Healthcare-associated infections remain a central hospital challenge, particularly in critical areas where invasive procedures and microbial contamination overlap. The hospital environment, including air and high-touch surfaces, acts as a persistent microorganism source that favors stability and spread. UV-C disinfection systems have become complementary tools to conventional cleaning. This study evaluated the disinfectant efficacy of a 254 nm multiemitter UV-C system under in situ and in vitro conditions. A 254 nm UV-C multiemitter system was deployed to eight hospital areas selected for epidemiological relevance. Air and surface sampling were conducted before and after standardized UV-C cycles. The bacterial and fungal aerobiome was quantified (CFU/m³) and surfaces were characterized by MALDI-TOF mass spectrometry. In vitro assays tested efficacy against planktonic cultures and mature biofilms of clinical ESKAPE isolates and C. albicans. The UV-C intervention achieved mean aerobiome reductions above 91.5%, with complete elimination in multiple critical zones. Surface contamination was reduced by 96.1%, including total disinfection across several sampled points. In vitro testing showed ≥99.99% to 100% elimination of planktonic microorganisms. Mature biofilms exhibited full loss of viability after UV-C exposure, independent of biofilm architecture and structural complexity. Therefore, the 254 nm UV-C multiemitter system significantly reduced environmental microbial burden in critical hospital areas, supporting its integration within infection-prevention programs and reinforcing environmental biosafety through the control of the microbial sources involved in transmission dynamics.

Hospital wastewater (HWW) is increasingly recognized as an environmental hotspot for the selection and dissemination of antimicrobial resistance (AMR). Although surveillance programs primarily target ESKAPE pathogens, the contribution of environmental bacteria such as Aeromonas spp. remains poorly characterized. The aim of this work was to investigate antimicrobial resistance mechanisms, focusing on carbapenem and cephalosporin resistance, in Aeromonas spp. recovered from HWW. Thirty Aeromonas isolates were identified by rpoD restriction fragment length polymorphism analysis and characterized by antimicrobial susceptibility testing, detection of β-lactam resistance genes, class 1 integrons, and genetic relatedness using ERIC-PCR fingerprinting. All isolates exhibited operationally defined multidrug-resistant (MDR) or extensively drug-resistant (XDR) phenotypes, with resistance predominating against cephalosporins, carbapenems, and trimethoprim–sulfamethoxazole. The clinically relevant gene families/groups bla_KPC family, bla_OXA-48-like, bla_CTX-M group 1, and bla_SHV were detected by PCR, whereas bla_NDM, bla_VIM, bla_IMP, and mcr-1 were absent. Class 1 integrons were identified in 36.7% of isolates, revealing diverse cassette arrays carrying dfrA and aadA resistance genes. ERIC-PCR demonstrated high fingerprint diversity with limited genetic relatedness. Microbiological surveillance of HWW revealed that Aeromonas populations constitute an environmental reservoir of clinically relevant β-lactam resistance determinants, supporting further evaluation of their potential role in AMR surveillance strategies at the hospital–environment interface.