BACKGROUND A new, fast 'low cost and density' DNA microarray (LCD array), designed for the detection of mutations that confer isoniazid or rifampicin resistance in Mycobacterium tuberculosis isolates, has been developed and was evaluated using 46 resistant clinical isolates from Barcelona. METHODS LCD chips are pre-structured polymer supports using a non-fluorescent detection principle based ...

This is an open-access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Multidrug-resistant (MDR) strains of Mycobacterium tuberculosis represent an obstacle in tuberculosis control and stress the need for rapid and reliable diagnostic tools for drug sus...

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...

The World Health Organization had endorsed Xpert® MTB/RIF (Xpert) as the initial diagnostic for multidrug-resistant tuberculosis (TB) or TB suspects co-infected with the human immunodeficiency virus. We investigated an unexpected case of rifampicin (RMP) resistance on Xpert using repeat Xpert, smear microscopy, MTBDRplus assay, culture, drug susceptibility testing, spoligotyping and rpoB gene ...

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...

BACKGROUND Studies conducted on Mycobacterium spp. isolated from human patients indicate that sequencing of a 711 bp portion of the rpoB gene can be useful in assigning a species identity, particularly for members of the Mycobacterium avium complex (MAC). Given that MAC are important pathogens in livestock, companion animals, and zoo/exotic animals, we were interested in evaluating the use of r...

The rpoB gene for the beta subunit of rice chloroplast RNA polymerase was found to be highly expressed in unexpanded immature leaves that contained proplastids, indicating the specific expression of rpoB at an early stage of chloroplast development. A putative transcription start site (tss) was identified, but the 5' upstream region of the tss had no sequences resembling typical --35 and --10 e...

Modifications to transcriptional regulators play a major role in adaptation. Here, we compared the effects of multiple beneficial mutations within and between Escherichia coli rpoB, the gene encoding the RNA polymerase β subunit, and rho, which encodes a transcriptional terminator. These two genes have harbored adaptive mutations in numerous E. coli evolution experiments but particularly in our...

INTRODUCTION It is perceived wisdom that within the host macrophage, Mycobacterium tuberculosis frequently encounters oxidative stress. Exposure of bacteria to reactive oxygen intermediates can have a mutagenic effect on the DNA. Various mutations are thought to arise as a consequence, including the oxidation of guanine residues, leading to G?C-->T?A substitution, and oxidation of cytosine resu...

The objective of this study was to investigate the cross-resistance between rifampin (RIF) and rifabutin (RFB) among clinical Mycobacterium tuberculosis (MTB) isolates, and the correlations between specific rpoB mutations and the minimum inhibitory concentrations (MICs) of RIF and RFB. A total of 256 RIF-resistant isolates were included from the National Tuberculosis Clinical Laboratory in Chin...