Browsing by Author "Ferreira, Catarina"
Now showing 1 - 10 of 19
Results Per Page
Sort Options
- Carbapenem-resistant klebsiella pneumoniae clinical isolates harbouring similar conjugative plasmidsPublication . Ferreira, Catarina; Brito, Margarida; Lameiras, Catarina; Frykholm, Karolin; Saga, Pohjanen; Bikarolla, Santosh K.; Westerlund, Fredrik; Nunes, Olga C.; Manaia, Célia M.
- Characterization of oral enterobacteriaceae prevalence and resistance profile in chronic kidney disease patients undergoing peritoneal dialysisPublication . Costa, Carolina F. F. A.; Merino-Ribas, Ana; Ferreira, Catarina; Campos, Carla; Silva, Nádia; Pereira, Luciano; Garcia, Andreia; Azevedo, Álvaro; Mesquita, Raquel B. R.; Rangel, António O. S. S.; Manaia, Célia M.; Sampaio-Maia, BeneditaChronic Kidney Disease (CKD) is a growing public-health concern worldwide. Patients exhibit compromised immunity and are more prone to infection than other populations. Therefore, oral colonization by clinically relevant members of the Enterobacteriaceae family, major agents of both nosocomial and dialysis-associated infections with frequent prevalence of antibiotic resistances, may constitute a serious risk. Thus, this study aimed to assess the occurrence of clinically relevant enterobacteria and their antibiotic resistance profiles in the oral cavity of CKD patients undergoing peritoneal dialysis (CKD-PD) and compare it to healthy controls. Saliva samples from all the participants were cultured on MacConkey Agar and evaluated regarding the levels of urea, ammonia, and pH. Bacterial isolates were identified and characterized for antibiotic resistance phenotype and genotype. The results showed that CKD-PD patients exhibited significantly higher salivary pH, urea, and ammonia levels than controls, that was accompanied by higher prevalence and diversity of oral enterobacteria. Out of all the species isolated, only the prevalence of Raoultella ornithinolytica varied significantly between groups, colonizing the oral cavity of approximately 30% of CKD-PD patients while absent from controls. Antibiotic resistance phenotyping revealed mostly putative intrinsic resistance phenotypes (to amoxicillin, ticarcillin, and cephalothin), and resistance to sulfamethoxazole (~43% of isolates) and streptomycin (~17%). However, all isolates were resistant to at least one of the antibiotics tested and multidrug resistance isolates were only found in CKD-PD group (31,6%). Mobile genetic elements and resistance genes were detected in isolates of the species Raoultella ornithinolytica, Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, and Enterobacter asburiae, mostly originated from CKD-PD patients. PD-related infection history revealed that Enterobacteriaceae were responsible for ~8% of peritonitis and ~ 16% of exit-site infections episodes in CKD-PD patients, although no association was found to oral enterobacteria colonization at the time of sampling. The results suggest that the CKD-induced alterations of the oral milieu might promote a dysbiosis of the commensal oral microbiome, namely the proliferation of clinically relevant Enterobacteriaceae potentially harboring acquired antibiotic resistance genes. This study highlights the importance of the oral cavity as a reservoir for pathobionts and antibiotic resistances in CKD patients undergoing peritoneal dialysis.
- Cuidados de enfermagem de proximidade: estudo de casoPublication . Costa, Tânia; Almeida, Armando; Bastos, Vera; Silva, Simão; Ferreira, Catarina
- Development and validation of novel PCR primers for identification of plasmid-mediated colistin resistance (mcr) genes in various environmental settingsPublication . Gorecki, Adrian; Musialowski, Marcin; Wolacewicz, Mikolaj; Decewicz, Przemyslaw; Ferreira, Catarina; Vejmelkova, Dana; Grzesiuk, Malgorzata; Manaia, Célia M.; Bartacek, Jan; Dziewit, LukaszAntibiotic resistance is considered one of the biggest threats to public health and has become a major concern for governments and international organizations. Combating this problem starts with improving global surveillance of antibiotic resistance genes (ARGs) and applying standardized protocols, both in a clinical and environmental context, in agreement with the One Health approach. Exceptional efforts should be directed to controlling ARGs conferring resistance to Critically Important Antimicrobials (CIA). In this study, a systematic literature review to synthesize data on the identification of mcr genes using a PCR technique was performed. Additionally, a novel set of PCR primers for mcr-1 – mcr-9 genes detection was proposed. The developed primers were in silico and experimentally validated by comparison with mcr-specific PCR primers reported in the literature. This validation, besides being a proof-of-concept for primers’ usefulness, provided insight into the distribution of mcr genes in municipal wastewater, clay and river sediments, glacier moraine, manure, seagulls and auks feces and daphnids from four countries. This analysis proved that commonly used primers may deliver false results, and some mcr genes may be overlooked in tested samples. Newly-developed PCR primers turned out to be relevant for the screening of mcr genes in various environments.
- Do Klebsiella pneumoniae environmental strains maintain clinically relevant genomic and phenotypic traits?Publication . Rocha, Jaqueline; Ferreira, Catarina; Mil-Homens, Dalila; Brito, Margarida; Lameiras, Catarina; Fialho, Arsénio; Henriques, Isabel; Gomila, Margarita; Manaia, Célia M.
- Dynamics of carbapenem resistance in urban wastewater treatment plants and receiving water bodies: drivers and opportunities for actionPublication . Abreu-Silva, Joana; Ferreira, Catarina; Vaz-Moreira, Ivone; Manaia, Célia M.
