Identificación de Mycobacteria no pigmenteda de crecimiento rápido por el Método Molecular de Micobacterium de Genotipo CM / Identification of Fast-Growing Non-Pigmented Mycobacteria by the Genotype® Mycobacterium CM Molecular Method

Introducción: la micobacteria no terberculosa (NTM) forma un grupo heterogéneo de microorganismos que pueden causar infección en humanos. Las micobacterias no pigmentadas de rápido crecimiento (MNPCR) son de interés clínico debido al creciente número de pacientes infectados por ellos y a la dificultad del tratamiento. Dentro de este grupo, Mycobacterium fortuitum, Mycobacterium abscessus y Mycobacterium chelonae son reconocidos como patógenos potenciales; estas especies se han aislado de infecciones pulmonares y extrapulmonares. Objetivo: el objetivo de este trabajo es encontrar la frecuencia de aislamiento de especies micobacterianas de rápido crecimiento, específicamente el complejo Mycobacterium fortuitum, de muestras clínicas utilizando la técnica molecular de diagnóstico GenoType Mycobacterium CM. Material y Método: se analizaron 249 aislados de micobacterias no tuberculosas obtenidas de muestras pulmonares y extrapulmonares de pacientes sintomáticos en el período enero 2018-diciembre de 2022. La técnica molecular GenoType Mycobacterium CM se utilizó para identificar la especie. Resultados: Se obtuvieron 77 (3,9%) aislados de especies no pigmentadas de rápido crecimiento, estas se identificaron en orden decreciente: Mycobacterium fortuitum 65 (84,41%), Mycobacterium abcessus 9 (11,68%) y Mycobacterium chelonae 3 (4%). Conclusiones: los resultados reafirman que el complejo Mycobacterium fortuitum es responsable de la mayoría de las infecciones causadas por la micobacteria en rápido crecimiento en humanos. La técnica diagnóstica GenoType Mycobacterium CM es una herramienta útil para la rápida identificación de micobacterias; proporciona resultados precisos en menos tiempo, acortando significativamente el tiempo diagnóstico, permite la aplicación temprana de tratamiento específico, evitando así la propagación de la infección.

Introduction: non-tuberculous mycobacteria (NTM) form a heterogeneous group of mi-croorganisms that can cause infection in humans. Fast-growing non-pigmented my-cobacteria (MNPCR) are of clinical interest due to the increasing number of patients infected by them and the difficulty of treatment. Within this group, Mycobacterium fortuitum, Mycobacterium abscessus and Mycobacterium chelonae are recognized as potential pathogens; these species have been isolated from both pulmonary and ex-trapulmonary infections. Objective: the objective of this work is to find the frequency of isolation of fast-growing non-pigmented mycobacterial species, specifically the Myco-bacterium fortuitum complex, from clinical samples using the GenoType® Mycobacteri-um CM diagnostic molecular technique. Material and Method: 249 isolates of non-tu-berculous mycobacteria obtained from pulmonary and extrapulmonary samples from symptomatic patients in the period January 2018-December 2022 were analyzed. The G e n oTy p e® Mycobacterium CM molecular technique was used to identify the species. Results: 77 (30.9%) isolates of fast-growing non-pigmented species were obtained, these were identified in decreasing order: Mycobacterium fortuitum 65 (84.41%), Myco-bacterium abcessus 9 (11.68%) and Mycobacterium chelonae 3 (4%). Conclusions: the results reaffirm that the Mycobacterium fortuitum complex is responsible for most in-fections caused by fast-growing mycobacteria in humans. The GenoType® Mycobacte-riumCM diagnostic technique is a useful tool for the rapid identification of mycobacte-ria; it provides accurate results in less time, significantly shortening the diagnostic time, it allows the early application of specific treatment, thus avoiding the spread of infec-tion.

Actualización del manejo de microbacterias no tuberculosas / Update on the management of non-tuberculous mycobacteria

Desde el año 2007 se han generado guías de diagnóstico y tratamiento de micobacterias no tuberculosas (MNTB), la última de las cuales fue desarrollada en el año 2020 por ATS/ERS/ESCMID/IDSA, en ella se actualizan los criterios diagnósticos, los criterios para determinar el inicio de tratamiento y recomendaciones de esquema de antibióticos para las especies más frecuentes. En paralelo se han ido desarrollando terapias alternativas como la fagoterapia. El objetivo de la presente revisión es dar a conocer los cambios que traen estas últimas guías y actualizar algunas de las últimas novedades con respecto al manejo de las micobacterias no tuberculosas.

