Enhanced Sensitivity of Germ-Free Mice to the Botulinal Neurotoxin

Summary

Germ-free and conventional mice were tested for their response to crystalline botulinal type-A toxin. Data were analyzed on the basis of graded and quantal response. Slopes of responses were linear throughout the entire response range, and that of the germ-free animals was slightly smaller than for conventional animals. This observation was statistically significant when all tests were combined. Based on time-to-death analysis, the germ-free animals were 2.3 times more susceptible than conventional animals. An increased susceptibility of 1.4 times was observed for the quantal response. Specific pathogen-free mice by time of death test appear more susceptible to the toxin than conventional mice.

In conducting the research reported herein, the investigators adhered to“Guide for Laboratory Animal Facilities and Care of the Institute of Laboratory Animal Resources”, NAS-NRC.