Identification of CTX-M-15 and CTX-M-27 in Antibiotic-Resistant Gram-Negative Bacteria Isolated from Three Rivers Running in Central Italy.

The main goal of this study was to identify Gram-negative bacteria resistant to antibiotics, in particular ß-lactams, in stream waters and effluents from urban wastewater treatment plants draining into Fino, Tavo, and Saline rivers of the Abruzzo region, Italy. Eight sampling sites were selected because they were the most contaminated by coliforms during previous sampling campaign. One sample for each site was collected for the detection of total and fecal coliforms, Escherichia coli and Enterococcus species by Colilert-18 and Enterolert-E Quanti-Tray/2000. Antibiotic-resistant bacteria, selected on ampicillin and cefotaxime-supplemented agar plates, were identified by EnteroPluri test systems and then confirmed by MALDI-TOF. The resistant determinants were identified and characterized by PCR and sequencing. The microbiological analysis allowed to detect E. coli, total coliforms, fecal coliforms, and enterococci with a coefficient of variation of 215.7%, 212.8%, 242.5%, and 188.5%, respectively. Several Gram-negative bacteria were identified: Serratia liquefaciens, E. coli, Enterobacter cloacae, Citrobacter freundii, Raoultella ornithinolytica, Acinetobacter johnsonii, Aeromonas veronii, Aeromonas hydrophila, and Pseudomonas koreensis. All strains possessed class 1 integrons, insertion sequences, and genes encoding for serin- and metallo-ß-lactamases. Extended-spectrum ß-lactamases, such as CTX-M-15 and CTX-M-27, were found in Enterobacteriaceae, whereas CphA metallo-ß-lactamase was found in A. veronii and A. hydrophila. The main resistance's mechanism to ß-lactams observed among the analyzed strains is represented by the production of serin ß-lactamases (CTX-M-15, CTX-M-27, and SHV-1) and metallo ß-lactamase (CphA).

Phthalates, heavy metals and PAHs in an overpopulated coastal region: Inferences from Abruzzo, central Italy.

Phthalates are an emerging class of environmental pollutants whose distribution and effects in aquatic environments are not well characterized. We analyzed intertidal and emerged beach sediments from the Abruzzo coastline, along the Adriatic Sea, finding significant phthalate concentrations in marine sediments. Phthalate baseline levels in the intertidal environment, marked by substantial interplay of sediment, water and air, were determined. We used statistical rank methods to select representative phthalate compositions, for which we derived risk levels for ingestion, dermal absorption and inhalation. Our study shows that phthalates are a major cause of pollution along the Abruzzo coast, with river transport of sediments a continuous source of replenishment. Phthalate concentrations in two specific sites were determined to be of the same order of magnitude as the safety, remediation-warranting, threshold set by Italian law. Phthalates, heavy metals, PAHs appear to be correlated. We discuss possible intervention and mitigation strategies.