Percorrer por autor "Novais, Carla"
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- Caracterização de Indicadores Microbiológicos de Higiene em superfícies de unidades de restauração coletivaPublication . Peixoto, Andreia; Santos, Susana; Rodrigues, João; Saraiva, Margarida; Belo Correia, Cristina; Btista, Rita; Novais, Carla; Antunes, PatríciaA Segurança dos Alimentos tem impacto direto na proteção dos consumidores e na Saúde Pública, sendo as empresas do setor alimentar os principais responsáveis pela segurança dos géneros alimentícios. Os operadores das empresas de restauração devem garantir a preparação e distribuição de refeições seguras, prevenindo, eliminando ou minimizando os riscos em todas as fases. A contaminação cruzada por microrganismos pode ocorrer na fase final de preparação dos alimentos se não forem mantidas normas de higiene adequadas, como a limpeza e a desinfeção das superfícies. No setor alimentar a diminuição do risco de contaminação dos alimentos é influenciada pelas práticas de manuseamento dos alimentos e pela limpeza e higienização das superfícies. A persistência de microrganismos no ambiente de preparação de alimentos influencia a ocorrência de contaminações cruzadas, comprometendo a segurança alimentar. Assim, é essencial que a avaliação da higiene de superfícies em unidades alimentares seja integrada no sistema de Segurança Alimentar. Objetivos: - Avaliar a ocorrência e a diversidade de bactérias indicadoras de higiene (Enterobacteriaceae, Escherichia coli e Enterococcus), isoladas de ensaios que avaliam o estado higiénico de superfícies em unidades de restauração coletiva (URC) de Portugal. - Correlacionar a utilização de biocidas (desinfetantes e antisséticos) com bactérias indicadoras de higiene (Enterobacteriaceae, Escherichia coli e Enterococcus) detetadas nas diferentes áreas e superfícies do ambiente de preparação e distribuição de alimentos. - Caracterizar as bactérias recorrentes nas unidades de restauração coletiva, avaliando a persistência e possíveis mecanismos de resistência. Conclusão: - Embora os biocidas sejam utilizados em concentrações recomendadas em todas as URC, foram identificadas superfícies que contactam com alimentos com resultados insatisfatórios (>VMA) para os indicadores de higiene clássicos.- Os esfregaços de mãos e de outras superfícies apresentaram uma elevada diversidade de espécies bacterianas, incluindo potencialmente patogénicas e recorrentes ao longo do tempo em algumas URC. - Estas superfícies representam pontos críticos de contacto para estirpes que são geneticamente semelhantes às que circulam nos alimentos, no ambiente e em fontes clínicas humanas, incluindo estirpes portadoras de genes AMR clinicamente relevantes.
- Clinical Salmonella Typhimurium ST34 with metal tolerance genes and an IncHI2 plasmid carrying oqxAB-aac(6')-Ib-cr from EuropePublication . Campos, Joana; Mourão, Joana; Marçal, Sara; Machado, Jorge; Novais, Carla; Peixe, Luísa; Antunes, PatríciaFluoroquinolones are critical antibiotics for treating severe Salmonella infections, and the widespread of resistant isolates included in diverse epidemiological scenarios and carrying plasmid-mediated quinolone resistance (PMQR) is a global threat. Among PMQR mechanisms, those encoded by oqxAB and aac(6′)-Ib-cr genes are of special concern as they also confer reduced susceptibility to other antibiotics (oqxAB: chloramphenicol, trimethoprim, olaquindox; aac(6′)-Ib-cr: aminoglycosides) and biocides [oqxAB: quaternary ammonium compounds (QACs)].2,3 Although oqxAB ± aac(6′)-Ib-cr are prevalent and widespread in Asia, where olaquindox is still widely used in animal production, they remain scarce in Europe. Here we describe the molecular characterization of clinical ciprofloxacin-resistant Salmonella enterica Typhimurium with concomitant presence of oqxAB and aac(6′)-Ib-cr recovered for the first time in Europe.
- Genomic diversity of Enterobacteriaceae on food-processing surfaces: an overlooked non-clinical setting with public health implicationsPublication . Peixoto, Andreia; Nova, Lúcia; Mourão, Joana; Matos, Cátia; Santos, Susana; Rodrigues, João; Saraiva, Margarida; Correia, Cristina Belo; Batista, Rita; Peixe, Luísa; Novais, Carla; Antunes, PatríciaBacterial hazards on contaminated surfaces in food-processing environments pose significant food safety risks. Hygiene monitoring of surfaces in direct or indirect contact with food typically relies on a limited set of bacterial indicators, such as Enterobacteriaceae counts. However, their genomic diversity remains poorly characterised. The aim of this study was to provide a comprehensive genomic characterisation of Enterobacteriaceae recovered from food-contact surfaces after cleaning and disinfection with biocides in foodservice units. Diverse strains were identified, with some STs shared across samples and/or foodservices. - A diverse Enterobacteriaceae population persists on food-contact surfaces even after cleaning and disinfection with biocides, with evidence of cross-contamination. - These surfaces represent critical points of contact for strains that are genetically similar to those circulating in food, environment, and human clinical sources, including strains carrying clinically relevant AMR genes. - Further research is needed to understand the factors driving their persistence and dissemination in foodservice environments, aiming to enhance food safety risk management protocols and protect public health.
