HYDROALCOHOLIC EXTRACT OF Achyrocline satureioides: PHYTOCHEMICAL COMPOSITION AND ANTIBACTERIAL POTENTIAL AGAINST ANTIBIOTIC-RESISTANT Salmonella spp.

Bacteria of the genus Salmonella are widely distributed in the environment and are considered to be an issue for animal and human health, as they might cause diseases such as salmonellosis, which is one of the major foodborne zoonoses. The fact that these bacteria are resistant to disinfectant, antiseptic and antibiotics makes it necessary to search for new antimicrobials. In this respect, plant extracts represent an alternative. The aims of this study were to test the hydroalcoholic extract of Achyrocline satureioides against antibiotic-resistant strains of Salmonella spp. and detect existing phytochemical compounds in the extract. Dried inflorescences of A. satureioides were kept in 70 °GL ethyl alcohol from cereals, in the ratio (plant/extracting liquid) of 5 g: 100 mL for fifteen days. After that, the alcohol was evaporated from the solution and the initial volume was restored with sterile distilled water. A total of 51 Salmonella spp. were isolated from raw material and poultry and pork products and showed resistance to antibiotics (amoxicillin, tetracycline, ampicillin, gentamicin, ceftiofur, florfenicol, sulfa-trimethoprim, and enrofloxacin). These microorganisms were kept frozen in cryovials. The strains were inoculated using the European quantitative suspension test, with decimal dilution and incubation of plates at 36 °C (+/- 1 ºC) for 24 hours, and viable colony-forming units (CFU/mL) were counted after this period. The analysis of phytochemical compounds aimed at analyzing the presence of phenolic compounds, tannins, flavonoids, coumarins, quinones, saponins, and alkaloids. The hydroalcoholic extract of A. satureioides was capable of inactivating resistant Salmonella isolates, and the required contact time was directly related to population density in the suspension. The largest number of cells was inactivated after the contact period of 5 hours, and all isolates had been inactivated 10 hours after the beginning of the test. In conclusion, hydroalcoholic extract of “Marcela” shows high antibacterial activity. Further analyses are required according to population density in the contaminated sample and sanitary conditions of the place where it has been collected in order to determine the necessary exposure time for effectiveness. Phenolic compounds were identified in the phytochemical detection of ‘Marcela” extract, e.g., hydrolisable and condensed tannins, flavonoids, and saponins, which are proven to have antimicrobial activity and are mostly found in inflorescences.