Does microbial resistance or adaptation to biocides create a hazard in infection prevention and control?

An investigation of the bactericidal activity of chlorhexidine digluconateagainst multidrug-resistant hospital isolates

“…However, a resistance can be relevant if the logarithmic decrease value is also below 5. This means that it is important to evaluate the bactericidal impacts rather than the inhibitory effects of biocides (4,6,20). Thus, in comparing the results of different studies, the methods employed should also be taken into consideration.…”

“…There is no clear evidence that there is a link between antibiotic resistance and biocide resistance and studies still continue in this area (3,5,7,20,23). The fact that antibiotic and biocide resistance mechanisms are similar suggests that there is a possible link between them (3).…”

“…Some published studies demonstrate that, in hospitals, the contact of bacteria with biocides at low concentrations can create selective pressure for some isolates, similar to the subinhibitory concentration effects of antibiotics (2,3,20,27). In a recent study, it was also reported that quaternary ammonium compounds used in lower concentrations caused an increase in expression of virulence genes in bacteria (28).…”

“…Thus, it appears that biocide concentration is a major factor in the development of bacterial resistance. If the surface to be disinfected was not clean and yet to be dried after disinfection, if the disinfectant was prepared at lower concentrations than in-use concentrations, and if the diluted disinfectant was kept longer than suggested by the manufacturer, then a low concentration of biocide is in contact with the bacteria (20). Irrizary et al showed that chlorhexidine digluconate residues can have a selective effect on MRSA isolates (29).…”

Effects of biocide exposure on P. Aeruginosa, E. coli and A. Baumannii complex isolates from hospital and household environments

“…baumannii has been also reported as a frequently isolated pathogen at ICU (49%) 64.7% showing multidrug resistance 8 . One way to reduce the spread of nosocomial infections is through the strict monitoring of cleaning and disinfection protocols 9 . Most commonly used biocides have bactericidal effects at the concentrations recommended by the manufacturer, however some studies have suggested that over time, bacteria may develop resistance to these compounds, allowing their survival even at concentrations considered to be lethal 2 .…”