Resistance to rifampin in Mycobacterium tuberculosis results from mutations in the gene coding for the beta subunit of RNA polymerase (rpoB). At least 95% of rifampin-resistant isolates have mutations in rpoB, and the mutations are clustered in a small region. About 40 distinct point mutations and in-frame insertions and deletions in rpoB have been identified, but point mutations in two codons,...

The aim of this study was to use DNA sequencing analysis to analyze the mutations in the most commonly targeted genes (katG, inhA, rpoB, rpsL) in isoniazid (INH)-, rifampin (RIF)- and streptomycin (SM)-resistant Mycobacterium tuberculosis strains obtained from subjects in Duzce, Turkey. Four isolates were found to be INH-resistant, 3 were RIF-resistant and 5 were SM-resistant, out of a total of...

Most Mycobacterium tuberculosis rifampin-resistant strains have been associated with mutations in an 81-bp rifampin resistance-determining region (RRDR) in the gene rpoB. However, if this region alone were targeted, rifampin-resistant strains with mutations outside the RRDR would not be detected. In this study, among 51 rifampin-resistant clinical isolates analyzed by sequencing 1,681-bp-long D...

results slow and fast-growing groups of the mycobacterium strains were clearly differentiated based on the constructed tree of 56 common mycobacterium isolates. each species with a unique title in the tree was identified; in total, 13 nods with a bootstrap value of over 50% were supported. among the slow-growing group was mycobacterium kansasii, with m. tuberculosis in a cluster with a bootstra...

In this study, a pyrosequencing method for monitoring two genes related to isoniazid (INH)-resistance and a region of the rpoB gene linked to rifampin (RMP)-resistance in Mycobacterium tuberculosis was developed and evaluated. Specifically, a 20-base pair (bp) region of inhA (from -24 to -4), a 35-bp region of ahpC (from -39 to -4), and a 57-bp region of rpoB (from codon 515 to 533) were analys...

OBJECTIVE To examine the frequency and distribution of mutations in the 'hot spot regions' of drug-resistant genes. METHODS The study was conducted at Provincial Tuberculosis Reference Laboratory, Peshawar, Pakistan, from April 2015 to March 2016, and comprised sputum samples. Isolates were tested for drug susceptibility and resistant isolates were investigated for mutations analysis in the '...

Mutations in the rpoB locus confer conformational changes leading to defective binding of rifampin (RIF) to rpoB and consequently resistance in Mycobacterium tuberculosis. Polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) was established as a rapid screening test for the detection of mutations in the rpoB gene, and direct sequencing has been unambiguously applied to c...

The 81-bp region of the rpoB gene in 66 Rif(r) Mycobacterium tuberculosis isolates from China, Japan, Korea, and Taiwan was analyzed. Twelve single-nucleotide substitutions in the rpoB gene were detected. The most prevalent mutations were at Ser-531 (52%), Asp-516 (17%), and His-526 (11%). Mutations were not found in seven (11%) of the isolates. Higher mutation rates in 50 Beijing family isolat...

objective: the rifampicin resistance and susceptibility of mycobacterium tuberculosis are caused by mutations in the 81-base pair region of the rpob gene encoding the b-subunit of rna polymerase. methods: isoniazid resistance of m. tuberculosis is related to mutations in inha , oxyr and ahpc genes which 30 to 90 percent of isoniazid resistance is occurred in 3015 codons of katg gene. the rpob a...

The prevalence of recently described mutation V176F, located in the beginning of the rpoB gene and associated with rifampin resistance and the wild-type cluster I sequence, was determined by analyzing the distribution of rpoB mutations among 80 rifampin (RIF)-resistant Mycobacterium tuberculosis strains isolated in Germany during 1997. The most frequent rpoB mutations were changes in codon 456 ...