Understanding the interplay between antifungal resistance, stress adaptation, and virulence in Aspergillus fumigatus is critical for more effective treatment outcomes. In this study, we investigate six clinical isolates of A. fumigatus from the hospitals of the Czech Republic, focusing on their resistance profiles, stress responses, and survival mechanisms under antifungal pressure. Notably, we have shown that azole-susceptible strains were able to form persister cells under supra-MIC concentrations, highlighting an emerging non-genetic survival mechanism. Stress response profiling demonstrated differential susceptibility to agents targeting signal transduction pathways, as principal component analysis proved that even azole-resistant strains might rely on these pathways. Combinatorial treatment with posaconazole and dithiothreitol enhanced antifungal efficacy regardless of the susceptibility of the strains. Fitness assays revealed that azole resistance imposed a competitive disadvantage in azole-free conditions. In vivo virulence assessment in Galleria mellonella larvae revealed strain-specific pathogenicity that did not directly correlate with resistance. Together, our findings illustrate the multifactorial nature of fungal survival and emphasize that stress adaptation, tolerance, and persistence significantly affect treatment efficacy and outcomes, even in the absence of classical resistance mechanisms. Targeting stress response pathways emerges as a promising strategy to enhance the efficacy of existing antifungal agents and manage resistance in A. fumigatus.

Antimicrobial-resistant faecal bacteria represent an increasing environmental concern in surface waters impacted by anthropogenic activities. Surveillance of enterococci and coliform bacteria, particularly Escherichia coli, is widely used to assess the dissemination of antimicrobial resistance in aquatic environments. These ecosystems may act as reservoirs of resistance determinants, where subinhibitory antibiotic concentrations promote their persistence and horizontal transfer, posing a potential public health risk. This study aimed to survey antibiotic‑resistant coliform bacteria and enterococci in surface waters and associated sediments in the southern part of central Slovakia. Total coliforms were detected in all analysed water and sediment samples. E. coli was present in 50% of water samples and 75% of sediment samples, with sediments generally containing higher concentrations of both total coliforms and E. coli. Resistant coliform isolates predominantly exhibited multidrug resistance and strong biofilm‑forming capacity. Genes encoding broad‑spectrum β‑lactamases were detected in most isolates, with bla_TEM being the most prevalent. In isolates with reduced carbapenem susceptibility, bla_NDM was detected. Enterococci were detected in 63% of water samples and 75% of sediment samples, including En. faecalis, En. faecium, and En. durans. High resistance to ampicillin and vancomycin was observed, and three isolates carried the vanA resistance gene. These findings highlight the role of surface waters in disseminating antimicrobial resistance in Slovakia and underscore the importance of continued surveillance in aquatic ecosystems.