Pay attention to the diagnosis and treatment of Mycobacterium avium-intracellulare complex infection / 中华临床感染病杂志

Mycobacterium avium- intracellulare complex is the term of a group of slow growing nontuberculous mycobacterium related to human infections, which has received more and more attention in recent years, and become an important public health issue. This article reviews the progress on clinical diagnosis and treatment of the infections caused by Mycobacterium avium- intracellulare complex.

Distribution and drug resistance of nontuberculous mycobacteria / 公共卫生与预防医学

Objective To analyze the distribution characteristics and drug resistance of nontuberculous mycobacteria(NTM),and to provide guidance for the selection of targeted agents in clinical treatment. Methods The clinical data of inpatients in our hospital from April 2019 to February 2021 were collected,the culture and strain identification of non tuberculosis mycobacteria were carried out,the drug sensitivity test of anti tuberculosis drugs was carried out,and the drug resistance of non tuberculosis mycobacteria to first-line anti tuberculosis drugs was analyzed. Results A total of 1 326 strains of mycobacterium were isolated,including 1 154(87.03%)strains of mycobacterium tuberculosis and 172(12.97%)strains of non-mycobacterium tuberculosis.Nine species of nontuberculous mycobacteria were detected,including slow-growing mycobacteria such as Mycobacterium kansasii and Mycobacterium avium-intracellulare complex,belonging to Groups I-III,and fast-growing mycobacteria such as Mycobacterium chelonae and Mycobacterium smegmatis,belonging to Group IV. Among them , Mycobacterium avium-intracellulare complex and Mycobacterium chelonae were dominant,accounting for 26.16%and 36.63%,respectively.Drug susceptibility tests showed that the resistance rate of Mycobacterium avium-intracellulare complex to streptomycin was 100.00%,the drug resistance rate of Mycobacterium chelonae to isoniazid,rifampicin and streptomycin was 100.00%,and the drug resistance rate of Mycobacterium smegmatis and Mycobacterium abscessus to most antibacterial drugs was 100.00%.The resistance rate of major NTM bacteria to clarithromycin was relatively low.There was no statistically significant difference in the susceptibility rates of slow and fast-growing mycobacteria to isoniazid and clarithromycin(P>0.05) ; The susceptibility rates of slow-growing mycobacteria to amikacin,clarithromycin and rifambutin were 62.86%,92.86%and 72.86%,all above 50.00%.The susceptibility rate of the fast-growing mycobacteria to clarithromycin was also more than 50.00%,being 87.25%.The susceptibility rate of slow-growing mycobacteria to other antibiotics was higher than that of fast-growing mycobacteria(P<0.05).The drug resistance of Mycobacterium tuberculosis to first-line anti tuberculosis drugs was significantly lower than that of non Mycobacterium tuberculosis(P<0.05). Conclusion Non-tuberculous mycobacteria have high drug resistance,especially fast-growing mycobacteria,so drug susceptibility tests are of great value in clinical treatment.

Identificación de especies micobacterianas ambientales u oportunistas en pacientes sintomáticos y con VIH/sida / Identification of environmental or opportunistic mycobacterial species in symptomatic symptomatic and HIV/AIDS patients

