The study of agglutination of trypsin-treated sheep red cells by Corynebacterium diphtheriae strains.

620 Corynebacterium diphtheriae strains from 472 sick and healthy persons were studied for their adhesive activity (AA) in direct agglutination of trypsin-treated sheep erythrocytes. Toxigenic strains had more active AA than non-toxigenic ones which was not dependent on the presence of toxin in the culture. Neither biotype nor serotype of the strains correlated with their AA. Several lysotypes among toxigenic and non-toxigenic strains were more active than others. Toxigenic strains from patients had higher AA than those from carriers. Both toxigenic and non-toxigenic strains isolated from the prolonged carriers possessed the highest AA. It was concluded that AA measured in this way was an important colonization factor for all diphtheria strains and a pathogenicity factor for toxigenic strains.

[The adhesive activity of diphtheritic strains in relation to the characteristics of the infectious process they induce]. / Adgezivnaia aktivnost' difteriinykh shtammov v zavisimosti ot osobennostei vyzyvaemogo imi infektsionnogo protsessa.

The degree of adhesiveness of 602 C. diphtheriae strains isolated from patients with different forms of diphtheria was studied on trypsinized sheep red blood cells (SRBC) used as an experimental model. The titer of bacterial suspension, i.e. its highest dilution ensuring the agglutination of 50% of SRBC, was assumed to be the index of adhesive activity. The toxigenic strains were more homogeneous with respect to the degree of their activity and proved to be moderately and highly adhesive, while among the nontoxigenic strains faintly and moderately adhesive ones prevailed. The degree of adhesiveness was not linked with the cultural biological strains variants, but depended on the form of C. diphtheriae infection. The toxigenic strains isolated from diphtheria patients were essentially more active than those isolated from carriers. Both toxigenic and nontoxigenic strains isolated in cases of prolonged carrier state (more than 4 weeks) did not differ in the degree of their adhesiveness and were essentially more active than the strains isolated from short-term carriers. The strains circulating in 10 closed groups with a high proportion of pronounced cases of carrier state (70.6% to 86.7%) were essentially more active than those circulating in 10 similar groups, but having a low proportion of pronounced cases of carrier state (6.7% to 23.8%). The conclusion was made that the degree of adhesiveness proved to be an important factor of C. diphtheriae pathogenicity, responsible for the formation of carrier state. Along with pathogenicity, this factor should be taken into consideration in the evaluation of the epidemiological importance of different sources of infection.

[The characteristics of Corynebacterium diphtheriae adhesins]. / Nekotorye osobennosti adgezinov Corynebacterium diphtheriae.

The study of the properties of C. diphtheriae adhesins revealed the absence of their thermostability, which suggested the protein nature of these adhesins. C. diphtheriae also showed pronounced mannose-resistant hemagglutinating activity, as this activity remained unchanged even in the presence of d-mannose. The comparison of the adhesive activity of C. diphtheriae with their phage and corycine sensitivity revealed essential differences between these macroorganisms in the degree of their adhesiveness. The phage lysability and corycine sensitivity of C. diphtheriae strains, determined by the properties of their surface structure, correlated with the degree of their activity.

[Adhesion of Corynebacterium diphtheriae]. / Adgeziia Corynebacterium diphtheriae.

The conditions for the direct hemagglutination test performed to determine the degree of adhesion of C. diphtheriae were defined. For this test sheep red blood cells, trypsin-treated ex tempore, were used. Only newly isolated cultures, subcultured for not more than 2-5 times and stored for not more than 2-7 days or freeze-dried, were employed. The culture to be tested was grown in nutrient agar with 10% of normal horse serum. The test was made in microtitrator round-bottom wells. The mixture of different dilutions of the culture was incubated for 2 hours at 37 degrees C, then left overnight at 4 degrees C. All 147 newly isolated or freeze-dried C. diphtheriae strains under test had different degrees of adhesion. Their adhesive activity was unrelated to their biovar. Toxigenic strains were significantly more active in hemagglutination (53.5 +/- 3.0%) than nontoxigenic ones (23.5 +/- 3.9%). The strains isolated from the nose, irrespective of their biological properties, were more active than those isolated from the pharynx.

[Data on the inoculation coverage against diphtheria, pertussis and tetanus of children in the 1st 3 years of life]. / Dannye ob okhvate privivkami protiv difterii, kokliusha i stolbniaka detei pervykh 3 let zhizni.

Selective analysis revealed the insufficient coverage of children aged up to 3 years with immunization against diphtheria, pertussis and tetanus in Baku, as well as lagging behind the established vaccination schedule. The absence of the prophylactic immunization of children during first 3 years of their life was mainly due to such medical contraindications as acute respiratory diseases, neurological diseases and various dermal manifestations. At the same time no sparing methods of immunization were used.