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)

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)

Identificación rápida de micobacterias no tuberculosas mediante técnicas proteómicas (MALDI-TOF) / A rapid proteomic system (MALDI-TOF) for nontuberculous-mycobacteria identification

La identificación proteómica de micobacterias no tuberculosas (MNTs) mediante MALDI-TOF presenta una mayor complejidad debido a la especial composición de su pared celular, que complica la extracción de proteínas. Un total de 106 aislamientos pertenecientes a diferentes especies de MNTs procedentes de muestras clínicas del Complejo Asistencial Universitario de León recogidas durante los años 2019 y 2020 se han identificado por un método proteómico abreviado (MALDI-TOF Biotyper Bruker®) desarrollado en nuestro laboratorio. La identificación se ha comparado con la realizada en paralelo en el Centro de Referencia de Majadahonda. Se analizaron un total de 22 especies diferentes de MNTs obteniendo una concordancia del 91,5%. Las nueve discrepancias detectadas se dieron entre especies pertenecientes al mismo grupo taxonómico. En el 67,92% de las identificaciones el score fue superior a 1,8. En el tiempo de procesamiento se obtuvo un ahorro aproximado de 24 minutos con respecto al recomendado por el fabricante.(AU)

Proteomic techniques relaying upon mass spectrometry (MALDI_TOF) applied to nontuberculous mycobacteria (NTM) identification, constitute a difficult goal. Cell wall structure features complicates the protein extraction procedure. A total of 106 isolates belonging to a variety of MNTs species isolated from clinical samples taken at the Complejo Asistencial Universitario de León for a two years period (2019-20) were identified following a simplified method (MALDI-TOF Biotyper Bruker®) developped in our laboratory. The resultant identification was compared to a parallel one ruled on the Centro de Referencia de Majadahonda. A total of 22 different MNTs species were tested, obtaining an agreement of 91,5%. Only 9 minor discrepancies between species belonging to the same taxonomic group of MNTs were detected. The score obtained in the 67.92% of the cases was higher than 1.8. A time-saving of 24 minutes compared to the manufacturer‘s proceeding was achieved.(AU)

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.

Development of a nucleic acid chromatography assay for the detection of commonly isolated rapidly growing mycobacteria.

Introduction. Non-tuberculosis mycobacterium infections are increasing worldwide, including those caused by rapidly growing mycobacteria (RGM).Gap Statement. The identification of the aetiological agent in the context of infections is essential for the adoption of an adequate therapeutic approach. However, the methods for the rapid distinction of different RGM species are less than optimal.Aim. To develop a nucleic acid chromatography kit to identify clinically common RGM.Methodology. We tried to develop a nucleic acid chromatography kit designed to detect four RGM species (including three subspecies) i.e. Mycobacterium abscessus subsp. abscessus, Mycobacterium abscessus subsp. bolletii (detected as M. abscessus/bolletii) Mycobacterium abscessus subsp. massiliense, Mycobacterium fortuitum, Mycobacterium chelonae and Mycobacterium peregrinum. The amplified target genes for each species/subspecies using multiplex PCR were analysed using a nucleic acid chromatography assay.Results. Among the 159 mycobacterial type strains and 70 RGM clinical isolates tested, the developed assay correctly identified all relevant RGM without any cross-reactivity or false-negatives. The limits of detection for each species were approximately 0.2 pg µl-1.Conclusion. The rapid and simple nucleic acid chromatography method developed here, which does not involve heat denaturation, may contribute to the rapid identification and treatment of RGM infections.

Evaluation of a new assay for nontuberculous mycobacteria species identification in diagnostic material and cultures.