Since 2007, guidelines for diagnosis and treatment of non-tuberculous Mycobacteria have been generated, the latest of which was developed by ATS/ERS/ESCMID/IDSA, in which the diagnostic criteria, and the criteria for determining the initiation of treatment and antibiotic scheme recommendations for the most frequent species are updated. At the same time, alternative therapies such as phage therapy have been developed. The objective of this review is to show the changes that these latest guidelines bring and update some of the latest developments regarding the management of non-tuberculous Mycobacteria.

GATA2 variants in patients with non-tuberculous mycobacterial or fungal infections without known immunodeficiencies

ABSTRACT Introduction Haploinsufficiency of the hematopoietic transcription factor GATA2 is associated with a broad spectrum of diseases, including infection susceptibility and neoplasms. We aimed to investigate GATA2 variants in patients with non-tuberculous mycobacterial (NTM) and/or fungal infections (FI) without known immunodeficiencies. Method We performed GATA2 genotyping in patients with NTM and/or FI. Results Twenty-two patients were enrolled (seventeen FI, four NTM and one with both infections). The pathogenic variant NG_029334.1:g.16287C>T was found in one patient (4.5%) and two asymptomatic offsprings. We also found the likely-benign variant NG_029334.1:g.12080G>A (rs2335052), the benign variant NG_029334.1:g.16225C>T (rs11708606) and the variant of uncertain significance NG_029334.1:g.16201G>A (rs369850507) in 18.2%, 27.3%, and 4.5% of the cases, respectively. Malignant diseases were additionally diagnosed in six patients. Conclusion Although detected in 45.4% of the patients, most GATA2 variants were benign or likely benign. Identifying a pathogenic variant was essential for driving both the patient's treatment and familial counseling. Pathogenic variants carriers should receive genetic counseling, subsequent infection prevention measures and malignancies surveillance. Additionally, case-control genotyping should be carried out in Brazil to investigate whether the observed variants may be associated with susceptibility to opportunistic infections and/or concurrent neoplasms.

Epidemiological profile and follow-up of patients with pulmonary disease by non-tuberculous mycobacteria in Baixada Santista area, São Paulo

ABSTRACT Objective To present the frequency and species diversity of non-tuberculous mycobacteria, estimate the prevalence of non-tuberculous mycobacterial pulmonary disease, describe the epidemiological profile, and determine the follow-up of patients with non-tuberculous mycobacterial pulmonary disease living in a region with a high burden of tuberculosis. Methods This a retrospective cohort observational study using data records obtained from the Instituto Adolfo Lutz - Santos and from the São Paulo Sistema de Vigilância de Tuberculose do Estado de São Paulo in the period between 2000 and 2009. The studied variables were: socio-demographic characteristics, current and past history of tuberculosis, aspects related to diagnosis, and treatment and associated diseases. Results We included 319 non-tuberculous mycobacteria isolates in the study, corresponding to 257 patients. The species Mycobacterium kansasii (28.5%) and Mycobacterium fortuitum (16.6%) presented the higher occurrence. In 10.9% (24) of the patients, there was a criterion for confirming a case of pulmonary disease due to non-tuberculous mycobacteria. In relation to gender and age, male and individuals over 50 years old were the most frequent. Considering the confirmed cases, 47.8% had a past history of tuberculosis. Conclusion The lack of information about the cases is evident, since pulmonary disease due to non-tuberculous mycobacteria is not mandatory. The therapeutic regimen according to the identified species is fundamental for success in combating the infections caused by non-tuberculous mycobacteria. Besides that, information about the regional epidemiology of pulmonary disease caused by non-tuberculous mycobacteria and the search for associations with other comorbidities are important to establish the correct treatment. In order to improve surveillance of pulmonary diseases by non-tuberculous mycobacteria, we suggest the implantation of a sentinel surveillance and of population-based studies.

Cord factor producer Mycobacterium abscessus subsp. bolletii in asymptomatic immunocompetent host sputa samples

Abstract We report a case of Mycobacterium abscessus subsp. bolletii colonization in upper respiratory tract of an immunocompetent patient, who was misdiagnosed as tuberculosis by Acid Fast Bacilli (AFB) and cord factor formation observed directly from the sputa culture in liquid medium. This fact reflected a significant impact on the individual case's life and showed the importance to identify the mycobacteria isolated from clinical sample at species level, and to determine the true implication of nontuberculous mycobacteria (NTM) detected in clinical samples.

