The Journal of Medical Microbiology, Vol 8, Issue 1 11-18, Copyright © 1975 by Society for General Microbiology
An erythrocyte-sensitising antigen from Vibrio cholerae
G. A. Garabedian, E. L. Barsumian and A. Malakian
Erythrocyte-sensitising antigens (AE) were prepared from Vibrio cholerae
serotypes, from EL-Tor vibrio, Escherichia coli and Salmonella enteritidis
by digesting the organisms with NaOH followed by precipitation with
alcohol. When AE was used in indirect haemagglutination (IHA) tests, the
results in a number of cases were somewhat more sensitive and more specific
than those obtained in classical agglutination tests. No cross reactions
occurred between V. cholerae serotypes and E. coli and S. enteritidis. Much
of the reactive part of the AE was not sedimentable at 100,000 g for 1 h.
The eluant from the B. cholerae AE on Sephadex G-200 yielded three
fractions, one of which was the most active in IHA tests. Treatment of the
AE with trypsin resulted in an appreciable increase in the heterotypic
serum titres in IHA tests. The spectrophotometric absorption of the AE at
260 nm showed a hump that may have been indicative of the presence of
nucleic acid. Treatment of the antigen with ribonuclease reduced its
nucleic acid content but did not change to any significant extent the
reactivity of the preparation. The AE antigen of V. cholerae was
Molisch-positive and was capable of sensitising untanned erythrocytes in
IHA tests. It is suggested that the reactive part of the AE antigen is a
carbohydrate complex.
