UPLC-MS/MS analysis of antibiotics in pharmaceutical effluent in Tunisia: ecotoxicological impact and multi-resistant bacteria dissemination.

The UPLC MS/MS analysis showed the presence of the two antibiotics in the pharmaceutical industry discharges during 3 months; norfloxacin and spiramycin which were quantified with the mean concentrations of 226.7 and 84.2 ng mL-1, respectively. Sixteen resistant isolates were obtained from the pharmaceutical effluent and identified by sequencing. These isolates belong to different genera, namely Citrobacter, Acinetobacter, Pseudomonas, Delftia, Shewanella, and Rheinheimera. The antibiotic resistance phenotypes of these isolates were determined (27 tested antibiotics-discs). All the studied isolates were found resistant to amoxicillin and gentamicin, and 83.33% of isolates were resistant to ciprofloxacin. Multiple antibiotic resistances were revealed against ß-lactams, quinolones, and aminoglycosides families. Our overall results suggest that the obtained bacterial isolates may constitute potential candidates for bioremediation and can be useful for biotechnological applications. Genotoxic effects were assessed by a battery of biotests; the pharmaceutical wastewater was genotoxic according to the bacterial Vitotox test and micronuclei test. Genotoxicity was also evaluated by the comet test; the tail DNA damages reached 38 and 22% for concentrated sample (10×) and non-concentrated sample (1×), respectively. However, the histological sections of kidney and liver's mice treated by pharmaceutical effluent showed normal histology and no visible structural effects or alterations as cytolysis, edema, or ulcerative necrosis were observed. Residual antibiotics can reach water environment through wastewater and provoke dissemination of the antibiotics resistance and induce genotoxic effects.

Identification and risk assessment of human and veterinary antibiotics in the wastewater treatment plants and the adjacent sea in Tunisia.

In the following study, we came up with and validated a prompt, sensitive and precise method for the simultaneous determination of 56 antimicrobial drugs (tetracyclines, sulfonamides, ß-lactams, macrolides and quinolones) using the ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). This method was implemented with success to determine antibiotics in samples collected from four wastewater treatment plants and five coasts in Tunisia. Results showed the presence of high concentrations of antibiotics that ranged from 0.1 to 646 ng mL-1, which can induce many negative impacts on health and the environment. For this reason, we have opted to evaluate toxicity of wastewater samples using a battery of biotests. In fact, genotoxicity was assessed using three tests: Vitotox, comet and micronucleus assays. The input and output of wastewater treatment plants induced a strongly genotoxic effect on the Salmonella typhimurium TA104 prokaryotic Vitotox assay. This result was confirmed using the comet and the micronucleus assays performed on the human liver hepatocellular carcinoma cells. The genotoxic power of the tested wastewater treatment plants' samples could be attributed to the presence of the higher quantities of antibiotics that are detected in these samples and to the antibiotic and organic compound cocktails.

Occurrence of antibiotics in pharmaceutical industrial wastewater, wastewater treatment plant and sea waters in Tunisia.

Antibiotics are among the most commonly used group of pharmaceuticals in human medicine. They can therefore reach surface and groundwater bodies through different routes, such as wastewater treatment plant effluents, surface runoff, or infiltration of water used for agricultural purposes. It is well known that antibiotics pose a significant risk to environmental and human health, even at low concentrations. The aim of the present study was to evaluate the presence of aminoglycosides and phenicol antibiotics in municipal wastewaters, sea water and pharmaceutical effluents in Tunisia. All analysed water samples contained detectable levels of aminoglycoside and phenicol antibiotics. The highest concentrations in wastewater influents were observed for neomycin and kanamycin B (16.4 ng mL(-1) and 7.5 ng mL(-1), respectively). Chloramphenicol was found in wastewater influents up to 3 ng mL(-1). It was observed that the waste water treatment plants were not efficient in completely removing these antibiotics. Chloramphenicol and florfenicol were found in sea water samples near aquaculture sites at levels up to, respectively, 15.6 ng mL(-1) and 18.4 ng mL(-1). Also aminoglycoside antibiotics were found near aquaculture sites with the highest concentration of 3.4 ng mL(-1) for streptomycin. In pharmaceutical effluents, only gentamycin was found at concentrations up to 19 ng mL(-1) over a sampling period of four months.

