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Biomedical subjects

A L Gintsburg

Publications and source records attributed to A L Gintsburg.

At least 19 recordsLinked to original sources
PubMed2003

[Correlation between activity of the phosphoenol-pyruvate-dependable phosphotransferase system (PTS) and synthesis of adhesion P1 protein in Mycoplasma pneumoniae].

Three isogenous strains M. pneumoniae, i.e. virulent FH, avirulent FH400 and a revertant with a restored virulence (FHR) and isolated from an avirulent strain, were studied. The mechanism of hemadsorption and the ability to cause an infection in Syrian hamsters were found to be damaged in the avirulent strain. The detection of a specific mRNA by the RT-PCR method showed, apart from the loss of the main adhesin (protein P1), a lack of general components of the phosphoenol-pyruvat-dependable phosphotranspherase system (PTS), i.e. enzyme 1 and protein HPr. The recovery of virulence by passing an attenuated strain through animals with induced immunodeficiency correlated with the recovery of the activity of a gene encoding the P1 adhesion protein and with the onset of the PTS function activity. An analysis of published data was made use of to try to detect a correlation between the functional PTS activity in cell and virulence of M. pneumoniae.

Adhesins, Bacterial↗
PubMed2001

[Differential gene expression in culturable and non-culturable Salmonella typhimurium].

Differential gene expression in culturable and non-culturable forms of Salmonella typhimurium was studied by the molecular display method. Six fragments of differentially expressed gene cDNA, depending on culturable or non-culturable state of the cultures, were isolated, cloned, and sequenced. Identification of corresponding S. typhimurium differentially expressed genes was carried out by comparing the sequences of cDNA fragments with the bacterial genome data base.

DNA Primers↗
PubMed2001

[Mobile genetic elements and their role in evolution of pathogenic bacteria].

The review discusses a role of mobile genetic elements in the evolution of pathogenic bacteria. Particularly great emphasis is placed on two recent thoroughly studied mobile genetic elements--the islets of pathogenicity and cassettes containing antibiotic resistant genes. The matters associated with the structural organization of these types of mobile elements, mechanisms of their translocations and involvement in the production of pathogenic bacteria are considered in detail. The data on the impact of macroorganisms on the horizontal dissemination of genetic information are discussed.

Bacteria↗
PubMed2001

[Strategies of adaptive changes in Vibrio cholerae in natural water reservoirs].

The currently available data on different variations in cholera vibrio habiting in water reservoirs are summarized. The pattern of variations of the main signs of vibrions is discussed in the context of "typical-atypical-inactive-resting (uncultivable) forms". Emphasis is placed on the reversible pattern and adaptive essence of variation whose basis is clonal and selective processes in the heterogeneous bacterial population. Possible populational mechanisms responsible for the development of epidemic types of cholera vibrions in the aqueous ecosystems as a prerequisite for human morbidity are discussed. The efficiency of ecological and molecular genetic studies for the epidemiology of cholera is recognized.

Adaptation, Physiological↗
PubMed2000

[The use of polymerase chain reaction for detection of tetracycline resistance urogenital mycoplasma ].

PCR was used for detecting tetracyclin resistance genes tet-M and tet-O in Mollicutes. The tet determinants were detected in U. urealyticum and M. hominis genomes in 60 and 57.14%, respectively. PCR was used to detect urogenital mycoplasma in patients with different urogenital infections. The rate of detection of U. urealyticum was 10.71-25.1% in males and 23.08-61.91% in females, for M. hominis these values were 6.25-11.45% and 3.85-22.99%, and for M. genitalium 6.25-29.64% and 4.76-30.0%, respectively. Hence, the detection rate of tet determinants in mycoplasma by PCR was high (7-60%) in all groups of patients.

Female↗
PubMed2000

[Ultrastructural organization of Salmonella typhimurium cells during long-term starvation and transfer to an unculturable state].

Electron microscopic and immunocytochemical studies of Salmonella typhimurium culture were carried out under conditions of cell transfer into an unculturable state induced by carbon, phosphorus, and nitrogen starvation. Morphological variants of bacterial cells were detected in the course of cell culturing under conditions of starvation. Electron microscopy showed that O-antigen was retained in salmonella after long starvation and transfer into an unculturable state.

Culture Media↗
PubMed2000

[Development of a quantitative PCR variant, and use of it for assessing gene expression].

The data on the development of a quantitative PCR technique are presented, including the synthesis of modified primers, the choice of conditions for the removal of reaction-mixture components from the amplified DNA, and the colorimetric detection of the PCR product. The application of this technique to the assessment of the level of gene expression in nonculturable bacterial forms characterized by a drastically reduced metabolism is described.

Colorimetry↗
PubMed2000

[Use of molecular-biological methods for identifying brucella in a comparative analysis of strains, isolated from sick dogs].

