Browsing by Author "Cabecinha, Edna"
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- Antimicrobial resistance in aeromonads isolated from a tributary of River Douro (Portugal)Publication . Saavedra, Maria José; Fernandes, Conceição; Gomes, Sónia; Monteiro, Sandra Mariza; Cabecinha, Edna; Teixeira, Amílcar; Varandas, SimoneThe inappropriate use of antibiotics, one of the causes for high incidence of antimicrobial resistant bacteria isolated from aquatic environments, represents a danger for aquatic organisms and human health
- Antimicrobial susceptibility profiles of multidrug-resistant aeromonads isolated from Northern Portugal freshwater ecosystemPublication . Varandas, Simone; Fernandes, Conceição; Gomes, Sónia; Monteiro, Sandra Mariza; Cabecinha, Edna; Teixeira, Amílcar; Saavedra, Maria JoséThe inappropriate use of antibiotics, one of the causes of the high incidence of antimicrobial-resistant bacteria isolated from aquatic ecosystems, represents a risk for aquatic organisms and the welfare of humans. This study aimed to determine the antimicrobial resistance rates among riverine Aeromonas, taken as representative of autochthonous microbiota, to evaluate the level of antibacterial resistance in the Tua River (Douro basin). The prevalence and degree of antibiotic resistance were examined using motile aeromonads as a potential indicator of antimicrobial susceptibility for the aquatic environment. Water samples were collected from the middle sector of the river, which is impacted by several anthropogenic pressures. Water samples were plated on an Aeromonas-selective agar, with and without antibiotics. The activity of 19 antibiotics was studied against 30 isolates of Aeromonas spp. using the standard agar dilution susceptibility test. Antibiotic resistance rates were fosfomycin (FOS) 83.33%, nalidixic acid (NA) 60%, cefotaxime (CTX) 40%, gentamicin (CN) 26.67%, tobramycin (TOB) 26.67%, cotrimoxazole (SXT) 26.67%, chloramphenicol (C) 16.67%, and tetracycline (TE) 13.33%. Some of the nalidixic acid-resistant strains were susceptible to fluoroquinolones. Multiple resistance was also observed (83.33%). The environmental ubiquity, the natural susceptibility to antimicrobials and the zoonotic potential of Aeromonas spp. make them optimal candidates for studying antimicrobial resistance in aquatic ecosystems. Aquatic environments may provide an ideal setting for the acquisition and dissemination of antibiotic resistance because anthropogenic activities frequently impact them. The potential risk of multi- and pan-resistant bacteria transmission between animals and humans should be considered in a “One Health-One World” concept.
- Antimicrobial susceptibility profiles of multidrug-resistant aeromonads isolated from Northern Portugal freshwater ecosystem.Publication . Varandas, Simone; Fernandes, Conceição; Gomes, Sónia; Monteiro, Sandra Mariza; Cabecinha, Edna; Teixeira, Amílcar; Saavedra, Maria JoséExtensive use of water and anthropogenic activities contribute to water body pollution. Agricultural, urban, and animal waste, often characterized by numerous toxic and carcinogenic chemicals, pathogenic bacteria, and antibiotics, as well as antibiotic resistance genes (ARGs), loaded with microflora, can contaminate water and enter the food chain, posing a considerable danger to public health [1,2]. The inappropriate use of antibiotics, one of the causes of the high incidence of antimicrobial-resistant bacteria isolated from aquatic ecosystems, represents a risk for aquatic organisms and the welfare of humans. Infectious diseases, both human and animal, are closely related through the environment in the One World - One Medicine - One Health concept, in order to deal with the growing problem of antibiotic resistance. Aeromonas spp. can acquire antimicrobial resistance mechanisms, with the potential to spread via horizontal gene transfer, so they could be a good candidate as an indicator to follow antimicrobial resistance dissemination in water [3,4]. This study aimed to determine the antimicrobial resistance rates among riverine Aeromonas spp., taken as representative of the autochthonous microbiota, to evaluate the level of antibacterial resistance in the Tua River (Douro basin).