- Genetic characterization of methicillin-resistant staphylococcus aureus isolates from human bloodstream infections: detection of mlsb resistancePublication . Silva, Vanessa; Hermenegildo, Sara; Ferreira, Catarina; Manaia, Celia M.; Capita, Rosa; Alonso-Calleja, Carlos; Carvalho, Isabel; Pereira, José Eduardo; Maltez, Luís; Capelo, José L.; Igrejas, Gilberto; Poeta, PatriciaIn this study we aimed to characterize antimicrobial resistance in methicillin-resistant Staphylococcus aureus (MRSA) isolated from bloodstream infections as well as the associated genetic lineages of the isolates. Sixteen MRSA isolates were recovered from bacteremia samples from inpatients between 2016 and 2019. The antimicrobial susceptibility of these isolates was tested by the Kirby–Bauer disk diffusion method against 14 antimicrobial agents. To determine the macrolide–lincosamide–streptogramin B (MLSB) resistance phenotype of the isolates, erythromycin-resistant isolates were assessed by double-disk diffusion (D-test). The resistance and virulence genes were screened by polymerase chain reaction (PCR). All isolates were characterized by multilocus sequence typing (MLST), spa typing, staphylococcal chromosomal cassette mec (SCCmec) typing, and accessory gene regulator (agr) typing. Isolates showed resistance to cefoxitin, penicillin, ciprofloxacin, erythromycin, fusidic acid, clindamycin, and aminoglycosides, confirmed by the presence of the blaZ, ermA, ermC, mphC, msrA/B, aac(6’)-Ie-aph(2’’)-Ia, and ant(4’)-Ia genes. Three isolates were Panton–Valentine-leukocidin-positive. Most strains (n = 12) presented an inducible MLSB phenotype. The isolates were ascribed to eight spa-types (t747, t002, t020, t1084, t008, t10682, t18526, and t1370) and four MLSTs (ST22, ST5, ST105, and ST8). Overall, most (n = 12) MRSA isolates had a multidrug-resistance profile with inducible MLSB phenotypes and belonged to epidemic MRSA clones.
- Genetic variation in the conjugative plasmidome of a hospital effluent multidrug resistant Escherichia coli strainPublication . Ferreira, Catarina; Bogas, Diana; Bikarolla, Santosh K.; Varela, Ana Rita; Frykholm, Karolin; Linheiro, Raquel; Nunes, Olga C.; Westerlund, Fredrik; Manaia, Célia M.Bacteria harboring conjugative plasmids have the potential for spreading antibiotic resistance through horizontal gene transfer. It is described that the selection and dissemination of antibiotic resistance is enhanced by stressors, like metals or antibiotics, which can occur as environmental contaminants. This study aimed at unveiling the composition of the conjugative plasmidome of a hospital effluent multidrug resistant Escherichia coli strain (H1FC54) under different mating conditions. To meet this objective, plasmid pulsed field gel electrophoresis, optical mapping analyses and DNA sequencing were used in combination with phenotype analysis. Strain H1FC54 was observed to harbor five plasmids, three of which were conjugative and two of these, pH1FC54_330 and pH1FC54_140, contained metal and antibiotic resistance genes. Transconjugants obtained in the absence or presence of tellurite (0.5 μM or 5 μM), arsenite (0.5 μM, 5 μM or 15 μM) or ceftazidime (10 mg/L) and selected in the presence of sodium azide (100 mg/L) and tetracycline (16 mg/L) presented distinct phenotypes, associated with the acquisition of different plasmid combinations, including two co-integrate plasmids, of 310 kbp and 517 kbp. The variable composition of the conjugative plasmidome, the formation of co-integrates during conjugation, as well as the transfer of non-transferable plasmids via co-integration, and the possible association between antibiotic, arsenite and tellurite tolerance was demonstrated. These evidences bring interesting insights into the comprehension of the molecular and physiological mechanisms that underlie antibiotic resistance propagation in the environment.
- Influência dos Sistemas de Informação em Enfermagem na aprendizagem dos estudantes de licenciatura, em ensino clínicoPublication . Almeida, Armando; Ferreira, Catarina
- Microbiological and chemical quality of portuguese lettuce - results of a case studyPublication . Ferreira, Catarina; Lopes, Filipa; Costa, Reginaldo; Komora, Norton; Ferreira, Vânia; Fernandes, Virgínia Cruz; Delerue-Matos, Cristina; Teixeira, PaulaIn addition to environmental pollution issues, social concerns about the sustainability, safety, and quality of conventionally grown fruits and vegetables have been increasing. In order to evaluate if there were any microbiological differences between samples of organic and conventional lettuce, a wide range of parameters were tested, including pathogens and indicator organisms: the enumeration of Escherichia coli; the detection of Salmonella spp.; the detection/enumeration of Listeria monocytogenes; the enumeration of lactic acid bacteria, Pseudomonas spp. yeasts and molds, and Enterobacteriaceae. This study also evaluated the chemical safety of the lettuce samples, quantifying the nitrate concentration and 20 pesticides (14 organochlorine and 6 organophosphorus pesticides). Significant differences (p<0.05) between the conventional and organic samples were only detected for the counts of total microorganisms at 30◦C. Pathogens were absent in all the samples. The analytical method, using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach for pesticide extraction, was suitable for detecting the targeted analyte s; the limit of quantification(LOQ) was between 0.6 and 1.8μg/kg (lower than the Maximum Residue Levels (MRLs) established by EU legislation). In three organic lettuce samples, one organochlorine pesticide (α-HCH) was observed below the MRLs. For the samples analyzed and for the parameters investigated, except for the total mesophilic counts, the organic and conventional lettuces were not different.