Resumo

Mastitis is an inflammatory reaction in the parenchyma of the mammary gland and can be infectious, traumatic or toxic. Antibiotic resistance in bacteria is one of the emerging health related problem in the world nowadays. Algal crude extracts can be natural source of efficient anti-microbial agents of valuable practice in pharmacology. This study aims to evaluate the antimicrobial activity of the extract obtained from chlorophyte Chlorella vulgaris (UTEX 1803) against Staphylococcus spp. isolated from bubaline mastitis in Brazilian state of Pernambuco. C. vulgaris grown in 1 L flasks with 400 mL of liquid medium Bold's Basal, an initial biomass concentration of 50 mg/L, under aeration with air pump, light intensity at 14 µmol photons m^-2 s^-1 and at room temperature. Microalgae biomass was collected in the early stationary phase of growth, which subsequently was centrifuged and lyophilized. Biomass lyophilized was resuspended in phosphate buffer (pH 7.0) at a concentration of 50 mg/mL, and sonicated for 10 minutes. After cell disruption, the cell extract was centrifuged and the supernatant (extract) was used to antimicrobial activity test of using disk and cup-well diffusion agar methods according NCCLS guidelines. Initially, we selected six bacteria of the genus Staphylococcus spp. isolated from bubaline mastitis (namely, 1A, 12A, 19, 21, 27A, 27B). In both techniques antimicrobial activity (disk and cup-well diffusion) the microbial strains evaluated were not inhibited by the C. vulgaris cell extract, showing resistance against substance antimicrobial presents in microalgae C. vulgaris extract. It is thought that, perhaps, using these techniques, there has been retaining the extract dispersion in the agar medium contained the bacteria, and, consequentially, preventing the extract antimicrobial activity. Other antimicrobial activity methods are being studied for strains of Staphylococcus spp. mastitis-infected buffalo.