A Pediatric Case of Atypical <i>Mycobacterium avium</i> Infection of the Skin

Noguchi, Hiromitsu; Hiruma, Masataro; Kawada, Akira; Fujimoto, Norihiro; Fujioka, Akira; Ishibashi, Akira

doi:10.1111/j.1346-8138.1998.tb02419.x

Cited by 18 publications

(8 citation statements)

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“…Additional experiments are needed to investigate this hypothesis. MAC can also enter the host by the intradermal route through cuts and skin punctures (53,54). Experimental work showed that intradermal bacillus administration resulted in infection of cervical and/or axillary lymph nodes in both BALB/c and nude mice, suggesting that skin lesions may also be responsible for the cervical lymphadenitis seen in humans (53).…”

Section: Discussionmentioning

confidence: 99%

Virulence and Immune Response Induced by Mycobacterium avium Complex Strains in a Model of Progressive Pulmonary Tuberculosis and Subcutaneous Infection in BALB/c Mice

et al. 2013

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eThe genus Mycobacterium comprises more than 150 species, including important pathogens for humans which cause major public health problems. The vast majority of efforts to understand the genus have been addressed in studies with Mycobacterium tuberculosis. The biological differentiation between M. tuberculosis and nontuberculous mycobacteria (NTM) is important because there are distinctions in the sources of infection, treatments, and the course of disease. Likewise, the importance of studying NTM is not only due to its clinical significance but also due to the mechanisms by which some species are pathogenic while others are not. Mycobacterium avium complex (MAC) is the most important group of NTM opportunistic pathogens, since it is the second largest medical complex in the genus after the M. tuberculosis complex. Here, we evaluated the virulence and immune response of M. avium subsp. avium and Mycobacterium colombiense, using experimental models of progressive pulmonary tuberculosis and subcutaneous infection in BALB/c mice. Mice infected intratracheally with a high dose of MAC strains showed high expression of tumor necrosis factor alpha (TNF-␣) and inducible nitric oxide synthase with rapid bacillus elimination and numerous granulomas, but without lung consolidation during late infection in coexistence with high expression of anti-inflammatory cytokines. In contrast, subcutaneous infection showed high production of the proinflammatory cytokines TNF-␣ and gamma interferon with relatively low production of anti-inflammatory cytokines such as interleukin-10 (IL-10) or IL-4, which efficiently eliminate the bacilli but maintain extensive inflammation and fibrosis. Thus, MAC infection evokes different immune and inflammatory responses depending on the MAC species and affected tissue.

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Section: Discussionmentioning

confidence: 99%

Virulence and Immune Response Induced by Mycobacterium avium Complex Strains in a Model of Progressive Pulmonary Tuberculosis and Subcutaneous Infection in BALB/c Mice

et al. 2013

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“…MAC has been shown to present as pulmonary infections in immunocompetent patients including elderly women and smokers, as well as immunocompromised individuals who have undergone organ transplantation or with inheritable defects in IFN-␥ (10,14). Cutaneous manifestations of MAC in immunocompetent individuals also occur, especially in children (15,16). All of these manifestations of MAC have in common infiltration by mononuclear cells and granuloma formation.…”

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confidence: 99%

Mycobacterium aviumInfection and Modulation of Human Macrophage Gene Expression

Greenwell-Wild

Vázquez

Sim

et al. 2002

The Journal of Immunology

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Mycobacterium avium is a facultative intracellular pathogen cleared rapidly via intact host defense mechanisms. In the absence of adequate T cell function, as occurs in HIV-1-induced immunodeficiency, M. avium becomes an opportunistic infection with uncontrolled replication and reinfection of macrophage hosts. How M. avium infects, survives, and replicates in macrophages without signaling an effective microbicidal counterattack is unresolved. To address whether M. avium signals the expression of molecules, which influence mycobacterial survival or clearance, human monocyte-derived macrophage cultures were exposed to M. avium. Within minutes, M. avium, or its cell wall lipoarabinomannan, binds to the adherent macrophages and induces a spectrum of gene expression. In this innate response, the most abundant genes detected within 2 h by cDNA expression array involved proinflammatory chemokines, cytokines including TNF-α and IL-1, and adhesion molecules. Associated with this rapid initial up-regulation of recruitment and amplification molecules was enhanced expression of transcription factors and signaling molecules. By 24 h, this proinflammatory response subsided, and after 4 days, when some bacteria were being degraded, others escaped destruction to replicate within intracellular vacuoles. Under these conditions, inducible NO synthase was not up-regulated and increased transferrin receptors may facilitate iron-dependent mycobacterial growth. Sustained adhesion molecule and chemokine expression along with the formation of multinucleated giant cells appeared consistent with in vivo events. Thus, in the absence of T lymphocyte mediators, macrophages are insufficiently microbicidal and provide a nonhostile environment in which mycobacteria not only survive and replicate, but continue to promote recruitment of new macrophages to perpetuate the infection.

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“…The MAI complex may infect virtually any tissue, and surgical excision of abscesses has been reported from cervical lymphatic [24], pulmonary [25], cutaneous [26], tenosynovial [27,28], meningeal [29], and paranasal sinus [30] sites. In our case, re-operation was decided against initially, despite clinical deterioration, because the patient had not received a multidrug regimen effective against MAI until that time and, ultimately, because of the patient's rapid improvement once effective treatment was instituted.…”

Section: Discussionmentioning

confidence: 99%