Novel homologs of the multiple resistance regulator marA in antibiotic-contaminated environments.

Antibiotics are commonly detected in the environment as contaminants. Exposure to antibiotics may induce antimicrobial-resistance, as well as the horizontal transfer of resistance genes in bacterial populations. We selected the resistance gene marA, mediating resistance to multiple antibiotics, and explored its distribution in sediment and water samples from surface and sewage treatment waters.

Gene expression profiles in zebrafish (Danio rerio) liver cells exposed to a mixture of pharmaceuticals at environmentally relevant concentrations.

The effects of a mixture of pharmaceuticals at environmentally relevant concentrations were studied on growth and transcriptional regulation in zebrafish liver (ZFL) cells. The mixture of 13 ingredients was assembled to mimic the association and low concentration (ng/l) of drugs as detected in the environment, and decidedly inhibited ZFL cells proliferation in vitro over a 72 h exposure time. Using an oligonucleotide DNA-microarray targeting 14,000 zebrafish transcripts, we profiled gene expression in ZFL cells treated with ecologically relevant levels of the drug mixture.

PCB contamination in farmed and wild sea bass (Dicentrarchus labrax L.) from a coastal wetland area in central Italy.

Food consumption is by far the main exposure route for polychlorinated biphenyls (PCBs) for the general population, and fish and fishery products seem to be the main contributors to the total dietary intake of these pollutants. In recent years some investigations have suggested that farmed fish may be more significantly contaminated than wild fish, because of polluted feed. This study measured the levels of PCBs in wild and farmed sea bass (Dicentrarchus labrax L.

Effects of a complex mixture of therapeutic drugs at environmental levels on human embryonic cells.

The potential risk associated with the presence of low levels of pharmaceuticals in aquatic environments is currently under debate. In this study we investigated the effects of 13 drugs merged to mimic both the association and low concentration (ng/L) profiles detected in the environment. The mixture comprised atenolol, bezafibrate, carbamazepine, cyclophosphamide, ciprofloxacin, furosemide, hydrochlorothiazide, ibuprofen, lincomycin, ofloxacin, ranitidine, salbutamol, and sulfamethoxazole.

Removal of pharmaceuticals in sewage treatment plants in Italy.

A listing of "priority pharmaceuticals" for human use in Italy resulted in the selection of 26 pharmaceuticals, belonging to 11 therapeutic classes. They were analyzed by liquid chromatography-tandem mass spectrometry, their occurrence was assessed in six sewage treatment plants (STPs), and the loads and the removal rates (RR) were studied. Total loads ranged from 1.

Pharmaceuticals in the environment in Italy: causes, occurrence, effects and control.

Background, Aim And Scope: Environmental contamination by pharmaceuticals is an emerging issue. Until recently, information on medicinal substances released into the environment was scant, but several studies have now been published. Data are, however, usually scattered and a systematic approach to this subject is generally lacking.

A multiresidue analytical method using solid-phase extraction and high-pressure liquid chromatography tandem mass spectrometry to measure pharmaceuticals of different therapeutic classes in urban wastewaters.

An analytical method with two extraction steps has been developed and validated for the simultaneous determination of 30 pharmaceuticals belonging to various therapeutic categories in urban wastewater. The aim was to boost the little available information on drugs' fates in sewage treatment plants (STPs) and in the receiving surface water. Aqueous samples were divided into two aliquots, each extracted by a different solid-phase extraction (SPE) method and analysed by reversed-phase liquid chromatography tandem mass spectrometry (HPLC-MS-MS).

Cocaine in surface waters: a new evidence-based tool to monitor community drug abuse.

Background: Cocaine use seems to be increasing in some urban areas worldwide, but it is not straightforward to determine the real extent of this phenomenon. Trends in drug abuse are currently estimated indirectly, mainly by large-scale social, medical, and crime statistics that may be biased or too generic. We thus tested a more direct approach based on 'field' evidence of cocaine use by the general population.

Screening the leaching tendency of pesticides applied in the Amu Darya Basin (Uzbekistan).