- Hygiene challenges in Foodservice Units: Biocide efficacy and bacterial diversity across surfacesPublication . Peixoto, Andreia; Santos, Susana; Rodrigues, João; Saraiva, Margarida; Correia, Cristina Belo; Batista, Rita; Novais, Carla; Antunes, PatríciaContaminated surfaces in food-processing environments represent a significant food safety risk, making the monitoring of hygiene on hands and food-contact surfaces a priority. This study aimed to assess the occurrence and diversity of hygiene indicator bacteria in Portuguese foodservice facilities and to evaluate their association with biocide use. A total of 1,128 hand and surface samples were collected from 107 facilities, with bacterial identification performed by MALDI-TOF-MS and information gathered on the type and concentration of biocides used. More than half of the samples showed unsatisfactory hygiene results, mainly due to high total viable counts and Enterobacteriaceae levels. Forty bacterial species were identified, with Enterobacter cloacae, Klebsiella pneumoniae and Klebsiella oxytoca being the most prevalent. Hygiene performance varied according to the type of biocide applied, with quaternary ammonium compound-based products showing greater effectiveness. Despite appropriate biocide concentrations, the persistence and diversity of bacteria highlight the need to further investigate microbial susceptibility and persistence in order to improve hygiene practices.
- Surface hygiene in food environments: challenges with biocide efficacy and bioindicatorsPublication . Peixoto, Andreia; Matos, Cátia; Santos, Susana; Rodrigues, João; Saraiva, Margarida; Belo Correia, Cristina; Batista, Rita; Peixe, Luísa; Novais, Carla; Antunes, PatríciaThe presence of bacterial hazards on contaminated surfaces in food-processing environments poses significant food safety risks. Monitoring and hygiene verification of surfaces in direct or indirect contact with food remains a top priority for food business operators. Sanitation uses antimicrobial compounds, biocides (disinfectants/antiseptics), whose effectiveness on surface microbiota depends on microorganisms’ susceptibility and factors such as concentration and contact time. The aim of this stydy was to assess the post-disinfection occurrence and diversity of hygiene indicator bacteria on kitchen surfaces of Portuguese foodservice facilities and correlate their presence with biocide usage. Despite recommended biocide use, poor hygiene of surfaces in direct or indirect contact with food was observed. The presence of diverse, potentially pathogenic and recurrent bacterial species suggests persistence, reintroduction, and/or cross-contamination. Identifying phenotypic and genetic markers of persistence, including biocide susceptibility, is crucial for developing real-time hygiene bioindicators and ensuring food safety.
- Tolerance of microorganisms to surface disinfection in food productionPublication . Peixoto, Andreia; Santos, Susana; Rodrigues, João; Saraiva, Margarida; Belo Correia, Cristina; Batista, Rita; Novais, Carla; Antunes, PatríciaFood safety has a direct impact on consumer protection and public health,with food industry companies being primarily responsible for the safety of food products. Operators of food service businesses must ensure the preparation and distribution of safe meals by preventing, eliminating, or minimising microbiological risks at all stages. Contamination can occur at the final stage of food preparation if proper hygiene standards, such as cleaning and disinfecting surfaces,are not maintained. The persistence of bacterial hazards in the food preparation environment influences the occurrence of cross-contamination, compromising food safety. Despite recommended biocide use, poor hygiene of surfaces in direct or indirect contact with food was observed for most of the foodservice facilities studied. The presence of several recurrent bacterial species suggests possible persistence, reintroduction, and/or cross-contamination events. Investigating biocide susceptibility and bacterial persistence is essential to improve hygiene practices and identify more reliable bioindicators.
- Tolerance to multiple metal stressors in emerging non-typhoidal MDR Salmonella serotypes: a relevant role for copper in anaerobic conditionsPublication . Mourão, Joana; Marçal, Sara; Ramos, Paula; Campos, Joana; Machado, Jorge; Peixe, Luísa; Novais, Carla; Antunes, PatríciaObjectives: Factors driving the expansion of particular MDR Salmonella serotypes/clones are not completely understood. We assessed if emergent MDR Salmonella serotypes/clones were more enriched in metal tolerance genes (e.g. to Cu/Ag) than other less frequent ones, as an additional feature to survive in environments contaminated with metals. Methods: Metal (Cu pco/Ag,Cu sil/Hg mer/As ars/Te ter) tolerance genes screening (PCR/sequencing), MICs of CuSO4/AgNO3 (aerobiosis/anaerobiosis), genetic element characterization (S1/I-CeuI PFGE) and conjugation assays were performed in a well-characterized Salmonella collection (n = 275 isolates; 2000–14; 49 serotypes/clones). Results The sil ± pco genes were detected in 37% of isolates from diverse serotypes, mainly in emergent Rissen/ST469 and Typhimurium/ST34 European clone (100%), which are mostly associated with pig settings where Cu is highly used. These genes were frequently co-located with merA ± terF and/or antibiotic resistance genes in plasmids (100–270 kb; IncHI2/IncHI1/IncN/IncFIIA; mostly transferable by conjugation) or in the chromosome. Most sil ± pco+ isolates (77%) were MDR contrasting with sil ± pco− ones (48%). The sil ± pco+ isolates presented significantly higher MICCuSO4 under anaerobiosis (MIC50/MIC90 = 28/32 mM) and MICAgNO3 after previous Ag contact (MIC50/MIC90 > 3 mM) than sil− ones (MIC50/MIC90 = 2/8 mM to CuSO4; MIC50/MIC90 = 0.125/0.16 mM to AgNO3). Use of these modified methodological approaches allowed the establishment of CuSO4/AgNO3 tolerance cut-offs to differentiate sil+ and sil− isolates, here firstly proposed. Conclusions: This study demonstrates that acquisition of Cu/Ag tolerance genes (sil/pco genes) might contribute to the emergence of particular clinically relevant MDR Salmonella serotypes/clones by facilitating their survival in diverse metal-contaminated settings, particularly in pig production. Assessment of control measures for the use and/or accumulation of metals in diverse environments are needed to prevent a wider expansion of such strains or the emergence of new ones.