Inga vitro subsp. antibacterial

Marinho, T. A., Oliveira, M. G., Menezes-Filho, A. C. P., Castro, C. F. S., Oliveira, I. M. M., Borges, L. L., Melo-Reis, P. R. & Silva-Jr, N. J., 2022, Phytochemical characterization, and antioxidant and antibacterial activities of the hydroethanolic extract of Anadenanthera peregrina stem bark, Brazilian Journal of Biology (e 234476) 82, pp. 1-12 : 3

2.7. In vitro antibacterial activity of A. peregrina extract

Under a laminar flow hood, Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922 samples were thawed to room temperature, and then transferred to trypticase soy broth ( TSB) liquid culture medium for sample dilution and incubated at 37 ° C for 4 h. The activated strains were inoculated on Cled Agar and incubated at 37 ° C for 24 h for the isolation of colonies. Using a sterile loop, the colonies were transferred to selective media, MacConkey for E. coli and mannitol salt agar for S. aureus ; after 24 h, the isolated colonies were verified.

Using sterile loops, the isolated colonies were collected from each selective medium, and then a bacterial suspension in saline solution (0.85% NaCl) was prepared for each strain until the turbidity reached 0.5 on the McFarland scale. For this procedure, a McFarland 0.5 calibrated tube was used as the reference. A swab soaked in bacterial suspension solution was inoculated (for each sample) on Mueller-Hinton agar, covering the entire plate. Immediately, wells of diameter 10 mm were created in the agar plate using autoclave and ultraviolet light-sterilized glass tubes. Each well was identified with letters A, B, and C and filled with 50, 100, and 200 ΜL A. peregrina extract , respectively. Meropenem discs were used as the positive control and 200 ΜL of saline solution as the negative control. The plates were incubated in a bacteriological oven for 24 h. There were five replicates for each microorganism on different days (Silveira et al., 2009).