Physicochemical and ecotoxicological approaches for Moknine Continental Sebkha in Tunisia

Degradation of water quality is an emerging issue in many developing countries. In this context, industrial and domestic effluents heavily contaminate the coast of Moknine Continental Sebkha in Tunisia. The present study aimed to biomonitor the seawater quality of the Moknine Continental Sebkha coast using physicochemical and ecotoxicological approaches. The ecotoxicological assessment was performed using three species representing different trophic levels, namely Vibrio fischeri, Selenastrum capricornutum, and Lepidium sativum. In the physicochemical analysis such as BOD (biochemical oxygen demand), COD (chemical oxygen demand), TSS (total suspended solids), TOC (total organic carbon), NO3− (nitrate), AOX (adsorbable organic halogen), the recorded levels of pH and total suspended solids did not comply with the Tunisian standard (NT.09.11/1983). The ecotoxicological data confirmed that the tested water samples displayed toxicity to two test indicators L. sativum and S. capricornutum. A targeted chemical screening of the Moknine Continental Sebkha coast previously performed revealed the presence of total mercury, four phthalate acid esters, and one non-phthalate plasticizer, a fact that could explain the observed ecotoxicological effects and therefore might harm the biotic area and the human health of the surrounding population

DNA as a Next-Generation Biomonitoring Tool of Hospital Effluent Contamination

A DNA biosensor based on a modified gold electrode with a Au/cysteine/DNA matrix was developed for ultratrace determination of genotoxicity antibiotics. The modified Au/cysteine/DNA electrode was characterized by cyclic voltammetry and impedance spectroscopy methods. The interaction between immobilized DNA and genotoxicity antibiotics in hospital wastewater was investigated using differential pulse voltammetry (DPV) technology. Using this technique, ciprofloxacin and ofloxacin were detected in real time in the hospital wastewater (HW) of the Tunisian cities of Gabes, Tozeur, Sfax, and Gbeli. In addition, physicochemical parameters such as the chemical oxygen demand (COD), biological oxygen demand (BOD), and total organic carbon (TOC) of HW samples that may affect the nature of the samples were studied. Comet assay (single-cell gel electrophoresis) was performed to measure the capacity of xenobiotics to induce DNA damage. In our conditions, this test indicated that all tested wastewater was able to alter cell integrity and cause DNA molecular damage, and the most genotoxic effect was found in the wastewater of Gabes hospital. Results show that the concentrations of the two antibiotics reached 33 and 40 ng/mL in the hospital wastewater of Gabes and Tozeur, respectively. The DNA biosensor based on the modified gold electrode exhibited superb performance and offers a probable application for the detection of genotoxicity antibiotics in hospital wastewater. The level of genotoxicity is proportional to the concentration of antibiotics detected in hospital wastewater. We will explore the application of this model for continuous monitoring downstream of hospital discharge and wastewater treatment plants for effective control of the presence of genotoxic products

Designation of pathogenic resistant bacteria in the Sparusaurata sea collected in Tunisia coastlines: Correlation with high performance liquid chromatography-tandem mass spectrometry analysis of antibiotics

International audienceVibrio is characterized by a large number of species and some of them are human pathogens causing gastro intestinal and wound infections through the ingestion or manipulation of contaminated fishes including Vibrio parahaemolyticus and Vibrio alginolyticus. In this study, we reported the phenotypic and molecular characterization of Vibrio parahaemolyticus and Vibrio alginolyticus strains isolated from wild and farm sea bream (Sparus aurata L) along the Tunisian coast from December 2015 to April 2016. Therefore, the antibiograms indicate a difference between farmed and wild fish. Resistance against amoxicillin antibiotic appears for the bacteria isolated from wild fish, while those from aquaculture farming presented sensitivity to amoxicillin and resistance to antibiotics colistin and fusidic acid. The chloramphenicol antibiotic exhibited a high sensitivity in all isolated bacteria. In fact, traces of amoxicillin in the organs of the fish from Hergla farm were detected by UPLC-MS/MS analysis during December 2016 to April 2016. In addition, antibiotics were detected in January 2014 with high concentration of norfloxacin 2262 ng/g in fish from Hergla coast. The results obtained in this work indicated that the use and presence of antibiotics in water impacts on the occurrence of resistant bacteria and the detection of antibiotic in fish. (C) 2017 Published by Elsevier Ltd

Persistent plasticizers and bisphenol in the cheese of Tunisian markets induced biochemical and histopathological alterations in male BALB/c mice

