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Presence of Alphacoronavirus in Tree- and Crevice-Dwelling Bats from Portugal
Publication . Hemnani, Mahima; da Silva, Priscilla Gomes; Thompson, Gertrude; Poeta, Patrícia; Rebelo, Hugo; Mesquita, João R.; LAQV@REQUIMTE; DQ - Departamento de Química; MDPI - Multidisciplinary Digital Publishing Institute
Coronaviruses (CoVs) are RNA viruses capable of infecting a wide range of hosts, including mammals and birds, and have caused significant epidemics such as the ongoing COVID-19 pandemic. Bats, the second most diverse mammalian order, are hosts for various CoVs due to their unique immune responses and ecological traits. This study investigates CoV prevalence in crevice- and tree-dwelling bats in Portugal, a country with limited prior research on bat CoVs. Using nested RT-PCR and sequencing, we screened 87 stool samples from bats, identifying one sample (1.15%) that was positive for Alphacoronavirus, belonging to Pipistrellus pipistrellus. Phylogenetic analysis revealed close genetic relationships with Alphacoronavirus strains from the same bat species in Europe. The low prevalence suggests habitat-specific differences in viral transmission, with cave-dwelling bats exhibiting higher CoV prevalence due to population density and behaviour. These findings underscore the necessity for sustained surveillance efforts aimed at comprehending CoV dynamics within bat populations, especially concerning the risk of spillover events and viral evolution. Vital to this understanding is the monitoring of bat migration patterns, which serves as a crucial tool for elucidating CoV ecology and epidemiology. Such efforts are essential for ongoing research endeavours aimed at mitigating the potential for future zoonotic disease outbreaks.
Histological analysis of Xylella fastidiosa infection in Quercus pyrenaica in Northern Portugal
Publication . Loureiro, Talita; Gonçalves, Berta; Serra, Luís; Martins, Ângela; Cortez, Isabel; Poeta, Patrícia; LAQV@REQUIMTE; AIMS Press - American Institute of Mathematical Sciences
Quercus pyrenaica Willd thrives in the intermediate zone between the Mediterranean sclerophyllous and the temperate deciduous forest. In December 2022, the presence of the bacteria Xylella fastidiosa (Xf) was confirmed in samples collected from a Quercus pyrenaica located in Sabrosa, Vila Real, Portugal. Following Xf infection, the transport of water and nutrients is hindered due to the occlusion of xylem vessels. This loss of hydraulic conductivity may lead to vessel blockage and subsequent embolism formation. The objective of this study was to investigate the interaction between Xf and Quercus pyrenaica tissues, as well as the mechanism by which the bacteria can spread through the plant’s xylem vessels, ultimately resulting in the formation of vascular plugs. At the time of the sample collection (10 months post-detection), symptoms of Bacterial Leaf Scorch (BLS) began to appear. Examination of xylem vessels using both light and scanning electron microscopy (SEM) revealed the presence of various types of occlusions, predominantly tyloses. Additionally, fibrillar networks, gums, starch grains, and crystals were observed. The stem vessels exhibited significantly more occlusions compared to the leaves. Furthermore, individual bacterial cells were observed to be attached to the vessel wall. This implies that occlusions were primarily induced by tyloses and gums as a defensive response to the invasion of vascular pathogens, in addition to the pathogen itself. This study highlights the presence of starch grains in stems, which may function as a refilling mechanism, thereby preventing the loss of hydraulic conductivity in plants and potentially acting as a means to entrap the bacteria. These mechanisms exemplify the constitutive defense systems of the plant against Xf. Understanding the interaction between Xylella fastidiosa and Quercus pyrenaica is crucial, given that the latter species occupies nearly 95% of the natural distribution area of Portugal.
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.
Caught in the ESKAPE
Publication . Silva, Vanessa; Araújo, Sara; Caniça, Manuela; Pereira, José Eduardo; Igrejas, Gilberto; Poeta, Patrícia; LAQV@REQUIMTE; MDPI - Multidisciplinary Digital Publishing Institute
The emergence of antimicrobial-resistant bacteria poses a significant global health challenge, with ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) playing a major role in multidrug-resistant infections. While traditionally associated with hospital settings, these bacteria have increasingly been detected in wildlife, suggesting a complex web of transmission between human, animal, and environmental reservoirs. Wildlife may act as both sentinels and reservoirs for resistant pathogens, contributing to their persistence and dissemination across ecosystems. This review explores the presence of ESKAPE bacteria in wild animals, examining their clonal lineages, resistance profiles, and virulence traits. Understanding how these pathogens circulate in natural environments is crucial for designing effective strategies to mitigate antimicrobial resistance. By adopting a One Health perspective—integrating human, animal, and environmental health—efforts to control ESKAPE bacteria can extend beyond clinical interventions to broader ecological and public health frameworks. Addressing this issue requires comprehensive surveillance, responsible antibiotic use, and policies aimed at reducing environmental contamination, ultimately safeguarding both biodiversity and global health.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
Concurso de avaliação no âmbito do Programa Plurianual de Financiamento de Unidades de I&D (2017/2018) - Financiamento Base
Número da atribuição
UIDB/00772/2020