THE POTENTIAL OF ALCOHOLIC PLANT EXTRACTS TO CONTROL PATHOBIONTS OF SWINE ON A LOW-INPUT FARM

Abstract Objective / Purpose: Plant extracts have long proven antimicrobial potential depending on both the plant and target animal species. Pathogenic bacteria expose animals to disease risk, thus their control being of utmost importance. This research aimed to investigate the natural potential of locally available traditional medicinal plants in controling the antibiotic resistante bacterial load in swine raised on low-input outdoor farms from North Western and Central Romania. Material and Methods: Aerobic bacterial strains (n=14) originating from the nasal cavities of extensively raised swine 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 indigenous Calendula officinalis, Saturaja hortensis, Coriandrum sativum, Artemisia absinthium, Cucurbita pepo, Allium sativum alcoholic extracts. Results: The antibiogram indicated a multiple antibiotic resistance (MAR) index > 0.2 in 86% of the bacteria (overall MAR=0.34). The highest average of inhibition diameters were 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). Considering for intermediate susceptibility towards the tested antibiotics the threshold diameter of 13 mm, 12/14 strains were susceptible to C. pepo, 4/14 to C. sativum and 1/14 to C. officinalis extracts, while other extracts exerted insignificant antimicrobial activity. The average inhibition diameter was of 18.43±1.68 mm for C. pepo and of 11.11±0.68 mm for C. sativum extract. The lowest average was found in Allium sativum - 6.86±0.35 mm. Conclusion / Discussion: Some of the tested plant extracts could display a considerable antimicrobial activity on pathobionts of swine. 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. Acknowledgements This research was funded by PPILOW project of the European Union’s Horizon 2020 programme, grant agreement 816172. Key Words: plant extracts, low-input swine farm, bacteria, antibiotic