Browsing by Author "Monteiro, Sandra Mariza"
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- Alterações morfológicas da brânquia de Mugil causadas pela exposição de metais pesados na lagoa de Esmoriz-Paramos, PortugalPublication . Fernandes, Conceição; Fontaínhas-Fernandes, A.; Monteiro, Sandra Mariza; Salgado, Maria Antónia
- 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).
- Bioaccumulation of metals by Mugil saliens under chronic exposure to contamined sediments: Gill histopathological changesPublication . Fernandes, Conceição; Monteiro, Sandra Mariza; Fontaínhas-Fernandes, A.; Salgado, Maria AntóniaThe Esmoriz/Paramos coastal lagoon, is a habitat of ecological importance due to the presence of unique animal and plant species. During the past few years its immersed area has been gradually reduced due to effluent discharges and siltation. The major contaminants in the lagoon are derived from a multitude of nonpoint sources associated with urbanization and industrial activities within the watershed. Heavy metals are probably a class of pollutants contributing to the observed decline of fish species. The metal content in the water and sediments in the lagoon were investigated as well as gill metal bioaccumulation and gill histopathological changes of the grey leaping mullet, Mugil saliens.
- Changes in plasma electrolytes and gill histopathology in wild Liza saliens from the Esmoriz-Paramos coastal lagoon, PortugalPublication . Fernandes, Conceição; Fontaínhas-Fernandes, A.; Monteiro, Sandra Mariza; Salgado, Maria AntóniaThe Esmoriz-Paramos is a lagoon of great ecological significance located on the Northwest coast of Portugal. The quality of water and sediment within this ecosystem has been gradually degraded due to the discharges of mostly untreated industrial waste and domestic sewage. Contaminants include heavy metals that can be taken up by fish from water, food, sediments, and suspended particulate material. Fish inhabiting polluted water bodies tend to accumulate many chemicals in high concentrations, even when the environmental contamination levels are low (Colombo et al. 1995). The leaping grey mullet (Liza saliens) is one of a few dominant species living in this environment. This species may contact xenobiotics in the water column or, when feeding, in the sediments.
- Histopathological gill changes in wild leaping grey mullet (Liza saliens) from the Esmoriz-Paramos coastal lagoon, PortugalPublication . Fernandes, Conceição; Fontaínhas-Fernandes, A.; Monteiro, Sandra Mariza; Salgado, Maria AntóniaThe histopathological changes are among the most recognized responses to environmental stressors, namely heavy metals. Liza saliens were sampled, in the Portuguese Esmoriz-Paramos coastal lagoon to assess their gill histopathological response to Cu and Zn contaminated sediments. A lesion prevalence index, severity, and extension scores of each lesion, as well as an assessment value (severity extension), were determined to evaluate the effect of environmental heavy metal exposure. The main histopathological changes observed were aneurisms, hyperplasia, lifting, and vasodilation. A high prevalence for each lesion (65–85%) was found, in addition to a high number of simultaneous lesions. Vasodilation and hyperplasia were the lesions that showed higher prevalence indexes. Lifting, followed by hyperplasia, were the lesions with highest assessment value. The prevalence of the number of the lesions found in L. saliens collected from the Esmoriz-Paramos lagoon was high when compared with mullet caught in the sea. A previous work revealed that fish collected in the lagoon showed elevated Cu and Zn levels in their gills, in a positive correlation with age. However, no positive correlation was observed between assessment value and gill metal levels.
- 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.