[Molecular-biologic analysis of avian influenza virus isolates which caused epizootics on the south of West Siberia and in Crimea].

The objective of the study was to determine reasons of poultry deaths in Crimea Republic in December 2005 as well as isolation, identification, and comparative analysis of pathogens, which caused epizootics in Siberia and Crimea. During epizootic in poultry in North-East Crimea highly pathogenic avian influenza virus H5N1 was isolated. Phylogenetic analysis of RNA sequences revealed that they belong to one big cluster. Isolated strain was close to viruses, which caused epizootic in July-August 2005 in the south of West Siberia. Conclusion about the high importance of the south of West Siberia in spreading of highly pathogenic influenza viruses H5N1 in Eurasia was made.

[Characterization of the natural foci of Congo-Crimean hemorrhagic fever on the territory of Ukraine].

The natural foci of the Congo-Crimean hemorrhagic fever (CCHF) in Ukraine were characterized by their geographical factors. The circulation of CCHF virus was found to occur mainly in forest and forest-steppe zones irrespective of the location of administrative regions. The territories found to be most favorable for the prolonged existence of the focus of CCHF were those having high humidity. The possibility of using geoinformation technologies for the correction of the boundaries of natural foci, the evaluation of the influence of geographical factors on the circulation of the virus was shown.

[Vibrio cholerae 01, variant eltor, in the environment]. / Vibrio cholerae 01 biovara eltor v okruzhaiushchei srede.

The possibilities of the autochthonous existence of V. cholerae in open water reservoirs, depending on the combined effect of different biotic and abiotic factors are considered. The role of adaptive variability of V. cholerae O1, biovar eltor for its preservation in the environment is emphasized. The data on the duration of the V. cholerae O1 isolation from different environmental objects in some regions of Ukraine are presented.

[Factors contributing to preservation of Vibrio cholerae in water reservoirs]. / Faktory sokhraneniia kholernykh vibrionov v vodoemakh.

The summarized data of literature concerning the survival of V. cholerae in the environment and the influence of abiotic and biotic factors on this process are presented. These data make it possible to regard cholera as sapronosis and to form an idea of the role of factors contributing to the survival of V. cholerae in the environment and to its spread among human population.

[Antibiotic sensitivity of Vibrio cholerae 01 isolated from humans]. / Chuvstvitel'nost' k antibiotikam kholernykh vibrionov 01, vydelennykh ot liudei.

Antibiotic susceptibility of 1479 Vibrio cholerae 01 strains isolated from humans between 1991 and 1995 was studied. The antibiotics used belonged to different chemical groups. The assay method was that of serial dilutions in solid media. The isolates showed high susceptibility to tetracyclines, gentamicin, erythromycin, rifampicin, ampicillin, carbenicillin and cefazolin. The susceptibility to kanamycin and monomycin was moderate and that to chloramphenicol, streptomycin and polymixin B was low. The time and area peculiarities of the circulating cultures were observed. The susceptibility of the isolates was either changing or unchanging. The constant susceptibility levels were detected with respect to gentamicin, erythromycin, monomycin, kanamycin, streptomycin and polymyxin B. The susceptibility changing in time was shown with respect to tetracyclines, rifampicin and chloramphenicol. A gradual increase in the resistance to betalactams with greater numbers of the plasmid resistance pattern strains was recorded. Regular surveillance of the changes in the V.cholerae 01 antibiotic susceptibility is needed to timely correct the treatment and prophylaxis regimens.

[The evaluation of the virulent properties of Vibrio cholerae O1 by using in-vitro methods]. / Otsenka virulentnykh svoistv Vibrio cholerae O1 s pomoshch'iu metodov in vitro.

The virulent properties of V. cholerae O1 (more than 1000 strains) were studied. For this purpose the following methods were used: the determination of hemolytic activity, the express method based on the determination of the speed of mannite oxidation, complex analysis and polymerase chain reaction (PCR). The comparative analysis of the results of the in vitro determination of virulence revealed that the most frequently occurring strains among the strains isolated from humans were vct+ strains (80.5%), hemolysis-negative strains (83.9%) which were virulent (faintly virulent) as determined by complex analysis (38.2%), cholerogenic as determined by the express method (60.2%). Among the strains isolated from the environment were vct- strains (87.4%), hemolysis-negative strains (63.2%) which were virulent as determined by complex (13.1%), as well as by the express method (74.3%). The data of the determination of the vct gene did not correlate with the results obtained by complex analysis. The use of complex analysis was expedient only in the detection of strains sensitive to eltor phage in the dilution routine test of V. eltor strains. The methods for the determination of virulence, available for practical laboratories, were Grieg's method for the determination of hemolytic activity and express method. PCR proved to reliable in vitro method for the determination of the vct gene.

