[The application of bacterophages in laboratory diagnostic of cholera.]

The capacity of cholera agent to develop, during the seventh pandemic, the forms differing by attribute of resistance to bacteriophage determines overall complexity of solving problem of their phage-diagnostics. The search of new races of diagnostic cholera phages is actual and in the first instance relates to necessity of confirmation of specific characteristics of cholera agent by efficient, simple and reliable mode. Thereupon, the target was established to search new race of cholera phages being active in relation to phage-resistant to commercial medication of diagnostic phage of strains of cholera comma bacilli of biovar El-Tor. The study used 131 museum resistant to diagnostic cholera phages strain Vibrio cholerae El Tor separated from various sources in 2001-2014. The activity of 25 cholera phages in relation to sampled strains was verified. The most promising for constructing phage medication are three bacteriophages with spectrum of lytic activity as 44%, 53% and 56% correspondingly. Out of number of selected strains only 20 cultures (15%) maintained resistance to all phages. The estimated bacteriophages have different spectrum of lytic activity in relation to cholera comma bacilli El Tor. The new avirulent test-strain was to be found for reproduction and control of cholera diagnostic bacteriophage. So, non-toxigenic culture Vibrio cholerae El Tor 19546 was used. The analysis of received results demonstrated that analyzed cholera phages with high lytic activity can be used in diagnostics of phage-resistant strains of cholera comma bacilli. The actuality of application of phage-diagnostic technique lies in the fact that it requires no expensive equipment and large material expenses.

[THE IDENTIFICATION AND DIFFERENTIATION OF BACTERIOPHAGES OF HUMAN PATHOGENIC VIBRIO].

The issue of identification and differentiation of large group of bacteriophages of human pathogenic vibrio is still unresolved. In research and practical applied purposes it is important to consider characteristics of bacteriophages for establishing similarity and differences between them. The actual study was carried out to analyze specimens of DNA-containing bacteriophages of pathogenic vibrio. The overwhelming majority of them characterized by complicated type of symmetry--phages with double-helical DNA and also phages with mono-helical DNA structure discovered recently in vibrio. For the first time, the general framework of identification and differentiation of bacteriophages of pathogenic vibrio was developed. This achievement increases possibility to establish species assignment of phages and to compare with phages registered in the database. "The collection of bacteriophages and test-strains of human pathogenic vibrio" (No2010620549 of 24.09.210).

[The bacteriophages Yersinia pseudotuberculosis: the detection in strains of different O-serovars and their identification].

The sample included five indicator pseudotuberculosis strains. The application of these strains permitted to isolate out of 161 strains of Y. pseudotuberculosis 9 bacteriophages identical by their morphologic and serologic characteristics but having individual particularities in their lytic activity. The test on sensitivity to bacteriophages can be used in laboratory diagnostic to differentiate the strains of Yersinia pseudotuberculosis.

[Identification of Vibrio mimicus bacteriophages].

Lysogeny was studied in Vibrio mimicus; the indicator V. cholerae El Tor strain was selected to identify phages. New V. mimicus phages were obtained and identified, which had a morphological similarity and an antigen affinity for morphological group I cholerae phages. Phage differentiation revealed that morphological group I V. mimicus phages showed certain differences manifested as their lytic activity against V. cholerae strain 1322-69 of serovar 37 while this property was absent in cholerae phages.

[Yersinia enterocolitica bacteriophages: detection and identification].

Five indicator strains of Yersinia enterocolitica 01, 03, 05, 012 serovars were selected, which were used to isolate 7 bacteriophages from 227 Y. enterocolitica strains and 2 bacteriophages from wastewater samples. The specificity of the antigenic composition (3 serovars) and the morphology of phage particles (3 morphological groups) were employed to identify bacteriophages; there were differences in the range of lytic activity and resistance to physical and chemical agents. The specific bacteriophage-susceptibility test showed it possible to differentiate Y. enterocolitica strains.

[Studies on halophilic vibrios causing a food poisoning outbreak in the city of Vladivostok]. / Galofil'nye vibriony, obuslovivshie vspyshku pishchevoi toksikoinfektsii vo Vladivostoke.