The purpose of the present study was to evaluate a real-time PCR system for 12 nontuberculous mycobacteria (NTM) species identification developed by Central Tuberculosis Research Institute (CTRI; Moscow, Russia) in cooperation with Syntol LLC (Moscow, Russia). NTM cultures (210 strains, 19 species), Mycobacterium tuberculosis complex (MTBC) cultures (21 strains, 2 species), non-mycobacterial microorganisms (18 strains, 13 species) were used for the first stage of the assay evaluation. Clinical samples (sputum, N = 973) positive for smear microscopy and MTBC/NTM DNA by a PCR-based screening assay collected from 819 patients were used for specificity and sensitivity evaluation. Sensitivity for determining the NTM species directly from diagnostic material was 99.71%, with the specificity of 100%. The sensitivity and specificity for NTM species identification in cultures was 99.67% and 100%, respectively. Both sensitivity and specificity for determining MTBC in cultures was 100%.

Direct Molecular Characterization of Acid-Fast Bacilli Smear of Nontuberculosis Mycobacterium Species Causing Pulmonary Tuberculosis in Guna Yala Region, Panama.

Mycobacterium tuberculosis (MTB) stands out as the main causative agent of pulmonary tuberculosis (TB). However, nontuberculous mycobacteria (NTM) species also have the potential to infect and cause TB in susceptible individuals. The objective of this study was to identify NTM species that cause public health problems in remote areas. The study was carried out using 105 sputum smears obtained from patients from the Guna Yala Region of Panama with clinical signs suggestive of TB. DNA was extracted from sputum smears. Nontuberculous mycobacteria and MTB were characterized using polymerase chain reaction restriction analysis (hsp65, rpob) and an evaluation of 24-mycobacterial interspersed repetitive units-variable number of tandem repeats loci. Twenty-six Mycobacterium species were characterized; 19 (18%) were identified as MTB, and 7 (6.7%) were identified as NTM (four M. avium complex, two M. haemophilum, one M. tusciae). These results suggest that at least one in five cases of pulmonary TB among this population is caused by an NTM. Thus, identifying the bacteria causing pulmonary disease is key even in remote regions of the world where standard diagnosis and culture are not available. Strengthening the laboratory capacity within the Guna Yala Region is needed to identify NTM infections promptly.

Combining comparative genomic analysis with machine learning reveals some promising diagnostic markers to identify five common pathogenic non-tuberculous mycobacteria.

Non-tuberculous mycobacteria (NTM) can cause various respiratory diseases and even death in severe cases, and its incidence has increased rapidly worldwide. To date, it's difficult to use routine diagnostic methods and strain identification to precisely diagnose various types of NTM infections. We combined systematic comparative genomics with machine learning to select new diagnostic markers for precisely identifying five common pathogenic NTMs (Mycobacterium kansasii, Mycobacterium avium, Mycobacterium intracellular, Mycobacterium chelonae, Mycobacterium abscessus). A panel including six genes and two SNPs (nikA, benM, codA, pfkA2, mpr, yjcH, rrl C2638T, rrl A1173G) was selected to simultaneously identify the five NTMs with high accuracy (> 90%). Notably, the panel only containing the six genes also showed a good classification effect (accuracy > 90%). Additionally, the two panels could precisely differentiate the five NTMs from M. tuberculosis (accuracy > 99%). We also revealed some new marker genes/SNPs/combinations to accurately discriminate any one of the five NTMs separately, which provided the possibility to diagnose one certain NTM infection precisely. Our research not only reveals novel promising diagnostic markers to promote the development of precision diagnosis in NTM infectious, but also provides an insight into precisely identifying various genetically close pathogens through comparative genomics and machine learning.

The lung microbiota in Korean patients with non-tuberculous mycobacterial pulmonary disease.

