Published online by Cambridge University Press: 15 May 2009
Our data suggest that there are four different thermolabile antigens in S. dysenteriae (Shiga) appearing in different combinations in the five variants described. These antigens are:
1. The agglutination-inhibiting factor ‘I’, found in variants 1 and 3, which is a typical surface antigen.
2. A precipitinogen, ‘N’, probably identical with the neurotoxin, found in variants 1, 2 and 5.
3. A labile precipitinogen, ‘A’, in the extracts of variants 1 and 2, occurring in the deeper layers of the bacterial cell.
4. An additional precipitinogen, ‘B’, found in extracts of variants 1, 2, 3 and 4. It differs from the other labile antigens as its combining- and immunizing-powers are not destroyed by heating at 100° C. for 2 hr.