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Fish is a protein source of high nourishing value consumed in the entire world. In Saharan countries it is consumed fresh, however as dried or smoked. However, fish is subject to both fungal and mycotoxins contamination. This study aims to identify fungal presumed producing mycotoxin and to evaluate the contamination level of aflatoxins B1, B2, and G2. A total of 150 samples of dried and smoked fish (Clarias sp. and Oreochromis sp.) have been collected in different islands of the Fitri lake. Standard methods of microbiology have been used for fungal isolation and identification. Aflatoxins content in fish has been determined using HPLC associate to GCMS. Fifty samples (50) were contaminated by four major fungal kinds. Frequency of fungal was to 40 % (Aspergillus niger), 26 % (Aspergillus fumigatus), 20 % (Mucor sp), 8% (Curvularia spp) and 6% (Scycadium). Twenty (20) samples suspected to be contaminated and analyzed, only seven (7) was contaminated with aflatoxins (B1, B2 and G2). The aflatoxin contamination level vary according to the fish species. Clarias sp. samples are 50 % contaminated by aflatoxins when Oreochromis sp are 20 % contaminated. Aflatoxins rates ranged from 0.01 to 2.78 and 0.09 to 0.32 µg/Kg respectively for aflatoxin B1 and aflatoxin B2 for Clarias sp and from 0 to 0.4 µg/Kg of aflatoxin B2 for Oreochromis sp. The mycotoxins level is in average high than the European Union recommendation for dried product. These results call for more sensitization and training for producer for safe dried and smoked fish.Contribution/Originality: This study is one of the very few studies which have investigated the contamination level of aflatoxins B1, B2, and G2 in dried and smoked fishes (Clarias sp and Oreochromis sp.) from Fitri lake in Chad. INTRODUCTIONFish is an important source of nutriments and animal proteins for a large part of the world population (Koranteng et al., 2014). Many processes are used for fish transformation and cooking in several countries in the Sahel. Fish is a protein source more than cow and pig meat and poultries. Fishing and aquaculture in the world

Introduction: Oxidative stress and bacterial infections are a public health problem in Chad. To reduce these problems, plant-based medicines were used to improve the development of traditionally drugs for infection treatments. The objective of this study was to evaluate the antiradical and antibacterial activities from ethanolic extract of Anogeissus leiocarpus. Material and Methods: In this study we used a stem bark of Anogeissus leiocarpus who used by different traditional practitioners in Chad for urinary infections treatment and diarrheal diseases caused by different types of bacteria (S. aureus, E. coli, S. typhi). Also the antiradical activity was evaluated by the method of DPPH colorimetric and the antibacterial activity by the method of disk diffusion. A phytochemical study was carried out to link the structure to the activity. Results: Our result showed a rate of 13.2% of ethanolic extract. The phytochemical analysis revealed the presence of flavonoids, tannins, saponosides, alkaloids, sterols, terpenoids and anthocyanins. Also the ethanolic extract of Anogeissus leiocarpus revealed an antiradical activity by the decolorization of DPPH from an initial purple color to yellow. This extracts inhibited the growth of Staphylococcus aureus, Salmonella typhi and Escherichia coli at the minimum inhibitory concentrations (MIC) of 1.25 mg/ml, 2.5 mg/ml and 5 mg/ml respectively. Conclusion: Our result showed that the ethanolic extract bark of Anogeissus leiocarpus could be a potential provider of secondary metabolites with antiradical and antibacterial activities, allowing the development of a new molecules to fight against oxidative stress, cardiovascular diseases, and microbial infections.

Salmonellosis is one of the most frequently reported foodborne illnesses and the majority of salmonellosis in humans comes from fresh fruits and vegetables. The objective of this work is to assess the level of contamination and to determine the biochemical profile and susceptibility to antibiotics of the strains of Salmonella spp. isolated from leafy vegetables produced in market garden farms in N'Djamena in Chad. 144 samples from six (6) different types of leafy vegetables were collected and analyzed according to standard food microbiology methods. ISO 6579 (2002) was used for microbiological analysis. The classical identification gallery and the API 20E gallery allowed the biochemical identification of isolated strains. The Kirby-Bauer method was used to test the antibiotic susceptibility of strains of Salmonella spp. The results obtained show microbiological contamination of vegetables analyzed in particular rocket and lettuce with a proportion of Salmonella spp. of 12.50% and 8.33% respectively. However, contamination varies according to the sites and is intimately linked to the poor bacteriological quality of irrigation water. The study determined the biochemical characteristics of each isolate. On the other hand, the susceptibility profiles of strains to antibiotics were varied. Indeed, the antibiotic sensitivity test of the isolates showed that the strains of Salmonella spp isolated are much more resistant to ceftriaxone, ampicillin and chloramphenicol. The most active antibiotics were amoxicillin/ clavulanic acid, nalidixicic acid, ciprofloxacin and imipenem with a sensitivity rate above 80%. However, the resistance of Salmonella spp to certain antibiotics is a real public health problem that challenges the authorities in charge of the issue.