Microorganisms of Public Health Significance Isolated from Salad Fruit and Vegetables in Dutsin-Ma, Katsina State, Nigeria

Background and Objective: In developing nations, vendors mostly handle fresh salad fruits and vegetables under poor hygienic and sanitary conditions. The study investigated microorganisms of public health significance that contaminate common salad fruit and vegetables in Dutsin-Ma. Materials and Methods: The sampling was carried out between June and August, 2018. Samples of fruit [Cucumis sativus (cucumber)] and 3 vegetables [Brassica oleracea (cabbage), Lactuca sativa (lettuce) and Allium cepa (onion)] were each collected from 15 kiosks and randomly selected for the investigation. Microscopy was used for geohelminths, selective and non-selective media were used to isolate and enumerate the bacteria. All the species were identified based on morphology, biochemical tests (IMViC) and selective differential culture media. Results: Ascaris lumbricoides is the only geohelminths reported and only in Lactuca sativa (46.67%). Bacillus subtilis, Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, Salmonella typhi and Staphylococcus aureus (bacteria) and Fusarium sp. and Rhizopus stolonifer (fungi) were randomly isolated and identified from the samples. The highest occurrence of 33.33% was of S. aureus while, the least occurrence of 8.33% was of each of P. aeruginosa and P. vulgaris. The fungal count showed Rhizopus stolonifer showed with the highest occurrence (75%) among the samples while the least (5%) occurred fungi was Fusarium sp. Conclusion: Salad fruit and vegetables in Dutsin-Ma are mostly contaminated with microorganisms of public health significance, with Lactuca sativa (lettuce) being the most contaminated with geohelminths, bacteria and fungi.