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- The antimicrobial effect of wine on bacillus cereus in simulated gastrointestinal conditionsPublication . Vaz, Miguel; Hogg, Tim; Couto, José AntónioSeveral studies demonstrate the antibacterial properties of wine against relevant food- borne pathogenic bacteria but none of them studied the effect on Bacillus cereus, a spore-forming bacterium that is a common contaminant in a wide variety of foods. Two distinct food-borne disease types are associated with B. cereus: the intoxication, or emetic syndrome (caused by a toxin produced in the food prior to consumption) and the toxic-infection, or diarrheal syndrome (caused by enterotoxins produced in the small intestine). This study aimed to evaluate the antimicrobial activity of wine against B. cereus vegetative cells and spores. The results clearly show that wine exerts a strong inactivation effect against vegetative cells of B. cereus. The red wine tested inactivated stationary phase cultures to undetectable numbers in less than 10 s. Thus, further inactivation assays were carried out with wine diluted with water (1:4 and 1:8). Diluted wine 1:4 caused a reduction of approximately 5 log cycles on viable cell counts in 20 s. On the other hand, B. cereus spores were found to be highly resistant to wine exposure. The influence of wine components (organic acids, ethanol and phenolic compounds) was investigated on vegetative cells. The wine organic acids tested exhibited a strong inactivation effect, and, when combined with ethanol, a slight synergistic effect was observed. The wine phenolic compounds assayed displayed no activity against the vegetative cells at the concentrations tested. At the simulated gastric conditions studied (in the presence of food), wine diminished considerably the number of B. cereus viable cells supplementing the effect of the synthetic gastric fluid. The behavior of B. cereus spores under gastrointestinal conditions was also evaluated. In a consumption-like scenario, the addition of wine led to lower total counts (vegetative cells + spores) of B. cereus in the simulated intestine conditions, showing that wine inhibits the proliferation of the vegetative cells obtained from the germination of spores. This work provides evidence that consumption of wine during a meal may diminish the number of viable cells of B. cereus and reduces the impact of the germination of spores that may occur in the small intestine.
- Sphingomonadaceae diversity and antibiotic resistance in water samplesPublication . Vaz-Moreira, Ivone; Faria, Cátia; Nunes, Olga C.; Manaia, Célia M.Sphingomonadaceae are ubiquitous bacteria in environment, including aquatic habitats. Nevertheless, their contribution for the acquisition and spread of antibiotic resistance in nature is poorly understood. We studied the diversity and the antibiotic resistance phenotypes of members of this family in isolates recovered from a drinking water treatment plant (n=6), tap water (n=55), cup filler of dental chairs (n=21) and a water demineralization filter (n=4). Bacterial isolates were identified based on the analysis of the 16S rRNA gene sequence and intra-species variation was assessed on basis of the atpD gene sequence analysis. Antibiotic resistance profiles were determined using the ATB PSE 5 strips (Biomérieux). The isolates were identified as members of the genera Sphingomonas (n=27), Sphingobium (n=28), Novosphingobium (n=12), Sphingopyxis (n=7) and Blastomonas (n=12). Susceptibility patterns were analysed and compared to the different sites of isolation and taxonomic groups. Colistin resistance was observed to be intrinsic (92%). The highest antibiotic resistance percentages were observed for the members of the genera Sphingomonas and Sphingobium, to the beta-lactams, ciprofloxacin and cotrimoxazol. Comparing the sites of isolation, the highest percentages of resistance were observed for tap and cup filler samples, where isolates of the genera Sphingomonas and Sphingobium predominated. These two genera presented different patterns of association of antibiotic resistance suggesting different paths of resistance acquisition. Antibiotic resistance patterns were often species- rather than site- or strain-related. This is the first study demonstrating that members of the Sphingomonadaceae family may play a roleas potential reservoirs of antibiotic resistance in aquatic environments, namely in drinking water.
- Selection of potential probiotic lactic acid bacteria isolated from Spanish fermented foodsPublication . Martín, Irene; Barbosa, Joana; Córdoba, Juan J.; Teixeira, PaulaFermented foods are products with an autochthonous microbiota which confers characteristic sensory attributes and plays a role in their preservation by the production of inhibitory compounds [1]. This autochthonous microbiota, composed mainly of lactic acid bacteria (LAB), also has interesting probiotic and functional properties. Probiotics are live microorganisms which when administered in adequate amounts could confer a health benefit to the host [2]. Their consumption has several beneficial effects, including balancing of colonic microbiota, protection of the normal intestinal microbiota and prevention of gastrointestinal disorders, reduction of serum cholesterol, antagonism against food-borne pathogens and improvement in the nutritional value of foods [3]. The objective of this work was to evaluate several LAB strains isolated from dry-cured fermented meat products and ripened cheese for potential use as probiotic strains, concerning their safety, antimicrobial and functional activities. For this purpose, 33 LAB strains obtained from Spanish fermented products were studied regarding the presence of virulence factors and genes, susceptibility to antibiotics, antimicrobial activity against different spoilage and pathogens bacteria, survival during simulated gastrointestinal tract (GIT) passage and adhesion to intestinal epithelium. Despite the production of proteinaceous compounds inhibiting several pathogens by all the LAB strains analyzed, only five strains were selected due to the absence of virulence factors and genes and antibiotic resistance: Lactilactobacillus sakei 205 and 197 (isolated from dry-cured fermented sausages), Lacticaseibacillus casei 116 and 31 and Lactococcus garvieae 151 (isolated from ripened cheeses). With this study, five strains from three species were found as potential candidates for future use as protective and probiotic strains in fermented foods. Further tests should be performed to evaluate their beneficial effects when incorporated into fermented food matrices during their shelf life.
- Food safetyPublication . Teixeira, Paula
- MicrobiologyPublication . Manaia, Célia
- NutritionPublication . Gomes, Ana
- International studentsPublication . Farrokhi, Mahsa
- BiotechnologyPublication . Castro, Paula
- Deliverable D7.4 Legumes network mapPublication . Davel, Anissa; Vasconcelos, Marta; Iannetta, PietroThe LegumES Network Map (Deliverable D7.4) documents the development of two complementary resources: an open-access EU Projects Database Tool, and an interactive visual LegumES Network Map. Together, these tools identify, organise, and display EU-funded projects aligned with the LegumES themes of legumes, ecosystem services, agroecology, and sustainable agrifood systems.
- Consumer perception and acceptance of foods in AfricaPublication . Tomlins, Keith; Bechoff, Aurélie; Monteiro, Maria João P.Foods in Sub-Saharan Africa are diverse and varied but little is known about consumer attitudes or how food behaviours evolve over time. Changes in consumer perception were explored by reviewing information about consumer demographics, analysing gross domestic agricultural production and studying published literature on sensory evaluation and consumer preference. Results suggest that consumer trends in Africa are swiftly changing, probably due to rapid population growth and urbanisation, along with increased purchasing power. These changes are also related to an increase in obesity and double burden of malnutrition, particularly in urban areas. The growing use of digital technology will lead to new ways of tracking food preferences and supporting healthy eating.