El aumento de las infecciones por micobacterias ambientales u oportunistas (MAO) coincide mundialmente con el declive de la infección tuberculosa e incremento de la infección por el virus de inmunodeficiencia humana (VIH). El presente trabajo es un estudio retrospectivo realizado en el Laboratorio Nacional de Referencia-Investigaciones de Tuberculosis/Micobacterias/Lepra (LNRI-TB/Lepra/Micobacterias), del Instituto de Medicina Tropical Pedro Kourí (IPK), La Habana, Cuba, durante el período enero 2014-diciembre 2018. El objetivo de nuestro estudio fue conocer la variabilidad de especies aisladas para establecer un referente actualizado sobre las infecciones causadas por estas. En este trabajo se clasificaron-identificaron 413 cepas procedentes de pacientes sintomáticos; 162 (39.22%) eran aislamientos de pacientes con VIH/sida atendidos en nuestro Hospital Nacional de Referencia a Atención al paciente VIH/sida (IPK), y el resto (n = 251 [60.77%]), procedentes de pacientes inmunocompetentes, incluyendo aislamientos recibidos de los Centros Provinciales de Higiene, Epidemiología, y Microbiología (CPHEM). Las muestras fueron analizadas con las técnicas convencionales establecidas: las pulmonares fueron descontaminadas por el método de Petroff modificado; las extrapulmonares, por el método del ácido sulfúrico al 4%; el cultivo se realizó en medio de Löwenstein-Jensen modificado. Posteriormente se realizó la clasificación-identificación de especies según el esquema fenotípico-bioquímico establecido. Las especies con mayor porcentaje de aislamiento pertenecieron a los Grupos III y IV, complejo Mycobacterium avium-intracellulare (34.14%) y complejo M. fortuitum (20.82%), respectivamente. Estos resultados permitirán conocer la prevalencia de estas especies en nuestro país, reafirmando la importancia diagnóstica de estos microorganismos para aplicar tratamiento específico, sobre todo en pacientes con factores de riesgo, en quienes es más probable la diseminación de la infección.

The increase in infections by environmental or opportunistic mycobacteria (MAO) coincides worldwide with the decline in tuberculosis infection and an increase in infection by the human immunodeficiency virus (HIV). The present work is a retrospective study carried out at the National Reference Laboratory-Tuberculosis/Mycobacterial/Leprosy Research (LNRI-TB / Leprosy / Mycobacteria), of the Pedro Kourí Institute of Tropical Medicine (IPK), La Habana, Cuba, during the period January 2014-December 2018. The objective of our study was to know the variability of isolated species to establish an updated reference on the infections caused by MAO. In this study, 413 strains from symptomatic patients were classified and identified; 162 (39.22%) were isolates from patients with HIV/AIDS treated at our National Hospital of Reference for Attention to HIV/AIDS patients (IPK), and the remaining (n=251 [60.77%]), from immunocompetent patients, including isolates received from the Provincial Centers of Hygiene, Epidemiology, and Microbiology (CPHEM). The samples were analyzed with the established conventional techniques: the lung samples were decontaminated by the modified Petroff method; the extrapulmonary, by the 4% sulfuric acid method; the culture was carried out in modified Löwenstein-Jensen medium. Subsequently, the classification-identification of species was carried out according to the established phenotypic-biochemical scheme. The species with the highest percentage of isolation belonged to Groups III and IV, Mycobacterium avium-intracellulare complex (34.14%), and M. fortuitum complex (20.82%), respectively. These results will allow us to know the prevalence of these species in our country, emphasizing the diagnostic importance of these microorganisms and thus apply a specific treatment, especially in patients with risk factors, in whom the spread of the infection is more likely

A prospective study of non-tuberculous mycobacterial disease among tuberculosis suspects at a tertiary care centre in north India

Background & objectives: The burden of non-tuberculous mycobacterial (NTM) disease is increasing worldwide. The disease shares clinicoradiological features with tuberculosis (TB), Nocardia and several fungal diseases, and its diagnosis is frequently delayed. The present study was performed to determine the frequency of NTM disease among TB suspects in a tertiary care centre in north India. Methods: In this prospective study, mycobacterial culture isolates from pulmonary and extrapulmonary specimens among TB suspects were tested with immunochromatographic assay (ICA). All ICA-negative isolates were considered as NTM suspects and further subjected to 16S-23S rRNA internal transcribed spacer gene sequencing for confirmation and species identification. Patients with active disease were treated with drug regimen as per the identified NTM species. Follow up of patients was done to determine clinical, radiological and microbiological outcomes. Results: Of the 5409 TB suspects, 42 (0.77%) were diagnosed with NTM disease. Patients with active disease consenting for treatment were treated and followed up. Thirty four patients had NTM pulmonary disease (NTM-PD) and the remaining eight had extrapulmonary NTM (EP-NTM) disease. Mycobacterium intracellulare and M. abscessus, respectively, were most frequently isolated from NTM-PD and EP-NTM patients. Fifteen NTM-PD and seven EP-NTM patients successfully completed the treatment. Ten patients died due to unrelated causes, five were lost to follow up and another four declined the treatment. Interpretation & conclusions: Our study showed that the frequency of NTM disease was low among TB suspects at a large tertiary care centre in north India and this finding was similar to other Indian studies. More studies need to be done in other parts of the country to know the geographical variation in NTM disease, if any.