Coinfección por Mycobacterium abscessus y Mycobacterium tuberculosis en un paciente con síndrome de Cushing exógeno y otras comorbilidades / Mycobacterium abscessus and Mycobacterium tuberculosis coinfection in a patient with exogenous Cushing syndrome and other comorbilities

RESUMEN Mycobacterium abscessus es una micobacteria no tuberculosa de crecimiento rápido, que produce infección pulmonar, cutánea, diseminada y otras, sobre todo en pacientes con comorbilidades. El diagnóstico se basa en la identificación de la micobacteria por medios de cultivo o por pruebas moleculares. El tratamiento con macrólidos y amikacina continúa siendo el ideal, aunque depende de la localización y de la gravedad de la infección, sin embargo, se han identificado genes de resistencia en algunas subespecies que limitan la eficacia antibiótica. Presentamos el caso de un paciente con coinfección cutánea por Mycobacterium abscessus y Mycobacterium tuberculosis, quien presenta un síndrome de Cushing exógeno, factor predisponente para estas infecciones. Además, se identificaron hidatidosis y aspergilosis pulmonares. El tratamiento antituberculoso del paciente se ajustó para manejar ambas micobacterias, y su evolución fue favorable.

ABSTRACT Mycobacterium abscessus is a fast-growing non-tuberculous mycobacterium that causes lung, skin, disseminated and other infections, mainly in patients with comorbidities. The diagnosis is based on the identification of the mycobacterium by culture media or molecular tests. Treatment with macrolides and amikacin remains the optimal choice, although it depends on the location and severity of the infection; however, resistance genes have been identified in some subspecies that limit antibiotic efficacy. We present the case of a patient with cutaneous coinfection by Mycobacterium abscessus and Mycobacterium tuberculosis, who presented exogenous Cushing syndrome, a predisposing factor for these infections. In addition, hydatidosis and pulmonary aspergillosis were identified. The patient's anti-tuberculosis treatment was adjusted to manage both mycobacteria, resulting in a favorable evolution.

Piauí Central Laboratory of Public Health: frequency of mycobacterial species and epidemiological aspects, 2014-2015 / Laboratorio Central de Salud Pública de Piauí: frecuencia de especies micobacterianas y aspectos epidemiológicos, 2014-2015 / Laboratório Central de Saúde Pública do Piauí: frequência de espécies de micobactérias e aspectos epidemiológicos, 2014-2015

Background and Objectives: Knowledge about species diversity of non-tuberculous mycobacteria (NTM) and the frequency of tuberculosis (TB) is an important issue in rural-urban regions such as Piauí (northeast of Brazil), of low incidence rate of TB , can help to improve diagnosis and prevention strategies. The aim of this study is to examine some epidemiological aspects and the frequency of Mycobacterium tuberculosis (Mtb) and NTM isolated at the central public health reference laboratory, Dr. Costa Alvarenga, Piauí (LACEN-PI). Methods: Data records of all mycobacterosis and tuberculosis cases from January 2014 to March 2015 were analyzed. Results : Of the 20% (142/706) positive growths, 70% (99) were Mtb and 10% NTM. The remainde was of inadequate clinical samples, not allowing the identification of even the suspected NTM. The most frequent clinical form was pulmonary with TB patients younger than those infected with NTM (p = 0.001), the majority living in Teresina (52%). NTMs identified were M. abscessus (36%), M. avium, M. intracellulare, Mycobacterium sp. (14% each) and M. asiaticum, M. szulgai, M. kansasii 7% (each). Mtb drug resistance (7.8%) and TB co-infection with the human immunodeficiency virus (HIV-TB) found to be high (49%, 19/39). Conclusion: The frequencies of Mtb infection, drug resistance and HIV-TB co-infection are still underestimated and failures in the identification of NTM may decrease the actual frequency of these infections. Therefore, there is a need for improvements in TB control and in the diagnosis of NTMs in Piauí.(AU)

