Comparison of the sputum microbiome between patients with stable nontuberculous mycobacterial pulmonary disease and patients requiring treatment.

BACKGROUND: We evaluated whether the sputum bacterial microbiome differs between nontuberculous mycobacteria pulmonary disease (NTM-PD) patients with stable disease not requiring antibiotic treatment and those requiring antibiotics. METHODS: We collected sputum samples from 21 clinically stable NTM-PD patients (stable group) and 14 NTM-PD patients needing antibiotic treatment (treatment group). We also obtained 13 follow-up samples from the stable group. We analyzed the 48 samples using 16S rRNA gene sequencing (V3-V4 region) and compared the groups. RESULTS: In the linear discriminant analysis effect size (LEfSe) analysis, the species Porphyromonas pasteri, Haemophilus parahaemolyticus, Prevotella nanceiensis, and Gemella haemolysans were significantly more prevalent in the sputum of the stable group compared to the treatment group. No taxa showed significant differences in alpha-/beta-diversity or LEfSe between the 21 baseline and 13 follow-up sputum samples in the stable group. In the stable group, the genus Bergeyella and species Prevotella oris were less common in patients who achieved spontaneous culture conversion (n = 9) compared to those with persistent NTM positivity (n = 12) (effect size 3.04, p = 0.039 for Bergeyella; effect size 3.64, p = 0.033 for P. oris). In the treatment group, H. parainfluenzae was more common in patients with treatment success (n = 7) than in treatment-refractory patients (n = 7) (effect size 4.74, p = 0.013). CONCLUSIONS: Our study identified distinct bacterial taxa in the sputum of NTM-PD patients based on disease status. These results suggest the presence of a microbial environment that helps maintain disease stability.

Clinical Characteristics and Treatment Outcomes of Pulmonary Diseases Caused by Coinfections With Multiple Nontuberculous Mycobacterial Species.

BACKGROUND: Coinfections with multiple nontuberculous mycobacterial (NTM) species have not been widely studied. We aimed to evaluate the clinical characteristics and treatment outcomes in patients with NTM-pulmonary disease (PD) caused by coinfection with multiple NTM species. METHODS: We retrospectively reviewed patients with NTM-PD at a tertiary referral hospital in Korea between March 2012 and December 2018. Coinfection was defined as two or more species of NTM pathogens isolated from the same respiratory specimen or different specimens within three months. RESULTS: Among 1,009 patients with NTM-PD, 147 (14.6%) NTM coinfections were observed (average age 64.7 years, 69.4% women). NTM species were identified more frequently (median 6 vs. 3 times, P < 0.001) in the coinfection group than in the single species group, and follow-up duration was also longer in the coinfection group (median 44.9 vs. 27.1 months, P < 0.001). Mycobacterium avium complex (MAC) and M. abscessus and M. massiliense (MAB) were the dominant combinations (n = 71, 48.3%). For patients treated for over six months in the MAC plus MAB group (n = 31), sputum culture conversion and microbiological cure were achieved in 67.7% and 41.9% of patients, respectively. We divided the MAC plus MAB coinfection group into three subgroups according to the target mycobacteria; however, no statistical differences were found in the treatment outcomes. CONCLUSION: In NTM-PD cases, a significant number of multiple NTM species coinfections occurred. Proper identification of all cultured NTM species through follow-up is necessary to detect multispecies coinfections. Further research is needed to understand the nature of NTM-PD in such cases.

An early and trustable indicator suggestive of non-tuberculosis mycobacteria isolation in a high tuberculosis burden setting.

BACKGROUND: Distinguishing between nontuberculous mycobacterial (NTM) lung infections and pulmonary tuberculosis becomes challenging due to their similar clinical manifestations and radiological images. Consequently, instances of delayed diagnosis or misdiagnosis are highly frequent. A feasible and reliable indicator of the existence of NTM in the early stages of the disease would help to solve this dilemma. METHODS: In this study, we evaluated the potential of smear-positive and Xpert assay (Cepheid, USA) negative outcomes as an early indicator of possible NTM infection in a high TB-burden setting retrospectively and prospectively. RESULTS: During the study period, 12·77% (138/1081) of the smear-positive cases yielded negative outcomes with the simultaneous Xpert assay. From the 110 patients who yielded smear-positive/Xpert-negative outcomes and cultivated strain as well, 105 (95·45%) were proved to have NTM isolated. By incorporating an additional criterion of a negative result from the Interferon-gamma release assay, the accuracy of the screening method reached 100%. Regarding the NTM presence prediction value, smear-positive/Xpert-negative has a sensitivity of 24·86% (45/181) in all NTM isolated cases but 93·75-96·55% accuracy in retrospective study or 93·75% accuracy in prospective study in smear-positive NTM isolated cases. In addition, the specificity was ∼99·47% (943/948) in smear-positive tuberculosis cases. CONCLUSION: The clue of the presence of NTM could be obtained on the first day of the hospital visit due to the point of care (POC) feature of smear testing and Xpert assay. About one-fourth of the NTM-isolated patients would benefit from this rapid, convenient, and reliable screening strategy in the given circumstance. Smear-positive/Xpert-negative outcome is an early, trustable indicator that is indicative of NTM isolation.

