Original scientific paper

https://doi.org/10.2478/aiht-2026-77-4065

Marked variations in the effectiveness of commercial disinfectants against clinically relevant antibiotic-resistant bacteria and fungi

Josip Figl ; University Hospital Centre Zagreb, Department of Surgery, Zagreb, Croatia
Stjepan Nemec ; University of Zagreb Faculty of Science, Department of Biology, Zagreb, Croatia
Zrinka Bošnjak ; University Hospital Centre Zagreb, Department of Clinical and Molecular Microbiology, Zagreb, Croatia
Ana Budimir ; University Hospital Centre Zagreb, Department of Clinical and Molecular Microbiology, Zagreb, Croatia
Tomislav Ivanković orcid.org/0000-0002-2293-9567 ; University of Zagreb Faculty of Science, Department of Biology, Zagreb, Croatia

Abstract

Effective disinfection of noncritical hospital surfaces may be essential for limiting the transmission of antibiotic-resistant bacteria (ARB), which seem to persist despite clear disinfection guidelines and raise concern about the potency of real-world disinfectants and about the consistency of disinfection practices. This study compared the bactericidal efficacy of eight commercially available disinfectants – alcohols, hydrogen peroxide, quaternary ammonium compounds (QACs), and chlorhexidine (CHX) – against multidrug-resistant clinical isolates of Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Enterococcus faecium, carbapenem-resistant Pseudomonas aeruginosa, and model organism Candida albicans as the most frequent causes of hospital-acquired infections in Croatia. Several formulations, particularly those based on QACs and CHX, retained full bactericidal activity even when diluted 10–32 times after only 1 min of contact, while alcohols were ineffective when diluted more than twice. However, all the formulations were effective when applied at full concentration. These findings highlight marked differences in the intrinsic bactericidal strength of commercial products, especially if not applied properly, which may explain variable outcomes observed in routine hospital disinfection practices. These issues may be overcome by rotating different disinfectant classes during routine surface decontamination and by optimising disinfectant strength to improve ARB and fungal control in clinical settings.

Keywords

Acinetobacter baumannii; alcohols; Candida albicans; carbapenem-resistance; chlorhexidine; Enterococcus faecium; hospital-acquired infections; hydrogen peroxide; Klebsiella pneumoniae; minimal bactericidal concentration; noncritical surfaces; quaternary ammonium compounds; Staphylococcus aureus

Hrčak ID:

348053

URI

https://hrcak.srce.hr/348053

Publication date:

19.6.2026.

Article data in other languages: croatian

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