Justificativa e Objetivos: O conhecimento da diversidade de espécies de micobactérias não tuberculosas (MNT ) e a frequência da tuberculose (TB) é uma questão importante em regiões rurais-urbanas como o Piauí (nordeste do Brasil), com baixa incidência de TB, pode ajudar a melhorar o diagnóstico e estratégias de prevenção. O objetivo deste estudo é examinar alguns aspectos epidemiológicos e a frequência de Mycobacterium tuberculosis (Mtb) e MNT isolados, no Laboratório Central de Referência em Saúde Pública, Dr. Costa Alvarenga, Piauí (LACEN-PI). Métodos: Dados de todo s os casos de micobacterioses e tuberculose de janeiro de 2014 a março de 2015 foram analisados. Resultados: Dos 20% (142/706), de amostras com crescimento positivo 70% (99) foram Mtb e 10% MNT . O restante era de amostras clínicas inadequadas, não permitindo a identificação inclusive de MNT suspeitos. A forma clínica mais frequente foi pulmonar com pacientes TB mais jovens do que os infectados com MNT (p = 0,001), a maioria morando em Teresina (52%). As MNT s identificadas foram M. abscessus (36%), M. avium , M. intracellulare , M. sp. (14%, cada) e M. asiaticum, M. szulgai , M. kansasii 7% (cada). A droga resistência de Mtb (7,8%) e a co-infecção TB e vírus da imunodeficiência humana (HIV-TB) mostraram-se altas (49%, 19/39).Conclusão: As frequências de infecção por Mtb, de resistência a medicamentos e co-infecção HIV-TB ainda são subestimadas e as falhas na identificação de MNT podem diminuir a real frequência destas infecções . Portanto, há necessidade de melhorias no controle da TB e no diagnóstico de MNT s no Piauí.(AU)

Justificacion y objetivos: Conocer la diversidad de especies de micobacterias no tuberculosas (MNT) y la frecuencia de tuberculosis (TB) es tema importante en regiones rurales-urbanas como Piauí (noreste de Brasil) con baja tasa de incidencia de TB, y puede ayudar a mejorar el diagnóstico y las estrategias de prevenció. El objetivo de este estudio es examinar algunos aspectos epidemiológicos y la frecuencia de Mycobacterium tuberculosis (Mtb) y MNT aislado, en el laboratorio central de referencia de salud pública, Dr. Costa Alvarenga, Piauí (LACEN-PI). Métodos: Se analizaron los datos de todos los casos de micobacteriosis de enero de 2014 a marzo de 2015. Resultados: Del 20% (142/706), de las muestras con crecimiento positivo el 70% (99) fueron Mtb y el 10% MNT. El resto fue de muestras clínicas inadecuadas, no permitiendo la identificación de MNT incluso sospechosas. La forma clínica más frecuente fue la pulmonar y los pacientes con TB eran más jóvenes que los infectados con MNT (p = 0.001), la mayoría viviendo en Teresina (52%).Los MNT identificados fueron M.abscessus (36%), M.avium, M.intracellulare, Mycobacterium sp. (14% cada) y M.asiaticum, M.szulgai, M.kansasii 7% (cada ). La resistencia a los medicamentos de Mtb (7,8%) y la coinfección de TB y el virus de la inmunodeficiencia humana (VIH-TB) fueron altas (49%, 19/39 )Conclusión: Las frecuencias aún subestimadas de resistencia a los medicamentos, coinfección por VIH-TB y fallas de identificaciónidentificación de MNT pueden disminuir la frecuencia real de estas infecciones. Consecuentemente, es necesario mejorar el control y diagnóstico de TB y MNT en Piauí.(AU)

Cutaneous infection by Mycobacterium lentiflavum after subcutaneous injection of lipolytic formula

Abstract The incidence of nontuberculous mycobacterial infections is increasing worldwide; by 2017, more than 190 species and subspecies have been documented. Although classically associated with immunosuppression, the recognition of these etiological agents in diseases affecting immunocompetent individuals and in healthcare-associated infections, such as after surgical and cosmetic procedures, makes the study of the epidemiology and pathogenesis of these microorganisms relevant in medical practice. Mycobacterium lentiflavum is slow-growing and rarely affects the skin. A case of cutaneous mycobacteriosis caused by M. lentiflavum is reported in an immunocompetent patient after subcutaneous injection of a lipolytic compound, treated with clarithromycin and levofloxacin.

Enfermedad pulmonar por Mycobacterium intracellulare en una paciente inmunocompetente: reporte de un caso en el Perú / Pulmonary disease by mycobacterium intracellulare in an immunocompetent patient: Report of a case in Peru

RESUMEN Presentamos una paciente inmunocompetente cuya enfermedad comenzó a los 49 años con tos, seguida de esputo purulento y hemoptoico, por lo que se diagnosticó bronquiectasias. Tres años después, luego de hemoptisis, le practicaron segmentectomía medial del lóbulo medio y quedó asintomática por meses. Al encontrarse tuberculosis en el informe de patología fue tratada con 4HREZ2R2H2. Cinco años después su BK fue 2+ recibiendo un nuevo esquema de 4HREZ2R2H2, con lo que no logro negativizar declarándose el fracaso al tratamiento. Al hallar en la genotipificación de su cultivo Mycobacterium intracellulare, la paciente recibió azitromicina, moxifloxacina y etambutol, hubo mejoría, pero abandonó el tratamiento a los ocho meses; lo reinició 18 meses después, junto con tratamiento para la depresión y el reflujo gastroesofágico. Al mes la paciente estuvo asintomática, pero hizo reacción dérmica a la moxifloxacina y se la reemplazó por amikacina. Salió de alta y al año estuvo curada, a los 64 años de edad.

