[Use of various methods to isolate exopolysaccharide of eltor cholera Vibrios and its immunochemical characteristics].

AIM: Isolation of Vibrio eltor exopolysaccharide and study of its immunochemical properties. MATERIALS AND METHODS: Rugose variants of strains V. eltor 18895 and V. eltor 18843 obtained by us by selection in M9 medium were used in the study. Exopolysaccharides (EPS) were isolated by K. Kierek (2003), S.P. Zadnova (2004), N.P. Elinova (1984) methods and analyzed for carbohydrate, protein, nucleic acid content and lipopolysaccharide impurity. EPS, LPS, R-LPS structure was compared by high-pressure chromatography. Neutral sugars and amino sugars were identified by thin layer chromatography. Polyclonal antibodies were produced against EPS preparation isolated by N.P. Elinova (1984) method. Specific activity of obtained mice sera was tested by DIA method. RESULTS: EPS isolated by N.P. Elinova method (1984) was shown not to contain extraneous impurities. V. eltor EPS structure differs from LPS and R-LPS. Monosaccharide composition of EPS from ctx+ V. eltor 18895 strain is presented by a wider specter of carbohydrates including glucose, mannose, rhamnose, galacturonic acid. Use in DIA of specific sera produced against EPS from toxigenic strain did not reveal general epitopes with capsule polysaccharides of V. cholerae O139, V. parahaemolyticus and V. vulnificus. CONCLUSION: Use of EPS as an immunogen promoted production of sera that are specific against EPS and rugose variants of Vibrio cholerae eltor that can be used for their detection or characterization.

[Serotyping and genotypic characteristic of Vibrio cholerae non-O1/non-O139 serogroups isolated from water of surface basins and sewages of Rostov-on-Don city in 2003 - 2008].

AIM: Determination of serogroup and PCR-genotyping of Vibrio cholerae non-O1/non-O139 strains isolated from surface basins and sewages of Rostov-on-Don city in 2003 - 2008. MATERIALS AND METHODS: Seven hundred strains of V. cholerae non-O1/non-O139 serogroups were studied in reaction of slide-agglutination with array of 80 diagnostic sera for non-O1/non-O139 serogroups. Selective screening of strains representing dominating serogroups was performed for extended number of genetic determinants of pathogenicity factors. RESULTS: It was established that V. cholerae belonging to serogroups O53, O67, O75, and O76 are dominating in water ecosystems of Rostov-on-Don city at this time. All studied strains were characterized by lack of cholera toxin genes and toxin-coregulated pili but had different combinations of genes of additional virulence factors. There was no correlation between genotypic characteristics and serogroup. CONCLUSION: The study showed that change of serologic landscape of V. cholerae non-O1/non-O139 occurred in water objects in studied area during last decades. Necessity of dynamic surveillance for circulation of V. cholerae non-O1/non-O139 in aquatic environment with widening of studied spectrum of their biological features was demonstrated.

[Dynamics of the isolation and biological properties of Vibrio cholerae cultures, serogroups 01 and 0139, isolated from water reservoirs and sewage water on the territory of the city of Rostov-on-Don]. / Dinamika vydeleniia i biologicheskie svoistva kul'tur kholernykh vibrionov 01 i 0139 serogrupp, vydelennykh iz poverkhnostnykh vodoemov i stochnykh vod na territorii g. Rostov-na-Donu.

The dynamics of the isolation of V. cholerae cultures from various water objects on the territory of Rostov-on-Don during the period of 1994-2001 was analyzed and biological properties of 14 such cultures were studied. In the absence of epidemic complications during the above-mentioned period, a growth in the amount of V. cholerae isolates, serogroups 01 and 0139, including toxigenic V. cholerae 01, was registered. The microbiological and epidemiological aspects of the monitoring of surface reservoirs and sewage were considered and the expediency of the profound and systematic study of its results for epidemiological surveillance on cholera was emphasized.

[Characterization of Vibrio cholerae eltor in the city of Kazan in 2001]. / Kharakteristika kholernykh vibrionov él'tor, vydelennykh v g. Kazan' v 2001 g.

