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Browsing by Author "Berrached, Yousra Meriem"

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  • Exploring the Antibiotic-Resistance Profile of Staphylococcus aureus Recovered from Portuguese Fermented Meat Products
    Publication . Berrached, Yousra Meriem; Gonzales-Barron, Ursula; Cadavez, Vasco
    Chouriça and alheira are traditional Portuguese sausages with culinary, cultural, and economic significance. However, its artisanal production is often linked to non-standardised manufacturing processes and hygiene practices, which may result in contamination by foodborne pathogens and antimicrobial resistance (AMR) dissemination. In this study, forty-seven Staphylococcus aureus isolates from chouriça (RTE, n=22) and alheira (non-RTE, n=25) sausages were subjected to antimicrobial susceptibility testing by disk diffusion following EUCAST guidelines, against 14 antibiotics. The resulting data were analysed performing descriptive analysis and Principal Component Analysis (PCA) with the AMR R Package. Resistance was observed only to eight antibiotics, with 68.08% of isolates resistant to at least one agent and low rate of multidrug-resistant isolates (6.4%). All strains were susceptible to cefoxitin, indicating the absence of methicillin-resistant S. aureus isolates. Benzylpenicillin resistance was most common, especially in RTE (50%) and non-RTE (40%), erythromycin resistance was higher in RTE (40.9%), and norfloxacin resistance appeared only in non-RTE products (16%). PCA extracted two components that explain the majority of resistance variation and revealed clear clustering by sausage type, indicating distinct resistance profiles between RTE and non-RTE sources. Detection of antibiotic-resistant S. aureus in fermented sausages, particularly to antibiotics so common in human treatment, probably results from poor hygiene practices during manufacturing and improper fermentation, allowing the survival of human-derived strains in the end product. Improving hygiene is important to curb AMR spread; therefore future research should focus on resistance transmission and genotypic characterization.
    2025Master thesis Open access Show more