scholarly journals The Spectrum of Spontaneous Rifampin Resistance Mutations in the rpoB Gene of Bacillussubtilis 168 Spores Differs from That of Vegetative Cells and Resembles That of Mycobacterium tuberculosis

2002 ◽  
Vol 184 (17) ◽  
pp. 4936-4940 ◽  
Author(s):  
Wayne L. Nicholson ◽  
Heather Maughan
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Bacillus Subtilis ◽  
Rpob Gene ◽  
Β Subunit ◽  
Resistance Mutations ◽  
New Mutation ◽  
Gene Encoding ◽  
Vegetative Cells ◽  
Dormant Cells ◽  
Rifampin Resistance

ABSTRACT Mutations causing rifampin resistance in vegetative cells of Bacillus subtilis 168 have thus far been mapped to a rather restricted set of alterations at either Q469 or H482 within cluster I of the rpoB gene encoding the β subunit of RNA polymerase. In this study, we demonstrated that spores of B. subtilis 168 exhibit a spectrum of spontaneous rifampin resistance mutations distinct from that of vegetative cells. In addition to the rpoB mutations Q469K, Q469R, and H482Y previously characterized in vegetative cells, we isolated a new mutation of rpoB, H482R, from vegetative cells. Additional new rifampin resistance mutations arising from spores were detected at A478N and most frequently at S487L. The S487L change is the predominant change found in rpoB mutations sequenced from rifampin-resistant clinical isolates of Mycobacterium tuberculosis. The observations are discussed in terms of the underlying differences of the DNA environment within dormant cells and vegetatively growing cells.

scholarly journals Novel rpoB Mutations Conferring Rifampin Resistance on Bacillus subtilis: Global Effects on Growth, Competence, Sporulation, and Germination

2004 ◽  
Vol 186 (8) ◽  
pp. 2481-2486 ◽  
Author(s):  
Heather Maughan ◽  
Belinda Galeano ◽  
Wayne L. Nicholson
Keyword(s):  
Bacillus Subtilis ◽  
Amino Acid ◽  
Rna Polymerase ◽  
Amino Acid Change ◽  
Β Subunit ◽  
Resistance Mutations ◽  
Rifampin Resistance

ABSTRACT Previously, spontaneous rifampin resistance mutations were isolated in cluster I of the rpoB gene, resulting in amino acid replacements (Q469R, H482R, H482Y, or S487L) in the Bacillus subtilis RNA polymerase β subunit (W. L. Nicholson and H. Maughan, J. Bacteriol. 184:4936-4940, 2002). In this study, each amino acid change in the β subunit was observed to result in its own unique spectrum of effects on growth and various developmental events, including sporulation, germination, and competence for transformation. The results thus establish the important role played by the RNA polymerase β subunit, not only in the catalytic aspect of transcription, but also in the regulation of major developmental events in B. subtilis.

scholarly journals Amplification Refractory Mutation System – Polymerase Chain Reaction for Rapid Detection of rpoB Gene Mutations in Mycobacterium tuberculosis

2017 ◽  
Vol 5 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Hemanta Kumari Chaudhary ◽  
Mitesh Shrestha ◽  
Prakash Chaudhary ◽  
Bal Hari Poudel
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Rpob Gene ◽  
Amplification Refractory Mutation System ◽  
Chain Reaction ◽  
Arms Pcr ◽  
Mutation System ◽  
Mdr Tb ◽  
Total Dna ◽  
Polymerase Chain ◽  
Rifampin Resistance

Multidrug-resistant tuberculosis (MDR-TB) has become a serious worldwide threat including in Nepal. MDR-TB refers to the pathological condition whereby Mycobacterium tuberculosis becomes resistant to the first line of drug treatment i.e. rifampin and isoniazid. Resistance to rifampin (RIF) is mainly caused by the mutations in the rpoB gene which codes for the β-subunit of RNA polymerase. In this study, Amplification Refractory Mutation System – Polymerase Chain Reaction (ARMS – PCR) technique has been used to detect mutations in the rpoB gene of Mycobacterium tuberculosis. Total DNA samples of 34 phenotypic MDR-TB were subjected to ARMS – PCR using three different codon specific primers (516, 526 and 531). These three codons occupy large portion of total mutation responsible for rifampin resistance. Out of the total DNA samples, all were bearing mutation in at least one of the three codons mentioned. Of those bearing mutation, the highest number had mutation in codon 531 (97.05 %) followed by codon 516 (17.64 %) and finally in codon 526 (11.76%) respectively. Hence, ARMS – PCR may be used as an alternative diagnostic technique for detection of rifampin resistance in Mycobacterium tuberculosis strains, especially for a developing country like Nepal.Int. J. Appl. Sci. Biotechnol. Vol 5(1): 81-85

Rifampin resistance mutations in the rpoB gene of Enterococcus faecalis impact host macrophage cytokine production

Cytokine ◽  
2022 ◽  
Vol 151 ◽  
pp. 155788
Author(s):  
Darya V. Urusova ◽  
Joseph A. Merriman ◽  
Ananya Gupta ◽  
Liang Chen ◽  
Barun Mathema ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Cytokine Production ◽  
Rpob Gene ◽  
Resistance Mutations ◽  
Host Macrophage ◽  
Rifampin Resistance ◽  
Macrophage Cytokine

scholarly journals Rifampin Resistance in Mycobacterium kansasii Is Associated with rpoB Mutations

2001 ◽  
Vol 45 (11) ◽  
pp. 3056-3058 ◽  
Author(s):  
John L. Klein ◽  
Timothy J. Brown ◽  
Gary L. French
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Molecular Basis ◽  
Strong Association ◽  
Missense Mutations ◽  
Β Subunit ◽  
Mycobacterium Kansasii ◽  
Bacterial Rna ◽  
Rifampin Resistance ◽  
Potent Drug

