A mechanism of rifamycin inhibition and resistance in Pseudomonas aeruginosa.
J Antimicrob Chemother
; 38(1): 133-7, 1996 Jul.
Article
em En
| MEDLINE
| ID: mdl-8858465
ABSTRACT
We sought to study the nature of rifampicin resistance in Pseudomonas aeruginosa. We hypothesized that the rifamycin regions of RNA polymerase are conserved in P. aeruginosa and that rifampicin resistance is mediated by a mutation in the rpoB gene encoding the beta subunit of RNA polymerase. Transcription assays showed that 50 nM of rifampicin inhibited transcription > 99% in a clinical isolate (MIC = 32 mg/L) and only < 40% in the rifampicin resistant mutant (MIC = 1000 mg/L). DNA sequencing revealed that the rifampicin regions are conserved in P. aeruginosa and the rifampicin regions of the rifampicin-resistant strain contained a mutation. Sodium hexametaphosphate lowered rifamycin MIC in a rifamycin-resistant mutant four-fold and in the clinical isolate 32-fold, suggesting that P. aeruginosa has a natural membrane barrier to rifamycins.
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Base de dados:
MEDLINE
Assunto principal:
Fosfatos
/
Pseudomonas aeruginosa
/
Rifampina
/
Rifamicinas
/
Transcrição Gênica
/
Antibacterianos
Idioma:
En
Ano de publicação:
1996
Tipo de documento:
Article