scholarly journals Regulatory Systems Controlling Latent Infection by Mycobacterium tuberculosis

2002 ◽  
Vol 1 ◽  
pp. 103-106
Author(s):  
Thomas C. Zahrt ◽  
Vojo Deretic
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Latent Infection ◽  
Regulatory Systems

Tuberculosis

2010 ◽  
pp. 810-831 ◽  
Author(s):  
Richard E. Chaisson ◽  
Jean B. Nachega
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Hiv Infection ◽  
Cause Of Death ◽  
Latent Infection

Tuberculosis is caused by organisms of the Mycobacterium tuberculosis complex, including M. tuberculosis (the most important), M. bovis, and M. africanum. It has been present since antiquity and is the second leading infectious cause of death after HIV infection. An estimated 2 billion people worldwide carry latent infection, when ...

scholarly journals Active Pulmonary Tuberculosis Triggered by Interferon Beta-1b Therapy of Multiple Sclerosis: Four Case Reports and a Literature Review

Medicina ◽  
2020 ◽  
Vol 56 (4) ◽  
pp. 202 ◽  
Author(s):  
Carmen Adella Sirbu ◽  
Elena Dantes ◽  
Cristina Florentina Plesa ◽  
Any Docu Axelerad ◽  
Minerva Claudia Ghinescu
Keyword(s):  
Multiple Sclerosis ◽  
Mycobacterium Tuberculosis ◽  
Literature Review ◽  
Interferon Beta ◽  
Latent Infection ◽  
Case Reports ◽  
Active Tuberculosis ◽  
Active Pulmonary Tuberculosis ◽  
Disease Modifying Therapies ◽  
Disease Modifying

In this paper, we reported on four cases of severe pulmonary active tuberculosis in patients with multiple sclerosis (MS) undergoing interferon beta-1b (IFNβ-1b) therapy. Disease-modifying therapies (DMTs) in MS may increase the risk of developing active tuberculosis (TB) due to their impact on cellular immunity. Screening for latent infection with Mycobacterium tuberculosis (LTBI) should be performed, not only for the newer DMTs (alemtuzumab, ocrelizumab) but also for IFNβ-1b, alongside better supervision of these patients.

scholarly journals Metabolic Switching of Mycobacterium tuberculosis during Hypoxia Is Controlled by the Virulence Regulator PhoP

2020 ◽  
Vol 202 (7) ◽  
Author(s):  
Prabhat Ranjan Singh ◽  
Anil Kumar Vijjamarri ◽  
Dibyendu Sarkar
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Nitrogen Metabolism ◽  
Electron Acceptor ◽  
Latent Infection ◽  
Critical Role ◽  
Hypoxic Stress ◽  
Content Type ◽  
Metabolic Switching ◽  
Virulence Regulator

ABSTRACT Mycobacterium tuberculosis retains the ability to establish an asymptomatic latent infection. A fundamental question in mycobacterial physiology is to understand the mechanisms involved in hypoxic stress, a critical player in persistence. Here, we show that the virulence regulator PhoP responds to hypoxia, the dormancy signal, and effectively integrates hypoxia with nitrogen metabolism. We also provide evidence to demonstrate that both under nitrogen limiting conditions and during hypoxia, phoP locus controls key genes involved in nitrogen metabolism. Consistently, under hypoxia a ΔphoP strain shows growth attenuation even with surplus nitrogen, the alternate electron acceptor, and complementation of the mutant restores bacterial growth. Together, our observations provide new biological insights into the role of PhoP in integrating nitrogen metabolism with hypoxia by the assistance of the hypoxia regulator DosR. The results have significant implications on the mechanism of intracellular survival and growth of the tubercle bacilli under a hypoxic environment within the phagosome. IMPORTANCE M. tuberculosis retains the unique ability to establish an asymptomatic latent infection. To understand the mechanisms involved in hypoxic stress which play a critical role in persistence, we show that the virulence regulator PhoP is linked to hypoxia, the dormancy signal. In keeping with this, phoP was shown to play a major role in M. tuberculosis growth under hypoxia even in the presence of surplus nitrogen, the alternate electron acceptor. Our results showing regulation of hypoxia-responsive genes provide new biological insights into role of the virulence regulator in metabolic switching by sensing hypoxia and integrating nitrogen metabolism with hypoxia by the assistance of the hypoxia regulator DosR.

