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Yeast diversity in chicken meat products
Publication . Saraiva, Sónia; Saraiva, Cristina; Lazou, Tomai; Chaintoutis, Serafeim; Mesquita, João R.; Coelho, Ana C.; Poeta, Patrícia; LAQV@REQUIMTE; German Multidisciplinary Publishing Center
Food spoilage poses a significant challenge for both the food industry and consumers, rendering products unfit for consumption and leading to substantial food waste and economic losses. This study aimed to assess the occurrence of yeasts in five distinct types of raw meat poultry products (feet, gizzard, heart, liver, and neck) under two packaging conditions, providing insights into potential spoilage agents. For this purpose, one hundred poultry samples were collected from retail markets and supermarkets in Portugal to evaluate the total yeast count and assess the profiles and diversity of mycological species. Species identification was based on culture morphology, microscopic examination, biochemical profile, and Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). Results showed that local markets and unpacked samples exhibited significantly higher total yeast counts, particularly in heart, gizzard, and liver samples. Yeasts were isolated from 96% (95% CI: 90-98%) of the samples, with an average count of 3.13±0.96 log colony-forming units (CFU)/g. All yeast isolates belonged to seven different genera, i.e., Candida, Debaryomyces, Malassezia, Zygosaccharomyces, Rhodotorula, Yarrowia, and Cryptococcus, which are commonly found in food and environmental samples. The yeast species identified included Candida zeylanoides (26.83%), C. ciferrii (2.44%), Debaryomyces hansenii (19.51%), Zygosaccharomyces sp. (7.34%), Rhodotorula mucilaginosa (9.76%), Cryptococcus laurentii (4.88%), Malassezia pachydermatis (2.44%), Yarrowia lipolytica (9.76%) and Yarrowia galli (2.44%). A yeast-like fungus, Aureobasidium pullulans, was also identified in one unpacked sample of feet obtained from the retail market, potentially introduced through contact with contaminated surfaces or handling equipment. Recognizing the prevalence and variety of yeasts in food is crucial for developing effective strategies to mitigate these spoilage agents and ensure food safety and suitability. In conclusion, this study provides valuable insights into the occurrence of yeasts in fresh chicken meat products, highlighting the importance of developing effective strategies to mitigate yeast spoilage throughout the poultry supply chain. Furthermore, identifying emerging health concerns associated with yeasts, such as Y. galli and A. pullulans, which are implicated in human infections, highlights the critical need for comprehensive contamination control and monitoring practices to ensure food safety and public health.
Rabbits as a Reservoir of Multidrug-Resistant Escherichia coli
Publication . Silva, Vanessa; López, María; Rojo-Bezares, Beatriz; Pereira, José Eduardo; Falco, Virgílio; Valentão, Patrícia; Igrejas, Gilberto; Sáenz, Yolanda; Poeta, Patrícia; LAQV@REQUIMTE; DQ - Departamento de Química; MDPI - Multidisciplinary Digital Publishing Institute
Escherichia coli, including extended-spectrum β-lactamases (ESBL)-producing strains, poses a global health threat due to multidrug resistance, compromising food safety and environmental integrity. In industrial settings, rabbits raised for meat have the highest consumption of antimicrobial agents compared to other food-producing animals. The European Union is facing challenges in rabbit farming as rabbit consumption declines and antibiotic-resistant strains of E. coli cause enteric diseases. The aim of this study was to investigate the antibiotic resistance profile, genetic diversity, and biofilm formation in cefotaxime-resistant E. coli strains isolated from twenty rabbit farms in Northern Portugal to address the effect of the pressing issue of antibiotic resistance in the rabbit farming industry. Resistance to critically antibiotics was observed, with high levels of resistance to several categories, such as tetracycline, ampicillin, aztreonam, and streptomycin. However, all isolates were susceptible to cefoxitin and imipenem. Multidrug resistance was common, with strains showing resistance to all antibiotics tested. The blaCTX-M variants (blaCTX-3G and blaCTX-M9), followed by the tetracycline resistance genes, were the most frequent resistance genes found. ST10 clones exhibiting significant resistance to various categories of antibiotics and harboring different resistance genes were detected. ST457 and ST2325 were important sequence types due to their association with ESBL-E. coli isolates and have been widely distributed in a variety of environments and host species. The strains evaluated showed a high capacity for biofilm formation, which varied when they were grouped by the number of classes of antibiotics to which they showed resistance (i.e., seven different classes of antibiotics, six classes of antibiotics, and three/four/five classes of antibiotics). The One Health approach integrates efforts to combat antimicrobial resistance in rabbit farming through interdisciplinary collaboration of human, animal, and environmental health. Our findings are worrisome and raise concerns. The extensive usage of antibiotics in rabbit farming emphasizes the urgent need to establish active surveillance systems.
