The Antigens of the Cholera Group of Vibrios

Abstract

1. Previous work on the antigenic structure of the cholera group of vibrios is experimentally reviewed, and the data amplified and systematised.2. The cholera group is defined as consisting of vibrios with similar biochemical characters and having a common heat-labile antigenic component.3. The heat-stable antigens are divisible into:(a) A considerable number of specific antigens, best demonstrated by O sera and H-O suspensions, which serve as a basis of classification into O subgroups.(b) A non-specific component, demonstrable with O sera and O suspensions.4. The first subgroup contains all the standard cholera vibrios from central laboratories, and the majority of other epidemic strains. We consider that it represents the only class of vibrios known for certain to cause epidemic cholera.5. The races of this subgroup I are further divisible into two (or perhaps three) “types”, as established by Japanese workers, according to differences in their subsidiary O antigens.6. The haemolytic “El Tor” vibrios are serologically diverse. The term “El Tor” should, as Shousha suggests, be reserved for those that have the same specific O component as the standard cholera vibrios.7. For the identification of the undoubted cholera vibrios a standard subgroup I O serum is recommended in conjunction with the haemolytic test. The serum should contain both the main and the subsidiary antigens of the subgroup.8. As a working rule it is suggested that bacteriological proof of “cholera” or a cholera carrier should rest on the isolation of a non-haemolytic vibrio with the specific O antigen of subgroup I.The studies and observations on which this paper is based were conducted while one of us (K. V. V.) was holding a Fellowship of the International Health Division of the Rockefeller Foundation.Our thanks are due to Mr P. Bruce White for constant help and advice, and to the numerous bacteriologists in various lands who have kindly supplied us with cultures and sera.