FIG. 5.

Enterotoxic activity of concentrated culture supernatants derived from 042 and the pet mutant strain JIF1. Supernatants from overnight cultures were size fractionated (saving the fraction with mass >50 kDa), and equivalent loadings were added to each Ussing chamber, into which had been mounted full-thickness rat jejunal tissue. Data points are the means of at least three experiments; error bars represent standard errors of the means. The supernatants from 042 and JIF1 generated significant rises in PD and I_sc compared with those of negative controls (P < 0.05, Student’s t test).