[Pathogenic potential of vibrio cholerae 01 isolated from the Mapocho river and Aguada ditch]

The pathogenic potential of 20 strains of Vibrio Cholerae 01 isolated from the Mapocho river and Aguada ditch in Santiago, Chile was studied using a rabbit intestinal loop biological model. The presence of cholera toxin (CT) was previously found by the detection of CT gene, ELISA and passive reserve agglutination in only one of these strains. After 24 h of intestinal loop inoculation, the 20 strains showed enterotoxic activity. In four of these strains the secretory reaction was particularly intense. In these same four strains, the presence of cholera toxin was detected after the passage through the animal model. Thus, the number of cholera toxin producing strains increased after the inoculation in intestinal loops. These results suggest that the enterotoxic activity of strains that do not produce CT is given by the new cholera toxin (NCT). It is concluded that most of the strains of Vibrio Cholerae isolated from Mapocho river and its affluents are producers of NCT toxin, that some strains recover the capacity to produce CT after colonization of intestinal loops of living organisms and that the additive effects of CT and NCT may explain the intense enterotoxic activity of the strains that produce CT.