BACKGROUND: The microbiota of the lower respiratory tract in patients with non-tuberculous mycobacterial pulmonary disease (NTM-PD) has not been fully evaluated. We explored the role of the lung microbiota in NTM-PD by analyzing protected specimen brushing (PSB) and bronchial washing samples from patients with NTM-PD obtained using a flexible bronchoscope. RESULTS: Bronchial washing and PSB samples from the NTM-PD group tended to have fewer OTUs and lower Chao1 richness values compared with those from the control group. In both bronchial washing and PSB samples, beta diversity was significantly lower in the NTM-PD group than in the control group (P = 2.25E-6 and P = 4.13E-4, respectively). Principal component analysis showed that the PSBs and bronchial washings exhibited similar patterns within each group but differed between the two groups. The volcano plots indicated differences in several phyla and genera between the two groups. CONCLUSIONS: The lower respiratory tract of patients with NTM-PD has a unique microbiota distribution that is low in richness/diversity.

Evaluation of a new culture medium for isolation of nontuberculous mycobacteria from environmental water samples.

Nontuberculous mycobacteria (NTM) are waterborne pathogens commonly found in building water systems where they are a primary concern to vulnerable patient populations and can cause severe disease. The recovery of NTM from environmental samples can be a laborious undertaking and current pre-treatment methods and selective media lack sensitivity. We explored the use of the highly selective Rapidly Growing Mycobacteria (RGM) medium for culturing NTM from environmental water samples compared to existing methods. In total, 223 environmental water samples, including potable and non-potable water, were cultured for NTM using three culture media. In addition to direct culture on RGM medium, each sample was cultured on Middlebrook 7H10 medium and Mitchison 7H11 medium after pre-treatment with 0.2M KCl-HCl. Additionally, 33 distinct species of NTM were inoculated onto RGM medium and 7H10 medium in parallel to directly compare their growth. The use of RGM medium alone without pre-treatment provided a sensitivity (91%) comparable to that offered by culture on both 7H10 and 7H11 with acid pretreatment (combined sensitivity; 86%) with significantly less overgrowth and interference from other organisms on RGM medium. The average concentration of NTM observed on RGM medium alone was comparable to or greater than the NTM concentration on either medium alone or combined. Thirty-three species were examined in parallel and all tested strains of 27 of these species successfully grew on RGM medium, including 19 of 21 from the CDC's healthcare-associated infections species list. RGM medium was successful at recovering environmental NTM without a pre-treatment, greatly reducing labor and materials required to process samples. Simplification of culture processing for environmental NTM will allow for a better assessment of their presence in building water systems and the potential for reduced exposure of susceptible populations.

Prevalence and speciation of non-tuberculous mycobacteria among pulmonary and extrapulmonary tuberculosis suspects in South India.

BACKGROUND AND OBJECTIVES: Non tuberculous mycobacteria (NTM) is an emerging opportunistic pathogen increasing globally and indistinguishable from tuberculosis (TB), which remains a challenge particularly in developing countries. This study aimed to identify the prevalence and diversity of NTM among both pulmonary TB (PTB) and extrpulmonary TB (EPTB) clinical isolates from south India. METHODOLOGY: A total of 7633 specimens from TB suspects (PTB, n = 4327 and EPTB, n = 3306) were collected during the study period (July 2018-March 2020) in a tertiary care hospital. The study specimens were subjected to Ziehl Neelsen (ZN) staining and Auramine phenol (AP) staining followed by Lowenstein-Jensen (LJ) and mycobacteria growth indicator tube (MGIT) culture. The MPT64 immunochromatographic test (ICT) was performed among mycobacterial cultures and ICT negative isolates were subjected to Line Probe Assay (LPA). In addition, 53 (PTB, 48 and EPTB, 5) NTM MGIT positive cultures were collected from Intermediate Reference Laboratory (IRL), Puducherry and subjected to LPA for speciation. RESULTS: Of the 7633 TB suspects, 0.6% were diagnosed as NTM diseases and 5.5% with Mycobacterium tuberculosis (MTBC). NTM infection was observed among 0.7% (31/4327) of PTB and 0.4% (14/3306) of EPTB. MTBC was detected among 6.1% (264/4327) of PTB and 4.6% (153/3306) of EPTB. Among 98 NTM cultures, 80.6% of isolates were recovered from PTB and 19.4% from EPTB specimens. Among pulmonary specimens, Mycobacterium intracellulare (26.6%), Mycobacterium abscessus (17.7%) and Mycobacterium kansasii (12.7%) were the most frequently detected species, while Mycobacterium intracellulare (21.1%), Mycobacterium scrofulaceum (15.8%) and Mycobacterium fortuitum (10.5%) were common in extrapulmonary specimens. CONCLUSION: The frequency of NTM infection among TB suspects was low at a South Indian tertiary care hospital. The most predominant NTM species isolated from both pulmonary and extrapulmonary specimens was M. intracellulare.

