[Retrospective VNTR-analysis of genotypes of Vibrio cholerae 01 strains isolated, during the 7th cholera pandemic, in Rostov Region]. / Retrospektivnyi VNTR-analiz genotipov shtammov Vibrio cholerae 01, vydelennykh na territorii Rostovskoi oblasti v gody VII pandemii kholery.

Antiplague Research Institute, Rostov-on-Don, Russia Retrospective multi-locus VNTR-analysis was made for 166 Vibrio cholerae strains isolated, 1967-2001, in Rostov Region from clinical samples (82 strains) and from water samples (84 strains). On the basis of cluster analysis of heterogeneous identification strain genotypes, 45 variations of individual strains were shared between 11 separate clusters, among which the F cluster vibrios were predominant. Having emerged, 1970, in the region, they were widely spread during the 1973-1975 cholera pandemic and were registered, among the isolated strains, till 1992 indicating the possibility of long persistence of V. cholerae 01 in the natural aquatic environment. Presumably, the ecosystem specificity contributed to the long-term vibrio persistence.

[Vibrio cholerae O139 isolated from humans and the water from open reservoirs: a comparative genotyping]. / Vibrio cholerae O139, vydelennykh ot liudei i iz vody otkrytykh vodoemov: sravnitel'noe genotipirovanie.

The comparative study of the genomes of V. cholerae O139 isolated from humans and from water of surface reservoirs was carried out with the use of single- and double-primer polymerase chain reaction (PCR). The profiles of polymorphic DNA fragments obtained in this study made it possible to find out differences between groups of strains, as well as the individual features of some of them. The comparison of strains isolated from humans and from water in single-primer PCR revealed that they, in spite of the general similarity of their genomes, essentially differed, which was probably due to changes in the genome of this infective agent. Strains of aqueous origin lacked genes ctx and tcpA, which made them epidemiologically unimportant.

[A monoclonal antibody-based study of the antigenic interrelations of typical and R forms of Vibrio cholerae]. / Izuchenie antigennykh vzaimosviazei tipichnykh i R-form kholernykh vibrionov na osnove monoklonal'nykh antitel.

Monoclonal antibodies to surface determinants of V. cholerae R forms (R-McA) were obtained. R-McA and monoclonal antibodies to lipopolysaccharide (LPS) of V. cholerae S forms (S-McA) were used to show that the LPS of deeply altered vibrios, agglutinating only with RO serum, completely lost its O-side chain. Some common O determinants on the basis of S-McA were detected in typical cultures of V. cholerae O1 and RO vibrios which agglutinated to 1/4 T with O serum and, in low titers, with RO serum. V. cholerae O1 were not capable of specifically binding with R-McA. Not all R strains under study were identified with the use of available R-McA due to essential differences of their terminal monosaccharides responsible for serological specificity.

[The reasons for the resistance of Vibrio cholerae to diagnostic phages]. / Prichiny ustoichivosti kholernykh vibrionov k diagnosticheskim fagam.

Phage resistance of 225 strains of cholera germs of O1 group obtained from different countries in 1988-1992 has been analyzed. Change of sensitivity to diagnostic phages was mostly connected with the decrease or loss of agglutinability in cholera sera. Phage resistance is rather conditioned by the change of the surface structures of the cell and by further change of phage reception zones. The increase in the number of strains sensitive to diagnostic phages after 6-12 months of storage evidenced for stabilization of cell wall structures and increase of their viability under relatively favourable conditions of storage.

[Cholera in a remote region of Dagestan]. / Kholera v oytdalennym raione Dagestana.

The epidemic situation in a remote region of Daghestan at the period of the cholera outbreak in the republic is considered with the use of concrete examples. The analysis of cases of cholera, as well as Vibrio carriership, at the period of August 5 to October 5, 1994, is presented. The territorial and temporal separation of different cases of the disease and Vibrio carriership were indicative of the periodic import of the causative agent to the territory of the town and the region from other places, unfavorable with respect to cholera, without the involvement of the water factor of infection transmission. Timely and complete antiepidemic measures prevented this infection from acquiring the character of developed epidemic.

[The isolation of the Vibrio cholerae dermotoxin and the characterization of its biological properties]. / Vydelenie dermotoksina Vibrio cholerae i kharakteristika ego biologicheskikh svoistv.