Drug resistance and pathogenic spectrum of patients coinfected with nontuberculous mycobacteria and human-immunodeficiency virus in Chengdu, China / 中华医学杂志(英文版)

Background@#Human-immunodeficiency virus (HIV) infection is increasing worldwide and nontuberculous mycobacteria (NTM) is an established microbiologic cause of pulmonary disease, lymphadenitis, and disseminated disease in cases of advanced immune suppression. Data on patients coinfected with HIV and NTM are limited. Thus, this study aimed to analyze the clinical characteristics, drug resistance, and pathogen spectrum of patients coinfected with both HIV and NTM in the Chengdu area of China.@*Methods@#Data of 59 patients coinfected with both HIV and NTM collected from the Public Health Clinical Center of Chengdu, between January 2014 and December 2018, were analyzed. NTM drug sensitivity testing was performed using the microporous plate ratio method. Data were analyzed using SPSS 19.0, and the change in drug resistance rate was analyzed using the chi-square (χ2) test.@*Results@#Seven species/complex of NTM were identified from patients coinfected with HIV and NTM in this study, with Mycobacterium avium–intracellulare complex (52.5%) and M. kansasii (27.1%) as the predominant species. Male patients were more affected 50/59 (84.7%); the mean age of the 59 cases was 45 years. The clinical characteristics mainly included anemia (86.4%), cough and expectoration (79.7%). The baseline CD4 count was <50 cells/μL (84.7%). Patients were mainly in advanced acquired immunodeficiency syndrome (AIDS) stage. Chest imaging mainly showed patchy shadows (42.4%) and nodules (32.2%), with various degrees of AIDS-defining diseases. The drug resistance of NTM was severe, and the rate of isoniazid resistance (100.0%) was the highest, followed by rifampicin (94.9%), streptomycin (94.9%), ofloxacin (93.2%), and others. Ethambutol (52.5%) and clarithromycin (33.9%) were relatively low. No significant difference was found in the drug resistance rate of NTM strain against nine antituberculosis drugs in 5 years (P > 0.05).@*Conclusions@#The immune level of patients coinfected with HIV and NTM is low in advanced AIDS stage; more male are affected in patients who are mainly infected with MAC and M. kansasii and with serious drug resistance. The drug resistance rate of ethambutol and clarithromycin is relatively low.

CT characteristics of mycobacterium intracellulare pulmonary diseases: Compared with mycobacterium kansasii, mycobacterium abscess/chelonei pulmonary diseases / 中国医学影像技术

Objective: To explore CT characteristics of mycobacterium intracellulare pulmonary diseases compared with mycobacterium kansasii, mycobacterium abscess/chelonei pulmonary diseases. Methods: CT images of 35 patients with mycobacterium intracellulare pulmonary diseases, 18 with mycobacterium kansasii pulmonary disease and 22 with mycobacterium abscess/chelonei pulmonary disease confirmed by clinical data and laboratory tests were retrospectively analyzed, and imaging findings were evaluated and compared. Results: Mycobacterium intracellulare pulmonary disease involved both lungs (33/35, 94.29%), multiple lobes (18/35, 51.43%) or all lobes (16/35, 45.71%). CT characteristics included cord shadow (34/35, 97.14%), air space consolidation (33/35, 94.29%), centrilobular nodules or tree in bud (32/35, 91.43%), thickened pleura (32/35, 91.43%), ground glass opacity (31/35, 88.57%), traction bronchiectasis (30/35, 85.71%), non-traction bronchiectasis (25/35, 71.43%), nodes (24/35, 68.57%), calcification (24/35, 68.57%) and cavity (23/35, 65.71%). Ground glass opacity was more frequently observed in mycobacterium intracellulare than mycobacterium kansasii (P=0.001) and mycobacterium abscess/chelonei pulmonary disease (P<0.001). Walls of the cavity were thicker in mycobacterium intracellulare than mycobacterium kansasii (P=0.019) and mycobacterium abscess/chelonei pulmonary disease (P=0.024). Calcifications were more frequently observed in mycobacterium intracellulare than in mycobacterium kansasii (P=0.014) and mycobacterium abscess/chelonei pulmonary disease (P=0.007). Conclusion: Compared with mycobacterium kansasii and abscess/chelonei pulmonary disease, CT findings of mycobacterium intracellulare have certain characteristics, which may be helpful to differential diagnosis.

