sodium-nitrite and Tuberculosis--Pulmonary

Susceptibilities of 12 clinical Mycobacterium tuberculosis isolates to acidified sodium nitrite (ASN) were compared. The results demonstrate that 8 of the 12 isolates exhibited enhanced survival levels in 1.5 mM ASN compared to levels in medium alone, suggesting that low concentrations of reactive nitrogen intermediates have a hormetic effect on M. tuberculosis in vitro.

Topics: Colony Count, Microbial; Culture Media; Dose-Response Relationship, Drug; Humans; Microbial Sensitivity Tests; Mycobacterium tuberculosis; Nitric Oxide; Reactive Nitrogen Species; Sodium Nitrite; Tuberculosis, Pulmonary

Susceptibility of six isolates of Mycobacterium tuberculosis (CB3.3, CDC1551, RJ2E, C.C.13, H37Rv, and H37Ra) and two isolates of Mycobacterium bovis (Ravenel and BCG) to reactive oxygen intermediates (ROI) and reactive nitrogen intermediates (RNI) was determined by standard in vitro survival assays. After 21 days of incubation, the survival of most strains exposed to either acidified sodium nitrite (ASN) or hydrogen peroxide (H(2)O(2)) was significantly lower than the same strains unexposed to these RNI or ROI products. However, after 50 days of incubation, these differences in susceptibility became less apparent for strains exposed to ASN but not for strains exposed to H(2)O(2). The recovery of these strains after exposure to RNI suggests that the effect of RNI on M. tuberculosis is bacteriostatic. The in vitro concentrations of ROI and RNI used in these assays were higher than those expected in vivo. These observations suggest that, in vivo, RNI expression at physiologically achievable concentrations may keep M. tuberculosis from proliferating but that removal of RNI may allow the organisms to proliferate. Furthermore, the ability of some M. tuberculosis strains to cause rapidly progressive disease may relate to their intrinsic levels of RNI and ROI resistance.

Topics: Humans; Hydrogen Peroxide; Microbial Sensitivity Tests; Mycobacterium tuberculosis; Reactive Nitrogen Species; Reactive Oxygen Species; Sodium Nitrite; Tuberculosis, Pulmonary

Resistance to reactive oxygen intermediates and reactive nitrogen intermediates in vitro of a clinical isolate of Mycobacterium tuberculosis (CDC1551) that caused a large outbreak of tuberculosis was compared to that of M. tuberculosis strains CB3.3, H37Rv, H37Ra, Erdman, RJ2E, C.C. 13, and C.C. 22 as well as M. bovis strains Ravenel and BCG. CDC1551 and CB3.3 were significantly more resistant to both hydrogen peroxide (H(2)O(2)) and acidified sodium nitrite than were the other strains tested. This biological phenotype may serve as an in vitro marker for clinical strains of M. tuberculosis likely to cause a large outbreak of tuberculosis.

Topics: Disease Outbreaks; Drug Resistance, Bacterial; Humans; Hydrogen Peroxide; Kentucky; Mycobacterium tuberculosis; Oxidants; Reactive Nitrogen Species; Reactive Oxygen Species; Sodium Nitrite; Tennessee; Tuberculosis, Pulmonary