The dermonecrotic factor (dermotoxin) inducing skin necrosis in rabbits has been isolated from V. cholerae strain B-53-2-38 and partially purified. Dermotoxin has a molecular weight of about 110 kD and possesses pronounced cytotoxic and general toxic action, differing from that of enterotoxin. The introduction of this factor into the blood and peritoneum of laboratory animals causes their death.

[The properties of the Vibrio cholerae strains isolated in large districts in western Dagestan in 1994]. / Svoistva shtammov Vibrio cholerae, vydelennykh v krupnykh raionakh na zapade Dagestana v 1994 g.

190 V. cholerae cultures isolated by the specialized antiepidemic brigade of the Rostov-on-Don Research Institute for Plague Control in the Khasavyurt, Babayurt and Novolaksk regions of Daghestan in August-October 1994. All isolated strains were typical with respect to their morphological and cultural properties and could be agglutinated (with the exception of one strain) to the titer or half-titer with diagnostic cholera serum and Ogawa serum. 4 strains had signs of RO-dissociation, 4 strains were agglutinated with Inaba serum in a low titer. All strains were resistant to diagnostic bacteriophages. Cyproxin and doxicycline proved to be the most active agents for the treatment of patients. Agglutinins, vibriocidins and antidermonectrotic antibodies in diagnostic titers were detected in the sera of all patients and Vibrio carriers.

[The dynamics of antibody formation to a vaccinal strain of Francisella tularensis in different immunization regimens]. / Dinamika obrazovaniia antitel k vaktsinnomu shtammu Francisella tularensis pri razlichnykh skhemakh immunizatsii.

The use of different schemes of albino mice immunization either by living or by killed preparations of the vaccine strain of Francisella tularensis when obtaining monoclonal antibodies to the tularemia microbe made it possible to reveal definite regularities in the dynamics of antibody formation. The highest titres of antibodies in sera of animals-donors of splenocytes were obtained during the daily (for 3 days) intraperitoneal immunization of mice with living vaccine or with its thrice administration to the spleen thrice with the interval of 10 days. Revaccination against a background of high titres of antibodies decreased their quantity in blood serum of mice, while that against a background of low titres increased them.

[Potentials and conditions for the reversion of pathogenic properties of the causative agent of cholera in an experiment]. / Vozmozhnosti i usloviia reversii patogennykh svoistv vozbuditelia kholery v éksperimente.

The passage of V. cholerae noncholerigenic strains and their mutants, both in vitro and in vivo, has demonstrated that strains in which one of such properties as mobility, viability, adhesive, lecithinase and neuraminidase activities, is sharply decreased or lost, are still capable of reversion to cholerigenic forms. V. cholerae strains which have lost two or more of these properties, as well as strains having stable hemolytic activity determined by Greig's test, seem to be incapable of such reversion.

[Assessment of the importance of certain properties for the virulence of Vibrio cholerae and the detection of their correlations]. / Otsenka znacheniia nekotorykh svoistv dlia virulentnosti Vibrio cholerae i vyiavlenie ikh korreliativnykh sviazei.

The study of 65 V. cholerae strains and mutants with different biological characteristics has revealed that their virulence directly correlates with their sensitivity to diagnostic cholera phages, lecithnase activity, viability and inversely correlates with their hemolytic activity. The role of lecithinase activity in a number of properties linked with cholerigenicity has been shown. Inverse correlation between the hemolytic activity of V. cholerae and some properties of this organism has been detected. The characteristics under study have been divided into 3 groups in accordance with correlations between them.

[Adhesive properties of Vibrio cholerae strains and mutants with varying biological characteristics]. / Adgezivnye svoistva shtammov i mutantov kholernykh vibrionov s razlichnoi biologicheskoi kharakteristikoi.

V. cholerae strains and mutants devoid of adhesive activity and possessing very high adhesive activity were found in the collection under study. As a rule, cholerigenic strains possessed high or moderate adhesive activity, while in noncholerigenic strains the coefficient of adhesiveness varied over a wide range. The existence of a definite pronounced correlation between lecithinase activity and adhesiveness was established. Hemolysin-producing strains were found to possess high adhesive activity considerably more frequently than nonhemolytic strains.