scholarly journals The emergence of latent infection in the early evolution of Mycobacterium tuberculosis

2016 ◽  
Vol 283 (1831) ◽  
pp. 20160499 ◽  
Author(s):  
Rebecca H. Chisholm ◽  
Mark M. Tanaka
Keyword(s):  
Mathematical Model ◽  
Immune Response ◽  
Mycobacterium Tuberculosis ◽  
Genetic Variation ◽  
Natural Selection ◽  
Natural History ◽  
Latent Infection ◽  
Human Populations ◽  
Safe Harbour ◽  
Active Disease

Mycobacterium tuberculosis has an unusual natural history in that the vast majority of its human hosts enter a latent state that is both non-infectious and devoid of any symptoms of disease. From the pathogen perspective, it seems counterproductive to relinquish reproductive opportunities to achieve a détente with the host immune response. However, a small fraction of latent infections reactivate to the disease state. Thus, latency has been argued to provide a safe harbour for future infections which optimizes the persistence of M. tuberculosis in human populations. Yet, if a pathogen begins interactions with humans as an active disease without latency, how could it begin to evolve latency properties without incurring an immediate reproductive disadvantage? We address this question with a mathematical model. Results suggest that the emergence of tuberculosis latency may have been enabled by a mechanism akin to cryptic genetic variation in that detrimental latency properties were hidden from natural selection until their expression became evolutionarily favoured.

scholarly journals Comparison of Two Commercially Available Gamma Interferon Blood Tests for Immunodiagnosis of Tuberculosis

2007 ◽  
Vol 15 (1) ◽  
pp. 168-171 ◽  
Author(s):  
Jose Domínguez ◽  
Juan Ruiz-Manzano ◽  
Malú De Souza-Galvão ◽  
Irene Latorre ◽  
Celia Milà ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Tuberculin Skin Test ◽  
Skin Test ◽  
Mycobacterium Bovis ◽  
Latent Infection ◽  
Positive Tuberculin Skin Test ◽  
Gamma Interferon ◽  
Bcg Vaccination ◽  
Blood Tests

ABSTRACT We evaluated the T-SPOT.TB and Quantiferon-TB Gold In tube (QFN-G-IT) tests for diagnosing Mycobacterium tuberculosis infection. T-SPOT.TB was more sensitive than QFN-G-IT in diagnosing both active and latent infection. Both gamma interferon tests were unaffected by prior Mycobacterium bovis BCG vaccination. Among children who were not BCG vaccinated but had a positive tuberculin skin test, QFN-G-IT was negative in 53.3% of cases, and T-SPOT.TB was negative in 50% of cases.

scholarly journals Extrapulmonary Locations of Mycobacterium tuberculosis DNA During Latent Infection

2012 ◽  
Vol 206 (8) ◽  
pp. 1194-1205 ◽  
Author(s):  
Jorge Barrios-Payán ◽  
Milena Saqui-Salces ◽  
Mangalakumari Jeyanathan ◽  
Avissai Alcántara-Vazquez ◽  
Mauricio Castañon-Arreola ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Latent Infection

scholarly journals Higher human CD4 T cell response to novel Mycobacterium tuberculosis latency associated antigens Rv2660 and Rv2659 in latent infection compared with tuberculosis disease

Vaccine ◽  
2010 ◽  
Vol 29 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Lerisa Govender ◽  
Brian Abel ◽  
E. Jane Hughes ◽  
Thomas J. Scriba ◽  
Benjamin M.N. Kagina ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
Cell Response ◽  
Latent Infection ◽  
T Cell Response ◽  
Cd4 T Cell ◽  
Tuberculosis Disease
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