Anais do Congresso Paranaense de Microbiologia
IV Congress of Microbiology in Paraná

In view of the increasing resistance to synthetic antimicrobials and the incidence of pathogens in public health, there has been great interest in researching native brazilian species in the search for bioactive plants with biological potential that can act in the control of pathogenic microorganisms. Myrsine umbellata Mart. belongs to the family Primulaceae, is a native Brazilian plant found in the Northeast and South regions and due to its therapeutic effects is widely used in folk medicine in herbal medicine.This plant is used to treat liver disease, skin disease and leprosy. Therefore, the objective of this study was to identify the phytochemical compounds of the leaves of the native species Myrsine umbellata Mart. (Primulaceae); assess the antibacterial potential of methanolic, acetonic, ethanolic and hexanic extracts in eleven standard bacterial strains (ATCC) of clinical and veterinary importance and determine the yield of the extracts. The presence of secondary metabolites was analyzed by observing color changes or precipitate formation reactions and the antimicrobial activity was determined by the broth microdilution methodology. Phytochemical prospecting detected the presence of classes of compounds: saponins, free steroids, alkaloids, anthocyanins, anthocyanins, flavonoids, flavones, flavanonols and tannins. Hexanic extract showed the greatest diversity of secondary metabolites, with nine different classes of compounds: alkaloids, free steroids, anthocyanins, anthocyanidins, flavonoids (flavanonoids, flavones, flavonois and xanthons) and tannins. Hexane was considered the best extraction solvent. The methanolic extract presented the best yield with value of 24.75%, followed by ethanolic extract of 13.28%, acetic extract of 8.39%, and the lowest yield was observed in hexanic extract of 5.98%. All extracts of leaves of M. umbellata showed antibacterial activity in the strains tested. The methanolic extract presented the best results of minimum inhibitory concentration (MIC) for the standard strains, ranging from 3.12 mg/mL to 25 mg/mL. The most susceptible bacterial strains were gram-positive: Staphylococcus epidermidis (ATCC 12228) (MIC 3,12 mg.mL-1) and Enterococcus faecalis (ATCC 19433) (MIC 6,25 mg.mL-1) and gram-negative: Salmonella enterica Typhimurium (ATCC 14028) (MIC 6,25 mg.mL-1), Pseudomonas aeruginosa (ATCC 27853) (MIC 3,12 mg.mL-1), Proteus mirabilis (ATCC 25933) (MIC 3,12 mg.mL-1). The results of this study suggest that M. umbellata represents a promising species for obtaining bioactive plants and developing natural antimicrobials.