Browsing by Author "Teixeira, A. Margarida"
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- Antibiotic resistance and organic micropollutants monitoring in municipal full-scale constructed wetlands systemsPublication . Teixeira, A. Margarida; Matos, Diana; Halwatura, Lahiruni M.; Aga, Diana S.; Vaz-Moreira, Ivone; Castro, Paula M. L.; Manaia, Célia M.
- Bacteriological safety and quality of composted products from animal, urban or sewage sludge wastesPublication . Vaz-Moreira, Ivone; D’Arnese, Angelo; Knoll, Maurice; Teixeira, A. Margarida; Barbosa, Joana Bastos; Teixeira, Paula; Manaia, Célia M.Abstract: This study investigated the presence of culturable bacterial pathogens, and antibiotic resistance and associated genes (quantitative PCR) in commercially available composted products from animal excrements or manure (n=7), urban wastes (n=1) or (sewage sludge) (n=1). Metals quantification and 16S rRNA-based bacterial community composition analyses supported the results to infer potential risks to downstream environments (e.g., soils). Bacilli and Actinomycetes were the dominant bacterial classes in seven composts, while two were dominated by different classes of Pseudomonadota or the class Bacteroidia. Salmonella spp. was not detected in all composts, meeting recommended quality criteria, while Escherichia coli and Listeria monocytogenes were only detected in the sewage sludge compost. The antibiotic resistance genes ermB and ermF were detected in most of the composts, and the antibiotic resistance gene sul1 and the intI1 gene (proxy for antibiotic resistance recombination) in all composts in the range of 6-9 log gene copy number/g dry weight. Listeria spp. and the gene blaCTX-M were detected only in chicken/poultry composts suggesting increased risk. All composts, except the urban waste compost, presented at least one metal (zinc, copper, and/or cadmium) above the recommended value. The genes uidA, crAssphage, ermB and blaCTX-M were negatively correlated with the abundance of total heterotrophs and moisture content, and the genes intI1 and sul1 were negatively correlated with the concentration of the metals Cr, Ni and Pb. Overall, the urban waste compost presented the best quality, exhibiting the lowest antibiotic resistance load. These findings alert for the fact that composts may contribute to the dissemination of antibiotic resistance, highlighting the need of regular assessment. It is suggested that multiple factors, including the raw materials, may influence the safety of the final compost, and the knowledge of the variables affecting compost safety need to be thoroughly investigated and understood.
- Biomarkers for monitoring antibiotic resistance in aquatic environmentsPublication . Teixeira, A. Margarida; Vaz-Moreira, Ivone; Franco, David Calderón; Weissbrodt, David; Purkrtova, Sabina; Gajdos, Stanislav; Dottorini, Giulia; Nielsen, Per Halkjær; Khalifa, Leron; Cytryn, Eddie; Bartacek, Jan; Manaia, Célia M.
- Candidate biomarkers of antibiotic resistance for the monitoring of wastewater and the downstream environmentPublication . Teixeira, A. Margarida; Vaz-Moreira, Ivone; Calderón-Franco, David; Weissbrodt, David; Purkrtova, Sabina; Gajdos, Stanislav; Dottorini, Giulia; Nielsen, Per Halkjær; Khalifa, Leron; Cytryn, Eddie; Bartacek, Jan; Manaia, Célia M.Urban wastewater treatment plants (UWTPs) are essential for reducing the pollutants load and protecting water bodies. However, wastewater catchment areas and UWTPs emit continuously antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs), with recognized impacts on the downstream environments. Recently, the European Commission recommended to monitor antibiotic resistance in UWTPs serving more than 100 000 population equivalents. Antibiotic resistance monitoring in environmental samples can be challenging. The expected complexity of these systems can jeopardize the interpretation capacity regarding, for instance, wastewater treatment efficiency, impacts of environmental contamination, or risks due to human exposure. Simplified monitoring frameworks will be essential for the successful implementation of analytical procedures, data analysis, and data sharing. This study aimed to test a set of biomarkers representative of ARG contamination, selected based on their frequent human association and, simultaneously, rare presence in pristine environments. In addition to the 16S rRNA gene, ten potential biomarkers (intI1, sul1, ermB, ermF, aph(3′’)-Ib, qacEΔ1, uidA, mefC, tetX, and crAssphage) were monitored in DNA extracts (n = 116) from raw wastewater, activated sludge, treated wastewater, and surface water (upstream and downstream of UWTPs) samples collected in the Czech Republic, Denmark, Israel, the Netherlands, and Portugal. Each biomarker was sensitive enough to measure decreases (on average by up to 2.5 log-units gene copy/mL) from raw wastewater to surface water, with variations in the same order of magnitude as for the 16S rRNA gene. The use of the 10 biomarkers allowed the typing of water samples whose origin or quality could be predicted in a blind test. The results show that, based on appropriate biomarkers, qPCR can be used for a cost-effective and technically accessible approach to monitoring wastewater and the downstream environment.
