Maria José Saavedra

Date (Phoenix dactylifera L.) pits are a by-product of the date processing industry and are being explored as a source of bioactive compounds within the framework of the circular economy. This study aimed to perform a preliminary safety screening of the in vivo toxicity and mutagenic potential of ethanolic extracts obtained from different date pit varieties. Extracts from Alig (DA), Deglet Nour (DDN), and Kentichi (DK) varieties were administered to Galleria mellonella larvae at different concentrations, and health indices and survival were monitored for 4 days. No significant toxicity was observed at concentrations up to the MIC (6.25 mg/mL), while higher doses (≥2 MIC) had moderate effects on larval viability. The mutagenic potential was evaluated for two extracts (DDN and DK) using the Ames test with Salmonella enterica serovar Typhimurium strains TA98 and TA100, in the absence of metabolic activation. Mutagenic index values were below 2.0 for all conditions tested, with the exception of DDN on TA98, where values consistently exceeded 2.0 without a clear dose–response relationship. Due to the absence of metabolic activation and the limited strain panel, the results should be interpreted as preliminary. Overall, the combined preliminary in vitro and in vivo initial findings suggest that ethanolic extracts of date pits do not exhibit an evident mutagenic or toxic effects at biologically relevant concentrations under the conditions tested, providing a basis for further safety evaluation towards their application in the food industry.

Microplastics (MPs) and metals frequently co-occur in aquatic environments, yet their combined effects on gut health and antimicrobial resistance in fish remain poorly understood. This study investigated the chronic effects of polyethylene (PE) and polystyrene (PS) microplastics, alone or combined with copper (Cu), on intestinal integrity, the gut-associated Gram-negative cultivable fraction, and phenotypic antimicrobial resistance in adult zebrafish (Danio rerio). Fish were exposed for 21 days to MPs (1 mg/L), Cu (25 µg/L), or their combinations. Histopathological analysis revealed that Cu-containing treatments induced more severe intestinal alterations, including edema, villus degeneration, and necrosis, whereas MPs-only exposures produced milder and heterogeneous responses. The composition of the Gram-negative cultivable fraction varied among treatments, with Cu, particularly in combination with MPs, associated with a broader occurrence of opportunistic and potentially pathogenic taxa. Antimicrobial susceptibility testing showed a high prevalence of multidrug resistance across treatments, with broader resistance spectra observed in Cu-containing exposures, consistent with metal-driven co-selection. In contrast, MPs alone did not systematically increase resistance and, for some antibiotics, showed resistance levels comparable to or lower than controls. Integrated multivariate analyses indicated that intestinal pathology and antimicrobial resistance co-varied along gradients of overall stress severity and stressor type, with Cu acting as the dominant driver and MPs exerting a modulatory, context-dependent influence. Overall, these findings highlight the importance of integrated assessments of gut pathology, microbial composition, and antimicrobial resistance to better understand the ecological and One Health implications of combined microplastic–metal exposure in aquatic systems.

The environmental impact of conventional plastics has driven a shift toward biobased food packaging, shaped by consumer expectations, market trends, and regulatory policies within the European Union (EU). Despite extensive research on biopolymers such as starch, cellulose, chitosan, and polylactic acid (PLA), their use in commercial food packaging remains limited. A major challenge identified in the literature is the evaluation of biopolymer performance, in which environmental benefits are often considered independently of mechanical, barrier, and economic factors. This review addresses this gap by critically exploring the functional performance of biopolymers regarding their chemical structure and processing methods, with particular emphasis on the role of bioactive compounds in enhancing these materials’ properties. Although several biopolymers can achieve tensile strength values comparable to conventional petroleum-based plastics, their higher water vapor transmission rates remain an unsolved barrier to scalability. These limitations, together with challenges related to mechanical performance and production costs, are discussed to clarify their impact on industrial feasibility and to identify priorities for future research supporting scalable, cost-effective, and regulatory-compliant food packaging solutions.

Since their recognition as human pathogens in the 1970s, Campylobacter spp. have posed persistent challenges to microbiologists due to their fastidious growth requirements and environmental sensitivity. The continuous refinement of selective and differential culture media has been crucial for improving their detection, isolation, and characterization in both clinical and food microbiology. This comprehensive review provides a chronological overview of the evolution of Campylobacter culture media, highlighting the scientific milestones that shaped current cultivation practices—from early blood- and charcoal-based formulations to modern selective, chromogenic, and systems permitting incubation under less stringent atmospheric conditions. Emphasis is placed on the rationale behind medium composition, the transition from empirical experimentation to standardized formulations, and the integration of molecular and metabolic insights into media design. The evolution of Campylobacter growth media mirrors the broader trajectory of microbiology itself, moving from artisanal experimentation toward precision-driven innovation. Ongoing advancements in culture technology, including sustainable and data-guided formulations, will continue to enhance global surveillance, food safety, and pathogen ecology research.

