We present a case of tenosynovitis caused by a novel, slowly growing, nonchromogenic, nontuberculous mycobacterium (NTM). Originally misidentified as Mycobacterium tuberculosis complex, the NTM cross-reacts with the M. tuberculosis complex nucleic acid hybridization probe, a M. tuberculosis gamma interferon release assay, and is closely related to M. tuberculosis by 16S rRNA gene sequencing.

Mycobacterium tuberculosis is a highly successful pathogen that can persist and cause disease despite an immune response. One potential mechanism for resisting elimination is by inhibiting the action of IFN-gamma. We have previously shown that live M. tuberculosis inhibits selected macrophage responses to IFN-gamma, and that purified M. tuberculosis 19-kDa lipoprotein inhibits induction of sele...

The assumption that Mycobacterium tuberculosis infections should be considered clonally homogeneous has been weakened in the last few years. Recent studies have shown (i) the isolation of different M. tuberculosis strains from sequential episodes, (ii) mixed infections by two M. tuberculosis strains, and (iii) genetic variations in M. tuberculosis subpopulations due to microevolution events. Ne...

Complement receptor (CR)-mediated phagocytosis of Mycobacterium tuberculosis by macrophages results in intracellular survival, suggesting that M. tuberculosis interferes with macrophage microbicidal mechanisms. As increases in cytosolic Ca(2+) concentration (¿Ca(2+)(c)) promote phagocyte antimicrobial responses, we hypothesized that CR phagocytosis of M. tuberculosis is accompanied by altered C...

Mycobacterium tuberculosis grows within the phagocytic vacuoles of macrophages, where it encounters a moderately acidic and possibly nutrient-restricted environment. Other mycobacterial species encounter acidic conditions in soil and aquatic environments. We have evaluated the influence of pH and divalent cation levels on the growth of M. tuberculosis and seven other mycobacterial species. In a...

As the disease caused by Mycobacterium tuberculosis continues to be a burden, there is a concerted effort to find new vaccines to combat this problem. One of the important vaccine strategies is whole bacterial vaccines. This approach relies on multiple antigens and built-in adjuvanticity. Other mycobacterial strains which share cross-reactive antigens with M. tuberculosis have been considered a...

Of those individuals who are infected with M. tuberculosis, 90% do not develop active disease and represents a large reservoir of M. tuberculosis with the potential for reactivation of infection. Sustained TNF expression is required for containment of persistent infection and TNF neutralization leads to tuberculosis reactivation. In this study, we investigated the contribution of soluble TNF (s...

Tuberculosis (TB) remains a global health threat. Although it is generally accepted that TB results from intensive cross-talk between the host and the pathogen Mycobacterium tuberculosis, underlying mechanisms remain elusive. The first evidence of human polymorphisms related to susceptibilities to distinct M. tuberculosis lineages has been gathered. Confrontation of limited host resistance with...

Two nrdF genes, nrdF1 and nrdF2, encoding the small subunit (R2) of ribonucleotide reductase (RR) from Mycobacterium tuberculosis have 71% identity at the amino acid level and are both highly homologous with Salmonella typhimurium R2F. The calculated molecular masses of R2-1 and R2-2 are 36,588 (322 amino acids [aa]) and 36,957 (324 aa) Da, respectively. Western blot analysis of crude M. tuberc...

background & objectives: although isoniazid is the most efficient in killing the tuberculosis bacilli, resistance to this drug also develops most readily. mutations in katg, inha and ahpc are responsible for isoniazid resistance in a large proportion of tuberculosis cases. the frequency of these mutations varies with population samples, however. this study provided the first molecular character...