scholarly journals Molecular Analysis of Rifampicin Resistance Conferring Mutations in Mycobacterium tuberculosis

2020 ◽  
Vol 17 (2) ◽  
pp. 0444
Author(s):  
Fairuz Tawgozy et al.
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Rpob Gene ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Rifampicin Resistance ◽  
New Finding ◽  
Lowenstein Jensen ◽  
Proportion Method ◽  
Rpoa Gene ◽  
First Time

Mycobacterium tuberculosis resistance to rifampicin is mainly mediated through mutations in the rpoB gene. The effects of rpoB mutations are relieved by secondary mutations in rpoA or rpoC genes. This study aims to identify mutations in rpoB, rpoA, and rpoC genes of Mycobacterium tuberculosis isolates and clarify their contribution to rifampicin resistance. Seventy isolates were identified by acid-fast bacilli smear, Genexpert assay, and growth on Lowenstein Jensen medium. Drug susceptibility, testing was performed by the proportional method.  DNA extraction, PCR, and sequencing were accomplished for the entire rpoA, rpoB, and rpoC genes. Twenty-three isolates (32.85%) showed resistance to rifampicin by either proportion method or Genexpert assay. Sequence analysis of the rpoB gene revealed fourteen different mutation patterns. Inside the rifampicin resistance determining region (RRDR), codons: S531L, D516V were highly mutated with frequencies of (21.73%, 17.39%) respectively. Outside the RRDR, there were nine different types of mutations, and M479L was the most prevalent one. Out of 23 RIF resistant isolates, seven isolates (30.43%) carried mutations in the rpoA gene, and twelve isolates (52.17%) harbored a mutation in rpoC. Most of the mutations were identified for the first time in this study. The current study demonstrated that mutations in rpoB, rpoA, and rpoC contributed to RIF resistance in Mycobacterium tuberculosis and this new finding may be relevant to realize how compensatory mutations in the rpoA and rpoC genes restore the fitness cost caused by rifampin resistance-conferring mutations in rpoB.

scholarly journals Effect of Piper nigrum (Linn.) seeds extract and second line anti-tuberculosis drugs on a few Mycobacterium tuberculosis strains

2021 ◽  
Vol 13 (1) ◽  
pp. 402-406
Author(s):  
G. V. Zodape ◽  
S. N. Dharmashale ◽  
V. S. Gaikwad
Keyword(s):  
Mycobacterium Tuberculosis ◽  
In Vitro Study ◽  
Ethanolic Extract ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Piper Nigrum ◽  
Amino Salicylic Acid ◽  
Lowenstein Jensen ◽  
Proportion Method

Piper nigrum (Linn.) belonging to the family Piperaceae have been reported for its multitudinous medicinal values. The present study was undertaken to examine the direct effect of Ethionamide (ETH), Para amino salicylic acid (PAS), ethanolic extracts of P. nigrum on Mycobacterium tuberculosis (MTB) strain H37Rv and Multi drug-resistant (MDR)-strains-12, 19 and 21. The proportion method was used to detect the anti-mycobacterial drug susceptibility testing for mycobacteria using Lowenstein Jensen (LJ) medium. It was found that P. nigrum does not interfere with single or in the combination of both ETH and PAS showing the bioenhancer activity. In vitro study of ethanolic extract of P. nigrum observed that the extract inhibited the growth of H37Rv strains and MDR strains-12, MDR strains 19, and MDR strains 21. The present results will pave new avenues to find a new medicine that possesses P. nigrum alone or in combination with drugs to combat MDR-strains controlling tuberculosis.

scholarly journals Occurrence ofrpoBMutations in Isoniazid-Resistant but Rifampin-Susceptible Mycobacterium tuberculosis Isolates from Germany

2013 ◽  
Vol 58 (1) ◽  
pp. 590-592 ◽  
Author(s):  
Sönke Andres ◽  
Doris Hillemann ◽  
Sabine Rüsch-Gerdes ◽  
Elvira Richter
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Content Type ◽  
Indicator Tube ◽  
Lowenstein Jensen ◽  
Proportion Method ◽  
Rifampin Resistance ◽  
Growth Indicator

ABSTRACTFour out of 143 phenotypically isoniazid-resistant but rifampin-susceptibleMycobacterium tuberculosisstrains that were isolated from patients in Germany in 2011 had mutations in the rifampin resistance-determining region ofrpoB. After performing drug susceptibility testing (DST) with two methods, the proportion method on Löwenstein-Jensen medium and using the Bactec 960 Mycobacteria Growth Indicator Tube system, we conclude that the two methods are equally reliable for phenotypic DST and MIC determination.

