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I M Medvedeva

Publications and source records attributed to I M Medvedeva.

10 recordsLinked to original sources
PubMed2001

[Components of monitoring drug resistance of tuberculosis agent in the evaluation of effectiveness of the national tuberculosis control program].

The authors analyzed the changes and pattern of drug-resistance in tuberculosis pathogen by using the reports of over 700 microbiological laboratories of tuberculosis control service in Russia in the past 20 years (1979-1998), which yielded a monitoring system for drug resistance in the pathogen in this country. Seven underlying informational blocks were identified. These included more than 20 different quantitative and qualitative parameters covering the characteristics of a patient and the pathogen and regionally environmental and epidemiological indices. Analysis of the data on the united northern, west-northern, and Baltic regions is given as an example of successful use of the monitoring system.

Antibiotics, Antitubercular↗
PubMed2000

[Molecular mechanisms of mycobacterium tuberculosis strains resistance to rifampicin and isoniazid].

The levels and spectra of the drug resistance of clinical M. tuberculosis strains were defined. There was a relationship of treatment regimens to the drug resistance of mycobacteria isolated from the strains. The fragments of genes rpoB, inhA, and katG were analyzed by polymerase chain reaction and sequencing. In addition to earlier identified substitutions, new mutations were found in rpoB: A-->T/233, G-->A/395, C-->T/232, G-->T/202, C-->T/221, C-->T/260, GA-->TT/202-203, delta 199-207 ATGGACCAG. Strain 12/7 was found to have 30 point mutations leading to substitution of only 3 amino acids and to have GGG(Gly)354 deletion as well. Most mutations in this strain are "silent". Substitutions at 944 and 463 positions were revealed in katG.

Antibiotics, Antitubercular↗
PubMed2000

[The monitoring of the drug resistance of the causative agent of tuberculosis in Russia in 1979-1998].

The Russian 1979-1998 annual reports of the centralized microbiology laboratories of the tuberculosis controlling service were used to examine the pattern and trends of formation of drug-resistance in the tuberculosis pathogen. The data on over 1.2 million cases of drug resistance to 7 antituberculous drugs were pooled. The analysis indicated that drug resistance had increased in two steps in the past 2 decades. The maximum levels of the drug resistance of Mycobacterium tuberculosis to some drugs were limited (7.8 and 37.2%), which are not greater those as indicated by the international statistics.

Antitubercular Agents↗
PubMed1999

Drug-resistant strains of Mycobacterium tuberculosis isolated in Russia.

SETTING: State Research Center for Applied Microbiology, Russian Research Institute of Phthisiopulmonology (Ministry of Health, Moscow). OBJECTIVE: To analyze drug-resistant clinical isolates of Mycobacterium tuberculosis obtained from patients referred to the institute from different parts of Russia, and to study the mechanisms of their rifampicin resistance. DESIGN: Fifty clinical isolates of M. tuberculosis were analysed. Polymerase chain reaction (PCR) and sequencing were used to study the mechanisms of rifampicin resistance in 25 isolates. RESULTS: Among cultures isolated from 50 patients, drug resistance was detected in 33. Most of the isolates were resistant to rifampicin (25 isolates), isoniazid (14 isolates), and streptomycin (seven isolates). Only 6% of the isolates were resistant to one drug, while 14% were resistant to two, 32% to three, 40% to four, and 8% to five drugs. Susceptible isolates were derived from 17 patients. The following point mutations and deletions in the rpoB locus, responsible for high level rifampicin resistance (more than 50 microg/ml in egg-based medium), were detected: G-->A/395 (Arg-->Gln), C-->T/232 (His-->Tyr), C-->T/221 (Ser-->Leu), G-->T/202 (Asp-->Tyr), GA-->TT/202-203 (Asp-->Phe), deltaATGGACCAG/199-207 (Met, Asp, Gin), A-->T/91 (Met-->Leu), TG-->CC/227-228 (Leu-->Ser), GAG-->AGT/349-350-351 (Gln-->Ser), deltaGGG/354(Gly). CONCLUSION: A number of previously unrecognised genetic modifications in the rpoB region were found in rifampicin-resistant strains isolated from patients from different parts of Russia.

Adult↗
PubMedDate not supplied

[The use of molecular biological methods for the individual characterization of Mycobacterium tuberculosis strains].

The expediency of using molecular biological methods for the evaluation of M. tuberculosis clinical strains by individual genetic certification of circulating M. tuberculosis strains has been substantiated. Considerable genetic heterogeneity of M. tuberculosis strains isolated from patients in different regions of the Russian Federation has been established; this heterogeneity is due to the presence of differences in the number of copies (5-26) of element IS6110 in M. tuberculosis cells.

Base Sequence↗