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N A Khomenko

Publications and source records attributed to N A Khomenko.

At least 19 recordsLinked to original sources
PubMed1988

Suggestion to supplement Shigella flexneri classification scheme with the subserovar Shigella flexneri 4c: phenotypic characteristics of strains.

A new serovar of Shigella flexneri has been isolated with increasing frequency in the USSR. It has the antigenic formula IV:7,8. We suggest that it be incorporated into the classification scheme as S. flexneri subserovar 4c. The 212 strains of this proposed subserovar examined to date display biochemical and serological properties typical of the species, are sensitive to the genus-specific bacteriophage, and cause keratoconjunctivitis in the Sereny test.

Phenotype↗
PubMed1986

[Biochemical properties of Shigella flexneri and their practical significance].

As the result of the study of 921 S. flexneri strains 1-6 and 4 (IV: 7,8), isolated in 31 regions of the USSR in 1975-1984, their biochemical characterization by 33 tests was made. All the strains under study proved to be typical in most of their constant signs, only some of strains 2a showed deviations in mannitol and some of strains 4a, in acetate. In strains of serovar 6, circulating in the USSR, specific features with respect to dulcitol and xylose were noted. The possibility of the biochemical subserovar typing of S. flexneri 1-5, X- and Y-var., with respect to maltose, arabinose, sorbitol and rhamnose was confirmed.

Arabinose↗
PubMed1984

[Unusual serovar of the causative agent of Flexner's dysentery. I. Its distribution and biochemical properties].

The data on the circulation of some S. flexneri strains in the USSR are presented. The antigenic structure of these strains (type antigen 4 and group antigens 7, 8) is not characteristic of known serological subvariants 4a, 4b or var. X. The time course of changes in their spreading on certain base territories controlled by the All-Union Shigellosis Center in 1980-1983 is shown. The biochemical characteristics of S. flexneri strains IV:7,8 under study, isolated in the USSR and abroad (Czechoslovakia, London) from humans, from a monkey and from the environment, are given. Similarities in the biochemical reactions of these strains with respect to indole, rhamnose, saccharose, maltose, arabinose and raffinose have been revealed. The strains isolated in the USSR have shown differences in the spectra of their resistance to antibiotics, depending on their territorial origin.

Animals↗
PubMed1981

[Collection of Shigella strains of provisional serovars. II. Antigens and antigenic relations].

In the serological study of 17 strains from the collection of Shigella provisory serovars (3873-50, 2000-53, 3341-55, 3615-53, 2710-54, 1621-54) differences in the content of K-antigens were revealed: some of them (3341-55, 3615-53) were in the K-form, others (2000-53, 1621-54) in the O-form, and the rest in the OK-form. No antigenic affinity between the representatives of the enterobacterial group under study was established. The partial composition of O-antigen in bacteria of serovar 2000-53 and antigenically affined E. coli strains, serogroup 06, was studied. E. coli 06 O-antigen was shown to be heterogeneous and had the structure of type a, b--a, c. On the basis of the antigenic structure thus established, as well as its cultural and biochemical properties described in earlier works, serovar 2000-53 should be excluded from the group of Shigella provisory serovars and classified with the genus Escherichia under the designation E. coli 06a. 6b : K? : H--.

Adsorption↗
PubMed1978

[Study of a collection of Shigella strains of provisional serovars (cultural and biochemical properties)].

The author studied 17 standard and local strains of shigellae of provisional serological variants (3873-50, 2000-53, 3341-53, 3615-53, 2710-54, 1621-54). By a number of biochemical signs (alkalization of citrate agar of Christiansen and Molke's lacmus, the growth on acetate medium, utilization of soluble starch) and resistance to the genus-specific dysentery bacteriophage the cultures of serological variant 2000-53 possessed no properties of shigellae and were escherichia according to the general characteristics. The enzymatic and cultural properties of the rest of provisional serological variants corresponded to the characteristics of bacteria belonging to Shigella genus.

Culture Media↗
PubMed1977

[Checking the reliability of the PathoTec biochemical test system for bacterial identification].

Tests of the PathoTec system intended for express bacteriological diagnosis were checked in comparative experiments with the common biochemical methods. Cultures of the following microbes were used: Schigella, Salmonella, Escherichia, Citrobacter, Klebsiella, Enterobacter, Proteus, Providencia, Pseudomonas, Bordetella, Staphylococcus, Streptococcus. In a number of tests, such as determination of cytochromoxidase, nitrate reduciase, phenylalaninedeaminase, indol, acetoin (for the differentiation of enterobacteria), detection of plasmocoagulation and mannite fermentation (for staphylococci) there was revealed a complete coincidence of the results. However, discrepancies were revealed with three of the reagents tested (for lysine decarboxylase, urease, citrate utilization) with regard to some groups of enterobacteria. The advantages of the PathoTec system consisted in more rapid results, simplicity of procedures, economy of media and ware.

Bacteria↗
PubMed1977

[Diagnostic value of individual tests for classification of Shigella].

A total of 1243 strains of enterobacteria were studied by four tests (mobility, lysis with dysentery polyvalent bacteriophage, relation to Christensen's citrate and salicin) for the purpose of determining shigellae genera. A combination of signs characteristic of Shigella genus was observed in 99.1% of laboratory and in 100% of freshly-isolated strains. No such combination was found in any other of the representatives of Enterobacteriaceae family. The tests under study are recommended for the work in practical laboratories to ascertain the reference to Shigella genus of cultures suspected of being Shigellae by the results of growth on combined medium (Olkenisky's, Kligler's, etc.).

Bacteriological Techniques↗
PubMed1977

[Features of the monosaccharide composition and ultrastructure of lipopolysaccharides of different forms of Shigella sonnei].

The authors present the results of study of chemical monosaccharide composition and the ultrastructure of purified lipopolysaccharides (LPS) of the I and the II phases and the R-form of Sh. sonnei. The amount of lipids in LPS preparations increased with the change from S- into R-form. Galactose content in LPS of the II phase was less than in LPS of the I phase, and it was absent entirely in LPS of R-form. It was demonstrated by negative contrasting that LPS dissociation increased with S leads to R dissociation. A marked similarity was found between macromolecular aggregates of LPS of the II phase and of R-form.

Chemical Phenomena↗
PubMed1976

[Antigenic composition of different forms of Sh. sonnei].

Data are presented on the study, with the aid of immunophoresis, of the antigenic composition of the I, II phases and R-forms of Sh. sonnei. From 5 to 7 antigens differing by thermoresistance, electrophoretic and diffuse mobility were found in the composition of microbial cells of various forms Sh. sonnei. Differences between the I phase on the one hand and cells of the II phase and R-form, on the other hand, consisted both in the quantitative composition of components of their thermostable O-antigens and in the structure of specific lipopolysaccharides of the forms.

Antigens, Bacterial↗
PubMed1976

[Electron microscopic study of the I, II phases and R-forms of Sh. sonnei].

Electron microscopic study of the microbial cells of the I, II phases and the R-form was carried out. Intact cells were examined by negative contrasting, and morphological differences of various bacterial phases were shown: cells of the I phase had a relatively smooth surface, bacteria of the II phase had a smooth surface, but many cell wall fragments were split from them; the surface of the R-form cells was coarse, folded, and cell wall fragments were split from the majority of bacteria. Antigenic determinants responsible for phasic specificity in bacteria of the I and II phases were located at some distance from the external membrane of the cell wall; as to the R-form cells--they were localized on the wall.

Antigens, Bacterial↗