The Aerobic and Anaerobic Flora of Rattlesnake Fangs and Venom

Abstract

Venom from 100 rattlesnakes and swabs of the fangs of 50 of these snakes were cultured for aerobic and anaerobic bacteria. Agar-dilution antibiotic susceptibilities for 170 of 207 aerobes and disc susceptibilities for 65 of 113 Clostridia were determined. Clostridia were isolated from 48% of venom and 86% of fang specimens. Histotoxic species were found in 50% of the snakes. Ninety- seven strains of gram-positive cocci were isolated, but no coagulase-positive staphylococci. Of 110 strains of gram-negative rods, Aerobacter, Proteus, and Pseudomonas genera were most common. Four salmonella strains were found. All rattlesnake bites are potentially contaminated with Clostridia and a wide variety of aerobic bacteria. Inflammation and necrosis secondary to envenomation provide a favorable setting for proliferation of organisms. The antibiotic susceptibility results reported here provide guidelines for selection of antibacterial therapy.