[Biological and genetic characterization of strains of the pathogen of legionellosis, isolated from water on Russian territory]. / Biologicheskie i geneticheskie kharakteristiki shtammov vozvuditelia legionelleza, vydelennykh iz vody na territorii Rossii.

As the result of the study of the spread of Legionella in different regions of Russia, 69 cultures were isolated from different water systems. After serotyping most of these strains (85%) were identified as L. pneumophila, serogroups 1 and 6. 57% of the isolated Legionella strains were shown to be capable of causing fatal infection in guinea pigs, but only 50% of virulent cultures had a high level of virulence. More than a half of the isolated strains (67%) contained plasmid DNA with mol. weights ranging from 2.5 to 80 mD. In some strains of serogroup 1 the identity of plasmids was established by restriction analysis (endonucleases Hind III and Bam HI). The data thus obtained are indicative of the potential epidemic danger of L.pneumophila strains circulating in the environment.

[Analysis of genomic polymorphism in leptospira by polymerase chain reaction with random primers]. / Analiz genomnogo polimorfizma leptospir v polimeraznoi tsepnoi reaktsii s proizvol'nymi praimerami.

A test system for genetic typing of Leptospirae is developed, based on the polymerase chain reaction (PCR) with arbitrary primers. Thirteen strains of 4 Leptospira species were examined: L. interrogans, L. parva, L. illini, and L. inadai. Analysis of polymorphism of amplicon length (PAL) by the PCR with short Sh1 and Sh2 primers revealed genotypical differences at the inter- and intraspecias levels, as well as at the subserovar level. PAL of L. interrogans strains Rga and M-20, serovars icterohaemorrhagiae and copenhageni, were identical both with Sh1 and Sh2 primers. Moreover, PCR with Sh2 primer showed genotypical similarity between strains Moscow V and M. oeconomus, serovar grippotyphosa of the same serogroup. Analysis of PAL by the PCR with long Lgn1 and Lgn2 primers showed similar results. Analysis of the PAL values obtained by the PCR with all primers permitted us to differentiate 9 L. interrogans strains into 8 PAL genotypes and identify a different degree of genotypical relation between strains of different serovars of this species. Complete genotypical relationship between strains L. inadai N 10 and EMJH 86 (serovar lyme) was confirmed by the new test system. Therefore, PCR-based test system with different primers can be used to differentiate between closely related Leptospira strains and to investigate the genotypical relationships between the strains at the intra- and interspecies and inter- and subserovar levels.

[The theoretical and practical aspects of the nonspecific prevention of infectious diseases among the troops]. / Teoreticheskie i prakticheskie aspekty nespetsificheskoi profilaktiki infektsionnykh boleznei v voiskakh.

As possible alternative to a complex of sanitary-hygienic measures, directed on the infectious diseases prevention, not specific prophylaxis with the aid of immunomodulative preparations is offered. Prospects of the immunomodulative preparations application is defined by transition to popularized epidemiological thinking planned in modern conditions. Strategy of total and selective not specific prophylaxis, results of own researches on estimation of preventive efficiency of dibazolum and prodigiosanum during acute respiratory disease and virus hepatitis A are described.

[Molecular genetic approaches to the study of the persistence of pathogenic Mycoplasma]. / Molekuliarno-geneticheskie podkhody k izucheniiu persistentsii patogennykh mikoplazm.

The inhibition of the amplification of different regions of Mycoplasma pneumonia genome, depending on the conditions of cultivation, was observed with the use of polymerase chain reaction. A protein, stably associated with DNA, is responsible for this inhibitory effect. When selectively associated with different sites of DNA, the protein seems to be capable to inhibit the expression of genes, encoding pathogenicity factors of mycoplasmas and thus promoting their transformation into persistent forms.

[Genomic polymorphism in Mycobacterium tuberculosis strains]. / Issledovanie genomnogo polimorfizma shtammov Mycobacterium tuberculosis.

Different genomic fingerprinting techniques (universal probes, such as rRNA genes, phage M13 DNA, IS 6110 probe) have been used to investigate the genomic polymorphism of Mycobacterium tuberculosis strains isolated in different geographical regions of Russia and in some CIS countries. As shown with the use of these techniques and a specially developed PCR-mediated system for genetic typing, M.tuberculosis strains are genotypically heterogeneous in regions with a sporadic level of tuberculosis morbidity and genotypically homogeneous in regions with elevated morbidity and mortality levels. The evaluation of the effectiveness of the genetic typing of M.tuberculosis with the use of different genomic fingerprinting techniques has made it possible to propose the optimum 3-stage scheme for the differentiation of M.tuberculosis strains: (1) the typing of all isolated strains of the PCR-mediated test system; (2) the typing of several selected M.tuberculosis strains with the use of 1S 6110 probe (2-3 strains of each detected PCR-RFLP [correction of PLRF] genotypes); (3) the typing of M.tuberculosis strains, containing 1 copy of 1S 6110 or not containing such sequence, with the use of probes (phage M13 DNA) detecting hypervariable sequences in M.tuberculosis genomes.

