COMPARATIVE SENSITIVITIES OF SABIN AND MAHONEY POLIOVIRUS TYPE-1 PROTOTYPE STRAINS AND 2 RECENT ISOLATES TO LOW CONCENTRATIONS OF GLUTARALDEHYDE

Significant intratypic differences in the glutaraldehyde (GTA) sensiti vity of echovirus isolates have been shown. While exploring ways to op timize the study of GTA sensitivity of enteroviruses, we also observed intratypic differences in poliovirus type 1 isolates collected in Fra nce. A suspension procedure was used for assessing the virucidal effec t of GTA at low concentrations (less than or equal to 0.10%) against p urified viruses. Two recent isolates of poliovirus type 1 tested were first fully characterized by the PCR restriction fragment length polym orphism (RFLP) test. The RFLP pattern of clinical isolate 5617 was sim ilar to that of poliovirus type 1 LS-c, 2ab (Sabin strain), confirming the vaccine origin of strain 5617. The RFLP pattern of strain 5915 re covered from sewage was different from that of the Mahoney strain, sug gesting a genetic variation in this wild isolate. We then analyzed und er the same controlled conditions the GTA sensitivities of both isolat es and their respective prototype strains. The wild Mahoney and 5915 s trains exhibited significantly lower sensitivities to GTA than did the vaccine Sabin and 5617 strains. The inactivation rates of clinical is olates 5617 and 5915 were very similar to those of their corresponding reference Sabin and Mahoney strains. Both the conformational structur e of the capsid of each strain and the amino acid constitution of stru ctural polypeptides could be involved in the variations observed. The relevance of our comparative sensitivity studies to standardization of virucidal tests is discussed.