We reevaluated the BACTEC MGIT 960 antimicrobial susceptibility testing system (MGIT 960 AST) by using 1,112 isolates of Mycobacterium tuberculosis. When the results of MGIT 960 AST were compared with that of the proportion method using Ogawa medium (Ogawa PM), discrepant results were obtained for 30 strains with isoniazid, all resistant by MGIT 960 AST but susceptible by Ogawa PM. For 93% of t...

Catalase-peroxidases (KatGs) are unique in exhibiting an overwhelming catalase activity and a peroxidase activity of broad specificity. Similar to other peroxidases the distal histidine in KatGs forms a hydrogen bond with an adjacent conserved asparagine. To investigate the catalytic role(s) of this potential hydrogen bond in the bifunctional activity of KatGs, Asn153 in Synechocystis KatG was ...

The CDC classifies Francisella tularensis as a Category A bioterrorism agent. Due to the risk of potential release antibiotic-resistant F. strains, new therapeutics against must be developed. Resazomycins are resazurin (Rz)-based compounds that exhibit antimicrobial activity and other gram-negative bacteria. mode action resazomycins is not understood, but targets antibiotic were identified in h...

INTRODUCTION Tuberculosis remains the leading causes of death worldwide with frequencies of mutations in rifampicin and isoniazid resistant Mycobacterium tuberculosis isolates varying according to geographical location. There is limited information in Zimbabwe on specific antibiotic resistance gene mutation patterns in MTB and hence, increased rate of discordant results and mortality due to ina...

A mutation (CCG-->CTG [Arg-->Leu]) in codon 463 of katG (catalase peroxidase) of Mycobacterium tuberculosis has been found in isoniazid (INH)-resistant strains. A PCR restriction endonuclease analysis to detect this mutation was applied to 395 M. tuberculosis isolates from patients in The Netherlands. The proportion of isolates with a detectable mutation was 32% (32 out of 100) and 29% (85 out ...

The objective : to study prevalence and patterns of mutations in the katG, inhA, ahpC, rpoB genes associated with Mycobacterium tuberculosis (MTB) resistance isoniazid (H) rifampicin (R) patients various clinical manifestations pulmonary (TB). Subjects Methods . 441 sputum samples collected were tested using biological microchips. Tests carried out Group 1 - confirmed bacterial excretion (n = 2...

We studied the presence of mutations in the whole katG gene and specific regions of the oxyR-ahpC and mabA-inhA regulatory region in 61 Mycobacterium tuberculosis isoniazid-resistant isolates. An 81-bp region of the rpoB gene was also sequenced in 17 rifampin-resistant strains. Alterations in the katG gene were detected in 55% of the isolates. Mutation in codon 315 was the most prevalent (32%)....

OBJECTIVES Three Mycobacterium tuberculosis genetic loci--rpoB and katG genes and the fabG1(mabA)-inhA operon promoter region--were studied to reveal the mutations associated with rifampicin and isoniazid resistance. METHODS Four hundred and twelve isolates of M. tuberculosis from different regions of the Russian Federation were collected during 1997-2005. A matrix-assisted laser-desorption i...