Disseminated mycobacterium genavense infection with central nervous system involvement in an HIV patient: a case report and literature review.

BACKGROUND: Immunodeficient patients, particularly HIV patients, are at risk of opportunistic infections. Nontuberculous mycobacteria can cause severe complications in immunodeficient patients. CASE PRESENTATION: We describe a 57-year-old HIV patient, primarily presented with coughs and constitutional symptoms, with a unique Mycobacterium genavense abdominal, pulmonary, and central nervous system infection, accompanied by intracranial masses. CONCLUSION: The diagnosis of NTM, including M. genavense, must always be considered by clinicians in immunodeficient patients, especially those with HIV, who have a compromised immune system.

Spatial Heterogeneity of Nontuberculous Mycobacterial Pulmonary Disease in Shanghai: Insights from a Ten-Year Population-Based Study.

OBJECTIVE: To investigate the spatial heterogeneity of nontuberculous mycobacterial pulmonary disease (NTM-PD) in Shanghai. METHODS: A population-based retrospective study was conducted using presumptive pulmonary tuberculosis surveillance data of Shanghai between 2010 and 2019. The study described the spatial distribution of NTM-PD notification rates, employing hierarchical Bayesian mapping for high-risk areas and the Getis-Ord Gi* statistic to identify hot spots and explore associated factors. RESULTS: Of 1652 NTM-PD cases, the most common species was Mycobacterium kansasii complex (MKC) (41.9%), followed by Mycobacterium avium complex (MAC) (27.1%) and Mycobacterium abscessus complex (MABC) (16.2%). MKC-PD patients were generally younger males with a higher incidence of pulmonary cavities, while MAC-PD patients were more often farmers or had a history of tuberculosis treatment. MKC-PD hot spots were primarily located in the areas alongside the Huangpu River, while MAC-PD hot spots were mainly in the western agricultural areas. Patients with MKC-PD and MAC-PD exhibited a higher risk of spatial clustering compared to those with MABC-PD. CONCLUSIONS: Different types of NTM-PD exhibit distinct patterns of spatial clustering and are associated with various factors. These findings underscore the importance of environmental and host factors in the epidemic of NTM-PD.

Advances in diagnosis and treatment of non-tuberculous mycobacterial lung disease.

The prevalence of Non-tuberculous Mycobacterial Pulmonary Disease (NTM-PD) is increasing worldwide. The advancement in molecular diagnostic technology has greatly promoted the rapid diagnosis of NTM-PD clinically, and the pathogenic strains can be identified to the species level through molecular typing, which provides a reliable basis for treatment. In addition to the well-known PCR and mNGS methods, there are numerous alternative methods to identify NTM to the species level. The treatment of NTM-PD remains a challenging problem. Although clinical guidelines outline several treatment options for common NTM species infections, in most cases, the therapeutic outcomes of these drugs for NTM-PD often fall short of expectations. At present, the focus of research is to find more effective and more tolerable NTM-PD therapeutic drugs and regimens. In this paper, the latest diagnostic techniques, therapeutic drugs and methods, and prevention of NTM-PD are reviewed.

Mycobacterium flavescens Infection - An Unusual Case of Prosthetic Joint Infection.