Unveiling Antibiotic Resistance, Clonal Diversity, and Biofilm Formation in E. coli Isolated from Healthy Swine in Portugal
Publication . Silva, Vanessa; Dapkevicius, Maria de Lurdes Enes; Azevedo, Mónica; Pereira, José Eduardo; Valentão, Patrícia; Falco, Virgílio; Igrejas, Gilberto; Caniça, Manuela; Poeta, Patrícia; LAQV@REQUIMTE; DQ - Departamento de Química; MDPI - Multidisciplinary Digital Publishing Institute
Escherichia coli, a commensal microorganism found in the gastrointestinal tract of human and animal hosts, plays a central role in agriculture and public health. Global demand for animal products has promoted increased pig farming, leading to growing concerns about the prevalence of antibiotic-resistant E. coli strains in swine populations. It should be noted that a significant portion of antibiotics deployed in swine management belong to the critically important antibiotics (CIA) class, which should be reserved for human therapeutic applications. This study aimed to characterize the prevalence of antibiotic resistance, genetic diversity, virulence characteristics, and biofilm formation of E. coli strains in healthy pigs from various farms across central Portugal. Our study revealed high levels of antibiotic resistance, with resistance to tetracycline, ampicillin, tobramycin, and trimethoprim-sulfamethoxazole. Multidrug resistance is widespread, with some strains resistant to seven different antibiotics. The ampC gene, responsible for broad-spectrum resistance to cephalosporins and ampicillin, was widespread, as were genes associated with resistance to sulfonamide and beta-lactam antibiotics. The presence of high-risk clones, such as ST10, ST101, and ST48, are a concern due to their increased virulence and multidrug resistance profiles. Regarding biofilm formation, it was observed that biofilm-forming capacity varied significantly across different compartments within pig farming environments. In conclusion, our study highlights the urgent need for surveillance and implementation of antibiotic management measures in the swine sector. These measures are essential to protect public health, ensure animal welfare, and support the swine industry in the face of the growing global demand for animal products.
Carbohydrate composition of cow milk and plant-based milk alternatives
Publication . Antunes, I. C.; Roseiro, C.; Bexiga, R.; Pinto, C.; Lageiro, M.; Gonçalves, H.; Quaresma, M. A.G.; GeoBioTec - Geobiociências, Geoengenharias e Geotecnologias; Faculdade de Ciências e Tecnologia (FCT); American Dairy Science Association
The prevalence of lactose intolerance is one of the factors driving consumers toward plant-based milk alternatives (PBMA). This study aimed to analyze the carbohydrate profile of cows' milk (regular and lactose-free from both pasteurized and UHT milks; n = 80) and PBMA (n = 60) by HPLC. The study revealed that no significant difference was present in the energy content and total carbohydrate content between regular milk and lactose-free milk. Although milk and PBMA are entirely different food matrices, some PBMA types, as soya and coconut, may have energy contents and total carbohydrate contents comparable to those of milk. Furthermore, the variability observed in total carbohydrate content, as well as in carbohydrate profile, both between PBMA types and within samples of the same type, arises not only from variations in raw materials but also from the number of dilutions of the vegetable extract and the addition of different types and levels of carbohydrates, such as sucrose, fructose, or sorbitol, during PBMA manufacture. Although, milk presents a regular carbohydrate composition, differing solely between presentations (regular/lactose-free), the PBMA differs significantly between types and among the same type, not being for that reason regarded as a milk substitute.
Combined TLR2/TLR4 activation equip non-mucosal dendritic cells to prime Th1 cells with gut tropism
Publication . Zúquete, Sara; Ferreira, Mariana; Delgado, Inês L.S.; Gazalle, Paula; Andaluz, Stephanie; Rosa, Maria Teresa; Mendes, Ana Catarina; Santos, Dulce; Nolasco, Sofia; Graça, Luís; Leitão, Alexandre; Basto, Afonso P.; Faculdade de Ciências e Tecnologia (FCT); Elsevier
Activated CD4+ T cells located at mucosal surfaces orchestrate local effector immune mechanisms. When properly polarized, these cells contribute to block infections at early stages and may be essential to restrain the local growth of mucosal tumors, playing a critical role in host protection. How CD4+ T cells simultaneously integrate gut-homing instructions and Th polarization signals transmitted by TLR activated dendritic cells (DCs) is unknown. Here, we show that the combined activation through TLR2, which alone does not induce a clear Th polarization, and TLR4, which alone does not imprint mucosal tropism, equip non-mucosal DCs to prime gut-homing CD4+ T cells with reinforced Th1 polarization. These results show that targeting DCs with combined innate stimuli with distinct properties is a rational strategy to program the outcome of T cell polarization and simultaneously control their tissue tropism. Exploring this strategy could enhance the efficacy of vaccines and immune cell therapies.
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Fundação para a Ciência e a Tecnologia
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Concurso para Atribuição do Estatuto e Financiamento de Laboratórios Associados (LA)
Número da atribuição
LA/P/0059/2020