Application of acid-fast staining combined with GeneXpert MTB/RIF in the diagnosis of non-tuberculous mycobacteria pulmonary disease.

OBJECTIVE: To evaluate the clinical diagnostic value of positive acid-fast staining combined with negative GeneXpert MTB/RIF in the diagnosis of non-tuberculous mycobacteria pulmonary disease (NTM-PD). METHODS: A total of 133 inpatients with confirmed NTM-PD were included consecutively between January 1, 2018 and December 31, 2019, at Tongji Hospital and Jinyintan Hospital, Tongji Medical College of Huazhong University of Science and Technology, in Wuhan, China. One hundred patients with confirmed pulmonary tuberculosis (PTB) were randomly included as the control group. RESULTS: The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of positive acid-fast staining combined with a negative GeneXpert MTB/RIF result were 51.13% (95% confidence interval (CI) 42.52-59.73%), 97.00% (95% CI 93.60-100.40%), 95.78% (95% CI 90.98-100.57%), and 59.88% (95% CI 52.25-67.51%), respectively. When subjects were limited to patients with positive acid-fast staining, the sensitivity of a negative GeneXpert MTB/RIF result was 88.31% (95% CI 80.97-95.65%). When acid-fast staining was conducted ≥3 times, the sensitivity of this combination diagnosis method increased to 61.67% (95% CI 49.00-74.33%). CONCLUSIONS: Positive acid-fast staining combined with a negative GeneXpert MTB/RIF result could be an effective and time-saving method for the diagnosis of NTM-PD.

Mycobacterial infections in wild boars (Sus scrofa) from Southern Switzerland: Diagnostic improvements, epidemiological situation and zoonotic potential.

The occurrence of mycobacterial infections in different hosts and their implication as obligate or opportunistic pathogens remain mainly unclear. In addition to the well-known pathogenic members of the Mycobacterium tuberculosis - complex (MTBC), over 180 non-tuberculous mycobacteria (NTM) species have been described. Although the large majority of the NTM is assumed to be non-pathogenic to most individuals, an increasing trend in NTM infections has been observed over the last decades. The reasons of such augmentation are probably more than one: improved laboratory diagnostics, an increasing number of immunocompromised patients and individuals with lung damage are some of the possible aspects. Mandibular lymph nodes of 176 hunted wild boars from the pre-Alpine region of Canton Ticino, Switzerland, were collected. Following gross inspection, each lymph node was subjected to culture and to an IS6110 based real-time PCR specific for MTBC members. Histology was performed of a selection of lymph nodes (n = 14) presenting gross visible lesions. Moreover, accuracy of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) species identification was compared with sequence analysis of a combination of housekeeping genes. Mycobacteria of the MTBC were detected in 2.8% of the wild boars (n = 5; CI95% 1.2-6.5) and were all confirmed to be Mycobacterium microti by molecular methods. In addition, based on the examined lymph nodes, NTM were detected in 57.4% (n = 101; CI95% 50.0-64.5) of the wild boars originating from the study area. The 111 isolates belonged to 24 known species and three potentially undescribed Mycobacterium species. M. avium subsp. hominissuis thereby predominated (22.5%) and was found in lymph nodes with and without macroscopic changes. Overall, the present findings show that, with the exception of undescribed Mycobacterium species where identification was not possible (3.6%; 4/111), MALDI-TOF MS had a high concordance rate (90.1%; 100/111 isolates) to the sequence-based reference method.

