Microbial contamination of leafy vegetables in Porto-Novo, Republic of Benin

Abstract

Background: The vegetables provide important nutrients to human beings. Nevertheless, contaminated vegetables can cause health problems because of their microbial load. The aim of this study was to assess the microbial quality of three main leafy vegetables cultivated and consumed at Porto-Novo in Republic of Benin. Methods: Totally, 36 samples of amaranth, nightshade, and lettuce were taken from three districts of Porto-Novo at urban gardening level. The samples were tested microbiologically according to international standards for determination of aerobic mesophilic bacteria, total coliforms, faecal coliforms, Clostridium perfringens, faecal streptococci, and Salmonella spp. The results were analyzed using SPSS software v. 16.0. Results: In total, aerobic mesophilic bacteria counts in leafy vegetables ranged from 4.42x105 to 1.08x106 Colony Forming Unit (CFU)/g. The highest and lowest total coliform loads were found in lettuces (3.21x103 CFU/g) and the nightshades (1.78x102CFU/g), showing significant (p<0.05) difference. Faecal streptococci load ranged from 1.01x103 to 3.18x103 CFU/g and was significantly (p<0.05) higher in amaranths than in lettuces and nightshades. C. perfringens ranged from 0.633x101 to 1.18x101 CFU/g. Salmonella spp. was absent in all vegetables. Conclusion: High microbial contaminations were found in the three leafy vegetables in urban gardening at Porto-Novo, Benin. So, it is necessary to improve the microbial quality of leafy vegetables farmed at Porto-Novo for reduction of health risk in consumers.