Antimicrobial Activity of Selected Essential Oils against Bacteria Isolated from Freshwater Fish

The aim of study was to determine the antimicrobial activity of ten essential oils against ten microorganisms isolated from fish. The following essential oils were tested: Cymbopogon nardus Rendle, Citrus limon, Leptospermum petersonii Bailey, Gaultheria procumbens, Pelargonium graveolens, Citrus paradisi, Citrus aurantifolia, Litsea cubeba Pers., Citrus reticulata Blanko, Vetiveria zizanoides. The disc diffusion method and microdilution method were used for determination of antimicrobial activity. Rhodotorula spp., Aerococcus spp., Aerococcus viridans, Enterococcus faecium, Enterococcus moraviensis, Aeromonas spp., Delftia acidovorans, Pseudomonas gessardii, Yersinia spp., Yersinia ruckeri, Yersinia enterocolitica were tested in the present study. The best antimicrobial activity of Leptospermum petersonii Bailey were found against Aerococcus spp., Enterococcus faecium, E. moraviensis, Delftia acidovorans, Pseudomonas gessardii, Yersinia ruckeri and Y. enterocolitica. Litsea cubeba Pers. was effective against Delftia acidovorans, Yersinia enterocolitica, Enterococcus faecium using the disc diffusion method. The best minimal inhibition concentration (MIC 50 - 1.5 µL/mL resp. MIC 90 - 1.6 µL/mL) was found for Litsea cubeba Pers. against Aerococcus spp. and Yersinia spp. using microdilution method.