Collagenase activity in clinical isolates of Entamoeba histolytica maintained in xenic cultures.

Several isolates of pathogenic and non-pathogenic E. histolytica from xenic cultures were tested for their capacity to digest native type I collagen gels. The results demonstrate that the pathogenic isolate HM48:IMSS has a high collagenolytic activity. The non-pathogenic isolates, HM43:IMSS, HM44:IMSS and HM46:IMSS showed significantly lower collagenolytic activity. Six groups showing different degrees of collagenase activity or non-activity were separated from the non-pathogenic isolates by a Percoll gradient. The groups obtained from the pathogenic isolate HM48:IMSS always displayed enzymatic activity.