[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 variability of the biological characteristics of Vibrio cholerae isolated from environmental objects]. / Izmenchivost' biologicheskikh kharakteristik Vibrio cholerae, vydelennykh iz ob''ektov okruzhaiushchei sredy.

The study of the biological characteristics used for the identification of the species, biovar and serovar of V.cholerae O1 isolated from environmental objects on the territory of 8 regions of Ukraine for the period of 1974-1993 revealed the tendency towards an increase in the number of altered cultures. Phage sensitivity (60.7%) and capacity for agglutination with cholera species- and type-specific sera (24.6%) proved to be the most variable properties. Resistance to polymyxin (4.8%), the absence of hemagglutination with chick red blood cells (8.7%), the absence of diastatic activity (28.9%) were also detected. The study established that the temporal, ecosystemic and territorial geographical dependence could be observed in the character of variability of V.cholerae O1. The data thus obtained indicate the expediency of monitoring the dynamics of the properties of V.cholerae O1 in order to establish the relationship between its variability and the epidemic process.

[Antibiotic sensitivity of Vibrio cholerae 01, isolated in the Ukraine in 1994]. / Antibiotikochuvstvitel'nost' kholernykh vibrionov 01, vydelennykh na Ukraine v 1994 g.

One thousand and four hundred strains of V. cholerae 01 isolated in 1994 in the Ukraine were studied with respect to their antibiotic susceptibility and resistance. The study showed that it was possible not only to estimate the present tendencies in and the regularities of the change in their character but also to presuppose the probable circulation and incidence of the microbe based on the differences in the susceptibility, frequency and resistance pattern of the strains of V. cholerae 01 isolated from the environment and humans before and during the cholera outbreak. Unlike the strains of V. cholerae 01 isolated from the environment before the outbreak, the strains isolated during the outbreak from the environment and humans were characterized by resistance to levomycetin (chloramphenicol) and streptomycin. The results suggested that the cholera outbreak in 1994 was incidental. The data are useful for cholera epidemic surveillance. However, the final conclusion is possible after investigation of the gene type pattern in the circulating V. cholerae strains.

[Dynamics of changes in antibiotic sensitivity of Vibrio cholerae 01, isolated from environmental objects]. / Dinamika izmenenii antibiotikochuvstvitel'nosti kholernykh vibrionov 01, vydelennykh iz ob"ektov okruzhaiushchei sredy.

The analysis of the dynamics of the antibiotic susceptibility of 442 strains of V. cholerae 01 isolated within 1986-1994 from the environment showed that the susceptibility level was different. Strains of V. cholerae 01 with high susceptibility to tetracyclines, erythromycin, gentamicin, rifampicin and cefazolin and with moderate susceptibility to monomycin, kanamycin, ampicillin, carbenicillin and levomycetin (chloramphenicol) were detected as well as the strains resistant to streptomycin and polymyxin B. The susceptibility of the V. cholerae 01 strains to certain antibiotics (tetracyclines, levomycetin, streptomycin) changed in regard to the isolation time and object and its geographical location. In 1991-1994 a tendency was observed towards an increase in the number of the strains resistant to the drugs. The resistance of the isolates from the objects connected with the vital activity of humans (sewage, washings from the cholera foci, fish from polluted water reservoirs) was higher than that of the isolates from open water reservoirs. There were definite difficulties in the detection of the cultures with antibiotic susceptibility characteristic of various regions because of their different origin. The results of the study were indicative of a necessity of monitoring of the biological properties of V. cholerae 01 isolates from the environment important for cholera control.

[A possible mechanism for the endemicity of modern cholera (the role of noncultivated forms of Vibrio cholerae 01)]. / O vozmozhnom mekhanizme éndemichnosti sovremennoi kholery (rol' nekul'tiviruemykh form Vibrio cholerae 01).