Síndrome de Lady Windermere como causa de tos crónica. A propósito de un caso / Lady Windermere Syndrome as a cause of chronic cough. Report of a case

Resumen Las mycobacterias no tuberculosas son poco reconocidas en la actualidad, pero su prevalencia se incrementa al sospechar su presencia en inmunodeprimidos o en enfermedades crónicas como la fibrosis quística. Se presenta el caso de una paciente con diagnóstico de síndrome de Lady Windermere con tos crónica. Se realizó tomografía computarizada donde se observaron bronquiectasias en el segmento lingular del pulmón izquierdo y en los lóbulos medio e inferior del derecho. En la broncoscopia se aisló complejo Mycobacterium avium-intracellulare. El no considerar en el diagnóstico de pacientes con tos crónica y sin factores predisponentes a las mycobacterias atrasa el diagnóstico y se acelera el deterioro clínico del paciente.

Abstract The nontuberculous mycobacteria are rarely recognized today in the world, being increased their prevalence about to departure of their suspicion in chronic illnesses such as inmunocompromised patients and cystic fibrosis. We present a case with diagnosis of syndrome of Lady Windermere about to departure of a square of chronic cough. Computed tomography was performed where bilateral bronchiectasis is observed in the left lingual segment and right upper lobe. In the Bronchoscopy was isolated complex Mycobacterium avium-intracellulare. The lack of suspicion of nontuberculous mycobacteria in patient without risk factors, with a square of chronic cough leads to the delay in the diagnosis and the patient's clinical deterioration.

Vertebral Osteomyelitis due to Mycobacterium intracellulare in an Immunocompetent Elderly Patient After Vertebroplasty

Mycobacterium avium complex (MAC) comprises M. intracellulare and M. avium. MAC usually causes pulmonary diseases in individuals with intact immunity, disseminated disease in patients with acquired immunodeficiency syndrome, and cervical lymphadenitis. It can also cause cutaneous disease, but musculoskeletal infection is rare. Herein, we present a case of vertebral osteomyelitis due to M. intracellulare in an elderly immunocompetent patient who underwent vertebroplasty. The patient was successfully treated with antimycobacterial drugs without surgical intervention. MAC should be considered as a causative pathogen of vertebral osteomyelitis when the patient has a history of vertebroplasty.

Importancia diagnóstica de las infecciones extrapulmonares causadas por el género Mycobacterium / Diagnostic importance of extrapulmonary infections caused by the genus Mycobacterium

