| Congresso Brasileiro de Microbiologia 2023 | Resumo: 725-1 | ||||
Resumo:Mastitis is an inflammatory disease that affects mammary glands of animals, mainly goats and dairy cows, impacting on milk production and quality. The indiscriminate use of commercial antimicrobials causes bacterial resistance. Thus, the use of herbal medicines can help control microbial resistance. The aim with the work was to evaluate the in vitro antimicrobial activity of Commiphora leptophloeos crude ethanolic extract against isolates from goat and bovine mastitis cases. The study was carried out at the Laboratory of Animal Microbiology and Immunology at UNIVASF, Petrolina-PE. To obtain the extract, C. leptophloeos leaves were dried in a drying oven at an average temperature of 40 °C. After drying, the material was processed in a willey knife mill. Then, it was subjected to exhaustive maceration with 95% ethanol. To obtain the final extract, a rotary evaporator of reduced pressure with an average temperature of 50 °C was used. The broth microdilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract against six isolates of Staphylococcus aureus from bovine mastitis cases, four isolates of S. aureus and eight Staphylococcus warneri isolates from caprine mastitis cases, in addition to American Type Culture Collection (ATCC) strains: 25923 and 33591 of S. aureus, respectively, sensitive and resistant to methicillin, and 49454 of S. warneri. Initially, the bacteria were removed from the brain heart infusion plus 40% glycerol at -20 °C and cultured in Mueller - Hinton broth (MH broth) at 37 °C for 24 h. In 96-well microplates containing 100 µL of MH broth, 100 µL of extract at 25,000 µg/ mL diluted with 10% dimethyl sulfoxide, were added to the first three wells, followed by serial dilution 1:2. Then, 10 µL of the inoculum were added to all wells referring to the extract and positive control. Sterility and cell viability controls were performed. The microplate was incubated at 37 °C for 24 h for subsequent reading. With the aid of a replicator, the content of the wells was inoculated into a Petri dish containing MH agar, which was incubated at 37 °C for 24 h to obtain the MBC by bacterial growth observation. After that, 30 µL of 1% 2,3,5-triphenyl-tetrazolium chloride was added to each microplate wells, which was incubated for 40 min at 37 °C. The MIC was obtained by color changes. The extract, against S. aureus and S. warneri isolates from caprine mastitis cases and the ATCC of S. warneri, showed inhibitory activity at concentrations of 6,250 and 3,125 µ g/ml, respectively, but for CBM it was >12,500 µ g/ml. Bovine mastitis S. aureus isolates and ATCCs showed lower MIC (3,125 µg /ml) and MBC (3,125 to 6,250 µg /ml) than isolates of goat origin. It was concluded that C. leptophloeos crude ethanolic extract has potential to inhibit S. aureus and S. warneri growth from cases of caprine and bovine mastitis. Palavras-chave: antimicrobial activity, inhibitory concentration, herbal medicine, microorganisms Agência de fomento:Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) - Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco (FACEPE). | |||||