Acitretin induces an increased adherence of S. aureus to epithelial cells

Recently, synthetic retinoids have been implicated as causing a rise in the incidence of staphylococcal infections in patients orally treated with these compounds for various disorders of keratinization. Since the adherence of bacteria to epithelia is an important early event in the development of bacterial infections, in the present study we investigated the in vitro effects of acitretin on the adherence of Staphylococcus aureus to epithelial cells of the anterior nares of 15 healthy human subjects. It was found that pre-incubation of nasal epithelial cells with acitretin causes a statistically significant (p less than 0.001) increase in the adherence of S. aureus to these cells, as compared to the controls. The growth of S. aureus cultures in the presence of acitretin exerted no effect on the staphylococcal adherence. These results suggest that the oral acitretin-induced increase in S. aureus colonization and in the incidence of cutaneous staphylococcal infections may be related to the enhancement of staphylococcal adherence to epithelia caused by this compound.