INTRODUCTION: The onset of prosthetic joint infections (PJIs) is characterized by early onset defined as within 90 days of the procedure, delayed onset defined as within 3 to 12 months, and late onset defined as over 12 months. In only a scant number of case reports, Mycobacterium flavescens associated infections are typically found in sputum cultures and associated with various forms of penetrating joint traumas, particularly post-surgical interventions. Due to its rarity in presentation among cases of PJIs, we have presented a case of PJI caused by Mycobacterium flavescens. CASE PRESENTATION: We have, herein, reported a case of a 70-year-old male presenting with stabbing left knee pain over the past several months along with accompanying erythema and swelling with the presence of purulent discharge. Outpatient cultures have shown the growth of Mycobacterium flavescent; subsequently, the patient underwent a 2-stage revision arthroplasty and was treated with a three-drug regimen and implant 5 months later. Although being an atypical cause of PJIs, we emphasize the importance of considering NTM as a differential for immunocompromised patients, especially those with prior surgical intervention. DISCUSSION: Mycobacterium spp. related PJIs manifest clinical features similar to other bacteriacausing PJIs, such as warm, indurated edema at the surgical site resulting in wound dehiscence and joint effusion. Diagnosis of Mycobacterium spp. related PJIs includes history and physical examination findings, serum inflammatory markers, synovial fluid analysis, and culture. Concurrently with surgical interventions, utilization of antimicrobial agents provides additional control in Mycobacterium- related PJI. Mycobacterium flavescens should be included among other NTMs as a possible cause of PJIs.

Prevalence and risk factors of non-tuberculous mycobacterial pulmonary isolates and infection in interstitial lung disease associated with systemic autoimmune disease.

OBJECTIVES: Non-tuberculous mycobacterial (NTM) lung disease (NTM-LD) prevalence is increasing worldwide. In this study, we aimed to evaluate the clinical significance of NTM pulmonary isolates (NTM-PI) and NTM-LD in patients with systemic autoimmune disease (SAD) who had a concurrent interstitial lung disease (ILD) diagnosis. METHODS: We retrospectively identified patients with SAD who had a concurrent ILD diagnosis (SAD-ILD) and from whom clinically indicated sputum specimens were collected for NTM culture between 2003 and 2018 at a tertiary referral hospital. We analysed the prevalence and risk factors of NTM pulmonary isolates (NTM-PI; ≥1 positive culture) and NTM-LD (≥2 positive cultures). RESULTS: This study included 258 patients. Rheumatoid arthritis and Sjögren's syndrome were the most common SADs (32.2% and 26.7%, respectively). The NTM-negative subgroup had 204 patients (79.1%) and the NTM-PI subgroup had 54 patients (20.9%). In the NTM-PI subgroup, 33 patients had one NTM positive set of specimens (NTM 1+, 12.8% of the entire sample) and 21 had NTM-LD (8.1% of the entire sample). In a multivariable analysis, chronic kidney disease (CKD; adjusted odds ratio [aOR]: 3.10 [1.53, 6.29]) and chronic obstructive pulmonary disease (COPD; aOR: 2.59 [1.16, 5.78]) were significantly associated with NTM-PI. For NTM-LD, CKD (aOR: 2.79 [1.00, 7.76]) and COPD (aOR: 3.70 [1.23, 10.72]) remained significant risk factors. CONCLUSIONS: In patients with SAD-ILD, the NTM-PI and NTM-LD prevalence rates were 20.9% and 8.1%, respectively. COPD and CKD were independent risk factors of both NTM-PI and NTM-LD. Previous use of biological agents was associated with NTM-PI.

Análisis de la incidencia y epidemiología de las infecciones por micobacterias no tuberculosas en el área de salud III de la comunidad autónoma de Aragón / Analysis of the incidence and epidemiology of non-tuberculous mycobacterial infections in the health area III of Aragón

Objetivo. Conocer la incidencia y epidemiología de mico bacterias no tuberculosas (MNT) en nuestra área y la preva lencia de comorbilidades en pacientes con infección por MNT. Como objetivos secundarios, estudiamos la distribución por es pecies de MNT, las formas de enfermedad objetivadas y el tipo de muestra empleada para su diagnóstico. Material y métodos. Estudio retrospectivo en el que se incluyeron todos los aislamientos de micobacterias realizados por el Laboratorio de Microbiología del Hospital Clínico Uni versitario Lozano Blesa de Zaragoza durante el periodo com prendido entre el 1 de enero de 2011 y el 31 de diciembre de 2018. Resultados. Se aislaron un total de 533 micobacterias, de las cuales 295 (55,35%) eran micobacterias tuberculosas (MTB) y 238 (44,65%) MNT. Del total de aislamientos de MNT, el 15,54% fueron considerados clínicamente significativos. Se identificaron 21 especies y las más frecuentes fueron: M. gor donae (26,89%), M. fortuitum (19,75%) y M. avium (16,39%). El 32,72% de los aislamientos de MNT se realizaron en mayores de 70 años. Conclusiones. Podemos confirmar que el número de ais lamientos de MNT en nuestra área está siendo mayor que en periodos previos. La infección por MNT es más frecuente en varones y mayores de 70 años. La epidemiología, especialmen te los factores de riesgo, de la enfermedad por MNT está cam biando (AU)