[Urogenital mycoplasmosis and Mycoplasma carriage during pregnancy and in inflammatory processes of the genitalia in workers in the electronics industry]. / Urogenital'nyi mikoplazmoz i mikoplazmonositel'stvo pri beremennosti i vospalitel'nykh protsessakh genitalii u rabotnits élektronnoi promyshlennosti.

To find out the spread of urogenital Mycoplasma carriership urogenital mycoplasmosis (UGM) among women living and working under similar conditions and making up risk groups with respect to these infections, pregnant women, gynecological patients and clinically healthy women were specially surveyed. As revealed in this survey, UGM and Mycoplasma carriership were found in clinically healthy female workers significantly more often than in other similar groups of the same region. In the group of pregnant women the occurrence of Mycoplasma carriership and UGM reached 90%. In cases of sterility the facts of asymptomatic Mycoplasma carriership and UGM were registered.

[The laboratory diagnosis of mycoplasmosis and ureaplasmosis in urological and gynecological patients]. / Laboratornaia diagnostika mikoplazmoza i ureaplazmoza u urologicherskikh i ginekologicheskikh bol'nykh.

The survey of 630 patients with urogenital pathology, habitual miscarriage and sterility revealed that they were mostly (91-100%) infected with M. hominis and/or U.urealyticum. This fact indicates the necessity of organizing the epidemiological control of these infections. It is expedient to use the complex of laboratory methods for diagnosing these infections through the effectiveness of such methods may vary in different nosological forms. Thus, colpitis and nonspecific urethritis were shown to be most effectively diagnosed by the serological methods.

[Selective inhibition of DNA amplification in nonadhesive cultures of Mycoplasma pneumoniae]. / Izbiratel'noe ingibirovanie amplifikatsii DNK u neadgezivnykh kul'tur Mycoplasma pneumoniae.

Inhibition of amplification of various genome regions of Mycoplasma pneumoniae was observed in the polymerase chain reaction, and was dependent on cultivation conditions. A protein stably associated with DNA is responsible for the inhibitory effect. It is assumed that when the protein selectively associates with separate DNA regions, it can inhibit genes encoding pathogenicity factors, thus promoting mycoplasma transformation into persistent variants.

[The isolation and partial characterization of the cell wall proteins of Listeria monocytogenes]. / Vydelenie i chastichnaia kharakteristika belkov keltochnoi stenki Listeria monocytogenes.

The preparative scheme for the purification of proteins with molecular weights of 39 and 79 kD, obtained from L. monocytogenes membrane fractions, has been developed. This technology included the cultivation of bacteria in heart-brain broth, isolation of bacterial membranes, the extraction of their components with Triton-X-100 and chromatography on Superose columns. The purified proteins have been shown to form structures with a molecular weight of 500-100 kD and pl 4.7 in water solutions.

[Identification of tuberculosis pathogens in clinical material using the polymerase chain reaction]. / Identifikatsiia vozbuditelia tuberkuleza v klinicheskom materiale s pomoshch'iu metoda polimeraznoi tsepnoi reaktsii.

The authors examined the possibility of detecting M. tuberculosis cells in various types of diagnostic material (sputum, blood, bone marrow, bronchoalveolar lavage fluid) from tuberculosis patients using polymerase chain reaction (PCR). The developed PCR-based test systems helped detect M. tuberculosis in 48 (90.6%) out of 53 tuberculosis patients, in contrast to much slower microbiological methods which permitted detection of Mycobacteria in only 21 (39.6%) patients. High specificity and virtually no false-positive results of PCR were demonstrated in testing diagnostic material from patients with chronic nonspecific pulmonary diseases and from children with lympholeukemia and anemia.

[Cloning and expression of the phosphatidylinositol-specific phospholipase C gene from Listeria monocytogenes]. / Klonirovanie i ékspressiia gena fosfatidilinozitolspetsifichnoi fosfolipazy s Listeria monocytogenes.