Information on V. cholerae eltor isolated in the focus of cholera in Kazan in 2001 at different periods of the outbreak is presented. The identity of strains isolated from patients, vibriocarriers and environmental objects, including their antibioticograms (sensitivity to cyprofloxacin and resistance to trimethoprim--sulfamethoxazole, streptomycin, furazolidone and nalidixic acid, which may be regarded as markers), is shown. Variable tandem repetitions in the DNA of 30 isolates strains of different origin have been determined. The results of this determination make it possible to classify all these strains as one genotype, which confirms the suggestion on the circulation of one subclone of the infective agent of cholera in the focus. As revealed in this investigation, the isolated strains are labile with respect to diagnostic phage eltor, while ctx+ strains are resistant to phage eltor ctx+.

[A comparative study of the immunogenicity of a bacterial mass and of the cell membranes of Vibrio cholerae grown in vivo and in vitro]. / Sravnitel'noe izuchenie immunogennosti bakterial'noi massy i kletochnykh obolochek Vibrio cholerae, vyrashchennykh in vivo i in vitro.

The comparative study of the immunogenic and protective properties of V. cholerae, grown in vivo and in vitro, and cell walls and lysates obtained from these organisms. In the mouse protection test the efficacy of preparations obtained from vibrios grown in vivo did not exceed that of the preparations obtained from V. cholerae agar cultures.

[The virulence of Vibrio cholerae isolated under different epidemiological situations]. / O virulentnosti Vibrio cholerae, vydelennykh v razlichnykh épidemiologicheskikh situatsiiakh.

The virulence of V. cholerae isolated on the territory of Russia and other CIS countries from environmental objects and from humans in different epidemic situations during the period of 1987-1991 was studied. The analysis of the data obtained in this study revealed that intensive epidemic complications were linked with the realization of the pathogenic properties of strains, characterized by the presence of the ctx gene and the absence of hemolytic activity. As a rule, in single cases or in isolated group cases of cholera V. cholerae hemolysin-negative strains without the cholera toxin gene were isolated.

[Cholera in Ukraine and Moldova during the 7th pandemic]. / Kholera na Ukraine i v Moldove v period sed'moi pandemii.

The epidemic manifestations of cholera in the Ukraine and Moldova in 1970-1991 are analyzed. In the Ukraine the peak of cholera morbidity in 1970 was caused by infection brought to the ports of Odessa and Kerch with its subsequent spread to other territories. This infection was characterized by outbreaks transmitted through water, mainly sea water, with the isolation of Vibrio eltor toxigenic virulent strains and outbreaks of vibrio carriership of alimentary (dairy) origin with the isolation of avirulent strains. In Moldova local outbreaks of water origin were registered in 1970-1972. In both territories prolonged (up to 16 years and even longer) circulation of cholera vibrios, mainly nontoxigenic and avirulent, were registered. The retrospective epidemiological analysis and the epidemiological situation in some regions of the Ukraine in 1991 completely confirmed the prognostic importance of the division of territories into regions according to the type of epidemiological manifestations and the necessity of differentiating the measures to be taken in the system of epidemiological surveillance.

[Halophilic vibrios isolated from the Sea of Azov]. / Galofil'nye vibriony, vydelennye iz Azovskogo moria.

Halophilic vibrios (V. parahaemolyticus and V. alginolyticus) were for the first time isolated from the Azov sea in the Eisk district. These vibrios proved to be typical representatives of Vibrio genus and were distinctly differentiated by species according to the following signs: saccharose splitting, growth in peptone water with 10% NaCl solution, and acetylmethylcarbinol production. Swarming capacity on 1.5% agar with 3% NaCl proved to be a more variable sign. All the cultures isolated were typed by means of Japanese O- and K-sera and had the following antigenic formulae: O1:K32; O2:K28; O3:K57; O5:K17; O6:K18. Only in 3 cases it was impossible to determine completely the antigenic formula of vibrios referred by the O-antigen type +o the 7th and 11th groups. Thus, parahemolytic vibrios isolated from the Azov sea were referred to the serological types revealed in Japan in the sea water, hydrobionts and feces of patients with acute gastrointestinal diseases.