“…Several such tests are available for the aesculin-negative, biotype-1 American strains that belong mainly to serogroup 0:8: the Serhy test is positive (Feeley et al, 1979;Gemski et al, 1980;Schiemann and Devenish, 1980;Zink et al, 1980) and mice (Carter and Collins, 1974;Quan et al, 1974;Carter, 1975) or gerbils (Wetzler et al, 1968;Quan et al, 1974;Schiemann and Devenish, 1980) die after oral or intraperitoneal inoculation of calcium-dependent cells. However, these tests are inadequate for the human-pathogenic strains isolated outside the USA that belong to serogroups 0:3,0:9 and 0:5,27, as well as for members of serogroups 0: 1 and 0 : 2 that are pathogenic for some animals (Wauters, 1970); these strains fail to evoke a keratoconjunctivitis in guinea-pigs (Mollaret and Guillon, 1965;Mors and Pai, 1980;Schiemann et al, 1981;Vesikari et al, 1981) and they do not cause death or clearly identifiable clinical illness in mice (Mollaret and Guillon, 1965;Alonso et al, 1975;Pai and DeStephano, 1982;Aulisio et al, 1983) or gerbils (Schiemann and Devenish, 1980) when given by any route.…”