Disinfectant-induced bacterial resistance and antibiotic cross-resistance—mechanisms and clinical relevance

The rise of antibiotic-resistant bacteria has become an alarming global health challenge. Disinfectants, such as alcohols, aldehydes, chlorine compounds, phenols, quaternary ammonium compounds (QACs), peroxides, and chlorhexidine, are widely used in healthcare settings as a critical line of defense against infection. Nevertheless, their overuse or misuse, especially at subinhibitory concentrations, can promote the emergence of bacterial resistance, potentially leading to cross-resistance to antibiotics. Several mechanisms, including efflux pump activation, alterations in membrane permeability, and biofilm formation, drive this process. A possible concern, although currently supported by limited and sometimes conflicting evidence-is that biocide-induced resistance might contribute indirectly to adverse clinical outcomes, such as treatment challenges, prolonged hospital stays, and increased healthcare costs. This review examines the molecular mechanisms of disinfectant-induced resistance, the epidemiological impact of multidrug-resistant (MDR) pathogens, and contemporary infection control strategies. Furthermore, the review evaluates the benefits and risks associated with disinfectant use, underscoring the necessity for optimized, evidence-based disinfection protocols to minimize the development of resistance while ensuring effective infection prevention.