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The aim of this study is to determine physiochemical and bacteriological properties of seawater and sediments from the coast of Tunisia during six successive months. The conductivity was measured using previously calibrated Hach Conductivity meter. Total suspended solid was determined using Whatman GF/C glass fiber filter (Sigma Aldrich), and the turbidity was assessed using a spectrophotometer (UV/Vis). The pH was measured using pH electrodes. Other physiochemical parameters were determined using Pastel UV multiparameter water analyzer (Secomam, aqualabo). Bacterial analysis was displayed by membrane filtration method, and isolates were identified to the species level by Api strips. Susceptibility to antibiotics was determined by disk diffusion methods. Total suspended solid, turbidity, adsorbable organic halogen, chemical oxygen demand, and biochemical oxygen demand were higher than accepted norms in Tunisia. Enterococcus faecalis was detected in all the sites indicating a human fecal contamination, and all the isolates were highly resistant to rifampicin, gentamicin, chloramphenicol, ampicillin, and azithromycin. The situation in Mahdia coast is alarming particularly with the isolation of multidrug resistance strains. It is recommended that the local government provide restrict policies for the treatment and the assessment of municipal wastewater before its discharge into sea. Practitioner points Coastal Surveillance and Water Quality monitoring in the Rejiche Sea – Tunisia is crucial. Enterococcus faecalis was detected in sea water and sediment samples in the coast of Rejiche. Isolated strains were highly resistant to rifampicin, gentamicin, chloramphenicol, ampicillin and azithromycin.

Although it is known that textile wastewater contains highly toxic contaminants whose effects in humans represent public health problems in several countries, studies involving mammal species are scarce. This study was aimed to evaluate the toxicity profile of 90-days oral administration of textile dyeing effluent (TDE) on oxidative stress status and histological changes of male mice. The TDE was collected from the textile plant of Monastir, Tunisia and evaluated for the metals, aromatic amines, and textile dyes using analytical approaches. Metal analysis by ICP-MS showed that the tested TDE exhibited very high levels of Cr, As, and Sr, which exceeded the wastewater emission limits prescribed by WHO and Tunisian authority. The screening of TDE through UPLC-MS/MS confirmed the presence of two textile dyes: a triphenylmethane dye (Crystal violet) and a disperse azo dye (Disperse yellow 3). Exposure to TDE significantly altered the malondialdehyde (MDA), Conjugated dienes (CDs), Sulfhydryl proteins (SHP) and catalase levels in the hepatic and renal tissues. Furthermore, histopathology observation showed that hepatocellular and renal lesions were induced by TDE exposure. The present study concluded that TDE may involve induction of oxidative stress which ensues in pathological lesions in several vital organs suggesting its high toxicity. Metals and textile dyes may be associated with the observed toxicological effects of the TDE. These pollutants, which may have seeped into surrounding rivers in Monastir city, can cause severe health malaise in wildlife and humans.

Effluents discharged by poultry meat industries are heavily polluted with raw materials, such as fat, blood residues, and proteins. Thus, untreated effluents directly discharged into the environment may constitute a public health threat. This study aims to evaluate the bacterial diversity of three water qualities: industrial poultry wastewater (PWW), tap water (TW), and PWW diluted with TW (50 : 50) (V/V) (TWPWW) by the combination of culture-independent and culture-dependent approaches. The total bacterial DNA was extracted using phenol/chloroform method. The hypervariable 16S rRNA region V3-V5 was amplified by PCR using universal primers. The amplicons were separated by vertical electrophoresis on a polyacrylamide gel of increasing denaturing gradient according to their richness in GC bases. Selected bands were reamplified and sequenced. Pure isolated bacteria from nutrient agar medium were characterized according to their morphological and biochemical characteristics. Genomic DNA from pure strains was extracted by boiling method, and a molecular amplification of the 16S–23S ITS region of the 16S rRNA gene was performed using the universal primers. Selected isolates were identified by sequencing. Results showed a high bacterial load and diversity in PWW in comparison with TW and TWPWW. A collection of 44 strains was obtained, and 25 of them were identified by sequencing. Proteobacteria represented 76% of isolated bacteria Gamma-Proteobacteria was the predominate isolate (68%). Other isolates were Firmicutes (8%), Bacteroidetes (12%), and Actinobacteria (8%). These isolates belong to different genera, namely, Pseudomonas, Acinetobacter, Proteus, Empedobacter, Corynebacterium, Enterobacter, Comamonas, Frondibacter, Leclercia, Staphylococcus, Atlantibacter, Klebsiella, and Microbacterium.

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