterobacteriaceae isolates were subjected to acids tolerance test at pH 3.0 and bile salt tolerance test at 0.3% bile salt concentration after 1 and 3 hours of incubation. The total Heterotrophic bacteria count from this study ranged from 0.13±0.01(Sample H) to 1.01±0.03x106 (Sample A) cfu/g, while Enterobacteriaceae count ranged from 0.2±0.01 (Sample G) to 0.84±0.09x106 (Sample I) cfu/g. A total of eight isolates were identified in this study. They include; Klebsiella pneumonia, Serratia marcescens, Citrobacter spp, Enterobacter aerogenes, Proteus mirabilis and Bacillus spp. Klebsiella pneumonia, Serratia marcescens and Bacillus spp were the most occurring bacterial isolates (15.2%), while Klebsiella pneumonia1 was the least occurring isolate (6.1%).