Novel mutations in NADH dehydrogenase (ndh) were detected in 8 of 84 (9.5%) isoniazid (INH)-resistant isolates (T110A [n = 1], R268H [n = 7]), but not in 22 INH-susceptible isolates of Mycobacterium tuberculosis. Significantly, all eight isolates with mutations at ndh did not have mutations at katG, kasA, or the promoter regions of inhA or ahpC, except for one isolate. Mutations in ndh appear t...

A Bacteroides fragilis mutant resistant to hydrogen peroxide and alkyl peroxide was isolated by enrichment in increasing concentrations of hydrogen peroxide. The mutant strain was constitutively resistant to 100 mM H2O2 and 5 mM cumene hydroperoxide (15-min exposure). In contrast, the parent strain was protected against <10 mM H2O2 when the peroxide response was induced with a sublethal concent...

Campylobacter jejuni is an important foodborne pathogen. The molecular mechanisms for the regulation of oxidative stress resistance have not yet been understood fully in this bacterium. In this study, we investigated how PerR (peroxide stress regulator) modulates the transcriptional regulation of both peroxide and superoxide resistance genes in C. jejuni, particularly under oxidative stress con...

AhpF, a homodimer of 57 kDa subunits, is a flavoenzyme which catalyzes the NADH-dependent reduction of redox-active disulfide bonds in the peroxidase AhpC, a member of the recently identified peroxiredoxin class of antioxidant enzymes. The structure of AhpF from Salmonella typhimurium at 2.0 A resolution, determined using multiwavelength anomalous dispersion, shows that the C-terminal portion o...

We present a 2D high-order and easily accessible immersed-boundary adaptive harmonic polynomial cell (IB-AHPC) method to solve fully nonlinear wave-structure interaction problems in marine hydrodynamics using potential-flow theory. To reduce the total number of cells without losing accuracy, quad-tree refinements are employed close free-surface structure boundaries. The is simpler implement tha...

SETTING The incidence of tuberculosis (TB) and drug resistance in Italy is low compared to other countries. Mutations in several genomic regions of Mycobacterium tuberculosis are involved in the occurrence of isoniazid (INH) resistance. OBJECTIVE To investigate the mutations responsible for INH resistance among Italian isolates of M. tuberculosis, to assess the feasibility of predicting drug ...