Evaluation of microbial contamination of consumed fruits and vegetables salad (Kachumbari) around Egerton University, Kenya

Abstract

With increased student population and health consciousness in and around Egerton University, Kenya, there has been an upsurge in the vending of fruits and vegetable salad (Kachumbari). However, there have been safety concerns, and increased infections have been reported. This study evaluated the microbiological quality of salads served around Egerton University, particularly targeting Escherichia coli and Salmonella spp. contamination. Thirty salad samples, five each from different sampling zones (Egerton University gate, Nakuru bus stage, Nakuru town hawkers, food kiosks around Egerton University, Njokerio vendors, and Njoro town vendors), were collected randomly. The E. coli was determined on MacConkey Agar and Brilliant Green Bile Broth, while its confirmation was done on Eosin Methylene Blue agar. Salmonella spp. was determined on Salmonella Shigella Agar and confirmed using Triple Sugar Agar slants. Approximately 80% of the samples tested positive for E. coli with a mean value of log10 of 3.047 colony forming units (CFU)/g. On the other hand, 70% of the samples tested positive for Salmonella with a mean of log10 2.067 CFU/g. These values were above the Kenya Bureau of Standards of 10 CFU/g for E. coli and absence of Salmonella in fruits and vegetable salads. The present study revealed the potential hazards of street-vended salad and the illnesses affecting consumers may be attributed to these street-vended foods. Therefore, a Hazard Analysis and Critical Control Points Principles study is essential to identify the source of microbial contamination in the salads to guide the implementation of food safety measures by the public health officials.