Antimicrobial activity of the toxin VdTX-I from the spider Vitalius dubius (Araneae, Theraphosidae)

Abstract

BackgroundCurrently there is an urgent need to develop new classes of antimicrobial agents with different mechanisms of action from conventionally antibiotics used for the control of pathogenic microorganisms. The acylpolyamine called VdTX-I was isolated from the venom of the tarantula Vitalius dubius, and first described with activity as an antagonist of nicotinic cholinergic receptors. The main objective of this study was to investigate the antimicrobial activity found in the venom of the spider, with emphasis on the toxin VdTX-I.MethodsAntimicrobial assays were performed in 96 well plates culture against 14 micro-organisms (fungi, yeasts and bacteria), which were tested concentrations from 0.19 to 100 μM of VdTX-I. After qualitative analysis, dose-response curve assays were performed in bacterial kill curve using MTT reagent and hemolytic assay.ResultsThe antimicrobial activity of the VdTX-I toxin was observed in 12 tested species of Candida, Trichosporiun, Staphylococcus and Micrococcus. The toxicity had a dose-response at 3.12 µM – 100 μM in Candida albicans, Candida guillermondii, Micrococcus luteus and Escherichia coli. VdTX-I took about 5 min to inhibit bacterial growth, which was faster than streptomycin. The toxin showed no hemolytic activity between 0.19 and 100 μM. At 2.5 µg/mL of toxin it was observed no growth inhibition against a mammalian cell lineage.ConclusionsThe VdTX-I toxin has a significant antimicrobial activity, with broad spectrum, and is experimentally inert to mammalian blood cells.General SignificanceThis paper explores the antimicrobial potential of the spider toxin VdTX-I, which can provide a new model to design new antimicrobial drugs.

Brazilian Theraphosidae: a toxicological point of view

“…VdTX-1 has antimicrobial activity described by Sutti et al [63]. The toxin presented activity against multiple fungi and bacteria (Table 1), among Candida species, Gram-positive bacteria and two strains of E. coli with MICs ranging from 6.25 to 50 µM [63].…”

Non-clinical evidence supports anti-inflammatories as more effective medication than antihistamines against tarantula local effects envenomation

“…The venom composition of the two species considered in this work has been studied and share characteristics such as the presence of hyaluronidase and lack of phospholipase and proteinolytic activity [10,19]. V. dubius is the only specie of the genus that has already published data on venom composition, including an ionotropic blocker polyamine with yet antimicrobial activity [20,21]. The described oedema activity [22] was not associated to a specific toxin since it was demonstrated to be induced by various pathways.…”

Antimicrobials from Venomous Animals: An Overview

“…Venom components responsible for this antimicrobial activity were also investigated. This includes acylpolyamines, such as the polyamine toxin VdTX-I from Vitalius dubius [22], and low molecular mass molecules, such as those extracted from Laxosceles spider, which affected the virulence of Pseudomonas aeruginosa strains [23]. Many other antimicrobial peptides were identified from spider venom.…”