Background: Domestic refrigeration and egg handling are key factors in ensuring household food safety. Inadequate temperature control and poor hygiene in refrigerators can promote the survival and growth of foodborne pathogens. This study aimed to (i) characterize refrigerator temperature profiles and surface microbial contamination and (ii) screen eggs and egg-storage areas for the presence of Salmonella spp. and Campylobacter spp. Methods: Fifty domestic refrigerators were monitored twice in 2024 and 2025 in Porto, Portugal. The temperatures were continuously logged on the lowest shelf, which was swabbed for microbiological analysis. Surface hygiene was evaluated using total viable counts (TVC), Enterobacteriaceae, and Escherichia coli enumerated following ISO methods. Detection of pathogens Listeria monocytogenes, Salmonella spp., and Campylobacter spp. was performed using real-time PCR. Eggs (n = 92 in 2024; n = 88 in 2025), and domestic egg storage areas (total n = 76) were screened for Salmonella and Campylobacter. Results: The mean refrigerator temperatures were 6.0 ± 0.5 °C in 2024 and 6.1 ± 0.5 °C in 2025; 44% and 50% of the units, respectively, exceeded the recommended 6 °C threshold. In 2025, 31 (62%) and 33 (66%) refrigerators showed higher TVC and Enterobacteriaceae counts compared to 2024, whereas E. coli was only detected sporadically. L. monocytogenes, Salmonella spp., or Campylobacter spp. were not recovered from the refrigerator surfaces. Likewise, Salmonella and Campylobacter were not detected in any of the eggs or egg-storage sites. Indicator microorganism’s counts were not associated with the mean temperature. Conclusions: The absence of correlation between ΔT and Δ microbial counts suggests that behaviour-driven hygiene factors, rather than the relatively small year-to-year temperature differences observed, are more influential in determining household bioburden. Maintaining refrigerator temperatures ≤ 6 °C together with simple hygiene practices remains essential for reducing household food safety risks.

This review, within the One Health framework, compiles information on plant-derived bioactive compounds and emphasises their multifunctional role in improving environmental, animal, and human health. These compounds support sustainable health and ecological stability by influencing biological and environmental processes. Data from literature research are combined to explain the mechanisms and potential uses of different key bioactive compounds. Mechanistic insights focus on their capacity to regulate oxidative stress, inflammation, and microbial balance, linking these effects to therapeutic benefits in human health, enhanced animal productivity, and environmental sustainability. These compounds show antioxidant, anti-inflammatory, antimicrobial, and metabolic activities, helping prevent chronic diseases, strengthen immunity, and reduce reliance on antibiotics and pollution. Examples like quercetin, resveratrol, and curcumin demonstrate their roles in modulating inflammatory and metabolic pathways to foster sustainable health and ecological balance. Bioactive compounds are linked to the One Health strategy, providing benefits across biological systems. Nonetheless, challenges such as variability, bioavailability, and standardization remain. Future directions should aim to develop sustainable extraction and formulation methods, leverage omics technologies and artificial intelligence for discovery and characterization, and foster industry partnerships to validate these compounds and secure global regulatory approval.

Escherichia coli is a significant cause of Neonatal Calf Diarrhoea (NCD). Its extensive antigenic diversity, coupled with the ability to acquire antimicrobial resistance determinants, hampers treatment effectiveness and compromises the control measures. This study investigated the link between the presence of multidrug-resistant (MDR) E. coli and virulence factors (VFs) in NCD from central France (Departments of Cantal, Haute-Loire, Loire, and Puy-de-Dôme), between 2016 and 2022. E. coli was identified at TERANA Laboratories, France, using API 20E (BioMérieux^®) and MALDI-TOF Mass Spectrometry. Virulence factors, namely adhesins, were assessed with the slide agglutination method, and antimicrobial susceptibility testing was conducted across various antimicrobial classes. Out of 2367 E. coli strains isolated from cases of NCD, a high percentage were resistant to aminopenicillins (88.8%), aminoglycosides (89.1%), tetracyclines (79.7%), quinolones (48.4%), and sulphonamides (42.4%). More than half (58.6%) carried VFs, and 84.9% exhibited MDR profile, of which 61.34% (1233/2010) also harboured VFs. The adhesin CS31A-producing E. coli was the most prevalent, followed by the fimbrial adhesins F5 and F17 (60.8%, 20.0%, and 8.3%, respectively), all of which were associated with a high prevalence of MDR strains (79.1–93.9%). The highest occurrence of MDR profiles was observed in E. coli strains carrying CS31A and in those lacking VFs, both groups showing co-resistance to aminopenicillins, aminoglycosides, and tetracyclines or sulphonamides. The calf production sector may act as a reservoir for MDR E. coli strains, regardless of the presence of VFs, posing a major threat to public health and safety.

