title: In vitro antimicrobial activity of plant-derived diterpenes against bovine mastitis bacteria.
abstract: We evaluated the antibacterial activity of three diterpenes isolated from natural sources against a panel of microorganisms responsible for bovine mastitis. ent-Copalic acid (CA) was the most active metabolite, with promising MIC values (from 1.56 to 6.25 µg mL-1) against Staphylococcus aureus (ATCC and clinical isolate), Staphylococcus epidermidis, Streptococcus agalactiae, and Streptococcus dysgalactiae. We conducted time-kill assays of CA against S. aureus, a commensal organism considered to be a ubiquitous etiological agent of bovine mastitis in dairy farms worldwide. In the first 12 h, CA only inhibited the growth of the inoculums (bacteriostatic effect), but its bactericidal effect was clearly noted thereafter (between 12 and 24 h). In conclusion, CA should be considered for the control of several Gram-positive bacteria related to bovine mastitis.
authors.affiliation: Nucleus of Research in Sciences and Technology, University of Franca, Armando Salles de Oliveira Road, 201, Franca 1404-600, Brazil.
authors.forename: Ariana P
authors.initials: AP
authors.lastname: Fonseca
authors.forename: Fernanda T
authors.initials: FT
authors.lastname: Estrela
authors.forename: Thaís S
authors.initials: TS
authors.lastname: Moraes
authors.forename: Luiza J
authors.initials: LJ
authors.lastname: Carneiro
authors.forename: Jairo K
authors.initials: JK
authors.lastname: Bastos
authors.forename: Raquel A
authors.initials: RA
authors.lastname: dos Santos
authors.forename: Sérgio R
authors.initials: SR
authors.lastname: Ambrósio
authors.forename: Carlos H G
authors.initials: CH
authors.lastname: Martins
authors.forename: Rodrigo C S
authors.initials: RC
authors.lastname: Veneziani
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002417:Cattle; D004224:Diterpenes / Q000737:chemistry / Q000494:pharmacology*; D005260:Female; D008414:Mastitis, Bovine / Q000188:drug therapy* / Q000382:microbiology; D035742:Mikania / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000472:pathogenicity
chemical_list: D000900:Anti-Bacterial Agents; D004224:Diterpenes; D010936:Plant Extracts; C556511:copalic acid