Microbiological Characteristics and Resistance Profile of Isolated Bacteria in Market Garden Products in N'Djamena, Chad

The phenomenon of antimicrobial resistance is a threat for public health. The aim of this study was firstly to assess the microbiological quality of fresh vegetables and fruits produced in the market gardens of N'Djamena-Chad; and secondly to study the antibiotic resistance profile of isolated strains. In order to achieve these objectives, data were collected through field surveys and the fresh fruits and vegetables harvested. The collected samples were microbiologically characterized using standardized methods. A total number of 180 fresh vegetables and fruits were analyzed. The results obtained on the prevalence of isolated pathogens showed a high microbial diversity (Aeromonas hydrophila, Aeromonas sobria, Escherichia coli, Salmonella spp., Staphylococcus aureus) and a high microbiological contamination of vegetables analysed. Lettuce was the most contaminated sample with about 46.7% of Escherichia coli and 7% Salmonella spp. However, contamination varied according to the site and was closely related to the poor quality of irrigation water. The study determined the biochemical characteristics of each isolate. The antibiotic sensitivity test of the isolates showed that the isolated pathogenic bacteria are all resistant to the antibiotics tested. A significant difference (p = 0.02) was observed between percentages mean of penicillin resistance (67%) and cephalosporins (29%). The consequences of this contamination are health risks for consumers and producers. Practical Applications Awareness on good farming practices for producers of vegetable and fruits is necessary to preserve consumers' health.