[Characterization of the rpoB gene mutations in clinical isolates of rifampicin-resistant Mycobacterium tuberculosis].
OBJECTIVE
Characterization and frequency of the rpoB gene mutations associated with rifampin resistance in Mycobacterium tuberculosis clinical isolates in Sevilla.


METHODS
Characterization of rpoB mutations in 21 rifampicin-resistant strains of M. tuberculosis isolated during a three-year period (1994-1996) by three different molecular methods: a nonradioactive Single-strand conformation polymorphism (SSCP) analysis, DNA sequence analysis and a commercial method the line probe assay InnoLiPA.


RESULTS
Five distinct rpoB mutations were identified. Ser531-->Leu mutation was detected in 14 strains (66.7%), H526-->Asp in 3 strains (14.3%), Ans512-->Ser in 1 strain (4.8%), Glu513-->Leu in 1 strain (4.8%). A nine nucleotide deletion (codon 510-513) was found in one strain (4.8%) while in the remaining resistant strain (4.8%) no mutation was detected.


CONCLUSIONS
The frequency of the different mutations found in the rpoB gene, associated with rifampicin resistance in Mycobacterium tuberculosis clinical isolates in Seville, are similar to those previously reported. However, two new mutations has been detected: a nine nucleotide deletion (codon 510-513), and the Asn512-->Ser point mutation. The characterization of the mutations in the rpoB gene could serve as epidemiological marker for the rifampicin resistant clinical isolates of M. tuberculosis.
González
N
N
Departamento de Microbiología, Universidad de Sevilla.
Torres
M J
MJ
Palomares
J C
JC
Aznar
J
J
D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000235:genetics*; D004252:DNA Mutational Analysis; D004269:DNA, Bacterial / Q000235:genetics; D012321:DNA-Directed RNA Polymerases; D004352:Drug Resistance, Microbial; D005798:Genes, Bacterial; D006801:Humans; D009154:Mutation; D020125:Mutation, Missense; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D010940:Plant Proteins / Q000235:genetics*; D018807:Polymorphism, Single-Stranded Conformational; D012293:Rifampin / Q000494:pharmacology*; D014376:Tuberculosis / Q000188:drug therapy / Q000382:microbiology*; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy / Q000382:microbiology
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D010940:Plant Proteins; C101305:RpoB protein, Oryza sativa; D012321:DNA-Directed RNA Polymerases; D012293:Rifampin