Effectiveness of Tetrodotoxin Extracted from the Pufferfish - Lagocephalus suezensis - against Streptococcus pyogenes and Proteus vulgaris and its Comparison with Some Synthetic Antibiotics

Abstract

This study aimed to evaluate the antibacterial activity of tetrodotoxin (TTX) extract derived from the toxic organs of the pufferfish Lagocephalus suezensis against Streptococcus pyogenes and Proteus vulgaris isolated from human clinical samples, and to compare its efficacy with three synthetic antibiotics: Cephalexin, Cefoperazone, and Ceftriaxone. The toxin was extracted using a chemical method according to standard protocols, and the inhibitory activity was assessed using the agar disk diffusion method at various concentrations via a ten‑fold serial dilution on Mueller‑Hinton agar, with sterile water‑impregnated discs used as negative controls and antibiotic discs as positive controls.

The results demonstrated a clear inhibitory effect of the extract against all tested bacterial species, with marked variations in susceptibility. The highest susceptibility was recorded for Streptococcus pyogenes, with a mean inhibition zone diameter of 3.0 cm at a concentration of 10⁰ µg/mL, whereas the mean inhibition zone diameter for Proteus vulgaris was 2.8 cm at the same concentration. Comparison of the extract's efficacy with the tested antibiotics revealed that TTX was distinctly superior to all of them against the examined species.

These findings suggest that tetrodotoxin could serve as a promising natural source for developing novel antibacterial agents, particularly in light of the escalating problem of bacterial resistance to conventional antibiotics