ABSTRACT We present the case of an immunocompetent patient whose illness began at age 49 with a cough, followed by purulent and hemoptoic sputum; bronchiectasis was diagnosed. Three years later, after hemoptysis, she underwent medial segmentectomy of the middle lobe and was asymptomatic for months. When tuberculosis was found in the pathology report, she was treated with 4HREZ2R2H2. Five years later her BK was 2+, thus receiving a new scheme of 4HREZ2R2H2, which did not succeed in obtaining negative results and the treatment was declared as a failure. After genotyping her Mycobacterium intracellulare culture, the patient received azithromycin, moxifloxacin and ethambutol. There was improvement, but she abandoned the treatment at 8 months; she restarted it 18 months later, along with treatment for depression and gastroesophageal reflux. After one month the patient was asymptomatic, but she had a dermal reaction to moxifloxacin which was replaced with amikacin. One year later, she was cured and discharged, at the age of 64.

Identification of nontuberculous mycobacteria species by multiplex real-time PCR with high-resolution melting

Abstract INTRODUCTION: Nontuberculous mycobacteria (NTM) species, as human pathogens, are increasing in the world, as is the difficulty of accurately identifying them. Differential diagnosis, especially between the M. tuberculosis complex and NTM species, and the characterization of NTM species is important. This study aimed to evaluate the performance of a molecular system based on multiplex real-time PCR with high-resolution melting (HRM) for the identification and differentiation of NTM species of clinical importance of an endemic area for tuberculosis in northeastern Brazil. METHODS: The technical protocol of the molecular system was based on multiplex real-time PCR-HRM, and evaluated the sensitivity and specificity of the detection of NTM species in mycobacterial clinical isolates from the studied region. The gold standard method was specific gene sequencing. RESULTS: The sensitivity and specificity of multiplex real-time PCR-HRM modified for differentiation between NTM and M. tuberculosis were 90% and 100%, respectively. The PCR-HRM sensitivities for the characterization of NTM species (M. kansasii, M. abscesses, M. avium, and M. fortuitum) were 94.59%, 80%, 57.14%, and 54%, respectively. CONCLUSIONS The multiplex real-time PCR-HRM modified assay has the potential to rapidly and efficiently identify nontuberculous mycobacteria of clinical importance, which is crucial for immediate implementation of the appropriate therapy and thus avoiding complications and sequelae in patients.

Desenvolvimento de método rápido de detecção de gene de resistência a claritromicina para o grupo Mycobacterium abscessus por PCR em tempo real / Development of a rapid method for detecting the clarithromycin resistance gene for the Mycobacterium abscessus group by real-time PCR

O grupo Mycobacterium abscessus (MAG) é a principal causa de infecções pulmonares e extrapulmonares entre as micobactérias de crescimento rápido. Para determinar a resistência à claritromicina (CLA), o método de concentração inibitória mínima (CIM) é realizado, no entanto, as leituras são feitas após três e 14 dias de incubação para detectar a resistência induzida (RI). A suscetibilidade a CLA é detectada pela deleção ou polimorfismo no gene erm(41). Quando o genótipo é selvagem (T28), a RI à claritromicina é verificada, enquanto para C28 não é observada. O presente estudo tem como objetivo padronizar um ensaio Taqman de PCR em tempo real (qPCR) para detecção do polimorfismo T28C e compará-lo aos resultados obtidos do sequenciamento do gene erm(41). O total de 207 isolados de MAG que preencheram os critérios bacteriológicos da American Thoracic Society, foi recebido no IAL entre 2010 e 2012. Os isolados foram identificados pelo método PRA-hsp65 como M. abscessus tipo 1 (n=135, 65,2%) e M. abscessus tipo 2 (n=72, 34,8%) e submetidos ao CIM para CLA com leitura nos dias três e 14. A PCR convencional foi utilizada para detecção da deleção; o sequenciamento do gene erm(41) foi realizado para detectar a mutação T28C; o sequenciamento dos genes rpoB e hsp65 foram utilizados para identificação das subespécies e o sequenciamento do gene rrl foi feito para detecção da mutação A2058G (resistência adquirida). A sequência de MAG EU590129 foi submetida ao Centro de Treinamento da empresa Thermo Fisher Scientific, a qual customizou o ensaio e forneceu os parâmetros de corrida. Dos 207 isolados, 33 eram M. a. massiliense, 136 M. a. abscessus e 38 M. a. bolettii pelo sequenciamento do gene rpoB, que apresentou sete (3,38%) isolados discordantes em relação ao sequenciamento do gene hsp65. Nenhum isolado apresentou mutação no gene rrl. No sequenciamento de erm(41), 197 isolados foram T28 e 10 C28, assim como na qPCR. Na comparação dos perfis genéticos com o perfil de suscetibilidade foram encontrados 10 isolados com resultados discordantes (4,8%), sendo nove isolados sensíveis com gene erm(41) selvagem e um...(AU)

