Aluminum-Marker of Wild Type 1 Poliovirus Strains

Abstract

Aluminum (A)-marker of 14 wild type 1 poliovirus strains (4 from the central nervous system of fatal cases, 10 from feces of paralytic cases) were studied. These strains were isolated in Japan from 1957 to 1961 before the implementation of the mass vaccination campaign with Sabin live poliovaccine. While an attenuated strain LSc, 2ab, and a virulent strain, Mahoney, were shown to be typically A^- and A⁺ respectively, only one of the wild strains examined was A⁺, 3 strains were A^- and the remaining 10 were apparently A^-, being thermoresistant in the presence or absence of Al³⁺ ions, when an ordinary stock virus was used. After three passages in primary monkey kidney cell cultures maintained with L-cystine-free synthetic medium No. 199 most of these strains became more or less thermosensitive in the absence of, but stabilized in the presence of Al³⁺. The results of the monkey neurovirulence test by intrathalamic inoculation with 2 A^- strains indicated that they are almost as neurovirulent as the reference A⁺ Mahoney strain. These results suggest that the A-marker is an attribute inherent to each strain of type 1 poliovirus without any correlation with neurovirulence in monkeys.