A liquid antimicrobial composition is provided for use in the disinfection of the skin of a human or an animal, in particular where disinfection of a drug resistant organism is required. The composition comprises a cationic, cell membrane-disrupting biocide and a cationic dendrimer. The cationic, cell membrane-disrupting biocide is chlorhexidine in the form of a gluconate or of an acetate salt that is present in a concentration between 0.25% and 6.00% w/v inclusive. The cationic dendrimer is any of a generation 0 to generation 3 dendrimer or a combination of same and is any or a combination of quaternary ammonium functionalised poly(propylene imine), polyamidoamine (PAMAM) dendrimers, polylysine, and dendrimers with surface groups based on a sugar. The dendrimer is provided to bind and disrupt the cell membranes of microorganisms in order to inhibit or destroy the cell's efflux pump mechanism thereby preventing microorganism strains resistant to the cationic membrane-disrupting biocide from becoming prevalent. The composition is in the form of an aqueous or aqueous alcohol solution, dispersion or emulsion that may have been adsorbed by a wipe.