The Mycobacterium abscessus (MAG) group is the main cause of pulmonary and extrapulmonary infections among fast-growing mycobacteria. To determine resistance to clarithromycin (CLA), the minimum inhibitory concentration (MIC) method is performed, however, readings are taken after three and 14 days of incubation to detect induced resistance (IR). Susceptibility to CLA is detected by deletion or polymorphism in the erm (41) gene. When the genotype is wild (T28), clarithromycin IR is checked, while for C28 it is not observed. The present study aims to standardize a SNP Taqman real-time PCR (qPCR) assay for the detection of the T28C polymorphism and compare it to the results obtained from the sequencing of the erm(41) gene. A total of 207 MAG isolates that met the bacteriological criteria of the American Thoracic Society, were received at the IAL between 2010 and 2012. The isolates were identified by the PRA-hsp65 method as M. abscessus type 1 (n=135, 65.2%) or M. abscessus type 2 (n=72, 34.8%) and submitted to CIM for CLA with reading on days three and 14. Conventional PCR was used to detect the deletion; sequencing of the erm (41) gene was performed to detect the T28C mutation; the sequencing of the rpoB and hsp65 genes were used to identify the subspecies and the sequencing of the rrl gene was done to detect the A2058G mutation (acquired resistance). The sequence of MAG EU590129 was submitted to the Training Center of the company Thermo Fisher Scientific, which customized the test and provided the running parameters. Of the 207 isolates, 33 were M. a. massiliense, 136 M. a. abscessus and 38 M. a. bolettii by sequencing the rpoB gene, that demonstrated discrepancy between seven isolates (3.38%) compared to sequencing the hsp65 gene. No isolate showed a mutation in the rrl gene. In the erm(41) sequencing, 197 isolates were T28 and 10 C28, as well as in qPCR. When comparing the genetic profiles with the susceptibility profile, 10 isolates were found with discordant results (4,8%), with nine sensitive isolates with wild erm(41) gene and an isolate with erm(41) deletion presenting IR. The qPCR agreement with the sequencing of the erm (41) gene was 100%. The sensitivity and specificity of qPCR was 100%. QPCR has less reaction time, less chance of error and contamination and has easy interpretation of results, decreasing waiting for diagnosis by doctor and patient. (AU)

Non-tuberculous mycobacterial lung disease: a brief review focusing on radiological findings

Abstract The incidence and prevalence of lung disease caused by non-tuberculous mycobacteria (NTM-LD) has increased worldwide and its diagnosis represents a complex challenge. This article aims to review the tomographic findings of NTM-LD in order to facilitate their definitive diagnosis. The search for publications on the subject was performed in PMC and Scielo using the keywords 'non-tuberculous mycobacteria', 'lung disease and computed tomography (CT)' and 'radiological findings'. The radiological findings described by 18 articles on mycobacteriosis were reviewed. In addition, CT images of patients diagnosed with NTM-LD were considered to represent radiological findings. Eighteen publications were used whose main findings were pulmonary cavitation (88.9%), bronchiectasis (77.8%), and pulmonary nodules (55.6%). Despite the overlaps in imaging-related analysis of myocobacterioses with other pulmonary infections, such as tuberculosis, the predominant involvement of the middle lobe and lingula should raise suspicion for NTM-LD.

