COMPARATIVE SENSITIVITY OF THE ECHOVIRUS TYPE-25 JV-4 PROTOTYPE STRAIN AND 2 RECENT ISOLATES TO GLUTARALDEHYDE AT LOW CONCENTRATIONS

The sensitivity of two recently isolated antigenic variants of echovir us type 25 (Montpellier 76-1262 and Thionville 86-222) to glutaraldehy de (GTA) at low concentrations was compared with that of the JV-4 prot otype strain. The purified viruses were treated under the same conditi ons with GTA at concentrations ranging from 0.002 to 0.10%. The wild s trains exhibited significantly lower sensitivity to GTA than did the p rototype strain; with 0.10% GTA, a 2 log(10) unit reduction was obtain ed in 5 min for JV-4 and in 60 and 80 min for Montpellier 76-1262 and Thionville 86-222, respectively. A comparison with previous results ob tained with poliovirus type 1 showed that the inactivation rates of ec hovirus type 25 wild strains were fivefold lower than those of the pol iovirus type 1 Sabin strain. The comparative electrophoretic and immun oblot analyses showed differences in the results of GTA binding with c apsid proteins of the viruses. Unlike in the poliovirus type 1 Mahoney strain and in the echovirus type 25 JV-4 reference strain, GTA produc ed only minor intermolecular cross-linkings in the viral particles of the two wild strains of echovirus type 25. Our results suggest that th ere are both intertypic and intratypic differences in the GTA sensitiv ities of enterovirus strains. They are of relevance to disinfection pr ocedures in digestive endoscopy and to the choice of the enterovirus s train used for evaluating the efficacy of disinfectants.