Phenotypic and Genotypic Characterization of Resistance and Virulence Markers in spp. Isolated from Community-Acquired Infections in Bucharest, and the Impact of AgNPs on the Highly Resistant Isolates.

Background: This study aimed to determine, at the phenotypic and molecular levels, resistance and virulence markers in spp. isolated from community-acquired infections in Bucharest outpatients during 2021, and to demonstrate the efficiency of alternative solutions against them based on silver nanoparticles (AgNPs).

Methods: A total of 62 spp. strains were isolated from dermatomycoses and identified using chromogenic culture media and MALDI-TOF MS, and then investigated for their antimicrobial resistance and virulence markers (VMs), as well as for metabolic enzymes using enzymatic tests for the expression of soluble virulence factors, their biofilm formation and adherence capacity on HeLa cells, and PCR assays for the detection of virulence markers and the antimicrobial activity of alternative solutions based on AgNPs.

Results: Of the total of 62 strains, 45.16% were ; 29.03% ; 9.67% ; 3.22% , and ; and 1.66% , , , and . Aesculin hydrolysis, caseinase, and amylase production were detected in the analyzed strains. The strains exhibited different indices of adherence to HeLa cells and were positive in decreasing frequency order for the , , and , genes (/). An inhibitory effect on microbial growth, adherence capacity, and on the production of virulence factors was obtained using AgNPs.

Conclusions: The obtained results in and non- circulating in Bucharest outpatients were characterized by moderate-to-high potential to produce VMs, necessitating epidemiological surveillance measures to minimize the chances of severe invasive infections.