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.

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.

A Case of Bain Abscess caused by Mycobacterium intracellurare / 감염과화학요법

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.