Análise da eficácia do extrato da folha da amendoeira-da-praia (Terminalia catappa) sobre o crescimento da Aeromonas hydrophila e Staphylococcus aureus

Abstract

The use of natural products as a way to reduce the use of chemicals in production has been gaining prominence in the means of animal production. The present study aimed to analyze the antimicrobial activity of Terminalia catappa dry leaf extracts in vitro on the antimicrobial growth capacity of Aeromonas hydrophila and Staphylococcus aureus. The strains of Aeromonas hydrophila and Staphylococcus aureus used were isolated from naturally infected fish with lesions compatible with aeromonose from commercial fish culture. The bacteria were reactivated by overnight cultivation in TSB broth and then cultivated on soybean tryptone agar for 18 hours. suspended in 0.9% NaCl saline to the MacFarland 0.5 concentration. To obtain the extract, 60 grams of the ground material wrapped in a filter paper (Whatman) was weighed and hot extracted in the Soxhlet extractor apparatus with the aid of the PA alcohol solvent, then the extract was evaporated in a rotary evaporator and stored in vials. Four concentrations of 100mg of sample for 2.5 and 5 ml of distilled water and 200mg of sample for 2.5 and 5 ml of distilled water were used for in vitro tests. Petri dishes (150x20 mm) containing 60 ml were used. of Mueller Hinton agar (KASVI), being prepared and inoculated with the suspension of Aeromonas hydrophila and Staphylococcus aureus with the aid of swab. After that, 6 mm paper discs were inoculated with 10 µl of the tested extracts and placed on the previously prepared plate, where discs without inoculation of extracts were also added. The assay was done in 3 repetitions each. The plates were incubated at 37 ° C for 24 hours and the formation of inhibition halos around the discs was evaluated. The results showed that the concentrations of Terminalia catappa extract (100 mg sample for 2.5 and 5 ml distilled water and 200 mg sample for 2.5 and 5 ml distilled water) showed no inhibition halo formation.