RESUMO
The study of DNA in parasitic leptospirae of different serovariants by the method of molecular hybridization has revealed two groups differing in their homology level. The homology of nucleic acids has been found to correlate with serological properties. The serovariants ensuring cross immunity are characterized by the high level of homology of their DNA.
Assuntos
DNA Bacteriano/genética , Leptospira/genética , Nucleotídeos/análise , Reações Cruzadas , DNA Bacteriano/imunologia , Leptospira/imunologia , Leptospira interrogans serovar canicola/genética , Leptospira interrogans serovar canicola/imunologia , Hibridização de Ácido Nucleico , Nucleotídeos/genéticaRESUMO
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. In single examination 1:100 and over should be considered as a positive MAT titre for man, 1:200 and over - for cattle, 1:20 and over - for swine, and 1:20 and over for murine rodents. In repeated investigations any level of the titre in case of its dynamics should be taken into consideration.
Assuntos
Leptospirose/diagnóstico , Testes de Aglutinação , Animais , Portador Sadio/diagnóstico , Bovinos , Doenças dos Bovinos/diagnóstico , Humanos , Leptospirose/veterinária , Doenças dos Roedores/diagnóstico , Suínos , Doenças dos Suínos/diagnósticoRESUMO
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. According to overall guanine and cytosine contents, the investigated strains of pathogenic leptospirae fall into 3 groups and differ from the seprophytic strains. With respect to the limited number of the investigated strains, the DNA nucleotide composition of leptospirae can be used as a supplementary biochemical criterion in the classification of leptospirae.
