Enterococci are environmentally persistent bacteria that are relevant to both water quality and the spread of antimicrobial resistance. This study aimed to phenotypically and genotypically characterize Enterococcus spp. isolated from freshwater (lakes and rivers) in north–central Poland, with a focus on antimicrobial susceptibility, virulence genes, and biofilm-forming capacity. Surface water samples were collected during the vegetation seasons of 2022 and 2023. Enterococci were isolated by culture-based methods and confirmed by MALDI-TOF MS. Antimicrobial susceptibility testing (AST) was performed using the disk diffusion method, virulence-associated genes were detected by multiplex PCR, and biofilm formation was evaluated using a crystal violet assay. In total, 96 Enterococcus spp. isolates representing 12 species were identified from 328 freshwater samples, with E. faecalis (24.0%) and E. hirae (21.9%) being the most frequently isolated. Thirty-one isolates (32.3%) were resistant to at least one antibiotic, and two isolates were classified as multidrug-resistant. The most prevalent virulence genes were gelE, srtA, and hyl. The ace gene was detected exclusively in E. faecalis. Most isolates were non-biofilm producers, while biofilm formation was confirmed in 8 strains (6 weak and 2 moderate producers), with no strong biofilm-forming strains detected. These findings suggest that freshwater ecosystems may constitute important reservoirs of antimicrobial-resistant and virulence-associated Enterococcus spp., underscoring the importance of continuous surveillance within the One Health framework.

Cisplatin remains a widely used anticancer agent; however, its effectiveness can be influenced by systemic toxicity, resistance mechanisms, and interactions with exogenous compounds. Nicotinamide (vitamin B3), an NAD⁺ precursor and a commonly used dietary supplement, is involved in cellular metabolism, redox homeostasis, and DNA repair pathways, which may potentially modulate the cellular responses to Platinum-based agents. Here, we combine chemical synthesis, computational studies, spectroscopic analysis, and biological assays to investigate the molecular and biological aspects of Cisplatin–Nicotinamide interactions. A novel cis-[Pt(NH₃)₂NicotinamideCl]NO₃ complex was obtained and its structure analyzed. Density functional theory (DFT) calculations indicate a thermodynamically favorable coordination of Nicotinamide to the first hydrolysis product of Cisplatin (CisPt1) with binding energies comparable to those calculated for nucleobase coordination under the same theoretical conditions. In non-small cell lung cancer cell lines (A549 and PC-9), in vitro results suggest that Nicotinamide pre-treatment reduces Cisplatin cytotoxicity under specific experimental conditions, but the pre-formed complex does not exert anticancer effects. These data are consistent with a model in which Nicotinamide may interact with reactive Cisplatin species, potentially contributing to the reduced availability of reactive Platinum(II) species. This work provides mechanistic insight into potential drug–nutrient interactions involving Platinum-based chemotherapy and highlights the need for further investigation under clinically relevant conditions in the near future.

The recent SARS-CoV-2 pandemic—which had significant worldwide health, economic, and other effects—indicated the need to monitor zoonotic viruses with pandemic potential. The aim of this review is to assess bat-borne viruses as a potential pandemic risk, with a particular focus on Europe. The presence and activity of bats, as well as diseases emerging in humans in various regions of the world, point to their importance in the context of a possible outbreak of future epidemics. The rate of genetic change observed among viruses requires constant scrutiny on all continents, including Europe. Bats are a considerable source of many zoonotic viruses, including coronaviruses, filoviruses and paramyxoviruses. Among viruses associated with bats, RNA viruses are the dominant ones, characterized by high pathogenicity and often leading to interspecies transmission. The majority (about 80%) of RNA viruses were identified in bats from three families: Vespertilionidae, Rhinolophidae and Pteropodidae. Understanding how viruses are transmitted in the environment and the role of reservoir organisms and intermediate hosts is crucial to determining the level of epidemic risk. This review discuses viruses identified in bats globally, with a special focus on Europe, and evaluates their potential to cause epidemics.

Environmental microbiology provides essential tools for understanding and managing biological risks in sustainable agricultural systems. Organic farming, which prioritises closed nutrient cycles, soil biological activity and reduced reliance on synthetic inputs, exemplifies the principles of sustainable agriculture. Yet the same practices that support agroecosystem functioning—application of animal manure, outdoor livestock access and limited use of chemical disinfectants—can increase the environmental occurrence of pathogenic microorganisms, antimicrobial-resistance determinants and other biological contaminants. This review examines how concepts and methods of environmental microbiology can be adapted to strengthen pollution control, food safety and agroecosystem resilience in organic production. Major biological hazards are evaluated, including enteric bacteria (Campylobacter spp., Shiga toxin-producing Escherichia coli, Salmonella spp., Listeria monocytogenes), antimicrobial-resistant bacteria and resistance genes, foodborne viruses, intestinal parasites and mycotoxins (as secondary metabolites of filamentous fungi). Quantitative microbial risk assessment (QMRA) is presented as a framework that links environmental occurrence data to public-health outcomes and identifies critical control points along the farm-to-fork continuum. Transmission pathways through organic fertilisers, soil, irrigation water and agricultural bioaerosols are analysed together with microbial survival strategies (biofilm formation, the viable-but-non-culturable state and internalisation into plant tissues). Available evidence indicates that microbiological risks appear to be driven more by management practices than by the organic or conventional production label itself; however, this conclusion must be interpreted with caution because comparative studies are frequently confounded by geographical area, livestock and housing type, farm size, climatic conditions, antimicrobial-use patterns, manure-treatment regimes and methodological differences. Validated composting, appropriate pre-harvest intervals, protection of water sources, biosecurity measures and continuous environmental monitoring effectively reduce pathogen dissemination while preserving the ecological benefits of organic farming. Lower antimicrobial resistance in organic livestock further contributes to pollution control within a One Health perspective. Occupational exposure to bioaerosols remains a relevant concern for farmers’ health, yet differences between organic and conventional systems are driven more by activity type and housing conditions than by certification status. By integrating environmental microbiology, quantitative risk assessment and practical management strategies, this review provides a distinctive One Health framework for adapting microbial knowledge to organic systems in a way that simultaneously advances pollution control, food safety and agroecosystem functioning. Importantly, elevated occurrence of a hazard does not automatically equate to elevated health risk; the latter requires quantitative exposure assessment within a QMRA framework.