On the nature of Mycobacterium tuberculosis-latent bacilli

• Published in: The European respiratory journal Vol. 24; no. 6; pp. 1044 - 1051
• Main Authors: Cardona, P-J, Ruiz-Manzano, J
• Format: Journal Article
• Language: English
• Published: Leeds Eur Respiratory Soc 01.12.2004; Maney
• Subjects: Animals; Bacterial diseases; Biological and medical sciences; Disease Models, Animal; Human bacterial diseases; Humans; Infectious diseases; Medical sciences; Mycobacterium tuberculosis - pathogenicity; Pneumology; Tuberculosis - microbiology; Tuberculosis and atypical mycobacterial infections; Virulence Factors - physiology; Infection; Latent; Animal model; Tuberculosis; Mycobacterium tuberculosis; Mycobacteriales; Pathogenesis; Bacteriosis; Mycobacteriaceae; Bacteria; Actinomycetes; Mycobacterial infection
• ISSN: 0903-1936; 1399-3003
• DOI: 10.1183/09031936.04.00072604

Mycobacterium tuberculosis-latent bacilli are microorganisms that adapt to stressful conditions generated by the infected host against them. By slowing metabolism or becoming dormant, they may counterbalance these conditions and appear as silent to the immune system. Moreover, the dynamic turnover of the infected cells provokes a constant reactivation of the latent bacilli when the environmental conditions are favourable, or an activation after being dormant in necrotic and fibrotic lesions for a long period of time. Since there is no in vivo nor in vitro evidence for quick resuscitation of dormant bacilli, the current authors strongly favour the possibility that latent tuberculosis infection can be maintained for no longer than approximately 10 yrs, which is, nowadays, a time period very close to that considered for "primary" tuberculosis. This concept may also be helpful for newer epidemiological considerations regarding the real impact of reinfection in tuberculosis.