Introducción: el género Mycobacterium provoca infecciones pulmonares y extrapulmonares, dentro de estas últimas las localizaciones más frecuentes son; sistema nervioso linfático, central, circulatorio, genitourinario, gastrointestinal, tejido osteoarticular, y la piel. Objetivo: realizar las caracterizaciones etiológica de infecciones extra pulmonares producidas por el género Mycobacterium, destacar su importancia diagnóstica tanto en pacientes VIH- como VIH/sida. Métodos: se realiza un estudio descriptivo-prospectivo de corte transversal realizado de enero 2012 a mayo 2014. Durante este período se recibió un total de 825 muestras, 232 de pacientes VIH- y 593 de pacientes con VIH/sida. Las muestras que lo requerían se le aplicaron descontaminación cultivo, se utilizó el método de ácido sulfúrico al 4 por ciento, para el cultivo se usó el medio de Löwenstein-Jensen. Resultados: de las 825 muestras extra pulmonares en 29 (3,5 por ciento) se obtuvo cultivo positivo,14 (48,3 por ciento) con aislamiento de Mycobacterium tuberculosis (11 VIH+ y 3 VIH-), y 15 (51,7 por ciento) con aislamiento de otras especies micobacterianas (12 VIH+ y 3 VIH-), Mycobacterium avium-intracellulare, y Mycobacterium malmoense fueron las especies más aisladas. Conclusión: por todo lo anterior expuesto se recomienda mantener la vigilancia diagnóstica en este tipo de infección extra pulmonar, en especial en pacientes con sida, pues en muchos casos pueden tener fatales consecuencias por su diagnóstico tardío(AU)

Enfermedad pulmonar por especies del complejo Mycobacterium avium intracellulare y correspondencia terapéutica / Mycobacterium avium intracellulare complex pulmonary disease species and therapeutic match

Introducción: la preocupación mundial ante las enfermedades causadas por micobacterias ambientales es creciente, debido a las dificultades diagnósticas y de tratamiento. Objetivos: determinar el comportamiento de la enfermedad pulmonar por especies del complejo Mycobacterium avium intracellulare y la correspondencia con la terapéutica recibida en el Hospital Neumológico Benéfico Jurídico de La Habana, durante el período 2000-2010. Métodos: se realizó un estudio descriptivo retrospectivo, que abarcó 55 pacientes con el diagnóstico de la enfermedad, los cuales cumplieron con los criterios de inclusión-exclusión predefinidos; la tendencia en el registro de diagnósticos se basó en el coeficiente de correlación lineal; en las variables cualitativas y cuantitativas discretas se usaron distribuciones de frecuencia con el cálculo del porcentaje y su respectivo intervalo de confianza de 95 porciento. Resultados: se obtuvo una tendencia decreciente en el diagnóstico de enfermedad pulmonar por especies del complejo Mycobacterium avium intracellulare, el 47,3 porciento de los pacientes estudiados se encontraba entre los 50 y 69 años de edad. La mayor parte del grupo no tenía ocupación de riesgo epidemiológico y la comorbilidad pulmonar se detectó en 97,9 porciento, sobresaliendo la tuberculosis pulmonar. Se comprobó la no correspondencia entre la terapéutica recibida y el régimen recomendado por la American Thoracic Society, en 100 porciento de los pacientes. Conclusión: la instauración de un programa ajustado a las normativas de tratamiento internacionalmente aceptadas, constituye en el Hospital Benéfico Jurídico, una necesidad para la atención a este grupo de enfermos

Introduction: the global concern about diseases caused by environmental mycobacteria is growing since their diagnosis and treatment are difficult. Objectives: to determine the behavior of Mycobacterium avium intracellulare complex pulmonary disease, and the therapeutic match with the treatment given at Benéfico Jurídico Pneumological Hospital, during the 2000-2010 period. Methods: a retrospective descriptive study of 55 patients diagnosed with the disease, who met the previously defined inclusion/exclusion criteria. The diagnostic registration trend was based on the linear correlation coefficient; the qualitative quantitative discrete variables used frequency distributions with percentage calculations and their respective 95 percent confidence intervals (CI). Results: a decreasing trend in the diagnosis of pulmonary disease from Mycobacterium avium-intracellular complex species; 47.3 percent of the studied patients aged 50 to 69 years. Most of the group had no occupation with epidemiological risk, and the pulmonary comorbidity was detected in 97.9 percent of patients, mainly pulmonary tuberculosis. A mismatch between the received therapy and the recommended treatment by the American Thoracic Society (ATS) was proved in 100 percent of patients. Conclusion: the introduction of a therapeutic program adapted to the internationally accepted standards of treatment is a must for the care of this group of patients in Benefico Juridico Hospital