ABSTRACT Rifampin is the most potent drug used in the treatment of disease due to Mycobacterium kansasii. A 69-bp fragment ofrpoB, the gene that encodes the β subunit of the bacterial RNA polymerase, was sequenced and found to be identical in five rifampin-susceptible clinical isolates of M. kansasii. This sequence showed 87% homology with the Mycobacterium tuberculosis gene, with an identical deduced amino acid sequence. In contrast, missense mutations were detected in the same fragment amplified from five rifampin-resistant isolates. A rifampin-resistant strain generated in vitro also harbored an rpoB gene missense mutation that was not present in the parent isolate. All mutations detected (in codons 513, 526, and 531) have previously been described in rifampin-resistant M. tuberculosis isolates. Rifampin MICs determined by E-test were <1 mg/liter for all rifampin-susceptible isolates and >256 mg/liter for all rifampin-resistant ones. In addition, four of the five rifampin-resistant isolates were also resistant to rifabutin. We have thus shown a strong association between rpoB gene missense mutations and rifampin resistance in M. kansasii. Although our results are derived from a small number of isolates and confirmation with larger numbers would be useful, they strongly suggest that mutations within rpoB form the molecular basis of rifampin resistance in this species.

scholarly journals Epidemiology of Rifampicin Resistant Tuberculosis and Common Mutations in rpoB Gene of Mycobacterium tuberculosis: A Retrospective Study from Six Districts of Punjab (India) Using Xpert MTB/RIF Assay

2016 ◽  
Vol 8 (02) ◽  
pp. 096-100 ◽  
Author(s):  
Ramandeep Kaur ◽  
Neerja Jindal ◽  
Shilpa Arora ◽  
Shajla Kataria
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Surrogate Marker ◽  
Rpob Gene ◽  
Multidrug Resistant ◽  
Resistance Pattern ◽  
Resistance Mutations ◽  
Resistant Tuberculosis ◽  
Mdr Tb ◽  
Previously Treated Patients ◽  
User Friendly

ABSTRACT Background: Xpert MTB/RIF assay has revolutionized the diagnosis of tuberculosis (TB) by simultaneously detecting the bacteria and resistance to rifampicin (RIF), a surrogate marker for multidrug-resistant TB (MDR-TB) in <2 h. The RIF resistance pattern in Malwa region of Punjab, India, is not documented. Here, we report the epidemiology of RIF-resistant TB and mutations in rpoB gene of Mycobacterium tuberculosis (MTB). Materials and Methods: A total of 1612 specimens received between October 2013 and February 2015 were tested by Xpert MTB/RIF assay following manufacturer’s instructions. The results thus obtained were analyzed using SPSS version 20.0.0 (SPSS Inc., Chicago, IL, USA) statistical software. Result: RIF resistance was statistically higher in previously treated patients in comparison to the new patients (P = 0.006) and in patients with acid fast-Bacilli (AFB) positive smears to AFB-negative smears (P = 0.048). RIF resistance mutations in 130 specimens revealed frequency of E 73/130 (56%), B 28/130 (21.5%), D 18/130 (13.8%), A 11/130 (8.4%), and C 1/130 (0.7%) while in one specimen, mutation combination, i.e., mutations associated with more than one probe (A and B both) was present. Conclusion: Xpert MTB/RIF assay is a user-friendly screening tool for detection of MTB and RIF resistance from suspected TB/MDR cases in a shorter period of time. It could also serve as a useful technique to have simultaneous preliminary information regarding the mutation pattern of RIF resistance in MTB isolates.

scholarly journals Automatic Identification of Individual rpoB Gene Mutations Responsible for Rifampin Resistance in Mycobacterium tuberculosis by Use of Melting Temperature Signatures Generated by the Xpert MTB/RIF Ultra Assay

2019 ◽  
Vol 58 (1) ◽  
Author(s):  
Yuan Cao ◽  
Heta Parmar ◽  
Ann Marie Simmons ◽  
Devika Kale ◽  
Kristy Tong ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Melting Temperature ◽  
Gene Mutations ◽  
Test Sample ◽  
Rpob Gene ◽  
Automatic Identification ◽  
Content Type ◽  
Automated Algorithm ◽  
Wide Range ◽  
Rifampin Resistance

ABSTRACT Molecular surveillance of rifampin-resistant Mycobacterium tuberculosis can help to monitor the transmission of the disease. The Xpert MTB/RIF Ultra assay detects mutations in the rifampin resistance-determining region (RRDR) of the rpoB gene by the use of melting temperature (Tm) information from 4 rpoB probes which can fall in one of the 9 different assay-specified Tm windows. The large amount of Tm data generated by the assay offers the possibility of an RRDR genotyping approach more accessible than whole-genome sequencing. In this study, we developed an automated algorithm to specifically identify a wide range of mutations in the rpoB RRDR by utilizing the pattern of the Tm of the 4 probes within the 9 windows generated by the Ultra assay. The algorithm builds a RRDR mutation-specific “Tm signature” reference library from a set of known mutations and then identifies the RRDR genotype of an unknown sample by measuring the Tm distances between the test sample and the reference Tm values. Validated using a set of clinical isolates, the algorithm correctly identified RRDR genotypes of 93% samples with a wide range of rpoB single and double mutations. Our analytical approach showed a great potential for fast RRDR mutation identification and may also be used as a stand-alone method for ruling out relapse or transmission between patients. The algorithm can be further modified and optimized for higher accuracy as more Ultra data become available.

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