[A comparative evaluation of the sensitivity of different methods for the serological diagnosis of leptospirosis].

In this work the comparative evaluation of the sensitivity and serological specificity of the microcapsular agglutination (MCA) test, the passive hemagglutination (PHA) test and the microagglutination (MA) test are presented. In the MCA test leptospiral antigens, adsorbed on synthetic carrier capsules produced by Japan Lyophilization Laboratory, were used and the PHA test was made with the use of polyvalent erythrocyte diagnosticum. The study of blood serum samples from 46 leptospirosis patients revealed that the values of antibody titers in the PHA and MCA tests were 5.

[Use of microcapsular leptospiral antigens for detecting specific antibodies].

The sensitivity of microcapsular leptospiral antigens, produced by Japan Lyophilization Laboratory and intended for use in tests for the detection of antibodies to leptospires in the sera of experimentally immunized laboratory animals, were studied. The comparative study of the microcapsular agglutination (MCA) test and other serological tests, such as the microagglutination (MA) test and the indirect enzyme immunoassay (EIA), was made. The leptospiral antigens under study were found to actively react with serospecific and group-specific antibodies.

Investigation of hemolytic activity of leptospirae on solid culture media.

Results of investigation of hemolytic activity of leptospirae against red blood cells of various animal species on solid culture media using the technique of agar layers are presented. It has been shown that hemolytic properties of pathogenic and saprophytic leptospirae differ with respect to red blood cells of the sheep, the rabbit, the hamster, the albino rat and the albino mouse. Hemolytic activity of leptospirae regarding the erythrocytes of the cattle, the horse and the fowl depends on the strain of leptospirae.

[The use of direct immunoenzyme analysis with genus-specific peroxidase conjugate in leptospirosis].

For the first time anti-Patoc I peroxidase conjugate was obtained from the serum of a hyperimmunized guinea pig by the method of Nakane and Kawaoi (1974) in the modification of Mathiesen et al. (1978). In the experimental study of 37 Leptospira strains belonging to 19 serological groups, carried out with the use of direct EIA techniques, anti-Patoc I peroxidase conjugate was found to be genus-specific and highly active.

Influence of the mechanism of transmission of the infective agent on the aetiological structure of leptospiral foci.

It has been demonstrated that the differences observed in the aetiological structure of the individual foci of leptospirosis can be explained not only by the affinity of leptospiral serogroups to certain animal species, but also by different mechanisms of transmission of the causative agent of leptospiral infection which can be transferred both by sexual and alimentary routes (in water). It has been demonstrated that mostly one serotype of leptospires predominates in natural foci of leptospirosis, but several in anthropurgic ones. In the author's opinion, leptospiral infection in natural foci is mainly spread by the sexual route through the background species of animals--carriers of leptospirosis, and by the alimentary route in the anthropurgic foci.

[Dynamics of Leptospira colony formation on solid nutrient media].

The formation of Leptospira colonies on solid culture media varying in composition were studied. In all species of Leptospira 3 main periods of colony development were revealed, each of them having its characteristic morphological changes connected with the growth of the colony deeply into agar.

[Significance of an increase in the titer of agglutinins in the microagglutination test in leptospirosis].

The authors considered different views of investigators on the diagnostic antibody titre level in the microagglutination test (MAT) in leptospirosis of man and animals. Some of them took into consideration MAT in low titres (1:10-1:20), and others - in high only (1:400, 1:1000), which gave no possibility to assess the state of leptospirosis morbidity. The authors suggest that the assessment of the level of the titres in single and repeated studies should be approached differentially.

[Antigenic structure of saprophytic leptospirae and their classification].

The authors present the results of study of the serological properties of 46 strains of saprophytic leptospirae of different origin. On the basis of the affinity of the antigenic structure detected in the cross microagglutination reaction (MAR) 38 strains under study were united into 8 serological groups; the rest 8 strains were serologically independent in this reaction. The fact that 9 strains of water leptospirae isolated in the Armenian SSR belonged to one serological group was proved in the cross MAR and the test of aglutinin adsorption.

Leptospirosis infection through insemination of animals.

The semen of animals in spontaneous and experimental leptospirosis was investigated by bacteriological, immunological and biological methods. It has been found that pathogenic leptospirae (L. pomona, L.

Leptospirosis infection through insemination of animals.

The semen of animals in spontaneous and experimental leptospirosis was investigated by bacteriological, immunological and biological methods. It has been found that pathogenic leptospirae (L. pomona, L.

Nucleic acid content and nucleotide composition of DNA in leptospirae.

The contents of DNA and RNA were studied in 9 strains of leptospirae and the composition of nitrogen bases of DNA in 20 strains of pathogenic and saprophytic leptospirae. It has been found that leptospirae contain a high per cent ration of nucleic acids. According to the nucleotide composition, the family of Leptospira as a whole belongs to the AT-type.