V. parahaemolyticus and V. alginolyticus strains isolated from patients during an outbreak of an acute enteric disease in Vladivostok in 1997 were studied. All strains were found to possess typical taxonomic signs. V. parahaemolyticus isolated from humans had direct heat stable haemolysin exotoxin. The overwhelming majority of these strains belonged to serovar O3K6. Among the cultures under study 7 phage types were determined: phage types 1, 2, 7, 10 in 8 V. parahaemolyticus strains and phage types 2, 4. 5. 7 in 5 V. alginolyticus strains. The diagnostic halophilic phage lyzed vibrios in 30.2% of strains. The cultures under study were found to be highly sensitive to chloramphenicol, cefotaxime, nalidixic acid and cyprofloxacin. The study proved that the outbreak of alimentary toxicoinfection was caused by vibrios of serogroup O3:K6.

[Vibrio cholerae O139 bacteriophages]. / Bakteriofagi Vibrio cholerae O139.

Cholera bacteriophages have been isolated from 27 lysogenic cultures of V. cholerae O139. As shown the pages under study belong to two morphological groups A1 and F1 and serological types II and XII. The use of prophage typing and the sensitivity test to specific phage made it possible to differentiate V. cholerae strains, serogroup O139.

[Phagovars of halophilic vibrios]. / Fagovary galofil'nykh vibrionov.

The results of the phage typing of 164 halophilic vibrios revealed the most frequent combinations of lysing monophages, denoted by numbers: 1 (A, B, C, D), 2 (B, C, D), 3 (B, C) and 4 (C). In accordance with the proposed scheme, the phage typing of 398 cultures from different ecosystems was carried out. Phagovar was determined in 77.1% of the cultures. Most frequently occurred phagovars 1 (31.9%), 4 (15.8%), 3 (6%), and 2 (3.7%). Their proportion was 61%. 11 other phage combination causing the lysis of the cultures constituted 16.1%; 22.9% of the cultures could not be types. The use of the proposed scheme of phage typing permitted the determination of the temporal, regional, ecosystemic features of the circulation of halophilic vibrios in different ecosystems and regions, which was important for epidemiological analysis.

[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.

[The characteristics of Vibrio cholerae isolated in Dagestan in 1994]. / Nekotorye osobennosti Vibrio cholerae, vydelennykh v Dagestane v 1994 g.

A high degree of resistance to cholera diagnostic phages and carriership of prophages characteristic of V. cholerae eltor strains vct+ were shown to be the specific features V. cholerae isolated in Daghestan during the period of June-October 1994. Among the strains under study, isolated respectively in 12 and 18 out of 19 regions of Daghestan, a high proportion was found to have resistance to tetracycline (65%) and chloramphenicol (28.6%). Moreover, some strains were found to be resistant to furagin and erythromycin. Out of 242 strains resistant to antibacterial preparations, 163 strains were found to have multiple resistance. Gentamicin, cipropfloxacin and doxicycline were shown to have high in vitro activity with respect to the strains under study.

[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.

[A study of the biological properties of cholera phages and strains of El-Tor vibrions isolated from the external environment in Donetsk]. / Izuchenie biologicheskikh svoistv kholernykh fagov i shtammov vibrionov El-Tor vydelennykh iz vneshnei sredy Donetska.

Choleric phages were identified in 2 out of 44 samples of Donetsk sewage. Biological properties of phages were characterized.

[The lysogeny of Vibrio parahaemolyticus of serovar O4:K12]. / Lizogeniia paragemoliticheskikh vibrionov serovara O4:K12.

Lysogeny has been first established in strains of parahemolytic vibrios of serovar O4:K12. Moderate phages belonged to morphological group IV by home A. S. Tikhonenko's classification and were presented by one serological type. No correlation has been revealed between sensitivity to moderate phages of parahemolytic vibrios and specificity of "O"- or "K"-serotypes.

[The phages of halophilic vibrios and their use]. / Fagi galofil'nykh vibrionov i ikh primenenie.

The range of the lytic activity of 46 phages of parahemolytic vibrios isolated from lysogenic strains, sea water samples, crabs and mussels has been studied. The phages are represented by virions belonging to morphological groups II, IV, V according to the phage classification currently used in Russia and to different serological groups. No relationship between the sensitivity of vibrio strains to the phages under study and the specificity of serotypes O and K has been established. The preparation of diagnostic phage [see text] suitable for the identification of 82% of strains of parahemolytic vibrios has been proposed.