A Case of Chronic Arthritis Due to Mycobacterium intracellulare after Trauma / 결핵및호흡기질환

While nontuberculous mycobacterium (NTM) infections are recently on the rise, arthritis caused by NTM is hardly reported in Korea. NTM arthritis has no distinctive clinical characteristics from chronic arthritis. Tuberculosis of the joint specifically produces similar clinical and pathologic presentations to NTM arthritis, so it is not easy to distinguish between them. We report a case of Mycobacterium intracellulare in an arthritis patient after trauma and surgical repair of the injury. At the beginning, the patient was diagnosed as tuberculous tenosynovitis through pathology without microbiologic evidence. The final diagnosis was made after subsequent recurrences for several years. The misdiagnosis and delayed diagnosis led to irreversible joint destruction and functional impairment. NTM infection must be included in the differential diagnosis of chronic arthritis at the outset.

Linfadenitis por mycobacterium incluyendo pacientes infectados por el virus de inmunodeficiencia humana / Mycobacterium lymphadenitis including patients infected with human inmunodefi

El género Mycobacterium provoca infecciones pulmonares y extrapulmonares, de estas últimas predomina la infección ganglionar. Mientras Mycobacterium tuberculosis es el agente causal más importante, en las últimas décadas aumenta la incidencia de otras especies micobacterianas que se han hecho prevalentes en los pacientes positivos al virus de la inmunodeficiencia humana (VIH +) tanto en países desarrollados como en vías de desarrollo. Durante el período enero 2007 hasta diciembre 2009 se procesó en nuestro laboratorio 6540 muestras, 210 muestras fueron obtenidas por biopsia ganglionar, precisamente este constituyó nuestro universo de estudio, 190 (90.4%) muestras se obtuvieron por exéresis quirúrgica, 20 (9.5%) por punción espirativa;17 procedían de pacientes VIH– (8.1%) y 193 procedentes de pacientes VIH+(91.9%). En solo 16 muestras (7.6%) el cultivo BAAR fue positivo; 4 procedentes de pacientes VIH– (25%) y 12 VIH+(75%). La clasificación e identificación micobacteriana demostró la presencia de Mycobacterium tuberculosis en 13 de los casos (81.25%), mientras Mycobacterium avium-intracellulare fue aislado en 3 (18.7%). En los pacientes inmunodeprimidos con linfadenopatía incluidos los pacientes VIH/sida, es muy importante la búsqueda activa de la presencia de BAAR como coinfección oportunista, donde Mycobacterium tuberculosis se mantiene como el agente infeccioso más frecuente, sin embargo la posibilidad de que otras especies micobacterianas también estén presentes no se debe descartar. Nuestro objetivo en este estudio como Laboratorio Nacional de Referencia de TB- Micobacterias fue lograr la caracterización etiológica de linfadenopatías en pacientes en que se sospechaba clínicamente la participación del género Mycobacterium.

Mycobacterium tuberculosis is the most important etiological agent producing pulmonary as well as extrapulmonary infection. During these last decades, the increase in the incidence of infection due to other mycobacteria species is evident. Lymphadenopathy is the most frequent extrapulmonary presentation form of Mycobacterium Genera infection among HIV positive patients either in developed or underdeveloped countries. The aim of this work is to analyze the results obtained during January 2007 - December 2009 in our laboratory. Two hundred ten tissue samples were studied; 190 (90.4%) samples were lymph node biopsied tissues and 20 (9.5%) samples were obtained by fine needle aspiration; 17 were from HIV - patients (8.1%) and 193 from HIV + (91.9%). A total of 16 (7.6%) samples produced a positive culture for BAAR, 4 VIH- (25%) and 12 VIH+ (75%). Classification and identification for mycobacteria confirmed Mycobacterium tuberculosis in 13 of the cases (81.25%), and Mycobacterium avium-intracellulare in three patients (18.7%). The present study once again confirms that BAAR culture has more sensitivity and specificity than histopathologhic studies have. Lymphadenopathy in immunosuppressed patients should by studied for the presence of an BAAR coinfection where M. tuberculosis is still the agent most frequently found, nevertheless, other species of Mycobacteria may be causing infection and should be searched for. Our objective as National Reference Laboratory of Tuberculosis and Mycobacterial was to obtain the etiological characterization of Mycobacterium lymphadenopathy in clinically suspect patients.