Clinical evidences, experimental models, and epidemiology of many studies suggest that phthalate-based plasticizers, aliphatic ester, and bisphenol A (BPA) have major risks for humans by targeting different organs and body systems. The current study has been designed firstly to analyze three categories of cheese with and without their exposure to the sun and packed in packages with an inner surface plastic-covered film in order to identify the dibutyl phthalate (DBP); benzyl butyl phthalate (BBP); bis(2-ethylhexyl) phthalate (DEHP); diisodecyl phthalate (DiDP); diisononyl phthalate (DiNP); and 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) by GC-MS/MS, except for the bisphenol A, which is by UPLC-MS/MS, and secondly to assess the toxicity of the identified chemical molecules and cheese samples on the liver and kidney of mice. Our results showed that the cheese contains high quantities of DBP and DEHP with the concentrations up to 0.46 and 2.339 mg/kg, respectively. Other types of cheese, such as rolled and triangular cheeses, contain little quantities of the all substances at concentrations below the standard limits. In vivo, the obtained data clearly demonstrated that the acute administration of DBP, DEHP, and the tested cheese significantly induced liver and kidney injuries in mice manifested by a rise in plasma alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, lactate dehydrogenase, urea, creatinine, and uric acid when compared with control animals. In addition, the histopathological study confirmed the perturbation of biochemical parameters and showed that the hepatic and renal structures were altered. Indeed, the hepatotoxic and nephrotoxic effects are more pronounced when cheese was exposed to the sun

Optimization of extraction with salicylic acid, rheological behavior and antiproliferative activity of pectin from Citrus sinensis peels

International audienc

Cytotoxic effects of seven Tunisian hospital wastewaters on the proliferation of human breast cancer cell line MDA-231: correlation with their chemical characterization

International audienceHospital wastewaters contain large amounts of pharmaceutical residues, which may eventually be discharged into the aquatic environment through wastewater treatment plants, raising the question of their impact on human and environmental health. This has prompted the launch of several monitoring studies into the most commonly administered compounds in urban wastewater. The aim of this study was, therefore, to explore the cytotoxic potential of wastewaters samples collected from seven hospitals in Tunisia. The physicochemical analyses showed a large fluctuation of certain parameters in the collected samples, such as chemical oxygen demand (ranged from 860 to 1720 mg L-1), biochemical oxygen demand (ranged from 385 to 747 mg L-1), total organic carbon (ranged from 256 to 562 g L-1), total suspended solids (ranged from 905 to 1450 mg L-1), conductivity (ranged from 3.31 to 7.14 mu sm/cm), and turbidity (ranged from 100 to 480 NTU). The analysis using inductively coupled plasma mass spectrometry (ICP-MS) also showed that hospital wastewater contains high concentrations of Hg (ranged from 0.0024 to 0.019 mg L-1). This could be explained by the variation of the activity and the services in certain hospitals compared to others. All hospital wastewater samples induced the proliferation of human breast cancer cell line MDA-231, even at low concentrations (20 mu L/assay). Moreover, the maximum induction reached at the concentration of 60 mu L/assay in wastewater samples from hospitals located in Monastir, Sidi Bouzid, Mahdia, and Sfax with percentages of induction up to 42.33, 14, 7.61, and 5.42%, respectively. These observations could be due to the presence of endocrine disrupting compounds (EDCs) in these wastewaters. Given this, our results evidenced the potential risk of these hospital effluents to environmental and public health

Occurrence and seasonal variation of plasticizers in sediments and biota from the coast of Mahdia, Tunisia

Plasticizers are compounds often involved in the manufacturing of plastic products. Nevertheless, the ageing of the latter generates plasticizers that generally end up in the marine environment. In fact, marine pollution by phthalate acid esters (PAEs) and their alternatives has become an environmental and health issue of serious concern, as they are largely and ubiquitously present in the environment and aquatic organisms. In the present study, four PAEs, such as diethyl phthalate (DEP), diisobutyl phthalate (DiBP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP), and one non-phthalate plasticizer (NPP), namely di-2-ethylhexyl terephthalate (DEHT), are wanted in different marine compartments from the coast of Mahdia in Tunisia such as sediment, seagrass, and mussel. The most abundant and frequently detected congener was DEHT at the concentrations reached 1.181 mg/kg in the sediment, 1.121 mg/kg in the seagrass, and 1.86 mg/kg in the mussel. This result indicates that the DEHT could emerge through the food chain and therefore bioaccumulate in marine compartments. In addition, we noticed that the seasonal variations of plasticizers were seriously affected by environmental factors including industrial and urban discharges

A green sample preparation method for the determination of bisphenols in honeys

Bisphenol A is the most studied compound due to its adverse effects on human health and is one of the most widely used products in contact materials worldwide. However, in recent years, due to stringent restrictions on the use of BPA, structural analogues are substituting BPA in the production of some consumer products. A method based on the Micro-QuEChERS technique and ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was proposed, derived from a previous method based on standard QuEChERS and HPLC-MS/MS. The proposed method was compared with the previous method using the analytical Eco-scale as a verification tool. The results highlight that the proposed method achieved a metric value of 79 points, higher than the required value of 75 points for 'excellent green analysis'. The method was then tested on Algerian and Tunisian honey samples of different floral origins. The results showed that the developed method was satisfactory in terms of recovery, sensitivity, and analysis time, showing good applicability even in a complex matrix such as honey. Low levels of contamination of residues of bisphenol-analogues were found and it can therefore be concluded that the samples analysed do not pose a health risk to consumers with regard to these compounds