Advisor(s)
Abstract(s)
Antibiotics are the elective drugs in bovine mastitis (BM) treatment, despite their low
rates of e ciency and e ectiveness and increasing risk of pathogen resistance. In this sense, it
is urgent to discover new and e ective antimicrobial agents to apply in BM control and even
treatment. Plant extracts have been widely recognized as a rich source of phytochemicals with
antimicrobial potential. Thus, the present work aims to compare the bioactivity of Eucalyptus globulus
and Juglans regia extracts against Staphylococcus aureus bovine mastitis strains with penicillin G. At
non-toxic concentrations, E. globulus exerted a bacteriostatic e ect in planktonic cells and J. regia had
no antimicrobial activity. Penicillin G, at minimum inhibitory concentration (MIC), demonstrated
bactericidal activity, but just for S. aureus 3, 5, 6 and ATCC 25923, while the other strains seem to have
acquired resistance. On the other hand, E. globulus and penicillin G in combination demonstrated
synergy, being the most e ective approach against S. aureus 1, 2 and 4. Thus, penicillin alone
and in combination with E. globulus or J. regia seems to be promissory strategies to control bovine
mastitis infections.
Description
Keywords
Bovine mastitis Eucalyptus globulus Labill Juglans regia L. Penicillin G Staphylococcus aureus
Citation
Gomes, Fernanda; Rodrigues, Maria Elisa; Martins, Natália; Ferreira, Isabel C.F.R.; Henriques, Mariana (2019). Phenolic plant extracts versus penicillin G: In vitro susceptibility of Staphylococcus aureus isolated from bovine mastitis. Pharmaceuticals. ISSN 1424-8247. 12, p. 1-8