Percorrer por autor "Dapkevicius, Maria de Lurdes Enes"
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- Assessment of Antibiotic Resistance Among Isolates of Klebsiella spp. and Raoultella spp. in Wildlife and Their Environment from Portugal: A Positive Epidemiologic OutcomePublication . Sabença, Carolina; de la Rivière, Rani; Barros, Paulo; Cabral, João Alexandre; Sargo, Roberto; Sousa, Luís; Dapkevicius, Maria de Lurdes Enes; Silva, Filipe; Lopes, Filipa; Abrantes, Ana Carolina; Vieira-Pinto, Madalena; Caniça, Manuela; Igrejas, Gilberto; Torres, Carmen; Poeta, PatríciaOne of the significant challenges facing modern medicine is the rising rate of antibiotic resistance, which impacts public health, animal health, and environmental preservation. Evaluating antibiotic resistance in wildlife and their environments is crucial, as it offers essential insights into the dynamics of resistance patterns and promotes strategies for monitoring, prevention, and intervention. and genera isolates were recovered from fecal samples of wild animals and environmental samples using media without antibiotic supplementation. Antibiograms were performed for 15 antibiotics to determine the phenotypic resistance profile in these isolates. Extended-spectrum β-lactamase (ESBL) production was tested by the double-disc synergy test, and one ESBL-producing isolate was screened by PCR and whole-genome sequencing. Biofilm production was analyzed using the microtiter plate method. A total of 23 spp. and 3 spp. isolates were obtained from 312 fecal samples from wild animals, 9 spp. and 4 spp. isolates were obtained from 18 river and stream water samples, and 4 spp. and 3 spp. isolates from 48 soil samples. Regarding antibiotic resistance, only one isolate of from soil samples was an ESBL-producer and showed resistance to six antibiotics. This isolate harbored multiple β-lactams genes (, , , and ), as well as genes of resistance to quinolones, sulfonamides, tetracycline, aminoglycosides, and chloramphenicol, and belonged to the lineage ST307. Most of the spp. and spp. isolates were biofilm producers (except for one isolate), and 45.6% were weak biofilm producers, with the remaining being moderate to strong biofilm producers. We can conclude that antibiotic resistance is not widespread in these environment-associated isolates, which is a positive epidemiological outcome. However, identifying a single ESBL- isolate should serve as a warning of potential hotspots of resistance emergence.
- Escherichia coli as Commensal and Pathogenic Bacteria among Food-Producing Animals: Health Implications of Extended Spectrum β-Lactamase (ESBL) ProductionPublication . Ramos, Sónia; Silva, Vanessa; Dapkevicius, Maria de Lurdes Enes; Caniça, Manuela; Tejedor-Junco, María Teresa; Igrejas, Gilberto; Poeta, PatríciaEscherichia coli are facultative, anaerobic Gram-negative rods with many facets. Within resistant bacterial populations, they play an important ecological role and can be used as a bioindicator of antimicrobial resistance. All animal species used for food production, as well as humans, carry E. coli in their intestinal tracts; plus, the genetic flexibility and adaptability of this bacteria to constantly changing environments allows it to acquire a great number of antimicrobial resistance mechanisms. Thus, the prevalence of antimicrobial resistance in these commensal bacteria (or others, such as enterococci) can be a good indicator for the selective pressure caused by the use of antimicrobial agents, providing an early warning of the emergence of antimicrobial resistance in pathogens. As many as 90% of E. coli strains are commensals inhabiting the intestinal tracts of humans and warm-blooded animals. As a commensal, it lives in a mutually beneficial association with its hosts and rarely causes diseases. However, E. coli also remains as one of the most frequent causes of several common bacterial infections in humans and animals. In humans, it is the prominent cause of enteritis, community- and hospital-acquired urinary tract infection (UTI), septicemia, postsurgical peritonitis, and other clinical infections, such as neonatal meningitis, while, in farm animals, it is more prominently associated with diarrhea. On a global scale, E. coli can be considered the most important human pathogen, causing severe infection along with other major bacterial foodborne agents, such as Salmonella spp. and Campylobacter. Thus, the importance of resistance in E. coli, typically considered a benign commensal, should not be underestimated.
- Unveiling Antibiotic Resistance, Clonal Diversity, and Biofilm Formation in Isolated from Healthy Swine in PortugalPublication . Silva, Adriana; Silva, Vanessa; Dapkevicius, Maria de Lurdes Enes; Azevedo, Mónica; Cordeiro, Rui; Pereira, José Eduardo; Valentão, Patrícia; Falco, Virgílio; Igrejas, Gilberto; Caniça, Manuela; Poeta, PatríciaEscherichia coli, a commensal microorganism found in the gastrointestinal tract of human and animal hosts, plays a central role in agriculture and public health. Global demand for animal products has promoted increased pig farming, leading to growing concerns about the prevalence of antibiotic-resistant E. coli strains in swine populations. It should be noted that a significant portion of antibiotics deployed in swine management belong to the critically important antibiotics (CIA) class, which should be reserved for human therapeutic applications. This study aimed to characterize the prevalence of antibiotic resistance, genetic diversity, virulence characteristics, and biofilm formation of E. coli strains in healthy pigs from various farms across central Portugal. Our study revealed high levels of antibiotic resistance, with resistance to tetracycline, ampicillin, tobramycin, and trimethoprim-sulfamethoxazole. Multidrug resistance is widespread, with some strains resistant to seven different antibiotics. The ampC gene, responsible for broad-spectrum resistance to cephalosporins and ampicillin, was widespread, as were genes associated with resistance to sulfonamide and beta-lactam antibiotics. The presence of high-risk clones, such as ST10, ST101, and ST48, are a concern due to their increased virulence and multidrug resistance profiles. Regarding biofilm formation, it was observed that biofilm-forming capacity varied significantly across different compartments within pig farming environments. In conclusion, our study highlights the urgent need for surveillance and implementation of antibiotic management measures in the swine sector. These measures are essential to protect public health, ensure animal welfare, and support the swine industry in the face of the growing global demand for animal products.