- Emergence, Spread of Antimicrobial-Resistant Bacteria and Phylogenetic Relationships in Coastal Ecosystems—Gastropod Phorcus lineatus as a BioindicatorPublication . Santos, Dércia; Pinto, Ana Rita; Barata, Rita; Fernandes, Conceição; Guedes, Hugo; Almeida, Gonçalo; Cabecinha, Edna; Monteiro, Sandra M.; Varandas, Simone; Saavedra, Maria JoséCoastal environments have been recognized as key reservoirs for antibiotic-resistant bacteria. The present study evaluated marine gastropods, Phorcus lineatus, as potential bioindicators to assess the spread of antibiotic-resistant bacteria. P. lineatus was sampled in four sites, with different anthropogenic pressures, along the northwest Portuguese coastal area. From these specimens, bacteria were isolated and tested for their antimicrobial susceptibility, followed by their phylogenetic and pathotypic determination. All the Escherichia coli isolates showed resistance to at least one antimicrobial agent. The highest levels of multidrug resistance (25%) were observed in E. coli isolates obtained from SITE 2, which is impacted by the city of Porto and industrial settlements, while nearly 17% of these isolates showed a multiple antibiotic resistance (MAR) index higher than 0.2. Among the isolates, phylogroups A and B2 were the most prevalent, followed by phylogroup B1. The isolates of phylogroup A showed a higher prevalence of antimicrobial resistance. This study offers valuable insights into the antibiotic resistance risks posed to marine ecosystems and underscores the need for microbiological monitoring and the development of effective management strategies. The findings suggest P. lineatus as a potential bioindicator of antibiotic-resistant bacteria in marine environments.
- Escherichia coli phylogenetic and antimicrobial pattern as an indicator of anthropogenic impact on threatened freshwater musselsPublication . Varandas, Simone; Fernandes, Conceição; Cabecinha, Edna; Gomes, Sónia; Silva, Gabriela Jorge da; Saavedra, Maria JoséFreshwater bivalves are widely used as accumulation indicators and monitoring tools for assessing contaminant effects on different levels of biological integration. This pilot study aimed to explore the phylogenetic diversity of Escherichia coli isolated from freshwater mussels (Margaritifera margaritifera and Potomida littoralis) and characterize their phenotypes and antibiotic resistance profiles. Samples were collected in the Rabaçal and Tua Rivers, in the Douro basin, Portugal—two sites representing different levels of anthropogenic contamination. Antimicrobial susceptibility testing was performed via the disk diffusion method with 21 antibiotics. Results showed that 31% of isolates were multidrug-resistant (MDR). Thus, freshwater mussels provide an effective and time-integrated approach for identifying/quantifying fecal indicators, including MDR bacteria. PCR-based assays were designed for assessing phylogenetic E. coli groups. Among the E. coli isolates, the highest prevalence (44%) was observed in group D or E, followed by group E or Clade I (25%), group A (19%), and group B1 (13%). E. coli isolated from M. margaritifera predominantly exhibited a higher prevalence of phylogroups D or E, whereas E. coli from P. littoralis showed associations with phylogroups E or clade I, B1, A, and D or E. Our results provide new insights into the phylogenetic diversity of E. coli in freshwater bivalves. Additionally, the findings highlight the possible linkage of phylogroups with the host species, the geographical location in the water stream, and human activity. Using E. coli as a bioindicator isolated from freshwater mussels helps us grasp how human activities affect the environment. This study has important implications for those interested in safeguarding water resources, especially in tackling antibiotic resistance in aquatic ecosystems.