Background/Objectives: The health benefits of Tamus communis fruits have been associated with their high phenolic content, which comprises several flavonoids. However, the extraction methods might significantly impact these valuable compounds’ bioactivity. Therefore, the current study assesses how different extraction techniques affect T. communis extracts’ antioxidant, anti-aging, antimicrobial, cytotoxic, anti-inflammatory, and phenolic contents. Methods: Conventional method (TCE-CM) and ultrasound-assisted extraction (TCE-UM) were the methods employed. Results: The increased phenolic content of TCE-UM, particularly flavonoids and phenolic acids, was demonstrated to be a contributing factor to its higher biological activity. Key enzymes linked to dermatological conditions, such as elastase, collagenase, hyaluronidase, and tyrosinase, were significantly inhibited by both extracts at 1 mg/mL; TCE-UM showed the highest tyrosinase inhibition (65.61 ± 5.21%) compared to TCE-CM (21.78 ± 2.19%). TCE-UM also demonstrated exceptional antibacterial performance, showing notable antibiofilm and metabolic inactivation effects and potent activity against pathogens such as Staphylococcus aureus, Escherichia coli, and Candida albicans. Both extracts showed concentration-dependent anti-inflammatory properties; TCE-UM had a lower IC50 value (26.46 ± 2.30%) in nitric oxide inhibition tests, suggesting stronger anti-inflammatory capabilities. Conclusions: These findings underscore the superior bioactivity of TCE-UM and suggest that ultrasonic extraction is a more efficient method for isolating bioactive phenolic compounds from T. communis fruits, presenting promising applications in anti-aging and antimicrobial formulations.

Coastal environments have been recognized as key reservoirs for antibiotic-resistant bacteria. The present study evaluated marine gastropods, Phorcus lineatus, as potential bioindicators to assess the spread of antibiotic-resistant bacteria. P. lineatus was sampled in four sites, with different anthropogenic pressures, along the northwest Portuguese coastal area. From these specimens, bacteria were isolated and tested for their antimicrobial susceptibility, followed by their phylogenetic and pathotypic determination. All the Escherichia coli isolates showed resistance to at least one antimicrobial agent. The highest levels of multidrug resistance (25%) were observed in E. coli isolates obtained from SITE 2, which is impacted by the city of Porto and industrial settlements, while nearly 17% of these isolates showed a multiple antibiotic resistance (MAR) index higher than 0.2. Among the isolates, phylogroups A and B2 were the most prevalent, followed by phylogroup B1. The isolates of phylogroup A showed a higher prevalence of antimicrobial resistance. This study offers valuable insights into the antibiotic resistance risks posed to marine ecosystems and underscores the need for microbiological monitoring and the development of effective management strategies. The findings suggest P. lineatus as a potential bioindicator of antibiotic-resistant bacteria in marine environments.

The oral microbiota has a diversity of microorganisms that together maintain the homeostasis of the oral cavity. Disruptions in the balance of these microbial populations can lead to the development of oral and dental diseases. To characterize the normal oral microbiota of captive ophidians, samples were obtained from the oral cavity of eight Burmese pythons (Python bivittatus) and 11 royal pythons (Python regius), using oral swab, during routine evaluations. In the Laboratory-Antimicrobials, Biocides and Biofilms Unit at University of Trás-os-Montes e Alto Douro, the identification and antimicrobial susceptibility profile was determined using the Vitek^® 2 Compact automated device (bioMérieux, Marcy-l’Étoile, France). Of the 106 bacterial isolates obtained, 69% were Gram-negative species and 31% were Gram-positive bacteria. The genus Pseudomonas was the most frequently isolated. Chryseobacterium indologenes, Escherichia coli and Pseudomonas aeruginosa were the most isolated species. Antimicrobial susceptibility testing revealed that the phenotypic resistance was highest for nitrofurans (47.2%), beta-lactams (45.8%) and sulfonamides (30.6%). Twenty-one multidrug-resistant isolates (58.3%) were identified with Acinetobacter baumannii, Serratia plymuthica, Chryseobacterium indologenes, Providencia rettgeri and Pseudomonas aeruginosa showing the highest resistance frequencies.