A Case of Bain Abscess caused by Mycobacterium intracellurare

Mycobacterium avium intracellulare complex (MAC) usually causes an opportunistic pulmonary infection in immunocompromised hosts who have underlying structural lung disease. Central nervous system infection due to MAC is very rare even in an immunocompromised host. Most previous reports of central nervous system infection due to MAC have been meningoencephalitis in patients infected with human immunodeficiency virus (HIV). Only four cases of brain abscess due to MAC have been reported worldwide. We report a case of brain abscess due to MAC in a non-HIV patient. Although drugs used for treatment of MAC have limited central nervous penetration, an azithromycin-based anti-tuberculous therapy after surgical drainage of the abscess showed improvement. To the best of our knowledge, this is the first reported case of MAC brain abscess in the Korean literature.

Respiratory Review of 2009: Nontuberculous Mycobacterium / 결핵및호흡기질환

As the prevalence of tuberculosis declines, the proportion of nontuberculous mycobacterial (NTM) lung disease is increasing in Korea. The combined use of liquid and solid media increases the sensitivity of mycobacterial culture and shortens culture time. Because NTMs are ubiquitous in the environment, NTM lung disease requires strict diagnostic criteria to prevent over-diagnosis of NTM lung disease. Mycobacterium avium complex is the most common pathogen of NTM lung disease in Korea and present in two forms: upper lobe cavitary and nodular bronchiectatic form. Decision of treatment of NTM lung disease depends on the infecting species and overall condition of the patient. Because medical therapy requires the use of multiple drugs over 18 to 24 months, surgery for localized disease may be useful for those species refractory to medical therapy.

Respiratory Review of 2009: Nontuberculous Mycobacterium / 결핵및호흡기질환

As the prevalence of tuberculosis declines, the proportion of nontuberculous mycobacterial (NTM) lung disease is increasing in Korea. The combined use of liquid and solid media increases the sensitivity of mycobacterial culture and shortens culture time. Because NTMs are ubiquitous in the environment, NTM lung disease requires strict diagnostic criteria to prevent over-diagnosis of NTM lung disease. Mycobacterium avium complex is the most common pathogen of NTM lung disease in Korea and present in two forms: upper lobe cavitary and nodular bronchiectatic form. Decision of treatment of NTM lung disease depends on the infecting species and overall condition of the patient. Because medical therapy requires the use of multiple drugs over 18 to 24 months, surgery for localized disease may be useful for those species refractory to medical therapy.

Diagnosis and treatment of nontuberculous mycobacterial lung disease / 대한내과학회지

As the prevalence of tuberculosis declines, the proportion of mycobacterial lung disease due to nontuberculous mycobacteria (NTM) is increasing worldwide. In Korea, Mycobacterium avium-intracellulare complex and Mycobacterium abscessus account for most of the pathogens encountered, whilst Mycobacterium kansasii is a relatively uncommon cause of NTM lung diseases. When NTM lung disease occurs, it is likely to present in one of two forms: apical fibrocavitary disease often affecting older male smokers with previous tuberculosis or chronic obstructive pulmonary disease; nodular bronchiectasis classically occurring in middle-aged or older woman who never smoked and present with cough. Because its clinical features are frequently indistinguishable from those of pulmonary tuberculosis and NTMs are ubiquitous in the environment, the isolation and identification of causative organisms are mandatory for diagnosis, and some specific diagnostic criteria have been proposed. Treatment of disease depends on the infecting species, extent and form of disease, and overall condition of the patient, but decisions concerning the institution of treatment are never easy. Treatment requires the use of multiple drugs for 18 to 24 months. Thus, treatment is expensive, often has significant side effects, and is frequently not curative. Surgery for localized disease may be useful for those species expected to be refractory to medical therapy. Observation without treatment may be appropriate for some patients with slowly progressive disease that is expected to be particularly difficult to treat.

