Snake venoms and purified toxins as biotechnological tools to control Ralstonia solanacearum

Abstract

The objective of this work was to evaluate the in vitro antibacterial activity of snake venoms and purified toxins on the phytopathogenic bacterium Ralstonia solanacearum. The evaluations were performed with 17 crude venoms (13 from Bothrops, 3 from Crotalus, and 1 from Lachesis) and seven toxins (1 from Bothrops and 6 from Crotalus). Antibacterial activity was assessed in MB1 medium containing solubilized treatments (1 μL mL-1). A total of 100 μL bacterial suspension (8.4 x 109 CFU mL-1) was used. After incubation at 28°C, the number of bacterial colonies at 24, 48, and 72 hours after inoculation was evaluated. SDS-PAGE gel at 15% was used to analyze the protein patterns of the samples, using 5 μg protein of each sample in the assay. Furthermore, the minimum inhibitory concentration (MIC) and lethal concentration (LC50) values were determined by the Probit method. Venoms and toxins were able to reduce more than 90% of R. solanacearum growth. These results were either equivalent to those of the positive control chloramphenicol or even better. While MIC values ranged from 4.0 to 271.5 μg mL-1, LC50 ranged from 28.5 μg mL-1 to 4.38 mg mL-1. Ten crude venoms (7 from Bothrops and 3 from Crotalus) and two purified toxins (gyroxin and crotamine) are promising approaches to control the phytopathogenic bacterium R. solanacearum.

Bactericidal Effects of Snake Venom Phospholipases A2: A Systematic Review and Analysis of Minimum Inhibitory Concentration

“…Furthermore, it was reported that p-bromophenacyl bromide (p-BPP) presents a significant decrease in enzymatic activity and associated antibacterial activities, thereby destabilizing the membrane bilayer. Regarding PLA 2 crotoxin A or B (PLA 2 -CA and PLA 2 -CB), Alves et al [11] reported that both from C. durissus terrificus showed high bactericidal activity against R. solanacearum. Similarly, Samy et al [19] reported that crotoxin B of C. durissus terrificus and daboiatoxin of Daboia russelli presented the most robust bactericidal activity against the two strains of B. pseudomallei (TES and KHW).…”