The surface water sources of some CIS territories have been screened for cholera toxin genes by the polymerase chain reaction. The vct-genes have been found in the majority of water samples indicating the presence of noncultivated vibrio cholerae cells of an epidemiologic significance. The bacteriological methods failed to isolate the active causative agent of cholera. Additional criteria are proposed for epidemiological typing of territories for cholera. The absence of long deletions or insertions in the vct-genes of noncultivated cholera vibrios has been shown in comparison with analogous gene of the active causative agent of cholera.

[The comparative characteristics of the antibiotic sensitivity of psychrophilic and mesophilic aeromonads]. / Sravnitel'naia kharakteristika antibiotikochuvstvitel'nosti psikhrofil'nykh i mezofil'nykh aéromonad.

The general regularities of the antibiotic susceptibility of psychrophilic and mesophilic aeromonads were determined. The antibioticograms were in general similar. Still, there was observed a higher susceptibility of Aeromonas salmonicida to tetracycline, chloramphenicol and rifampicin, as well as a larger number of strains susceptible to semisynthetic broad spectrum penicillins (ampicillin and carbenicillin) and cephazoline. The susceptibility to aminoglycosides was lower.

[The microbiology of halophilic vibrios]. / Mikrobiologiia galofil'nykh vibrionov.

The current literature data and results of the authors' studies on the taxonomy and biological characteristics of halophilic Vibrio such as V. parahaemolyticus and V. alginolyticus are presented. The morphological, cultural, biochemical and fermentative properties, phages, virulence, antigenic structure, resistance to the environment and ecology of the microbes and their susceptibility to antibiotics of various chemical groups are described.

[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.

[Sensitivity of Vibrio and Aeromonas to antibiotics]. / Chuvstvitel'nost' k antibiotikam vibrionov i aéromonad.

The antibiotic sensitivity of 696 cultures belonging to the family Vibrionaceae (V. cholerae O1, V. cholerae non-O1, V. albensis, V. parahaemolyticus, V. alginolyticus and Aeromonas spp.) was studied and general regularities of the antibiotic sensitivity were shown: a high sensitivity to broad-spectrum antibiotics (tetracycline and chloramphenicol) and a low sensitivity to ++beta lactams (carbenicillin and ampicillin). The comparative examinations revealed similarity in the antibioticograms of V. cholerae O1 (el Tor++), V. cholerae non-O1 and V. albensis, especially the latter two groups, as well as the tested halophilic Vibrio cultures by the range of the MICs, Mo, Me and the nature of the antibiotic resistance. Cultures of V. cholerae and luminescent Vibrio tended to preserve a high sensitivity. High resistance levels were noted in the halophilic Vibrio and Aeromonas cultures. No significant differences in the sensitivity of the strains of various origin (from man and environmental objects) were detected. However, several more resistant strains were isolated from the environmental objects.

[Antibiotic sensitivity of Vibrio cholerae 01 isolated from environmental objects]. / Chuvstvitel'nost' k antibiotikam kholernykh vibrionov 01, vydelennykh iz ob''ektov vneshnei sredy.

The sensitivity of 252 Vibrio cholerae-O1 strains isolated from environmental objects to antibiotics of various groups was assayed by the method of serial dilutions on solid media. The biological characteristics of the isolates are presented. The Vibrio cholerae isolates with serological variation were the most frequent (36.6 per cent), so are the cultures detected by their sensitivity to the specific phages (87.5 per cent). It was found that changes in some biological properties of the strains did not coincide with the changes in the antibiotic sensitivity. The isolates were highly sensitive to tetracycline, chloramphenicol, gentamicin, erythromycin and rifampicin and less sensitive to novobiocin and the other aminoglycosides. The sensitivity to the beta-lactams was the lowest. The resistance determinants were detected in single strains (6.3 per cent), the kanamycin and novobiocin resistance determinants being detected in 15 out of the 16 strains tested. The study showed that the cultures of Vibrio cholerae-O1 isolated from the environmental objects generally preserved their sensitivity to the diverse group antibiotics.

[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.

[The use of micromethods for the identification of Vibrios]. / Ispol'zovanie mikrometodov dlia identifikatsii vibrionov.

The authors recommend micromethods for laboratory studies of Vibrio; such methods may be widely used at bacteriologic laboratories for examinations of biochemical characteristics of these microorganisms, for rapid identification of V. cholerae 01, and for serologic identification (typing) of V. cholerae non 01, since they accelerate the diagnosis and are much simpler than macromethods.