Association between Effect of Biocides in Subinhibitory Concentrations and Antibiotic Resistance in Enterococcus faecalis

Abstract

Biocides are very effective against huge spectrum of microorganisms and are used in wide range. Recent research pointed out on fact that there could be connection between use of biocides and development of antibiotic resistance. This paper assesses long-term effect of common biocides in subinhibitory concentrations on the development of antibiotic resistance in Enterococcus faecalis. We have studied effect of three common biocides – NaClO, ClO₂ and H₂O₂/Ag. Obtained data showed, that all biocides decreased susceptibility of E. faecalis to ampicillin. In case of H₂O₂/Ag also gentamicin resistance has developed after long-term treatment. On the other hand, this biocide has caused loss of vancomycin resistance in E. faecalis. This suggests very important fact; however vancomycin resistant enterococci are according to WHO classified as pathogens with high priroty.