The gene for phosphatidylinositol-specific phospholipase C (PI-PLC) of Listeria monocytogenes has been cloned and shown to be expressed in Escherichia coli cells from own as well as from the lactose gene promoter. The recombinant plasmid has been constructed on the basis of pRIT2T vector and carries the hybrid gone. 3-end of which is a fragment of protein A gene of Staphylococcus aureus. 3-end is a gene for phospholipase plcA, both in the same reading frame. The resultant construction is shown to code in Escherichia coli cells for the hybrid recombinant protein A:Pl-PLC. Purified preparation of the hybrid protein and polyclonal rabbit antiserum to it were obtained. The obtained antiserum to the hybrid protein containing phospholipase as en C-end domain has been shown to react specifically to phospholipase in Escherichia coli recombinant strain harbouring the constructed recombinant plasmid as well as the one in the culture fluid of listeria.

[The effect of changes in the cultivation conditions on the amplification of different Mycoplasma pneumoniae genes]. / Vliianie izmenenii uslovii kul'tivirovaniia na amplifikatsiiu razlichnykh genov Mycoplasma pneumoniae.

In experiments carried out with the use of the polymerase chain reaction the inhibition of the amplification of several regions of M. pneumoniae genome, depending on the conditions of their cultivation, has been observed. We suggest that protein, selectively binding with individual sites of DNA, is capable of inhibiting the expression of genes coding pathogenicity factors and thus contributes to the transformation of mycoplasmas into persistent forms.

[The use of an amplification test system for detecting persistent mycoplasmas]. / Primenenie amplifikatsionnoi test-sistemy dlia vyiavleniia persistiruiushchikh mikoplazm.

A DNA amplification test system for the detection of Mycoplasma fermentans in clinical specimens was developed. The system was used for the analysis of biological specimens obtained from experimentally infected animals. The infective agent could be detected during the whole period of observation (6 months). High sensitivity of the polymerase chain reaction made it possible to detect M.fermentans in much greater number of cases than with the use of serological techniques.

[Is sarcoidosis a chronic persistent infection?]. / Iavliaetsia li sarkoidoz khronicheskoi persistiruiushchei infektsiei?

The study carried out with the use of microbiological diagnostic methods has revealed that in 67% of cases specimens obtained from sarcoidosis patients for analysis contain different forms of mycobacteria (typical Mycobacterium tuberculosis and granular forms of mycobacteria). The content of typical and granular forms of mycobacteria detected in diagnostic specimens has been shown to differ, depending on the clinical form of sarcoidosis: as a rule, in cases of the sluggish course of sarcoidosis granular forms of mycobacteria are detected, while during the exacerbation of the disease and in cases of the acute course of newly diagnosed sarcoidosis the proportion of typical M.tuberculosis increases. To verify M.tuberculosis with greater certainty, two highly sensitive and specific amplification test systems have been developed on the basis of polymerase chain reaction. In this article the goals of microbiological and molecular genetic investigations which may jointly give direct proofs of the etiological importance of mycobacteria in sarcoidosis are considered and discussed; sarcoidosis may probably be regarded as chronic persistence infection.

[The purification and characteristics of listeriolysin O from Listeria monocytogenes]. / Ochistka i kharakteristika listeriolizina O Listeria monocytogenes.

A scheme of the purification of listeriolysin O produced by L. monocytogenes strain NCTC 7973 was developed. The isolation procedure included the cultivation of the bacteria in heart-brain broth, the concentration of culture liquid free of bacteria with ammonium sulfate, cation exchange chromatography on a column packed with CM-Sepharose and Mono S, gel chromatography on a column packed with Superose 12. The preparation obtained with the use of this procedure was homogeneous, as confirmed by the data of SDS electrophoresis. The protein obtained in this investigation was no different from the protein studied earlier in its physico-chemical properties (molecular weight, heat stability, inhibition with thiole-active compositions, cholesterol, sensitivity to proteolytic enzymes) and corresponded to the characteristics of thiole-dependent hemolysins.

[Use of the polymerase chain reaction for studying the processes of Salmonella typhimurium cells to an noncultivated state]. / Ispol'zovanie metoda polimeraznoi tsepnoi reaktsii dlia izucheniia protsessa perekhoda kletok Salmonella typhimurium v nekul'tiviruemoe sostoianie.

The possibility to identify noncultivating forms of Salmonella by the polymerase chain reaction (PCR) has been shown. To do it the technique for Salmonella identification was elaborated, based on amplification of a 500 bp fragment of araC gene. Time course of populations of two Salmonella typhimurium strains during prolonged incubation in water was studied by the techniques of serial dilutions on solid nutrient media, acridine orange staining, and PCR. The strains differed in pathogenicity levels and genetic characteristics. Cells of nonvirulent strain were shown to loose gradually in the process of incubation the ability to grow on solid nutrient media and transform into noncultivating forms whose ability to proliferation can be restored under definite conditions. No difference in the dynamics identified by PCR or traditional microbiological techniques was found for population of virulent Salmonella typhimurium incubated in water indicating the possibility of fast degradation of cells having lost the ability to divide.