Mônica Jachetti Maciel

Phytochemical indicators and antibacterial activity of the crude hydroalcoholic extract of Achyrocline satureioides ("macela") against antibiotic-resistant Salmonella spp. isolated from animal products (swine and poultry)

Resistance to antibiotics, disinfectants and antiseptics motivates the search for new antimicrobials, having in plant extracts a bioactive potential. The objectives of the study were to test the crude hydroalcoholic extract of A. satureioides, against 51 strains of Salmonella spp. resistant to antibiotics isolated from animal raw material, and to detect the phytochemical compounds in the solution. Maceration was prepared in the proportion of 5g of the dried inflorescences: 100 mL of ethanol at 70°GL, and after 15 days the alcohol was removed with rotary evaporator. Recomposing the initial volume with sterile distilled water resulted in the crude extract at a concentration of 50 mg/mL. The European quantitative suspension test was used, comparing the inocula in the population densities (PD) of 10 7 , 10 6 and 10 5 CFU/mL, in contact times of 5, 15, 60 minutes, and hourly, up to 10 hours. In the PD 10 7 , in 5 h of contact 35%, and in 10h 100% of the isolates were inactivated; in PD 10 6 , in 5 h of contact 39% and in 9h 100% were inactivated; in the PD 10 5 , in 5 h 51% and in 9h 100% were inactivated. It was concluded that the crude extract inactivated all strains of Salmonella spp. resistant to antibiotics, and that the contact time required for the bactericidal activity was related to the initial PD of the suspension and with the intrinsic characteristics of the isolates. The phytochemical detection identified phenolic compounds such as hydrolysable and condensed tannins, flavonols, and saponins. Key-words: vegetable antimicrobial; vegetable extract; phenolic compounds. ______________________________ Revista Brasileira de Higiene e Sanidade Animal Brazilian Journal of Hygiene and Animal Sanity ISSN: 1981-2965