Open AccessAntimicrobial activity of selected essential oils against Streptococcus suis isolated from pigs
Author(s) -
de Aguiar Fabiana C.,
Solarte Ana Lucía,
Tarradas Carmen,
Luque Inmaculada,
Maldonado Alfonso,
GalánRelaño Ángela,
Huerta Belén
Publication year - 2018
Publication title -
microbiologyopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.881
H-Index - 36
ISSN - 2045-8827
DOI - 10.1002/mbo3.613
Subject(s) - broth microdilution , minimum inhibitory concentration , minimum bactericidal concentration , antimicrobial , streptococcus suis , essential oil , agar diffusion test , food science , traditional medicine , chemistry , microbiology and biotechnology , biology , antibacterial activity , bacteria , medicine , biochemistry , genetics , virulence , gene
The inhibitory potential by contact and vapor of basil, cinnamon, clove, peppermint, oregano, rosemary, common thyme, and red thyme essential oils ( EO s) against 20 strains of Streptococcus suis was determined by the disk diffusion test. The broth microdilution method was used to determine the minimal inhibitory and minimal bactericidal concentration ( MIC and MBC ) of the four selected oils. Furthermore, the bactericidal power (ratio MBC / MIC ) was calculated. The EO s with the major potential in the disk diffusion method were red thyme, common thyme, oregano, and cinnamon (∅ mean 16.5–34.2 mm), whereas cinnamon did not show vapor activity. In the microdilution test, all the EO s showed notable antimicrobial activity ( MIC 90 and MBC 90 312.5–625 μg·ml −1 ) and a strong bactericidal power (ratio = 1). This is the first study that selects essential oils against S . suis . New studies about the possible synergic effect of EO s with antibiotics and about toxicity and efficacy in in vivo conditions are recommended.