Genotypic analysis of nontuberculous mycobacteria isolated from raw milk and human cases in Wisconsin.

Nontuberculous mycobacteria (NTM) compose a group of mycobacteria that do not belong to the Mycobacterium tuberculosis complex group. They are frequently isolated from environmental samples such as water, soil, and, to a lesser extent, food samples. Isolates of NTM represent a major health threat to humans worldwide, especially those who have asthma or are immunocompromised. Human disease is acquired from environmental exposures and through consumption of NTM-contaminated food. The most common clinical manifestation of NTM disease in human is lung disease, but lymphatic, skin and soft tissue, and disseminated disease are also important. The main objective of the current study was to profile the farm-level contamination of cow milk with NTM by examining milk filters and bulk tank milk samples. Five different NTM species were isolated in one dairy herd in Wisconsin, with confirmed 16S rRNA genotypes including Mycobacterium fortuitum, Mycobacterium avium ssp. hominissuis, Mycobacterium abscessus, Mycobacterium simiae, and Mycobacterium avium ssp. paratuberculosis (Mycobacterium paratuberculosis). In tank milk samples, M. fortuitum was the predominant species in 48% of the samples, whereas M. chelonae/abscessus and M. fortuitum were the only 2 species obtained from 77 and 23% of the examined filters, respectively. Surprisingly, M. avium ssp. hominissuis, M. paratuberculosis, and M. simiae were isolated from 16.7, 10.4, and 4% of the examined milk samples, respectively, but not from milk filters. Interestingly, NTM isolates from human clinical cases in Wisconsin clustered very closely with those from milk samples. These findings suggest that the problem of NTM contamination is underestimated in dairy herds and could contribute to human infections with NTM. Overall, the study validates the use of bulk tank samples rather than milk filters to assess contamination of milk with NTM. Nontuberculous mycobacteria represent one type of pathogens that extensively contaminate raw milk at the farm level. The significance of our research is in evaluating the existence of NTM at the farm level and identifying a simple approach to examine the potential milk contamination with NTM members using tank milk or milk filters from dairy operations. In addition, we attempted to examine the potential link between NTM isolates found in the farm to those circulating in humans in Wisconsin.

Epidemiology and risk factors associated with NTM pulmonary and extrapulmonary infections in a high tuberculosis endemic Region.

Introduction: Non-tuberculous mycobacteria, although identified as pathogenic to humans long time ago, are emerging as the new threat in the past two decades. Even in tuberculosis endemic country such as India, they are being isolated from the clinical specimens more often than previously. This change in trend is of concern, because they are often misdiagnosed as Mycobacterium tuberculosis or even as drug-resistant tuberculosis. Objectives: A prospective, observational study was planned to identify the frequency and risk factors associated with pulmonary and extrapulmonary non-tuberculous mycobacterial (NTM) infections. Agreement between two commercially available molecular systems, namely GenoType Mycobacteria CM assay and matrix-assisted laser desorption/ionisation time of flight mass spectrometry (MALDI TOF MS) used in the identification of mycobacterial species is also analysed. Materials and Methods: NTM isolated from pulmonary and extrapulmonary clinical specimens over a period of 1½ year was included in the study. Patient demographics were collected, and the risk factors associated with NTM infections were analyzed. NTM grown on culture was speciated using GenoType Mycobacteria CM assay (HAIN Life Sciences, Germany) and MALDI TOF MS (bioMerieux, France). Drug-susceptibility tests were done for rapid-growing NTM using E-test (bioMerieux, France). Results: Eight hundred and fifty-four mycobacteria were isolated from 5009 specimens processed during the study period. Out of the mycobacteria grown, 74 (8.7%) were NTM and 780 (91.3%) were Mycobacterium tuberculosis complex. The NTM isolated from pulmonary specimens were 46 (62.16%) and from extrapulmonary sources were 28 (37.84%). The most common species isolated from pulmonary specimens was Mycobacterium intracellulare and from extrapulmonary specimens was Mycobacterium abscessus. Concordance between the two commercial assays used for the identification was 96.49%. The most common risk factor associated with pulmonary NTM was previous lung pathology, while with extrapulmonary NTM infection was previous surgical intervention. Drug-susceptibility tests for rapid growers showed amikacin and clarithromycin as the most active drugs in vitro. Conclusions: NTM plays a significant role in causing pulmonary and extrapulmonary infections even in our part of the country with high endemicity of tuberculosis. NTM has emerged as important pathogens even in the immunocompetent patients. There is a need for rapid diagnosis and susceptibility testing of NTM to aid physicians administer timely and appropriate treatment to the patients.

