Isolation and axenization of two entamoeba histolytica strains

We describe the isolation and axenization of two E. histolytica strains, obtained from the stools of two patients with the clinical diagnosis of dysentery. We used Pavlova's medium for initial polixenic culture, and TYI-S-33 (Diamond's) medium for monoxenic and axenic cultures. In order to eliminate the microorganism contaminating the stools the following antibiotics were used: penicillin, streptomycin, ampicillin, chloramphenicol, kanamycin, nistatin, ceftriaxone and amphoterycin B. Both strains grew in similar culture conditions with a yield of 2 x 10(6) microorganism per tube of 15 ml. Both strains belong to pathogenic zymodemes, and virulence was determined by the capacity for producing hepatic abscesses in 100% of the hamsters inoculated intrahepatically.