Microrganismos endofíticos isolados de Anacardium humile associados a óleos essenciais e fibras poliméricas para o tratamento tópico de infecções cutâneas

Abstract

Bacterial infections represent a widely recognized health problem and can be triggered by superficial or deep skin lesions. This scenario, combined with the growing number of cases of bacterial resistance, has intensified interest in research into new antimicrobials, both as complementary options and as more efficient forms of administration.Anacardium humile,A plant native to the Brazilian Cerrado and used in the food, cosmetic, and pharmaceutical industries, it has potential as a source of bioactive metabolites. The microorganisms that inhabit the internal tissues of plants stand out as a promising alternative to the excessive use of antibiotics, as they act in the biological control of phytopathogens and produce metabolites of biotechnological interest. Furthermore, submicron fiber mats have proven relevant in the development of dressings, as they enable the slow release of drugs due to their large surface area and high porosity. In this context, the present study aimed to evaluate the endophytic microbial diversity isolated fromAnacardium humile,with emphasis on its biological control potentialin vitro and in the characterization of enzymes produced by these microorganisms, that act as producers of secondary metabolites, evaluating their physiological and morphotintorial characteristics and their antagonic functions.Of the 65 bacterial isolates, amylase (73.8%), cellulase (43%), lipase (3%) and esterase (3%) enzymatic activities were observed, however, only 4 isolates obtained relevant inhibition halos, but only 2 isolates were identified that presented positive results for the 3 clinical strains.E. coli, S. aureus, and C. albicans. The 16S rDNA gene of 2 endophytic bacteria isolated fromAnacardium humilewas sequenced for taxonomic identification purposes. Molecular analysis revealed the presence of 2 bacterial species, namelyBacillus subtilisandBacillus amyloliquefaciensThese bacterial species were subjected to a growth curve characterization test to evaluate the best fermentation period for the endophytic microorganisms. The endophytic metabolic extracts were combined with basil, limonene, and clove essential oils, complementing the antagonistic action against strains ofE. coli, S. aureus and C.albicans and subsequently incorporated into polymeric fiber webs produced by solution blow spinning. The incorporation of lyophilized metabolic extracts ofB. amyloliquefaciens and B. subtilisassociated with essential oils in fiber sheets of the commercial biopolymer Ecovio F2332, were produced using the solution blow spinning (SBS) technique. Although the sheets presented a smaller inhibition zone when compared to the metabolic extracts associated with essential oils, their use was necessary because the extracts presented cytotoxic results, which was not observed in the spun polymer sheets, indicating the potential of these platforms for further studies for applications in skin dressings