INTRODUCTION. Staphylococcus aureus and Streptococcus pyogenes are microbial agents of bullous and non-bullous impetigo, respectively. Treatments are based on both topical and oral antibiotics. Adverse effects and the selection of resistant strains are the main drawbacks of the therapy. Essential oils (EOs) could be good candidates for new therapy.
MATERIALS AND METHODS. A bibliographic search was carried out to identify studies based on the efficacy of EOs against Impetigo strains. Nine EOs were selected and tested against nine clinical strains (three of S. aureus, three of S. pyogenes and three of Staphylococcus epidermidis) using the broth microdilutions test. Two of the most active OEs (L. stoechas and P. graveolens) were used to formulate four mixtures. An olfactory satisfaction study was conducted on 100 volunteers to identify the most pleasant blend. A commercial juice and a gel of Aloe vera (A. vera) were used to formulate topical gels that were analyzed both in solid-phase microextraction coupled to GCMS to evaluate their chemical composition and using a micro broth-dilution method to confirm the efficacy.
RESULTS. 16 articles and 14 EOs were selected from the literature. Eight EOs were chosen to develop microbiological investigations. Six of the eight EOs showed greater antimicrobial activity on non-bullous impetigo strain (S. pyogenes) than on the non-pathogenic one (S. epidermidis). L. stoechas and P. graveolens EOs were chosen to develop formulations for topical use, and a mixture of these, pleasant for both men and women, was selected. Two types of Aloe vera-based formulations were developed. The chemical analysis showed the overlapping composition of the two formulations, but only that obtained from the A. vera juice maintained its antimicrobial effectiveness.
CONCLUSIONS. L. stoechas and P. graveolens EOs showed microbiological effectiveness against non-bullous impetigo. However, these EOs must be formulated masterfully avoiding homemade formulations with commercial products containing preservatives.