Serological evidence for the identity of the vascular permeability factor and ileal loop toxin of Vibrio cholerae.

Abstract

Studies over the past 10 years, recently reviewed by Burrows [1], indicate that a heat-labile nondialyzable toxin liberated by Vibrio cholerae plays a key role in the massive outpouring of fluid into the intestinal lumen in cholera. The activity of this choleragenic toxin has been demonstrated in a variety of animal models including the rabbit ileal loop [2], the infant rabbit [3], and the dog [4]. Specific neutralization of this toxic activity by antitoxin has been demonstrated, and the rabbit ileal loop model has been standardized by Kasai and Burrows [5] to assay the toxin-neutralizing antibody response in cases of cholera. Associated with this choleragenic toxin is a vascular permeability factor (toxin), described in detail by Craig [6, 7]. This permeability factor, which induces leakage of a protein-containing fluid from capillaries when injected intradermally, is also heat-labile and nondialyzable and is neutralized by specific antisera. An antitoxin titration test performed in the skin of rabbits or guinea pigs has been described by Craig [6] and utilized