The effect of exposure to mupirocin on the survival and recovery of sensitive Staphylococcus aureus strains

A significant percentage survival, representing a large number of viable cells, can occur in a Staphylococcus aureus population exposed to concentrations of mupirocin up to 1,000 times the minimum inhibitory concentration. An elevated ratio of minimum inhibitory to minimum bactericidal concentration of mupirocin with staphylococci was recorded. Staphylococci which survive exposure to mupirocin may be less sensitive to the subsequent bactericidal action of the antibiotic. The observations may explain the re-colonisation with staphylococci seen in some studies.