The paper documents the high resistance of E. coli phage phi X 174, one of the small non-enveloped viruses of icosahedral symmetry, vis-a-vis certain physico-chemical factors. It is this property that makes the phage a suitable model for evaluating in practical terms the efficiency of antisepsis, disinfection and chemical sterilization. The phage is detected in smears, prints and on carriers using the plaque method. The system E. coli--phage phi X 174 may serve as a bioindicator of the viricidal efficiency of chemical sterilization eventually of the measure of absorbance of sterilizing agents on the treated material.

Institute of Hygiene and Epidemiology Prague Czechoslovakia