A COMPARATIVE EVALUATION OF PLANT EXTRACTS’ INHIBITING EFFECTES ON PORTED BACTERIA IN PIGS AND SMALL RUMINANTS

Summary

Abstract
Continuously increasing antimicrobial resistance urges for research in identifying new active compounds agains bacterial pathogens. This research aimed to monitor the potential of traditional medicinal plants in efficient control of antibiotic resistant bacteriome in swine and small ruminants raised on low-input outdoor farms from North Western Romania.
Aerobic bacterial strains (n=14) originating from the nasal cavities of extensively raised swine and sheep were subjected to biochemical identification (Vitek®2 Compact System) and further tested for susceptibility to antibiotics (n=12, antibiotic classes=6, Kirby-Bauer method). Simultaneously, the aromatogram technique was applied to alcoholic extracts Calendula officinalis, Saturaja hortensis, Coriandrum sativum, Artemisia absinthium, Cucurbita pepo, Allium sativum and essential oils of Anethum graveolens, Zingiber officinale, Geranium spp. and Lavandula angustifolia.
The antibiogram indicated a multiple antibiotic resistance (MAR) index > 0.2 in 86% of the pigs and 33% in sheep (overall MAR=0.34 and 0.13, respectively). In pigs the highest average of inhibition diameters was observed with chloramphenicol (20.75±0.92 mm) and norfloxacin (20.68±1.55 mm), while the lowest was shown by cefotaxime (7.5±0.79 mm); in sheep the amikacin was the most efficient. Out of the plant extracts, C. pepo was the most effective in pigs (12 out of 14 strains) while the in sheep, the highest efficacy was recorded for the essential oil of Geranium spp. (26.87±8.2 mm) and the lowest activity was noted for the Anethum graveolens oil (15.04±2.2 mm).
These plants could enhance the welfare of the animals by reducing the potentially pathogenic, antibiotic resistante bacterial load, as an alternative to classical antibiotic therapy. These results open the perspective of using essential oils in the prevention of staphylococcal infections.
Key words: low input farms, sheep, pigs, plant extracts, antimicrobial resistance