Mycobacterium intracellulare pulmonary infection accompanied with pleural effusion / 대한내과학회지

Nontuberculous mycobacterial infection is rarely accompanied by pleural involvement. We report a very rare case of Mycobacterium intracellulare pulmonary disease accompanied with pleural effusion. A 76-year-old man was admitted to our hospital because of dyspnea. A chest radiograph and CT showed bilateral bronchiectasis and bronchopneumonia accompanied with right pleural effusion. The fluid was lymphocyte-dominant exudative effusion, and microbiological examinations of the effusion, including staining and culturing, proved negative. However, one month after admission, subsequent cultures of bronchial washing fluid revealed the presence of M. intracellulare. The patient's effusion was gradually resolved with antibiotic treatment, including clarithromycin.

Acute pneumonia caused by mycobacterium intracellulare / 대한내과학회지

The Mycobacterium avium-intracellulare complex (MAC) is the most common pathogen in pulmonary disease caused by a nontuberculous mycobacteria. Patients with MAC pulmonary disease tend to be older, are more likely to have underlying lung disease than tuberculosis patients. The insidious nature of MAC pulmonary disease has been emphasized in many reports because symptoms may be present for months or years before a diagnosis can be made. Most patients experience chronic coughing, which is usually productive of purulent sputum. A MAC pulmonary infection is rarely accompanied by acute respiratory symptoms and lobar pneumonic consolidation on chest radiography. We report a very rare case of M. intracellulare pulmonary disease presenting as acute pneumonia.

Estudo da transmissão horizontal de Mycobacterium avium-intracellulare em suínos

Experimental infections were performed to study the horizontal transmission of Mycobacterium avium-intracellulare (MAI) in swine. Twelve 35 to 42 day-old pigs were divided into three groups of four pigs each. Each group was housed in separate rooms, and inoculated with three MAI strains: VPS1, SC1 and ATCC-13950. After inoculation, four non-inoculated swines were added to each group and maintained in the same pen up to 150 days of age, when were slaughtered. Other four non-inoculated swines were maintained as a control group. The infection was diagnosed by the tuberculin test at 140 days of age, by detection of macroscopic lesions at slaughter and histopathologic and bacteriologic examination of tissues collected at necropsy. Culture of fecal samples were made during the experiment indicating active excretion of MAI between 14 and 42 days post-inoculation. Transmission of MAI among pigs kept in the same pen was observed with all the three strains used. The most evident transmission was with strain SC1, in which four "in contact" pigs were infected, followed by ATCC-13950 (two pigs) and VPS1 (one pig). These results indicate that infected swine can be an important source of infection, favoring the dissemination of this disease.

O trabalho teve como objetivo estudar a transmissão horizontal de Mycobacterium avium-intracellulare (MAI) entre suínos. Doze suínos com 35 a 42 dias de idade, divididos em três grupos de quatro e alojados em salas independentes, foram inoculados por via oral com as cepas VPS1, SC1 e ATCC-13950 de Mycobacterium avium-intracellulare. A seguir, quatro suínos não inoculados foram colocados em cada grupo e mantidos na mesma baia até o abate aos 150 dias da idade. Outro grupo de quatro suínos não inoculados foi utilizado como controle. Pelo exame de fezes verificou-se que houve excreção ativa de MAI entre 14 e 42 dias pós-inoculação. A transmissão da infecção foi avaliada pelo teste de tuberculina aos 140 dias de idade e pelos exames de patologia macro e microscópica e de isolamento do MAI de órgãos. Os quatro suínos em contato com aqueles inoculados com a cepa SC1 foram contaminados, enquanto que com a cepa VPS1 apenas um e com a ATCC-13950 somente dois. Concluiu-se que houve transmissão de MAI entre os suínos mantidos na mesma baia, com as três cepas utilizadas, mas foi mais evidente com a cepa SC1, indicando que o suíno pode ser importante fonte de infecção na disseminação da doença.