Comet assay with gill cells of Mytilus galloprovincialis end point tools for biomonitoring of water antibiotic contamination: Biological treatment is a reliable process for detoxification.

This article investigates the ability of Pseudomonas peli to treat industrial pharmaceuticals wastewater (PW). Liquid chromatography-mass spectrometry (MS)/MS analysis revealed the presence, in this PW, of a variety of antibiotics such as sulfathiazole, sulfamoxole, norfloxacine, cloxacilline, doxycycline, and cefquinome.P. peli was very effective to be grown in PW and inducts a remarkable increase in chemical oxygen demand and biochemical oxygen demand (140.31 and 148.51%, respectively). On the other hand, genotoxicity of the studied effluent, before and after 24 h of shaking incubation with P. peli, was evaluated in vivo in the Mediterranean wild mussels Mytilus galloprovincialis using comet assay for quantification of DNA fragmentation. Results show that PW exhibited a statistically significant (p< 0.001) genotoxic effect in a dose-dependent manner; indeed, the percentage of genotoxicity was 122.6 and 49.5% after exposure to 0.66 ml/kg body weight (b.w.); 0.33 ml/kg b.w. of PW, respectively. However, genotoxicity decreased strongly when tested with the PW obtained after incubation with P. peli We can conclude that using comet assay genotoxicity end points are useful tools to biomonitor the physicochemical and biological quality of water. Also, it could be concluded that P. peli can treat and detoxify the studied PW.

Isolation and characterization of antibiotic-resistant bacteria from pharmaceutical industrial wastewaters.

Contamination of surface waters in underdeveloped countries is a great concern. Treated and untreated wastewaters have been discharged into rivers and streams, leading to possible waterborne infection outbreaks which may represent a significant dissemination mechanism of antibiotic resistance genes among pathogenic bacterial populations. The present study aims to determine the multi-drug resistance patterns among isolated and identified bacterial strains in a pharmaceutical wastewater effluent in north Tunisia. Fourteen isolates were obtained and seven of them were identified. These isolates belong to different genera namely, Pseudomonas, Acinetobacter, Exiguobacterium, Delftia and Morganella. Susceptibility patterns of these isolates were studied toward commonly used antibiotics in Tunisia. All the identified isolates were found to have 100% susceptibility against colistin sulfate and 100% resistance against amoxicillin. Among the 11 antibiotics tested, six patterns of multi-drug resistance were obtained. The potential of the examined wastewater effluent in spreading multi-drug resistance and the associated public health implications are discussed.

Treatment process and toxicities assessment of wastewater issued from anaerobic digestion of household wastes.

Modern society grapples with large amounts of household waste. The anaerobic digestion of this waste offers a promising source for energy-rich biogas production but generates high toxic effluents that require treatment before reuse or disposal into the environment. This study aimed to investigate three techniques, namely coagulation/flocculation, electro-coagulation, and activated sludge, in terms of efficiency in the treatment of these effluents. It also aimed to assess their toxicity effects on the germination and growth of durum wheat Triticum aestivum L. seeds before and after 6 days of treatment. Activated sludge was most efficient in reducing chemical oxygen demand, turbidity, and conductivity (95.7 %, 15.8 %, and 37.5 %, respectively). The effluent treated with this technique induced a marked delay in germination (low mean time of germination) and a significant reduction in the percentages of seed germination and root and leaf growths. It was also noted to strongly induce lipid peroxidation in roots and leaves, which presumably explained the germination/growth inhibition of the wheat seeds. The effluent also induced marked lipid peroxidation effects and strongly inhibited the activities of butyrylcholinesterase in mice bone marrows. The effluent shows a high ability to inhibit the growth of three microalgae; these endpoints are useful tools to biomonitor the physico-chemical quality of this wastewater. Overall, while no significant alterations were observed in terms of animal and vegetable toxicities when the effluent was treated by coagulation/flocculation, activated sludge treatment proved efficient in reducing the toxicities induced by the untreated effluents. The results indicate that the application of this technique is promising with regards to attaining efficient, eco-friendly, and cost-effective strategies for the management and treatment of household waste.