Disseminated cutaneous atypical mycobacteriosis by M. chelonae after sclerotherapy of varicose veins in a immunocompetent patient: a case report

Atypical mycobacteria are saprophytic organisms not transmitted from person to person, which affect mainly immunosuppressed but also immunocompetent individuals. We present a case of atypical mycobacteriosis after a vascular procedure, with widespread cutaneous lesions associated with polyarthralgia. Mycobacterium chelonae was identified by the polymerase chain reaction (PCR) method. The patient showed improvement after treatment with three antibiotics. Mycobacterium chelonae causes skin lesions after invasive procedures. The clinical form depends on the immune state of the host and on the entry points. The diagnosis is based essentially on culture and the mycobacteria is identified by PCR. We highlight the importance of investigating atypical mycobacteriosis when faced with granulomatous lesions associated with a history of invasive procedures.

Mycobacterium chelonae cutaneous infection in a patient with mixed connective tissue disease

Around 50 mycobacteria species cause human disease. Immunosuppressive states predispose to non-tuberculous mycobaterium infection, such as Mycobacterium chelonae: AFB, non-tuberculous, fast growth of low virulence and uncommon as a human pathogen. It may compromise the skin and soft tissues, lungs, lymph nodes and there is also a disseminated presentation. The diagnosis involves AFB identification and culture on Agar and Lowenstein-Jensen medium base. A 41-year-old female with MCTD (LES predominance) is reported, presenting painless nodules in the right forearm. She denied local trauma. Immunosuppressed with prednisone and cyclophosphamide for 24 months. Lesion biopsy has demonstrated positive bacilloscopy (Ziehl-Neelsen stain) and M.chelonae in culture (Lowenstein-Jensen medium base), therefore clarithromycin treatment has been started (best therapy choice in the literature).

Control of Mycobacterium fortuitum and Mycobacterium intracellulare infections with respect to distinct granuloma formations in livers of BALB/c mice

Mycobacterium fortuitum is a rapidly growing nontuberculous Mycobacterium that can cause a range of diseases in humans. Complications from M. fortuitum infection have been associated with numerous surgical procedures. A protective immune response against pathogenic mycobacterial infections is dependent on the granuloma formation. Within the granuloma, the macrophage effector response can inhibit bacterial replication and mediate the intracellular killing of bacteria. The granulomatous responses of BALB/c mice to rapidly and slowly growing mycobacteria were assessed in vivo and the bacterial loads in spleens and livers from M. fortuitum and Mycobacterium intracellulare-infected mice, as well as the number and size of granulomas in liver sections, were quantified. Bacterial loads were found to be approximately two times lower in M. fortuitum-infected mice than in M. intracellulare-infected mice and M. fortuitum-infected mice presented fewer granulomas compared to M. intracellulare-infected mice. These granulomas were characterized by the presence of Mac-1+ and CD4+ cells. Additionally, IFN-γmRNA expression was higher in the livers of M. fortuitum-infected mice than in those of M. intracellulare-infected mice. These data clearly show that mice are more capable of controlling an infection with M. fortuitum than M. intracellulare. This capacity is likely related to distinct granuloma formations in mice infected with M. fortuitum but not with M. intracellulare.

Nontuberculous Mycobacterial Pulmonary Diseases in Immunocompetent Patients

Nontuberculous mycobacterial (NTM) infections are an increasingly recognized cause of chronic lung disease in immunocompetent adults, and the M. avium complex, M. kansasii, and a rapidly growing mycobacteria such as M. abscessus, M. fortuitum, and M. chelonae account for most of the pathogens involved. Because the clinical features of NTM disease are not distinguishable from those of tuberculosis, and NTM are ubiquitous in the environment, diagnosis requires that the bacilli are isolated and identified. NTM diseases have been difficult to treat, though since the introduction of new macrolides, the outcome for patients with some NTM diseases has improved significantly. For correct diagnosis and the successful treatment of NTM pulmonary disease, a knowledge of the full spectrum of clinical and radiological findings is important.