Ten strains isolated from sick dogs in 1998 in St. Petersburg were studied by traditional and molecular biological methods of Brucella identification. PCR study confirmed that the isolated cultures were Brucellae, and comparative study of the traditional phenotypical characteristics and protein and antigenic composition allowed referring all the isolated strains to B. canis. Traditional identification showed similarity of 7 strains with the reference B. canis strain RM6/66, and 3 strains were similar to B. canis Mex 51 strain. These results confirmed the division of B. canis into two biovars. Polyacrylamide gel electrophoresis with sodium dodecyl sulfate demonstrated the identity of protein profiles of 10 strains isolated from dogs to the reference B. canis RM6/66 strain. Immunoblotting analysis with S- and R-specific rabbit antisera also demonstrated the identity of antigens binding IgG antibodies in the strains isolated from dogs to the reference B. canis RM6/66 strain.

Animals↗
PubMed1999

[Participation of mobile elements in formation of properties of pathogenic bacteria].

Published reports about structural organization of genes coding for pathogenicity factors are reviewed. Many of such genes are often united into "virulence blocks" or "pathogenicity islands" and are surrounded by mobile genetic elements, promoting their transposition between related bacteria genomes and leading to changes in virulence in the course of evolution. Data on the similarity of nucleotide sequences of virulence genes in different bacteria are presented, despite differences in their localization in the relevant genomes. The role of rRNA genes in dissemination of virulence genes among different bacteria during transduction or conjugation is shown.

Bacteria↗
PubMed1998

[Uncultured status of pathogenic bacteria: known and possible factors of reversible process induction].

Reviews published reports and authors' own data on the properties of unculturable bacteria, effects of environmental factors on the time course of transition in an unculturable state of different bacterial cells. Special attention is paid to reverse transfer of bacteria from unculturable to normal vegetative state. Conditions of inducing reverse transfer in in vitro laboratory conditions under different conditions of culturing and in vivo and injection of inoculates of uncultured forms of initially virulent bacteria to susceptible hosts are discussed. Probable role of some cytokinetic factors inducing transfer of bacteria from uncultured to cultured state during their transition from the environment into a host is discussed.

Bacteria↗
PubMed1997

[Development of polymerase chain reaction-based test systems for detecting leptospira in polytypical leptospirosis foci].

Two highly sensitive test systems G and B, based on the polymerase chain reaction, were developed for indication of pathogenic Leptospira interrogans, including the serovariants appearing during outbreaks in polytypical foci of leptospirosis in the tropical zone of China. These test systems can be used for rapid diagnosis of leptospirosis in humans in foci with different etiological structure.

China↗
PubMed1996

[The detection of mycobacteria in children and adolescents by using the polymerase chain reaction].

A polymerase chain reaction (PCR) was used for determination of mycobacterial DNA in clinical samples from children and adolescents. The results were positive in 23 and 53% of cases, respectively, while standard microbiological methods failed to show presence of any bacteria in the samples. Case histories contained information on high incidence of positive Mantoux test. Microbiologically the diagnosis was confirmed only in 7 adolescents. In children mycobacteria were not found.

Adolescent↗
PubMed1996

[Identification of genes controlling the transition of Salmonella typhimurium bacteria to a non-culturable state].

Mutants of Salmonella typhimurium with an impaired process of transition to the nonculturable state were tainted. Mutants were divided into four phenotypic groups. In four mutants (representatives of each phenotypic group), genes with TnPhoA transposon insertions were cloned; these insertions caused a disturbance in the process of mutant cell transition to the nonculturable state. Nucleotide sequences of mutant gene fragments were determined. Comparison of nucleotide sequences obtained with a data bank on DNA nucleotide sequences of enterobacterial genomes allowed the identification of four genes involved in the control of nonculturable form generation in salmonellae.

Base Sequence↗
PubMed1995

[Selective inhibition of DNA amplification in nonadhesive cultures of Mycoplasma pneumoniae].

Inhibition of amplification of various genome regions of Mycoplasma pneumoniae was observed in the polymerase chain reaction, and was dependent on cultivation conditions. A protein stably associated with DNA is responsible for the inhibitory effect. It is assumed that when the protein selectively associates with separate DNA regions, it can inhibit genes encoding pathogenicity factors, thus promoting mycoplasma transformation into persistent variants.

Bacterial Adhesion↗
PubMed1995

[PCR genetic typing of pathogenic microorganisms].

Basic principles, characteristics, methodical peculiarities, and strategy of choice of PCR-mediated methods of genetic typing are discussed. Existing and potential fields of application of these methods for tackling many unsolved problems of molecular epidemiology of bacterial infections are considered. Advantages of PCR-mediated methods of genetic typing compared with other techniques used for studying genomic polymorphism are demonstrated. Possibilities for developing novel PCR-mediated methods with the aim of improving genetic typing are analyzed.

Bacteria↗