In Vitro Antibacterial Activity of Plant Ethanolic Extracts against Fish Pathogens

Abstract

Fifteen commercial ethanolic extracts from medicinal plants were in vitro screened for antibacterial activity against Listonella anguillarum (serotypes O1 and O2), Yersinia ruckeri, Photobacterium damselae subsp. piscicida, and Lactococcus garvieae. Their antimicrobial potential was assessed by the disc diffusion assay, then minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were established by the broth microdilution method. The extracts of lavender, Lavandula officinalis; lemon balm, Melissa officinalis; basil, Ocimum basilicum; oregano, Origanum vulgare; rosemary, Rosmarinus officinalis; common sage, Salvia officinalis; and red bilberry, Vaccinium vitis‐idaea, showed a broad spectrum of inhibitory effects. The extracts of yarrow, Achillea millefolium; arnica, Arnica montana; marigold, Calendula officinalis; Icelandic lichen, Cetraria islandica; horsetail, Equisetum arvense; grindelia, Grindelia robusta; java tea, Orthosiphon stamineus; and thyme, Thymus vulgaris, were less or not active. P. damselae subsp. piscicida was the most susceptible bacterial strain, while Y. ruckeri was the most resistant. These results can be considered for further investigations aimed to identify novel natural antimicrobial compounds that could be used in aquaculture for the control of bacterial infections.

Antibacterial Activity of Thyme (Thymus vulgaris L.), Laurel (Lauris nobilis L.), Rosemary (Rosmarinus officinalis L.) and Parsley (Petroselinum crispum L.) Essential Oils against Some Fish Pathogenic Bacteria

“…piscicida, Yersinia ruckeri, Lactococcus garvieae), and Rosmarinus officinalis indicated weak antimicrobial activity with inhibition zones 0.3 and 4.3 mm against Y. ruckeri and L. garvieae, respectively. But, Thymus vulgaris showed no inhibitory activity against L. garvieae, and demonstrated inhibition zone with 0.5 mm on growth of Y. ruckeri (Bulfon et al, 2014). In the study used the disk diffusion method, Starliper et al (2015) reported that the diameters of inhibition zone of 20% emulsions of TEO and REO against Aeromonas salmonicida subsp.…”

“…Furthermore, bacterial resistance against antibiotics increases over time and consequently decreases the effectiveness of antibiotics (Choudhury et al, 2005;Dubber and Harder, 2008;Stratev et al, 2018). There is, therefore, a growing interest in the identification of effective, new antibacterial agents that would serve as a new agent to use preventing bacterial diseases in aquaculture (Bansemir et al, 2004;Dubber and Harder, 2008;Bulfon et al, 2014).…”

Effects ofPanax ginsengextract in practical diets for rainbow trout (Oncorhynchus mykiss) on growth performance, immune response and resistance toYersinia ruckeri

“…The results of the in vitro assays indicated that P. ginseng extract exhibits antibacterial activity against Y. ruckeri and L. garvieae , with MIC values in agreement with our previously published data concerning the antibacterial properties of other ethanolic plant extracts (Bulfon et al . ). Such activity may be due to its content of saponins, tannins, flavonoids, alkaloids and polysaccharides (Cowan ; Tan & Vanitha ).…”

Total Phenol Content and Antimicrobial Activity of Lingonberry (Vaccinium vitis-idaea L.) from Several Areas in the Eastern Carpathians

“…piscicida and Lactococcus garvieae (Bulfon et al, 2014). Tolmacheva et al (2014) applied aqueous and ethanolic extracts from Vaccinium vitis idaea in a radial growth inhibition assay against wild-type Chromobacterium violaceum ATCC 31532 and reporter Chromobacterium violaceum NCTC 13274 strains observed a prominent growth-inhibition activity.…”