Abstract
Raw vegetables are major vehicles for the transmission of foodborne infections. In Ethiopia, there is a habit of consuming raw vegetables as salad, particularly tomato (Solanum lycopersicum L.), cabbage (Brassica oleracea L.), carrots (Daucus carota L.), lettuces (Lactuca sativa L.) and green peppers (Capsicum annuum L.) without adequate treatment. The objectives of this study were to evaluate the microbiological loads, assess the prevalence of some food borne pathogens, and investigate the antimicrobial susceptibility of pathogens. A total of 180 vegetable samples were purchased from different sites and markets of Jimma town and analyzed for their microbial loads following standard microbiological methods. In addition, antibiotic resistance pathogens and prevalence of Salmonella and Staphylococcus aureus were also determined. Ninety percent of vegetable samples had aerobic mesophilic counts of ≥ 5 log10 CFU g-1. Similarly, 82.2, 92.8 and 97.8% of samples had coliform, Enterobacteriaceae and lactic acid bacteria counts of ≥ 4 log10 CFU g-1, respectively. However, most of staphylococci and aerobic spore counts varied between 2 - 3.9 log10 CFU g-1, but greater than 74% of yeasts and molds were counted ≤ 2.9 log10 CFU g-1. The aerobic mesophilic flora of the vegetable samples was dominated by Bacillus spp. (22.3%) followed by Staphylococcus spp. (17.7%). Salmonella and S. aureus were isolated from 23 (12.8%) and 18 (10%) vegetable samples, respectively. All of Salmonella and S. aureus isolates showed resistance to ampicillin and penicillin G, respectively. However, they were 100% sensitive to ciprofloxacin and gentamicin. Lettuce had high microbial load and Salmonella were most prevalent in lettuce but S. aureus were more prevalent in green pepper. Most of the pathogens were multiple drugs resistant. The use of food grade chemicals to kill pathogens and reduce the microbial load before consumption is recommended.
Key words: Drug resistance, prevalence, pathogens, raw vegetables.
