The agglutination reactions of cholera vibrios.

The present study with 11 strains of vibrio using single-dose and hyperimmune antisera confirmed earlier observations on the cross-reactivity of the flagellar (H) agglutinating antigens of cholera and NAG vibrios. The effect of several variables on the agglutinating sensitivity of cell suspensions was determined by measuring the reaction rate in the presence of constant O- or H-antibody. The variables investigated were culture conditions, antigen dilution, reaction temperature, formalin fixation and heat-treatment; all were found to affect cholera and NAG serovars similarly. The optimal conditions for the O- and H-tests were markedly different. Dilute, young living broth cultures were highly sensitive to O- but not H-antibody. Conditions favoring the H-reaction were 48-hr culture on firm dry agar, high suspension opacity, a reaction temperature of 45 C and formalin fixation. The inverse relationship of O- and H-sensitivity under these conditions indicated that the flagellar antigen in the growing vibrio is masked by an O-sensitive layer. The temperature of denaturation of the unfixed H-antigen before or after reaction with antiserum was 64 +/- 0.5 C and could be used as a criterion of the H-reaction.     

Specificity of lectin receptors of cholera vibrios

Spectrum of carbohydrate specificity of lectin receptors of epidemically significant cholera vibrios (ctx(+) tcp(+) Hly(-)) as well as non epidemic hemolytic variants with or without tcp A gene (ctx(-) tcp(-) Hly(+), ctx(-) tcp(+) Hly(+)) was studied under the carbohydrates-mediated inhibition of hemagglutination between human erythrocytes of four blood groups and sheep erythrocytes. It was demonstrated that in toxigenic cultures lectin receptors specific for glucose, mannose, sacharose, lactose dominate whereas receptors specific for aminosugars are virtually absent. The latter are detected in hemolytic vibrios that can explain their ecologic flexibility.     

Monoclonal antibodies to antigens of cholera vibrios of the Ogava serovar

A set of hybrids is obtained synthesizing monoclonal antibodies to the surface antigenic determinants of the choleric vibrio of the Ogava serovar. The antigenic structure of vibrios of the typical and atypical strains isolated from a man and from environmental objects is studied using a collection of highly specific immunoglobulins. The high-specific diagnostic preparations for identification of the 01-group cholera agent serovar may be created on their base.     

Chemotaxis of cholera vibrios: a study method and the relation to different substances

The chemotaxis of V. cholerae in response to 56 different substances (amino acids, carbohydrates, salts, etc.) has been studied by the methods of visual observation and quantitative determination. Attractants, neutral substances and one repellent have been revealed. Adler's method (1973) has been modified with regard to the requirements for the working procedures in handling the causative agents of highly dangerous infections.