Tatiana Alves Reis

Filamentous fungi are common airborne contaminants in hospitals, posing significant risks to immunocompromised patients. This study assessed the diversity, seasonal distribution, and antifungal susceptibility of airborne filamentous fungi, with a focus on Aspergillus spp., in two inpatient wards of a tertiary hospital in southeastern Brazil. Air samples were collected seasonally from November 2022 to September 2023 using a six-stage Andersen sampler. Fungal isolates were identified based on macro- and micromorphological characteristics, and Aspergillus spp. were further characterised by β-tubulin gene sequencing. In vitro susceptibility to amphotericin B (AMB), itraconazole (ITR), voriconazole (VOR), posaconazole (POS), and anidulafungin (AFG) was evaluated following CLSI guidelines. A total of 583 filamentous fungi were isolated, with Penicillium , Cladosporium and Aspergillus as the most prevalent genera. Fungal concentrations were higher in humidified air and decreased after installation and maintenance of the air-conditioning system. Fourteen Aspergillus species were identified across eight sections, including emerging and cryptic taxa such as A . subramanianii , A . sclerotiorum and A . alboviridis . Resistance to ITR was detected in one isolate of A . fumigatus and one of A . flavus , while isolates from emerging species of the section Circumdati exhibited elevated MICs for AMB and triazoles. All isolates demonstrated low AFG MECs. The study highlights the importance of routine environmental surveillance and antifungal susceptibility testing in hospital settings. The detection of potentially resistant Aspergillus species in hospital air emphasises the need to enhance ventilation, monitoring, and diagnostic capabilities to mitigate the risks of healthcare-associated fungal infections.

Penicillium piscarium can be indicated as promising in the treatment of sites contaminated with uranium. Thus, this research aimed to analyze the P. piscarium dead biomass in uranium biosorption. This fungus was previously isolated from a highly contaminated uranium mine located in Brazil. Biosorption tests were carried out at pH 3.5 and 5.5 in solutions contaminated with concentrations of 1 to 100 mg/L of uranium nitrate. Our results showed that the dead biomass of P. piscarium was able to remove between 93.2 and 97.5% uranium from solutions at pH 3.5, at the end of the experiment, the pH of the solution increased to values above 5.6. Regarding the experiments carried out in solutions with pH 5.5, the dead biomass of the fungus was also able to remove between 38 and 92% uranium from the solution, at the end of the experiment, the pH of the solution increased to levels above 6.5. The analysis of electron microscopy, Energy‐dispersive spectroscopy, and X‐ray fluorescence demonstrated the high concentration of uranium precipitated on the surface of the fungal biomass. These results were impressive and demonstrate that the dead biomass of P. piscarium can be an important alternative to conventional processes for treating water contaminated with heavy metals, and we hope that these ecofriendly, inexpensive, and effective technologies be encouraged for the safe discharge of water from industrial activities.

Fusarium verticillioides is one of the main pathogens of maize, causing ear and stalk rots. This fungus is also able to produce high levels of fumonisins, which have been linked to various illnesses in humans and animals. Previous studies have shown that maize hybrids genetically modified with the cry genes from the bacterium Bacillus thuringiensis (Bt) presented lower incidence of F. verticillioides and fumonisin levels, presumably through the reduction of insects, which could act as vectors of fungi. The aim of this study was to assess the incidence of F. verticillioides and the concentration of fumonisins in Bt and isogenic non-Bt hybrids (2B710Hx, 30F35YG, 2B710, and 30F35, respectively). The samples of 2B710Hx and 30F35YG presented lower F. verticillioides frequency than 2B710 and 30F35 samples. However, there was no statistical difference between fumonisin contamination when Bt and non-Bt samples were compared (P > 0.05). The results suggest that other environmental parameters could possibly trigger fumonisin production during plant development in the field; consequently, other management strategies should be applied to aid controlling fumonisin contamination in maize.

The aim of this study was to evaluate the effects of gamma radiation (GR) and electron beam (EB) on Brazil nut samples contaminated with Aspergillus flavus. Fifty samples were spread with an A. flavus suspension and incubated at 30°C and a relative humidity of 93%. After 15 days of incubation, mycobiota and aflatoxin analysis were performed. The samples were divided into three groups (control, group 1, and group 2) that received radiation doses of 0 kGy (control) and 5 and 10 kGy each of GR and EB (groups 1 and 2). Noninoculated samples were irradiated with the same doses for sensory evaluation. The results showed that after 15 days of incubation, the average water activity of the samples was 0.80. The irradiation with GR and EB at doses of 5 and 10 kGy was able to eliminate A. flavus in Brazil nut samples. Aflatoxin analysis showed that EB doses of 5 and 10 kGy reduced aflatoxin B1 levels by 53.32 and 65.66%, respectively, whereas the same doses of GR reduced the levels of this toxin by 70.61 and 84.15% ...