The Cultural Requirements of Endamoeba Coli and the Comparative Effects of Drying on the Cysts of E. Coli and E. Histolytica
Lucy V. Reardon,
Elisabeth Verder1 AND
Charles W. Rees
Laboratory of Tropical Diseases and Laboratory of Infectious Diseases, National Microbiological Institute, National Institutes of Health, Bethesda 14, Maryland
1. A modification of the zinc sulfate centrifugal flotationtechnique is described for concentrating cysts of E. coli andE. histolytica from stools and cultures in watch glasses withminimum amounts of foreign material.
2. Several strains ofE. coli have been cultivated from cyststhat were freed by microisolationfrom bacteria and transferredinto riced whole egg medium thatwas seeded with organism tand B. subtilis.
3. Encystationof E. coli in vitro was obtained by the methodof Dobell incultures with an undetermined number of speciesof bacteriaand also with only three species, organism t, B.subtilis andStreptococcus zymogenes.
4. On the basis of culturabilityand microscopic appearancethe cysts of E. coli were not demonstrablyaffected by drying;cysts of E. histolytica were irreversiblydamaged by drying.