Browsing by Author "Ferreira, E."
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- Antimicrobial drug resistance of Campylobacter spp and Salmonella enterica: national data in food producing animals and food of animal originPublication . Clemente, L.; Correia, I.; Ferreira, E.; Manageiro, V.; Jones-Dias, D.; Albuquerque, T.; Themudo, P.; Rocha, T.; Tavares, A.; Geraldes, M.; Barahona, M.J.; Caniça, M.Campylobacter spp and Salmonella enterica are the two most common causes of bacterial foodborne illnesses in humans in developed countries, being food producing animals one the main reservoirs. Antimicrobial susceptibility testing was determined through Minimum Inhibitory Concentration, in 448 isolates of Campylobacter spp recovered from broiler ceca at slaughter (n=351) and broiler carcasses (n=97); and 1600 isolates of S. enterica feed (n=43) and food products of animal origin (n=527). Screening and identification of beta-lactamase and plasmid-mediated quinolone resistance (PMQR) genes were performed by PCR and sequencing. The highest level of resistance in Campylobacter spp isolates recovered from broilers and carcasses was recorded to ciprofloxacin, followed by tetracycline, erythromycin and streptomycin. Four isolates of Campylobacter coli were resistant to gentamicin.
- Assessing the molecular basis of transferable quinolone resistance in Escherichia coli and Salmonella spp. from food-producing animals and food productsPublication . Jones-Dias, D.; Manageiro, V.; Francisco, A.P.; Martins, A.P.; Domingues, G.; Louro, D.; Ferreira, E.; Caniça, M.Enterobacteriaceae resistant to quinolones frequently arise in animals, being easily disseminated through the food-chain. The aim of this study was to investigate the presence of plasmid-mediated quinolone resistance (PMQR) determinants in Salmonella spp. (n=183) and Escherichia coli (n=180) isolates, collected from food-producing animals and food products among swine, poultry, rabbits and cattle. All isolates were subjected to antimicrobial susceptibility testing and molecular screening of PMQR determinants. β-Lactamase-encoding genes, and the quinolone resistance determining region (QRDR) of gyrA, gyrB, parC and parE genes were also investigated in PMQR-positive isolates. Plasmid characterization was performed by conjugation, followed by replicon-typing. Genetic relatedness of PMQR-positive E. coli was examined by Multilocus Sequence Typing, while Salmonella was previously serotyped. The association of mobile genetic elements and PMQR was investigated through PCR mapping assays. Overall, 4.1% (15/363) isolates harbored qnrB2 (n=3), qnrB19 (n=3), and qnrS1 (n=9) genes. All but one isolate presented one to four mutations in QRDR of gyrA or parC genes, which is consistent with the range of MIC values detected (0.19-64 mg/L) for ciprofloxacin; 60% (9/15) of qnr-harboring isolates were non-susceptible to β-lactam antibiotics which was justified by the presence of β-lactamases from TEM (TEM-1, n=8; TEM-135, n=1) and SHV (SHV-108, n=1) families. Analysis of mobile genetic elements revealed that qnr genes were detected nearby relevant genetic elements like intI1, ISEcl2, IS26 and ISCR1 and enclosed in diverse Inc. type plasmids. This study illustrated the existence of Qnr-producing E. coli and Salmonella from food-producing animals, associated to specific mobile elements that might mediate their transference between species and among distinct settings.
- Detection of plasmid-mediated colistin-resistance genes in Enterobacteriaceae isolates from food-producing animals and meat. Identification of the novel variant mcr-3, Portugal, 2010-2015.Publication . Clemente, L.; Manageiro, V.; Amaro, A.; Correia, I.; Albuquerque, T.; Themudo, P.; Ferreira, E.; Caniça, M.Following the original report of plasmid-mediated colistin resistance (PMCR) in China, several studies in different countries reported a worldwide distribution of the mcr-1 gene in Enterobacteriaceae. A novel variant, mcr-2, was also detected in colistin-resistant Escherichia coli isolates, from sick calves and piglets in Belgium; since that several other mcr-1 variants has been identified. In this study, we analysed colistin-resistant E. coli and Salmonella enterica isolates from different animal origins, for the presence of PMCR encoding genes. Thus, our aim was to understand the extension of the problem of colistin resistance and PMCR, as colistin is the last resort to treat human infections caused by Gram negative bacteria resistant to all antibiotics, namely carbapenems.