Antiseptics: Their Characteristics, Application and Challenges in the 21St Century Resulting from the Spread of Antimicrobial Resistance (AMR)

In the context of escalating microbial resistance to antibiotics, antiseptics are gaining prominence as a critical component of infection prevention. Concurrently, the widespread and increasing use of these biocides, particularly within healthcare settings, has prompted concerns regarding their potential contribution to the emergence of reduced microbial susceptibility to them and the phenomenon of cross-resistance to antibiotics. This review focuses on four widely utilized antiseptics: chlorhexidine, octenidine, povidone-iodine, and alcohols. It was discusses their antimicrobial activity, mechanisms of action, and applications, including available preparations and the minimum effective concentrations required for reliable pathogen eradication. Current evidence regarding the mechanisms underlying decreased susceptibility to these agents is summarized. Furthermore, the review presents data from studies investigating the impact of prolonged exposure to subinhibitory concentrations of antiseptics on the induction of reduced antimicrobial efficacy and the potential for co-selection of antibiotic resistance. Furthermore, the review presents methods of adaptation of bacteria and fungi to increasing concentrations of antiseptics, including techniques using liquid media - gradient method and incremental method, as well as methods based on solid media. Findings from recent studies suggest that long-term exposure of microorganisms to subinhibitory concentrations of antiseptics may result in reduced effectiveness of these agents and selection of mutants with changed sensitivity to antibiotics.