Nontuberculous mycobacteria in patients with suspected tuberculosis and the genetic diversity of Mycobacterium avium in the extreme south of Brazil / Micobactérias não tuberculosas em pacientes com suspeita de tuberculose e a diversidade genética de Mycobacterium avium no extremo sul do Brasil

ABSTRACT Objective: Nontuberculous mycobacteria (NTM) are a heterogeneous group of bacteria that are widely distributed in nature and associated with opportunistic infections in humans. The aims of this study were to identify NTM in patients with suspected tuberculosis who presented positive cultures and to evaluate the genetic diversity of strains identified as Mycobacterium avium. Methods: We studied pulmonary and extrapulmonary samples obtained from 1,248 patients. The samples that tested positive on culture and negative for the M. tuberculosis complex by molecular identification techniques were evaluated by detection of the hsp65 and rpoB genes and sequencing of conserved fragments of these genes. All strains identified as M. avium were genotyped using the eight-locus mycobacterial interspersed repetitive unit-variable-number tandem-repeat method. Results: We found that NTM accounted for 25 (7.5%) of the 332 mycobacteria isolated. Of those 25, 18 (72%) were M. avium, 5 (20%) were M. abscessus, 1 (4%) was M. gastri, and 1 (4%) was M. kansasii. The 18 M. avium strains showed high diversity, only two strains being genetically related. Conclusions: These results highlight the need to consider the investigation of NTM in patients with suspected active tuberculosis who present with positive cultures, as well as to evaluate the genetic diversity of M. avium strains.

RESUMO Objetivo: As micobactérias não tuberculosas (MNT) são um grupo heterogêneo de bactérias amplamente distribuídas na natureza e relacionadas com infecções oportunistas em seres humanos. Os objetivos deste estudo foram identificar MNT em pacientes com suspeita de tuberculose e culturas positivas e avaliar a diversidade genética de cepas identificadas como Mycobacterium avium. Métodos: Foram estudadas amostras pulmonares e extrapulmonares provenientes de 1.248 pacientes. As amostras que apresentaram resultado positivo em cultura e negativo para o complexo M. tuberculosis na identificação molecular foram avaliadas por meio da detecção dos genes hsp65 e rpoB e de sequenciamento de fragmentos conservados desses genes. Todas as cepas identificadas como M. avium foram genotipadas pelo método mycobacterial interspersed repetitive unit-variable-number tandem-repeat com oito loci. Resultados: Das 332 micobactérias isoladas, 25 (7,5%) eram MNT. Dessas 25, 18 (72%) eram M. avium, 5 (20%) eram M. abscessus, 1 (4%) era M. gastri e 1 (4%) era M. kansasii. As 18 cepas de M. avium apresentaram alta diversidade, e apenas duas eram geneticamente relacionadas. Conclusões: Esses resultados mostram a necessidade de considerar a investigação de MNT em pacientes com suspeita de tuberculose ativa e culturas positivas e de avaliar a diversidade genética de cepas de M. avium.

Diagnostic Performance of the GENEDIA MTB/NTM Detection Kit for Detecting Mycobacterium tuberculosis and Nontuberculous Mycobacteria With Sputum Specimens

The GENEDIA MTB/NTM Detection Kit (GENEDIA MTB/NTM; Green Cross Medical Science Corp., Chungbuk, Korea) is a multiplex real-time PCR assay used for differential identification of Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM). While the importance of differential identification of MTB/NTM is recognized, there is limited data on the performance of GENEDIA MTB/NTM assay to date. A total of 687 consecutive sputum specimens were cultured and analyzed with the GENEDIA MTB/NTM and GENEDIA MTB assays. Nineteen specimens (2.8%) were MTBC-positive, and 69 (10.0%) were NTM-positive based on mycobacterial culture. All specimens showed concordant results for MTBC using both assays, with a kappa value of 1.00, overall sensitivity of 63.2% (12/19), and specificity of 100% (668/668). The overall NTM sensitivity and specificity were 23.2% (16/69) and 99.7% (616/618) for GENEDIA MTB/NTM. The association between NTM-positivity using GENEDIA MTB/NTM and the diagnosis of NTM pulmonary disease was not statistically significant. In conclusion, the two real-time PCR assays showed similar diagnostic performance for MTBC detection. However, the sensitivity for NTM detection was lower than that for MTBC detection.