Objectives. The main objective of our investigation was to know the incidence and epidemiology of non-tuberculous mycobacteria (NTM) in our area and the prevalence of comor bidities in patients with MNT infection. As secondary objec tives, we studied the distribution by species of MNT, the forms of disease and the type of sample used for its diagnosis. Material and methods. A retrospective study was carried out in which all the isolates of mycobacteria carried out by the microbiology laboratory of the Hospital Clínico Universitario Lozano Blesa of Zaragoza during the period between January 1, 2011 and December 31, 2018 were included. Results. A total of 533 mycobacteria were isolated, of which 295 (55.35%) were tuberculosis (MTB) and 238 (44.65%) were MNT. Of the whole MNT isolates, only 15.54% were con sidered clinically significant. Twenty-one species were identi fied being the most frequent: M. gordonae (26.89%), M. for tuitum (19.75%) and M. avium (16.39%). 32.72% of the MNT isolates were found in people over 70 years of age. Conclusions. We can confirm that the reported number of MNT isolates in our area is higher than in previous periods. MNT infection is more common in men and those older than 70 years. The epidemiology, especially the risk factors, of MNT disease is changing (AU)

Plasmid-mediated drug resistance in mycobacteria: the tip of the iceberg?

Macrolides, such as clarithromycin, are crucial in the treatment of nontuberculous mycobacteria (NTM). NTM are notoriously innately drug resistant, which has made the dependence on macrolides for their treatment even more important. Not surprisingly, resistance to macrolides has been documented in some NTM, including Mycobacterium avium and Mycobacterium abscessus, which are the two NTM species most often identified in clinical isolates. Resistance is mediated by point mutations in the 23S ribosomal RNA or by methylation of the rRNA by a methylase (encoded by an erm gene). Chromosomally encoded erm genes have been identified in many of the macrolide-resistant isolates, but not in Mycobacterium chelonae. Now, Brown-Elliott et al. (J Clin Microbiol 61:e00428-23, 2023, https://doi.org/10.1128/JCM.00428-23) describe the identification of a new erm variant, erm(55), which was found either on the chromosome or on a plasmid in highly macrolide-resistant clinical isolates of M. chelonae. The chromosomal erm(55) gene appears to be associated with mobile elements; one gene is within a putative transposon and the second is in a large (37 kb) insertion/deletion. The plasmid carrying erm(55) also encodes type IV and type VII secretion systems, which are often linked on large mycobacterial plasmids and are hypothesized to mediate plasmid transfer. While the conjugative transfer of the erm(55)-containing plasmid between NTM has yet to be demonstrated, the inferences are clear, as evidenced by the dissemination of plasmid-mediated drug resistance in other medically important bacteria. Here, we discuss the findings of Brown-Elliott et al., and the potential ramifications on treatment of NTM infections.

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.

Spatial Epidemiologic Analysis and Risk Factors for Nontuberculous Mycobacteria Infections, Missouri, USA, 2008-2019.

Nontuberculous mycobacteria (NTM) infections are caused by environmental exposure. We describe spatial distribution of NTM infections and associations with sociodemographic factors and flooding in Missouri, USA. Our retrospective analysis of mycobacterial cultures reported to the Missouri Department of Health and Social Services surveillance system during January 1, 2008-December 31, 2019, detected geographic clusters of infection. Multilevel Poisson regression quantified small-area geographic variations and identified characteristics associated with risk for infection. Median county-level NTM infection rate was 66.33 (interquartile range 51-91)/100,000 persons. Risk of clustering was significantly higher in rural areas (rate ratio 2.82, 95% CI 1.90-4.19) and in counties with >5 floodings per year versus no flooding (rate ratio 1.38, 95% CI 1.26-1.52). Higher risk for NTM infection was associated with older age, rurality, and more flooding. Clinicians and public health professionals should be aware of increased risk for NTM infections, especially in similar environments.