Comparison of MB/BacT system and agar proportion method in drug susceptibility testing of Mycobacterium tuberculosis

2001 ◽  
Vol 39 (4) ◽  
pp. 229-232 ◽  
Author(s):  
Wing Wai Yew ◽  
Steena Ching Wa Tong ◽  
Kin Sang Lui ◽  
Simon Kwok Fai Leung ◽  
Chi Hung Chau ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Susceptibility Testing ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
Proportion Method

scholarly journals rpoB gene mutations in rifampin-resistant Mycobacterium tuberculosis isolates from rural areas of Zhejiang, China

2021 ◽  
Vol 49 (3) ◽  
pp. 030006052199759
Author(s):  
Mei-Chun Zeng ◽  
Qing-Jun Jia ◽  
Lei-Ming Tang
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Rural Areas ◽  
Gene Mutations ◽  
Gene Sequencing ◽  
Rpob Gene ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Drug Resistant ◽  
Extensively Drug Resistant

Objective The aim was to analyze genetic mutations in the rpoB gene of rifampin-resistant Mycobacterium tuberculosis isolates (RIFR-MTB) from Zhejiang, China. Methods We prospectively analyzed RIFR-associated mutations in 13 rural areas of Zhejiang. Isolates were subjected to species identification, phenotype drug susceptibility testing (DST), DNA extraction, and rpoB gene sequencing. Results A total of 103 RIFR isolates were identified by DST (22 RIFR only, 14 poly-drug resistant, 49 multidrug resistant, 13 pre-extensively drug resistant [pre-XDR], and 5 extensively drug resistant [XDR]) from 2152 culture-positive sputum specimens. Gene sequencing of rpoB showed that the most frequent mutation was S450L (37.86%, 39/103); mutations P280L, E521K, and D595Y were outside the rifampicin resistance-determining region (RRDR) but may be associated with RIFR. Mutations associated with poly-drug resistant, pre-XDR, and XDR TB were mainly located at codon 445 or 450 in the RRDR. Conclusions The frequency of rpoB RRDR mutation in Zhejiang is high. Further studies are needed to clarify the relationships between RIFR and the TTC insertion at codon 433 in the RRDR and the P280L and D595Y mutations outside the RRDR.

scholarly journals Drug Susceptibility Profile of Mycobacterium tuberculosis Isolated from Patients Visiting National Tuberculosis Centre, Nepal

2018 ◽  
Vol 5 ◽  
pp. 63-68
Author(s):  
S. Dahal ◽  
M.R. Banjara ◽  
D. Khadka ◽  
G. Ghimire ◽  
S. Sharma
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Drug Susceptibility ◽  
Cross Sectional Study ◽  
Drug Susceptibility Testing ◽  
Biochemical Tests ◽  
Cross Sectional ◽  
Resistant Tuberculosis ◽  
National Tuberculosis ◽  
Mdr Tb ◽  
Lowenstein Jensen

Objectives: The objective of this study was to assess drug susceptibility pattern of Mycobacterium tuberculosis (MTB). Methods: This cross-sectional study was carried out among 145 clinically suspected and previously treated pulmonary tuberculosis patients visiting National Tuberculosis Centre, Bhaktapur, Nepal. After obtaining written informed consent, questionnaire was administered and sputum samples were collected from each patient. Each sample was subjected to Ziehl-Neelsen (ZN) staining and cultured on Lowenstein Jensen (LJ) medium at 37ºC for 8 weeks. MTB isolates were identified by growth rate and colony morphology, confirmed by biochemical tests and drug susceptibility testing (DST) of identified isolates was performed by proportion method. Results: A total of 49.7% (n=72) sputum samples were positive for MTB by culture and 46.9% (n=68) were positive by ZN staining. Among culture positive isolates of MTB (n= 72), 25% (n=18) were resistant to at least one drug. The prevalence of multi drug resistant tuberculosis (MDR-TB) was 15.3% (n=11) of which 5.56% (n=4) were resistant to rifampicin (RIF) only, 1.39% (n= 1) were resistant to isoniazid (INH) only. Out of 18 resistant isolates, 61.1% (n=11) were resistant to both RIF and INH, 21.43% (n=3) resistant to INH were susceptible to RIF and 26.67% (n=4) resistant to RIF were susceptible to INH. Smoking (P=0.001) and coughing (P=0.009) were statistically significant with isolation of MTB. Conclusion: Since the prevalence of MDR-TB was high, MDR-TB strains should be identified in order to initiate second line treatment.

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