several reports have indicated that infection with non-tuberculosis mycobacteria (ntm) is increasing worldwide.therefore,monitoring species causing micobacterial infection in any region is of great importance. this study was going to detect, differentiate, and identify pathogenic mycobacteria in primary clinical samples. eighty samples collected from tuberculosis suspected patients in isfahan/i...

Merchant et al., by using ung+ and ung– Escherichia coli strains, demonstrated that total nitric oxide exposures in the μmol/L range can lead to C→T mutations by a mechanism probably involving cytosine deamination (8). On the other hand, in M. smegmatis, the abrogation of the Ung activity leads not only to increased mutator phenotype but also to growth inhibition by reactive nitrogen intermedia...

the aim of this study was to investigate the frequency, location and type of rpob gene mutations in mycobacterium tuberculosis (mtb) collected from patients in the southern endemic region of iran. drug susceptibility testing was determined by using the bactec system and the center for diseases control’s (cdc) standard conventional proportional method. in 29 rifampicin-resistant mtb (85%) isolat...

The purpose of the present study was to evaluate the usefulness of rpoB-PCR assay and concentration flurochrome (CF) staining against culture for direct detection of mycobacteria sp in respiratory specimen amongsymptomatic patients. Of the 900 specimens 52 were culture positive with Löwenstein-Jensen Medium (LJM). Of the 52 culture positive samples, 48 were positive by rpoB-PCR (sensitivity 92....

Rickettsiae are gram-negative, obligately intracellular bacteria responsible for arthropod-borne spotted fevers and typhus. Experimental studies have delineated a cluster of naturally rifampin-resistant spotted fever group species. We sequenced the 4, 122- to 4,125-bp RNA polymerase beta-subunit-encoding gene (rpoB) from typhus and spotted fever group representatives and obtained partial sequen...

The Escherichia coli GroP- phenotype, associated with some dnaB mutants and measured as a decreased ability to plate lambda bacteriophage, was altered by some rpoB mutations. The rpoB effect showed an allele specificity. The participation both of dnaB and of lambda P alleles in the GroP- phenotype was also allele specific. It was concluded that RNA polymerase, dnaB protein, and lambda P protein...

A cloned rpoB gene, specifying an apparently mutant RNA polymerase beta subunit, protected Escherichia coli against the cytocidal effects of the E3 protein of bacteriophage SPO1, suggesting that RNA polymerase is the primary cellular target of the E3 protein. Two segments of the wild-type E. coli genome, one of which specifies a suppressor of dnaK mutations, and thus, possibly, a molecular chap...

Resistance determinants that interfere with normal physiological processes in the bacterial cell usually cause a reduction in biological fitness. Fitness assays revealed that 17 of 18 in vitro-selected chromosomal mutations within the rpoB gene accounting for rifampin resistance in Staphylococcus aureus were associated with a reduction in the level of fitness. There was no obvious correlation b...

This study was designed with the aim of exploring efficacy RNA polymerase beta subunit, rpoB gene analysis for identification streptomycetes. A characteristic marine environment distinguished by their content streptomycetes were targeted, and two organisms genus Streptomyces isolated in Saudi Arabia. The spp., named isolates EH1 EH2 subjected to regular phenotypic characterization including mor...

We investigated the size and continuity of DNA segments integrated in Bacillus subtilis transformation. We transformed B. subtilis strain 1A2 toward rifampicin resistance (coded by rpoB) with genomic DNA and with a PCR-amplified 3.4-kb segment of the rpoB gene from several donors. Restriction analysis showed that smaller lengths of donor DNA integrated into the chromosome with transformation by...