L-Lysine-α-Oxidase: Acidovorax citrulli Bacterium Inhibitor.

Studies of the effects of Trichoderma harzianum Rifai F-180 culture fluid concentrate containing L-lysine-α-oxidase antitumor enzyme produced by the fungus and the homogenous enzyme, on ultrahazardous bacterium Acidovorax citrulli demonstrated the antibacterial activity of the concentrate. Trichoderma harzianum Rifai F-180 producing L-lysine-α-oxidase was cultured in a technological device at G. K. Skryabin Institute of Biochemistry and. Physiology of Microorganisms, Russian Academy of Sciences. Activity of L-lysine-α-oxidase in the resulted culture fluid concentrate was 0.54 U/ml, activity of the homogenous enzyme was 50 U/mg.

[Cultivation of Leptospira in a liquid culture medium with lysed rabbit blood]. / Kul'tivirovanie leptopir v zhidko pitatel;no srede s lizirovanno krolich'e krov'iu.

A new method of the preparation of liquid culture medium for the cultivation of Leptospira has been developed on the basis of multiple freezing and thawing of defibrinated rabbit blood. A higher productivity of the new medium in comparison with the medium used in common practice has been established. The medium having a new composition is suitable for cultivation of Leptospira and the accumulation of biomass. The advantage of the medium made is in addition to high growth properties, the its economic efficiency and availability for practical laboratories.

[Methodological aspects of serological diagnosis in leptospirosis]. / Metodicheskie aspekty serologicheskoi diagnostiki leptospiroza.

The results of serological study for leptospirosis of 515 blood serum specimens from patients coming to different clinics of the Republic of Bangladesh, are presented. The sera were tested in microagglutination test. To exclude intergroup reactions and to enhance reliability of results, immunoglobulin classes were determined with the use of cysteine as a reducing agent and immunoabsorption test. In 51 patients (9.9%) antileptospiral antibodies were detected in titers from 1:20 to 1:1600 against pathogenic leptospires of different serological groups.

[Dynamics of Leptospira colony formation on solid nutrient media]. / O dinamike formirovaniia kolomii leptospir na plotnykh pitatel'nykh sredakh.

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.

[Use of microcapsular leptospiral antigens for detecting specific antibodies]. / Ispol'zovanie leptospiroznykh mikrokapsul'nykh antigenov dlia vyiavleniia spetsificheskikh antitel.

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. In infected guinea pigs and rabbits specific antibodies could be detected from days 3-4 in the MCA test and only from days 5-7 in the MA test. The average antibody level determined by titration in the MCA test was 3.3 times higher and in indirect EIA, 4.3 times higher than that determined by titration in the MA test. These data make it possible to recommend the use of microcapsular leptospiral antigens for the early diagnosis of leptospirosis.

[Comparative study of the phospholipase activity of pathogenic and saprophytic Leptospira cultured on a serum-lecithin agar]. / Sravnitel'noe izuchenie fosfolipazmoi aktivnosti patogennykh i saprofitnykh leptospir pri kul'tivirovanii na syvorotochno-letsitinovom agare.

The phospholipase activity of leptospires cultivated on serum-lecithin agar has been studied. Two zones of changes in the medium have been found to appear around the colonies of saprophytic Leptospira strains: transparent (5.25 +/- 2.09 mm wide) and turbid (6.90 +/- +/- 1.46 mm wide), which is linked with the production of phospholipases A and C. Only a single clear zone is formed around the colonies of pathogenic strains due to the production of phospholipase A. At the same time virulent Leptospira strains show greater phospholipase activity (the zones are 6.0 +/- 1.2 mm wide) than avirulent strains (the zones are 1.6 +/- +/- 0.04 mm wide).

[The use of direct immunoenzyme analysis with genus-specific peroxidase conjugate in leptospirosis]. / Primenenie priamogo immunofermentnogo analiza s rodospetsificheskim peroksidaznym kon''iugatom pri leptospiroze.

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. The possibility of detecting Leptospira antigens of 7 serological groups in the blood and in suspensions of the liver and kidneys of golden hamsters by direct EIA with the use of the above-mentioned conjugate was established. The use of direct EIA with anti-Patoc I peroxidase conjugate for the diagnosis of leptospirosis is recommended.

[Detection of anti-Leptospira antibodies in sera of patients in the latex agglutination test]. / Vyiavlenie protivoleptospiroznykh antitel v syvorotkakh krovi bol'nykh liudei v reaktsii lateks-aggliutinatsii.

The results of the preliminary evaluation of the sensitivity and specificity of the newly developed diagnostic test based on the determination of genus-specific antibodies to leptospires in the latex agglutination test, are presented. This test makes it possible to detect anti-Leptospira antibodies of any serogroup. The advantages of the developed test have been determined.

[A comparative evaluation of the sensitivity of different methods for the serological diagnosis of leptospirosis]. / Sravnitel'naia otsenka chuvstvitel'nosti razlichnykh metodov serologichicheskoi diagnostiki leptospiroza.

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 5.5-8.1 times higher than the traditional MA test. In the MCA and PHA tests antileptospiral antibodies could be detected as early as on days 1-3 of the disease when the results of the MA test were negative or very low. The maximum values of antibody titers in the MCA and PHA tests were detected on days 11-15 of the disease and in the MA test, on days 21-25. The MCA and PHA tests are genus-specific and permit the detection of antileptospiral antibodies irrespective of the serogroup of the infective agent. In the study of the blood sera of 40 patients with diseases of nonleptospiral etiology the MCA and MA tests yielded false positive results in 7.5% and the PHA test, in 12.5% of cases in titers below the diagnostic level. These data are indicative of high sensitivity and specificity of the serological tests used in this study.

Latex test system for rapid diagnosis of Leptospira infection.

A diagnostic test system based on polymer latex carriers sensitized by IgG to Canicola and Icterohaemorrhagiae serogroup Leptospira was developed and tried.

Phospholipase activity and virulence of pathogenic leptospirae.

Results of investigation of phospholipase activity and virulence of pathogenic leptospirae on a solid nutrient medium using the method of agar layers with 1% of L-lecithin in the medium of the second layer are presented. It has been demonstrated that only one zone of translucent medium is formed around the colonies of pathological leptospirae, which is obviously due to the release of phospholipase A. The examined virulent strains of pathogenic leptospirae were found to exhibit greater phospholipase activity (width of the translucent zones being 5.0 +/- 0.34 mm) than the avirulent strains (width of the zones being 1.5 +/- 0.11 mm).

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 advantage of using solid nutrient media for the determination of hemolytic properties of leptospirae in comparison with liquid media has been demonstrated.