The Amu Darya River, one of the most important water resources for Uzbekistan and Turkmenistan, was declared a World Disaster Zone in 1991. The great increase in irrigation and the use of pesticides has led to both a lack of water and drinking water contamination. The aim of the present study, part of an EU project on water management guidelines, was to evaluate the leachability of 71 organic pesticides commonly employed in the area, and to assess compounds that could potentially contaminate the river and impair drinking water quality.

Effects of erythromycin, tetracycline and ibuprofen on the growth of Synechocystis sp. and Lemna minor.

Pharmaceutically active substances have recently been recognised as an emerging environmental problem. Human and veterinarian therapeutic agents can contaminate aquatic ecosystems via sewage discharges (human and animal excretion), improper disposal or industrial waste. Very little is known on the effects of pharmaceutical pollutants on aquatic photosynthetic organisms.

Methodological approaches for studying pharmaceuticals in the environment by comparing predicted and measured concentrations in River Po, Italy.

A predictive approach seems useful to study human and veterinary pharmaceuticals in the environment and provide an idea of overall levels of contamination, so as to restrict monitoring to those molecules which are most likely to represent possible environmental contaminants. Predicted environmental concentrations (PECs) can be calculated by a mass balance approach, while a recent proposal from the European Agency for the Evaluation of Medicinal Products (EMEA) suggests an alternative method for calculating PEC for each pharmaceutical and then focusing further work on molecules with high PEC values. We used the results of monitoring campaigns on the River Po, in Northern Italy, to assess the accuracy of predictive models with measured environmental concentrations (MECs).

Effects of saxitoxin (STX) and veratridine on bacterial Na+ -K+ fluxes: a prokaryote-based STX bioassay.

Saxitoxin (STX) is a potent natural sodium channel blocker and represents a significant health concern worldwide. We describe here the antagonistic effects of STX and veratridine (VTD), an Na+ channel activator, on three gram-negative bacteria and their application to an STX bioassay. STX reduced the total cellular levels of both Na+ and K+, as measured by flame photometry, whereas VTD increased the cellular concentrations relative to control ion fluxes in the cyanobacterium Cylindrospermopsis raciborskii AWT205.

Preliminary investigation on the environmental occurrence and effects of antibiotics used in aquaculture in Italy.

A preliminary investigation has been carried out on the occurrence and effects of antibiotics used in Italian aquaculture with the objective of identifying priorities for monitoring programmes. According to the information available on the most pertinent and diffuse fish diseases and their related therapies, the presence of flumequine and oxytetracycline in sediments sampled from two trout farms and three sea-bass farms and in their surrounding environments was selected for an analytical investigation. The concentrations of oxytetracycline and flumequine varied up to a maximum of 246.

Conifer needles as passive biomonitors of the spatial and temporal distribution of DDT from a point source.

Needles of two conifer species, Picea abies and Pinus nigra, were used as passive samplers for monitoring air contamination by sampling at increasing distances from a suspected point source of DDT. Needle concentrations declined with increasing distance downwind of the point source allowing to identify spatial and temporal trends of accumulation. This suggested that conifer needles are effective biomonitors of contamination levels in areas characterized by the presence of semi-volatile substances.

Long-term ecological assessment of West African rivers treated with insecticides: methodological considerations on quantitative analyses.

For the control of the aquatic stage of the blackfly vector of the onchocerciasis in West Africa, rivers had been partially sprayed weekly with insecticides from 1974 to 2002 on an area over 1 million km(2), as part of the onchocerciasis control programme (OCP). To evaluate the possible short- and long-term effects of insecticides on non-target fauna, an aquatic monitoring programme was set-up and carried on for over 20 years. A number of papers have been published concluding that biological variations found are ecologically acceptable.

Assessment of persistent and bioaccumulating chemicals in the aquatic environment.

In recent years several national and international organizations have initiated actions to control the use and release of persistent, bioaccumulative and toxic substances (PBTs). Consequently, a number of criteria have been proposed for the classification of these parameters. The scientific bases for PBTs assessment has grown a great deal over the last decades.

Environmental risk assessment of pesticides on aquatic life in Xiamen, China.

This paper describes the results of the environmental risk assessment of the pesticides used in agriculture in Xiamen, China. The goal was to assess the impact on water resources, particularly on fisheries and mariculture. Data on ecotoxicological properties of the pesticides and their physico-chemical profile were collected.