Immune response & modulation of immune response induced in the guinea-pigs by Mycobacterium avium complex (MAC) & M. fortuitum complex isolates from different sources in the south Indian BCG trial area.

A total of 139 guineapigs were used to study the immune response and its modulation induced by Mycobacterium avium complex (MAC) and M. fortuitum complex strains obtained from different sources in the south Indian BCG trial area. The guineapigs were divided into groups and some were directly sensitised/immunised with different MAC strains. M. fortuitum complex strain or BCG and others were sensitised with MAC or M. fortuitum complex and then immunised with BCG. The resulting delayed type hypersensitivity (DTH) response in the different groups of guineapigs was studied by skin tests using PPD-RT23 and PPD-B, and protective response was studied by challenging the guineapigs with a south Indian low virulent strain of M. tuberculosis and enumerating the bacilli in spleen at different points of time. The 3 strains of MAC induced similar low levels of DTH to PPD-RT23 but much higher and varying levels of DTH to PPD-B. MAC strains from soil and sputum induced different levels of immune modulation during subsequent immunisation with BCG on the DTH response to PPD-RT23 and PPD-B. At 2 wk after challenge, 23.8, 81 and 90.5 per cent protection was induced by the standard strain, soil isolate and sputum isolate of MAC, respectively, while 33.3 per cent protection was induced by the M. fortuitum complex strain compared to the protection induced by BCG alone. Prior exposure to MAC or M. fortuitum complex did not have any modulatory effect on the protective immunity due to BCG at this time point. However, at 6 wk after challenge, while the guineapigs immunised with BCG were protected, modulation of the protective response resulting from BCG was observed in the guineapigs sensitised with MAC and M. fortuitum from soil.

La intradermo-reacción con sensitinas en población paraguaya / The intradermal-reaction with sensitins in paraguayan population

La aplicación de Sensitinas utilizando la Intradermo-reacción de Mantoux nos permite investigar el perfil inmunológico de un organismo frente a determinadas cepas de Micobacterias no tuberculosas. La tasa de infección por estas Micobacterias no había sido estudiada hasta hoy en la población paraguaya, aunque nosotros ya habíamos comunicado el primer caso nacional de enfermedad por Mycobacterium fortuitum. La presente investigación nos permitió comprobar, sobre 210 pacientes estudiados, una tasa de reactores significativos de 24,7 por ciento a las sensitinas utilizadas, con neto predominio de reactores a M. avium y fortuitum

La intradermo-reacción con sensitinas en población paraguaya no becegeizada / Intradermal reaction with sensitins in paraguayan population who had never received BCG vaccine

Este trabajo constituye la 2a. parte del trabajo previo denominado "La intradermo-reacción con sensitinas en población paraguaya". En la presente investigación hemos incluído exclusivamente a individuos que no habían recibido la vacuna BCG, encontrando, sobre 44 pacientes estudiados, una tasa de reactores significativos de 29,7 por ciento a las sensitinas utilizadas. Dentro de estos pacientes reactores, constatamos en ambos estudios un neto predominio de reactores al M. avium (60 por ciento y 90,9 por ciento respectivamente). Con esto, queda comprobada la alta tasa de infección de la población paraguaya a las micobacterias no TBC y específicamente al M. avium

La patología humana causada por microbacterias atípicas en el momento actual / The human pathology caused by atypical mycobacterial in actual moment

En el momento actual, la patología de las micobacterias atípicas ha asumido una importancia creciente, no sólo desde el punto de vista clínico y diagnóstico, sino también en su aspecto inmunológico y en los problemas de prevención de la tuberculosis. Están ampliamente difundidas en el mundo y a las ya conocidas (M. kansasii, M. marinum, M. scrofulaceum, M. ulcerans, M. fortuitum y los grupos de complejo Avium-Battey), se han agregado cepas nuevas (M. szulgai, M. xenopi, M. simiae), y otros de rápido crecimiento o con caracteres particulares. Se describen observaciones personales del autor en cuanto a manifestaciones clínicas pulmonares y extrapulmonares de las micobacterias, información epidemiológica y recursos diagnósticos y terapéticos