Further Studies on IV-Variants of Salmonella typhi-murium (Aertrycke) with Special Reference to Cultures from Pigeons.

Landsteiner and Levine (1932) were the first workers to note that certain cultures of Salmonella typhi-murium were devoid of antigen V of the Kauffmann-White schema. They noted this deficiency in the Binns strain of Schiitze (1920). Kauffmann (1934) examined 256 cultures of S. typhi-murium and found 16 of them lacking in antigen V. The cultures exhibiting this peculiar deficiency in their somatic antigens, and designated by Kauffmann as S. typhi-murium var. Copenhagen, are commonly referred to as IV-variants. Their antigenic formula is IV XII: i: 1, 2, 3 instead of IV V XII: i: 1, 2, 3 which represents typical strains of S. typhi-murium. Zahn (1935) found one IV-variant in 74 cases of S. typhi-murium infection. All the TV-variants described by the investigators cited above were isolated from human sources. Since it is well known that S. typhi-murium infection in man almost invariably has its origin in some animal reservoir of infection, it is important from an epidemiologic as well as an academic standpoint that the zoological distribution of the IV-variants be determined. Edwards (1935) reported that six cultures of S. typhi-murium isolated from pigeons belonged to the IV-variety. Hoffmann and Edwards (1937) reported the presence of IV-variants in an infection of rabbits. The rabbits were housed in hutches which