Diversidad de especies de micobacterias no tuberculosas aisladas en ambientes acuáticos de la ciudad de General Pico, La Pampa, Argentina / Species diversity of non-tuberculous mycobacteria isolated from aquatic environments of General Pico city, Province of La Pampa (Argentina)

Las micobacterias no tuberculosas (MNT) no solo se estudian por su importancia como patógenos oportunistas, sino también por sus aplicaciones en biotecnología y biorremediación. Nuestro objetivo fue determinar la presencia de micobacterias en los distintos hábitats acuáticos de la ciudad de General Pico (provincia de La Pampa), así como su diversidad. Los porcentajes de muestras positivas a micobacterias fueron los siguientes: 37,5% en el sistema de distribución de agua de red, 32,6% en el acuífero que abastece dicho sistema, 36,8% en el agua proveniente de las precipitaciones, 53,1% en los humedales del área de influencia, 80% en los natatorios cubiertos y 33,3% en las fuentes decorativas ubicadas en plazas públicas. De los 90 aislamientos de MNT obtenidos el 8,9% no logró ser identificado a nivel de especie con los métodos utilizados, que incluyeron pruebas fenotípicas y métodos moleculares. Las especies más frecuentemente aisladas fueron Mycobacterium fortuitum y Mycobacterium gordonae. Algunas especies identificadas han sido reportadas en casos de micobacteriosis en nuestro país, entre ellas M. fortuitum, M. gordonae, M. intracellulare, M. vaccae, M. lentiflavum y M. nonchromogenicum. No se aislaron MNT en muestras de agua de red con concentraciones de cloro activo residual mayores de 0,8mg/l, mientras que en los natatorios la presencia de hasta 1,5mg/l de cloro activo residual no fue una limitante para la proliferación de estos microorganismos. Se puede considerar que la incidencia de micobacterias en los ambientes acuáticos de General Pico es cercana al 35%, y que la presencia de estos microorganismos y su diversidad se ve afectada por el contacto con el hombre y sus actividades, como así también por la existencia de vida animal.

Non-tuberculous mycobacteria (NTM) are studied not only for their importance as emerging opportunistic pathogens but also for their applications in biotechnology and bioremediation. Our aim was to determine the occurrence and diversity of mycobacteria in different aquatic habitats of General Pico city, Province of La Pampa. The percentage of samples with positive cultures for mycobacteria were the following: 37.5% recovered from the water supply distribution system; 32.6% from the aquifer that supplies water to the distribution system; 36.8% from rain water; 53.1% from the two wetlands in the area of influence; 80% from indoor swimming pools; and 33.3% from water fountains in downtown public squares. Of the 90 NTM isolates, 8.9% could not be identified at the species level with any of the used methods, phenotypic tests and molecular methods. Mycobacterium fortuitum and Mycobacterium gordonae were the most frequently isolated species. Some of the identified species such as, M. fortuitum, M. gordonae, M. intracellulare, M. vaccae, M. lentiflavum and M. nonchromogenicum, have been reported in cases of mycobacteriosis in Argentina. Mycobacteria with values higher than 0.8mg/ml of residual active chlorine were not recovered from the drinking water supply network, whereas in the swimming pools the presence of up to 1.5 mg/l was not a constraint. Based on our results, the presence of mycobacteria in aquatic environments is close to 35% and their occurrence and diversity is affected both by contact with man and his activities as well as by the existence of animal life.

Treatment of Mycobacterium avium Complex Pulmonary Disease / 결핵및호흡기질환

The pathogen Mycobacterium avium complex (MAC) is the most common cause of nontuberculous mycobacterial pulmonary disease worldwide. The decision to initiate long-term antibiotic treatment is difficult for the physician due to inconsistent disease progression and adverse effects associated with the antibiotic treatment. The prognostic factors for the progression of MAC pulmonary disease are low body mass index, poor nutritional status, presence of cavitary lesion(s), extensive disease, and a positive acid-fast bacilli smear. A regimen consisting of macrolides (clarithromycin or azithromycin) with rifampin and ethambutol has been recommended; this regimen significantly improves the treatment of MAC pulmonary disease and should be maintained for at least 12 months after negative sputum culture conversion. However, the rates of default and disease recurrence after treatment completion are still high. Moreover, treatment failure or macrolide resistance can occur, although in some refractory cases, surgical lung resection can improve treatment outcomes. However, surgical resection should be carefully performed in a well-equipped center and be based on a rigorous risk-benefit analysis in a multidisciplinary setting. New therapies, including clofazimine, inhaled amikacin, and bedaquiline, have shown promising results for the treatment of MAC pulmonary disease, especially in patients with treatment failure or macrolide-resistant MAC pulmonary disease. However, further evidence of the efficacy and safety of these new treatment regimens is needed. Also, a new consensus is needed for treatment outcome definitions as widespread use of these definitions could increase the quality of evidence for the treatment of MAC pulmonary disease.

Is Cross-reactivity with Nontuberculous Mycobacteria a Systematic Problem in the Xpert MTB/RIF Assay? / 결핵및호흡기질환

No abstract available.