Enfermedad pulmonar por micobacterias no tuberculosas: análisis de 62 casos / Non-tuberculosis mycobacterial lung disease: Analyses of 62 cases

Introducción El objetivo de nuestro estudio fue evaluar la frecuencia de aislamiento de la infección respiratoria por micobacterias no tuberculosas (MNT) y analizar las características clínico-epidemiológicas de los pacientes infectados por MNT. Métodos Estudio observacional retrospectivo de 83 muestras respiratorias con aislamiento de MNT de 62 pacientes entre los años 2015 y 2021 en el Hospital General Universitario Doctor Balmis. Resultados Se cumplían criterios de infección respiratoria por MNT en 15 pacientes (24,2%). Las MNT más frecuentemente aisladas en los pacientes que cumplieron criterios de infección fueron las pertenecientes al complejo Mycobacterium avium complex (M. avium complex). De los 15 pacientes infectados, 11 (73,3%) presentaban comorbilidad respiratoria y la comorbilidad respiratoria más frecuente en los pacientes infectados fueron las bronquiectasias (5 pacientes; 45,5%). De los pacientes infectados se pautó tratamiento antibiótico dirigido en el 83,3% de los casos. Conclusión Uno de cada 7 pacientes con aislamiento por MNT cumplen criterios de infección. Se corrobora el papel principal de las especies de M. avium complex y la relevancia del daño estructural pulmonar en el desarrollo de enfermedad pulmonar por MNT (AU)

Introduction The objective of our study was to evaluate the frequency of isolation of respiratory infection by non-tuberculous mycobacteria (NTM) and to analyze the clinical-epidemiological characteristics of patients infected with NTM. Methods Retrospective observational study of 83 respiratory samples with NTM isolation from 62 patients between 2015 and 2021 at the Doctor Balmis General University Hospital. Results MNT respiratory infection criteria were met in 15 patients (24.2%). The most frequently isolated NTM's in patients who met infection criteria were those belonging to the Mycobacterium avium complex. Of the 15 infected patients, 11 (73.3%) had respiratory comorbidity and the most frequent respiratory comorbidity in infected patients was bronchiectasis (5 patients; 45.5%). Of the infected patients, targeted antibiotic treatment was prescribed in 83.3% of the cases. Conclusion One in 7 patients with NTM isolation meets infection criteria. The main role of the species of Mycobacterium avium complex is corroborated, and the relevance of lung structural damage in the development of lung disease due to NTM (AU)

Prevalence of Non-Tuberculosis Mycobacterium Pulmonary Disease in HIV-1 Patients with Presumptive Pulmonary Tuberculosis in Western Kenya.

Background: Non-tuberculous mycobacteria (NTMs) are ubiquitous, free-living, environmental saprophytic microorganisms. NTMs belong to the genus Mycobacterium which includes Mycobacterium tuberculosis (MTB). NTMs have lately been a major cause of pulmonary disease (PD) in immuno-compromised individuals including HIV-1 patients. NTMs and MTB appear similar based on microscopy, radiology, and clinical symptoms; consequently, this may lead to misdiagnosis. This study sought to establish the prevalence of NTM pulmonary disease in HIV-1 patients presumed to have pulmonary tuberculosis. Methods: A cross-sectional analytical laboratory study design was used targeting 617 adult HIV-1 infected patients presenting with presumptive pulmonary TB at Bungoma County Hospital Comprehensive Care Clinic in Western Kenya between July 2021 to June 2022. Results: A total of 75 (12.2%, 4.6 -9.8 CI) of the participants presented with presumptive MTB and had TB-like symptoms while 542 (87.8%, 12.5 -30.7 CI) were negative. Additionally, 56 (9.1%) were infected with NTMs. HIV-positive participants had a significantly higher prevalence of NTMs 62 (11.8%, 5.6 -9.2 CI) compared to 2 (2.1%, 0.4 -1.8 CI). In HIV + study participants P<0.0001. M. avium was the most prevalent NTM, 25(33.3%), followed by M. fortuitum 20 (26.7%). A significant number of the isolates were M. tuberculosis 10 (13.3%) as well as M. kansasii 8 (10.7%). Conclusion: There seems to be a high prevalence of NTMPD in HIV-1 patients which is assumed to be pulmonary TB. Differential diagnosis of the mycobacterium species is necessary to help improve disease management and outcomes in this group of patients.

Non-Mycobacteria Tuberculosis in Africa: A Literature Review.