- Dynamics and interrelationships between antibiotic resistance, organic micropollutants and bacterial communities in full-scale rural constructed wetlandsPublication . Teixeira, A. Margarida; Matos, Diana; Coelho, Norberta; Halwatura, Lahiruni M.; Vaz-Moreira, Ivone; Castro, Paula M. L.; Aga, Diana S.; Manaia, Célia M.Constructed wetlands systems (CWs) are increasingly regarded as promising alternatives or complements to conventional wastewater treatment processes. However, the fate of chemical and biological contaminants in realworld treatment processes is understudied in this type of systems. This study aimed to fill this gap by evaluating the response of three horizontal subsurface flow CWs, in Northern Portugal, planted with Phragmites australis, in operation for >7 years, to reducing the load of fecal contamination, antibiotic resistance genes and organic micropollutants (OMPs). Influent, effluent and sediments samples (n = 36) were examined for abundance of cultivable Escherichia coli and total coliforms, total bacteria (16S rRNA gene), 10 genetic biomarkers associated with anthropogenic contamination (uidA, crAssphage, intI1, sul1, ermB, ermF, mefC, qacEΔ1, tetX and aph(3″)-Ib) by quantitative PCR, non-target LC-MS of OMPs and 16S rRNA gene-based bacterial community analysis. The three CWs showed reduction values (log-units/mL) up to 4.8 of E. coli and 3.6 of biomarkers, with the highest values observed in warmer periods. No evidence of for the accumulation microbiological contaminants in the sediments was observed. Among the 59 OMPs detected, reduction rates varied, and the concentration of the most abundant pharmaceutical compounds in the final effluent varied –reaching ng/L concentrations of ~36 000 for fenofibric acid, ~14 000 for acetaminophen, ~3000 for oxazepam and ~2000 for irbesartan, which can be considered high to discharge in the receiving environment. The bacterial community was dominated by members of the class Gammaproteobacteria, with treatment contributing to significant reduction of the relative abundance of members of the classes Clostridia, Bacilli and Actinomycetes. Compared with wastewater, sediments had significantly higher relative abundance of Alphaproteobacteria. The study confirms that CWs are an adequate alternative for the treatment of domestic wastewater in small communities, although it warns of the need for regular monitoring and adjustment of treatment conditions, especially during cooler periods.
- Monitoring antibiotic resistance in aquatic environmentsPublication . Teixeira, A. Margarida; Cachetas, Diogo; Vaz-Moreira, Ivone; Rocha, Jaqueline; Franco, David Calderón; Weissbrodt, David; Purkrtova, Sabina; Gajdos, Stanislav; Dottorini, Giulia; Nielsen, Per Halkjær; Khalifa, Leron; Cytryn, Eddie; Manaia, Célia M.
- Resistência a antibióticos e micropoluentes orgânicos em três sistemas de zona húmida construída implementados na região Norte de PortugalPublication . Teixeira, A. Margarida; Matos, Diana; Halwatura, Lahiruni M.; Vaz-Moreira, Ivone; Castro, Paula M. L.; Aga, Diana S.; Manaia, Célia M.As zonas húmidas construídas, também conhecidas como fito-estações de tratamento de águas residuais (fito-ETAR), têm vindo a ser consideradas promissoras alternativas ou complementos para os processos convencionais de tratamento de águas residuais. A relação custo-benefício e a integração na paisagem natural, com a criação de habitats para a vida selvagem, são vantagens importantes destas soluções naturais. Este estudo envolveu três fito-ETAR, localizadas num raio de 20 km, que operam com fluxo horizontal e leito de macrófitas (Phragmites australis) para tratar efluentes de comunidades com menos 400 habitantes. O principal objetivo foi o de avaliar a capacidade para reduzir a carga de contaminação fecal, genes de resistência a antibióticos e micropoluentes orgânicos nos efluentes e avaliar a possível acumulação de genes de resistência nos sedimentos, enquadrados pela observância dos valores recomendados para parâmetros padrão (ex: CBO, CQO, SST, N, P). As amostras (afluente, efluente e sedimentos, n=36) foram colhidas nos meses de março, maio, julho e outubro do ano de 2023 e foram examinadas quanto à abundância de Escherichia coli e coliformes totais, 10 biomarcadores associados à contaminação antropogénica (contaminação fecal: uidA, crAssphage; recombinação genética de genes adquiridos: intI1 e resistência: sul1, ermB, ermF, mefC, qacEΔ1, tetX e aph(3’’)-Ib) a e de bactérias totais: gene rRNA 16S, por PCR quantitativo, micropoluentes (LC-HRMS) e análise da comunidades bacterianas com base na sequenciação do gene rRNA 16S. A redução da contaminação fecal (em unidades logarítmicas de UFC ou número de cópias de genes/volume de amostra) variou entre 0,8 e 4,8 para coliformes totais e E. coli e entre -0,1 e 3,6 para os biomarcadores genéticos. A prevalência de genes foi significativamente inferior em sedimentos do que em afluente e efluente sugerindo que não há acumulação de resistência nos sedimentos. Os 59 micropoluentes detetados apresentaram taxas de remoção variáveis, com o paracetamol, ácido fenofíbrico, irbesartan e oxazepam persistindo após o tratamento. Afluente, efluente e sedimentos apresentaram comunidade bacterianas distintas e variáveis ao longo do ano, com os efluentes a denotarem persistência de Arcobacteraceae em março e acentuado aumento de Rhodocyclaceae e Sulfurimonadaceae em julho. Apesar de tais variações, as três fito-ETAR apresentaram eficácia semelhante, sendo que temperaturas mais elevadas e o crescimento das macrófitas pareceram favorecer a remoção de contaminantes microbiológicos. O estudo confirma que as fito-ETAR podem ser boas alternativas para o tratamento descentralizado de efluentes domésticos.