River water analysis using a multiparametric approach: Portuguese river as a case study Ana Barbosa-Vasconcelos, Ângelo Mendes, Flávia Martins, Elisabete Lopes, Ana Machado, Adriano A. Bordalo, Paulo Vaz-Pires, Natividade Vieira, Paulo Martins da Costa and Lucinda J. Bessa ABSTRACT The Ave River in northern Portugal has a history of riverbanks and water quality degradation. The river water quality was assessed by physicochemical, biological (macroinvertebrates) and microbiological (Enterococcus spp. and Escherichia coli) parameters in six locations (A–F, point A being the nearest to the source) throughout its course during a year. Epilithic biofilms were studied through polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). Antimicrobial susceptibility testing helped with selecting isolates (n ¼ 149 E. coli and n ¼ 86 enterococci) for further genetic characterization. Pursuant to physicochemical and macroinvertebrates-based parameters, the river water was of reasonable quality according to European legislation (Directive 2000/60/EC). However, the microbiological analysis showed increased fecal contamination downstream from point C. At point D, four carbapenem-resistant E. coli isolates were recovered. Paradoxically, point D was classified as a point of ‘Good Water Quality’ according to macroinvertebrates results. Point F presented the highest contamination level and incidence of multidrug-resistant (MDR) isolates in the water column (13 MDR enterococci out of 39 and 33 MDR E. coli out of 97). Epilithic biofilms showed higher diversity in pristine points (A and B). Thus, biological and microbiological parameters used to assess the water quality led to divergent results; an outcome that reinforces the need for a holistic evaluation. Ana Barbosa-Vasconcelos Ângelo Mendes Elisabete Lopes Paulo Vaz-Pires Paulo Martins da Costa Lucinda J. Bessa (corresponding author) Department of Aquatic Production, Abel Salazar Institute for the Biomedical Sciences (ICBAS), University of Porto, 4050-313 Porto, Portugal E-mail: lucinda.bessa@fc.up.pt Ana Barbosa-Vasconcelos Flávia Martins Natividade Vieira Department of Biology, Faculty of Sciences, University of Porto, 4169-007 Porto, Portugal Ana Machado Adriano A. Bordalo Laboratory of Hydrobiology and Ecology, ICBAS, University of Porto, 4050-313 Porto, Portugal Adriano A. Bordalo Paulo Vaz-Pires Natividade Vieira Paulo Martins da Costa Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Matosinhos, Portugal Lucinda J. Bessa LAQV, Requimte, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, 4169-007 Porto, Portugal Key words | Enterococcus spp., epilithic biofilms, Escherichia coli, macroinvertebrates, multidrug-resistant isolates, river water INTRODUCTION The assessment of water quality is an essential measure within environmental monitoring. When water quality is poor, it affects not only the aquatic life but also the surrounding ecosys- tems. Rivers are unquestionably important parts of the hydrological cycle, mainly because they are fluxes of water and not reservoirs of water. Rivers, along with water, drag off sediments and other suspended materials (biotic and abiotic) that ultimately will reach all the other aquatic environments (Davies-Colley ). In 2000, the European Parliament and the Council of the European Union approved the Direc- tive 2000/60/EC (http://eur-lex.europa.eu/legal-content/EN/ TXT/PDF/?uri=CELEX:02,000L0060-20141120&qid=1506 068744209&from=EN), which provided the guidelines to be followed by all member states in order to improve the 991 © IWA Publishing 2018 Journal of Water and Health | 16.6 | 2018 doi: 10.2166/wh.2018.047 Downloaded from https://iwaponline.com/jwh/article-pdf/16/6/991/511640/jwh0160991.pdf by guest on 05 June 2020