- Multidrug-Resistant Escherichia coli Accumulated by Freshwater Bivalves: An Underestimated Risk for Public Health?Publication . Martins, Joana; Gonçalves, Ana; Fernandes, Conceição; Cabecinha, Edna; Monteiro, Sandra Mariza; Guedes, Hugo; Almeida, Gonçalo; Garcia, Juliana; Silva, Gabriela Jorge da; Varandas, Simone; Saavedra, Maria JoséAs bioindicators, freshwater bivalves are crucial for the assessment of the contamination impact on different levels of biological integration. Escherichia coli is used as a bioindicator of water fecal contamination, representing a critical global concern, especially with the rise of multidrugresistant (MDR) strains. Phylogenetic diversity, pathotypic characterization, and antibiotic resistance profiles of E. coli isolated from freshwater bivalves (Anodonta anatina) were assessed. Samples were collected from the Tua River in Northern Portugal, from two different sites, Chelas and Barcel, representing different degrees of contamination. Antimicrobial susceptibility testing was performed by the disk diffusion method, and characterizations of the phylogenetic groups and pathotypes were assessed by PCR-multiplex and real-time PCR-multiplex, respectively. Results showed that 60% of isolates were characterized as MDR, including resistance to carbapenems, considered the last resort against multidrug-resistant bacteria. Within this study, it was also possible to verify the antimicrobial resistance (AMR) profile differences between the two sampling sites, with bivalve isolates from the Chelas site showing a higher percentage of antibiotic resistance. Among the E. coli isolates, the highest prevalence (55%) was observed in group B1, followed by group D or E (15%), group A (10%), and group E or Clade I (10%). None of the isolates were classified as diarrheagenic E. coli (DEC). This work highlights the potential transmission of antimicrobial-resistant bacteria through bivalves in the food chain. The ‘One Health’ approach is crucial for combating antimicrobial resistance, namely in edible freshwater species, emphasizing active surveillance to protect human, animal, and environmental health against the spread of antibiotic-resistant bacteria in aquatic environments.
- The role of aquatic ecosystems (River Tua, Portugal) as reservoirs of multidrug-resistant Aeromonas spp.Publication . Gomes, Sónia; Fernandes, Conceição; Monteiro, Sandra Mariza; Cabecinha, Edna; Teixeira, Amílcar; Varandas, Simone; Saavedra, Maria JoséThe inappropriate use of antibiotics, one of the causes of the high incidence of antimicrobialresistant bacteria isolated from aquatic ecosystems, represents a risk for aquatic organisms and the welfare of humans. This study aimed to determine the antimicrobial resistance rates among riverine Aeromonas spp., taken as representative of the autochthonous microbiota, to evaluate the level of antibacterial resistance in the Tua River (Douro basin). The prevalence and degree of antibiotic resistance was examined using motile aeromonads as a potential indicator of antimicrobial susceptibility for the aquatic environment. Water samples were collected from the middle sector of the river, which is most impacted area by several anthropogenic pressures. Water samples were plated on an Aeromonas-selective agar, with and without antibiotics. The activity of 19 antibiotics was studied against 30 isolates of Aeromonas spp. using the standard agar dilution susceptibility test. Antibiotic resistance rates were fosfomycin (FOS) 83.33%, nalidixic acid (NA) 60%, cefotaxime (CTX) 40%, gentamicin (CN) 26.67%, tobramycin (TOB) 26.67%, cotrimoxazole (SXT) 26.67%, chloramphenicol (C) 16.67%, and tetracycline (TE) 13.33%. Some of the nalidixic acid-resistant strains were susceptible to fluoroquinolones. Multiple resistance was also observed (83.33%). The environmental ubiquity, the natural susceptibility to antimicrobials and the zoonotic potential of Aeromonas spp. make them optimal candidates for studying antimicrobial resistance (AMR) in aquatic ecosystems. Aquatic environments may provide an ideal setting for the acquisition and dissemination of antibiotic resistance because anthropogenic activities frequently impact them. The potential risk of multi- and pan-resistant bacteria transmission between animals and humans should be considered in a “One Health-One World” concept.