The susceptibility of Mycobacterium tuberculosis to isoniazid and the Arg-->Leu mutation at codon 463 of katG are not associated.
A mutation (CCG-->CTG [Arg-->Leu]) in codon 463 of katG (catalase peroxidase) of Mycobacterium tuberculosis has been found in isoniazid (INH)-resistant strains. A PCR restriction endonuclease analysis to detect this mutation was applied to 395 M. tuberculosis isolates from patients in The Netherlands. The proportion of isolates with a detectable mutation was 32% (32 out of 100) and 29% (85 out of 295) among INH-susceptible isolates and INH-resistant or -intermediate isolates, respectively. Sequencing of five INH-susceptible isolates with such mutations showed that all five had the Arg463Leu mutation. We conclude that the Arg463Leu mutation of katG of M. tuberculosis is not a reliable indicator of INH resistance.
Academic Medical Center, Department of Medical Microbiology, Amsterdam, The Netherlands. h.r.vandoorn@amc.uva.nl
H R
HR
van Doorn
E J
EJ
Kuijper
A
A
van der Ende
A G
AG
Welten
D
D
van Soolingen
P E
PE
de Haas
J
J
Dankert
D000995:Antitubercular Agents / Q000494:pharmacology*; D001120:Arginine; D001426:Bacterial Proteins; D003062:Codon; D004352:Drug Resistance, Microbial; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology*; D007930:Leucine; D009154:Mutation; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D009426:Netherlands; D010544:Peroxidases / Q000235:genetics*; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014376:Tuberculosis / Q000382:microbiology
D000995:Antitubercular Agents; D001426:Bacterial Proteins; D003062:Codon; D001120:Arginine; D010544:Peroxidases; C076136:catalase HPI; D007930:Leucine; D007538:Isoniazid