Background: Non-tuberculous mycobacteria (NTM) have been reported to cause pulmonary and extrapulmonary infections. These NTMs are often misdiagnosed as MTB due to their similar clinical presentations to tuberculosis, leading to inappropriate treatment and increased morbidity and mortality rates. This literature review aims to provide an overview of the prevalence, clinical manifestations, diagnosis, and management of NTM infections in Africa. Methods: A systematic search was performed using various electronic databases including PubMed, Scopus, and Web of Science. The search was limited to studies published in the English language from 2000 to 2021. The following keywords were used: "non-tuberculous mycobacteria", "NTM", "Africa", and "prevalence". Studies that focused solely on the Mycobacterium tuberculosis complex or those that did not report prevalence rates were excluded. Data extraction was performed on eligible studies. Overall, a total of 32 studies met the inclusion criteria and were included in this review. Results: In our literature review, we identified a total of 32 studies that reported non-tuberculosis mycobacteria (NTM) in Africa. The majority of these studies were conducted in South Africa, followed by Ethiopia and Nigeria. The most commonly isolated NTM species were Mycobacterium avium complex (MAC), Mycobacterium fortuitum, and Mycobacterium abscessus. Many of the studies reported a high prevalence of NTM infections among HIV-positive individuals. Other risk factors for NTM infection included advanced age, chronic lung disease, and previous tuberculosis infection. Conclusion: In conclusion, this literature review highlights the significant burden of non-tuberculosis mycobacteria infections in Africa. The prevalence of these infections is high, and they are often misdiagnosed due to their similarity to tuberculosis. The lack of awareness and diagnostic tools for non-tuberculosis mycobacteria infections in Africa is a major concern that needs to be addressed urgently. It is crucial to improve laboratory capacity and develop appropriate diagnostic algorithms for these infections.

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.

Multicentre study on the reproducibility of MALDI-TOF MS for nontuberculous mycobacteria identification.

The ability of MALDI-TOF for the identification of nontuberculous mycobacteria (NTM) has improved recently thanks to updated databases and optimized protein extraction procedures. Few multicentre studies on the reproducibility of MALDI-TOF have been performed so far, none on mycobacteria. The aim of this study was to evaluate the reproducibility of MALDI-TOF for the identification of NTM in 15 laboratories in 9 European countries. A total of 98 NTM clinical isolates were grown on Löwenstein-Jensen. Biomass was collected in tubes with water and ethanol, anonymized and sent out to the 15 participating laboratories. Isolates were identified using MALDI Biotyper (Bruker Daltonics). Up to 1330 MALDI-TOF identifications were collected in the study. A score ≥ 1.6 was obtained for 100% of isolates in 5 laboratories (68.2-98.6% in the other). Species-level identification provided by MALDI-TOF was 100% correct in 8 centres and 100% correct to complex-level in 12 laboratories. In most cases, the misidentifications obtained were associated with closely related species. The variability observed for a few isolates could be due to variations in the protein extraction procedure or to MALDI-TOF system status in each centre. In conclusion, MALDI-TOF showed to be a highly reproducible method and suitable for its implementation for NTM identification.

Life-threatening Mycobacterium intracellulare pleuritis in an immunocompetent host: Case reports.

RATIONALE: Nontuberculous mycobacteria (NTM)-associated pleuritis is a very rare disease. Here, we describe 2 cases of life-threatening Mycobacterium intracellulare-associated pleuritis in immunocompetent hosts. PATIENT CONCERNS: A 78-year-old man with sudden onset-onset dyspnea (case 1) and an 80-year-old man with cough, sputum and fever (case 2) presented to our emergency room. DIAGNOSES: Both the patients were diagnosed with Mycobacterium intracellulare-associated pleuritis. INTERVENTION: In case 1, the patient underwent intubation with mechanical ventilation due to hypoxemic respiratory failure. Daily azithromycin, rifampin and ethambutol, and intravenous amikacin 3 times a week was administered. In case 2, the patient received daily azithromycin, rifampin and ethambutol, and intravenous amikacin 3 times a week. OUTCOMES: In case 1, after receiving NTM treatment for 14 months, NTM-associated pleuritis was cured, with radiologic improvement. In case 2, however, bronchopleural fistula was developed. Despite tube drainage, air leak continued. The patient refused surgical management and eventually died of respiratory failure. LESSONS: Pleural effusion arising from NTM lung disease located in the subpleural area should be considered a possible cause of NTM-associated pleuritis. Drainage and a multidrug regimen are required to treat NTM, and surgical treatment should be considered when complications occur.