Low Phenotypic Chlorhexidine Resistance in Methicillin-Resistant Staphylococcus aureus (MRSA) Despite the Presence of Resistance Genes

Decolonization strategies using chlorhexidine (CHX) aim to reduce methicillin-resistant Staphylococcus aureus (MRSA) infections and spread. Since CHX resistance has been reported in association with its use, we investigated CHX susceptibility of 78 MRSA clinical isolates, changes in their MICs upon exposure to sub-lethal CHX concentration and the prevalence of genes associated with CHX resistance. Despite the presence of resistance-associated genes, none of the isolates showed resistance to CHX and no induction of resistance was observed.