Abstract | OBJECTIVE: METHOD: The rpoB, rpsL, rrs, katG genes, and inhA regulatory sequence in 85 M. tuberculosis isolates were analyzed with polymerase chain reaction (PCR), PCR-single-stranded conformation polymorphism analyses (SSCP), PCR-nucleotide sequence analyses (NS) and PCR-restriction fragment length polymorphism (RFLP). RESULTS: The sensitivity of amplifying the drug-resistant genes with PCR was 1-10 pg DNA. Twenty-eight drug-sensitive strains had no alterations in the rpoB, rpsL, rrs, katG genes, and inhA regulatory sequences. 93.3% of 45 M. tuberculosis RFP-resistant (RFPr) isolates had rpoB mutations. Codon 531 and 526 of the rpoB are the most common sites of nucleotide substitutions. 72.5% of 40 SM-resistant (SMr) isolates had an identical mutation at codon 43 of the rpsL gene. No isolates had a mutation at codon 88 of the rpsL. Only 7.5% of these SMr isolates had A-to-C transversions at position 513 of the rrs gene. Of 34 INH-resistant (INHr) isolates, 11.8% had complete katG deletions, 55.9% had mutations in the selected region of katG. Only 8.8% had alterations in the inhA regulatory sequences. 60.9% of RFPr, INHr, and SMr isolates had mutations in genetic markers for these drug resistance. CONCLUSIONS: Most drug resistance in M. tuberculosis was due to simple mutations occurring in chromosomally encoded genes. Alterations in rpoB, rpsL and katG gene may be the important mechanism of M. tuberculosis resistance to RFP, SM, and INH. PCR, PCR-SSCP, PCR-NS, and PCR-RFLP are going to become the simple, rapid and reliable diagnostic tests for drug resistance in M. tuberculosis.
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Authors | X Wu, J Zhang, Y Zhuang, X Zhang, G Li, X He |
Journal | Chinese medical journal
(Chin Med J (Engl))
Vol. 112
Issue 6
Pg. 524-8
(Jun 1999)
ISSN: 0366-6999 [Print] China |
PMID | 11601331
(Publication Type: Journal Article)
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Chemical References |
- Antitubercular Agents
- DNA-Directed RNA Polymerases
- Isoniazid
- Rifampin
- Streptomycin
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Topics |
- Antitubercular Agents
(pharmacology)
- DNA-Directed RNA Polymerases
(genetics)
- Drug Resistance, Microbial
(genetics)
- Humans
- Isoniazid
- Mutation
- Mycobacterium tuberculosis
(drug effects, genetics)
- Polymorphism, Restriction Fragment Length
- Rifampin
- Streptomycin
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