Prevalencia e importancia de micobacterias no tuberculosas en pacientes adultos con fibrosis quística en un hospital de Madrid / Prevalence and importance of non-tuberculous mycobacteria in adult patients with cystic fibrosis in a hospital in Madrid

INTRODUCCIÓN: El papel de las micobacterias no tuberculosas (MNT) en los pacientes con fibrosis quística (FQ) está, en ocasiones, en controversia. El objetivo del trabajo es evaluar la prevalencia y las características clínicas/microbiológicas de pacientes adultos con FQ colonizados con MNT, destacando Mycobacterium abscessus (M. abscessus). MÉTODOS: Se ha realizado un estudio retrospectivo en 92 pacientes adultos con FQ en el que se diferenció: grupo control, 64 pacientes no colonizados por MNT, y grupo a estudio, 28 pacientes colonizados por MNT. Se han analizado variables como la edad, mutación F508del, función pulmonar, afectación pancreática, tinción de auramina y recolonizaciones entre ambos grupos. RESULTADOS: La prevalencia de MNT encontrada ha sido 30,4%. La MNT más prevalente fue Mycobacterium avium complex seguida por M. abscessus. Para M. abscessus, en el estudio comparativo con pacientes colonizados por otras MNT, se obtuvieron diferencias estadísticamente significativas en las variables de edad. DISCUSIÓN: Hemos encontrado alta prevalencia de MNT en pacientes adultos con FQ y relacionamos la aparición de M. asbcessus con edades inferiores a 30 años y F508del. Con el fin de conocer mejor el papel patógeno de las MNT, especialmente de M. asbcessus, se requieren estudios multicéntricos en población con FQ

INTRODUCTION: The role of non-tuberculous mycobacteria (NTM) among cystic fibrosis (CF) patients, on occasion, remains unknown. The aim of our study is to evaluate the prevalence and clinical/microbiological characteristics of CF adult patients colonized by NTM, highlighting Mycobacterium abscessus (M. abscessus). METHODS: A retrospective study was conducted with 92 CF adult patients: including a control group of 64 patients, not colonized by NTM, and a study group of 28 patients, colonized by NTM. We have analyzed variables such as age, F508del mutation, lung function, pancreatic involvement, auramine staining and co-colonizations between both groups. RESULTS: The prevalence of NTM found was 30.4%. The most prevalent was Mycobacterium avium complex followed by M. abscessus. For M. abscessus, in the comparative study with patients colonized by other NTM, significant results were obtained for variables age. DISCUSSION: We have found a high prevalence of NTM among adult patients with CF, and we associated the presence of M. asbcessus with ages less than 30 years and F508del. Due to the pathogenic role of NTM, especially M. asbcessus, multicenter studies are required within the population suffering from CF

Isolation, identification and associated risk factors of non-tuberculous mycobacteria infection in humans and dromedary camels in Samburu County, Kenya.

Non-tuberculous mycobacteria are of public health significance, and zoonotic infection is attributed to the sociocultural practice of consumption of raw milk and the close human-livestock contact in pastoral communities. This study aimed at isolation, identification of mycobacteria from human sputum and camel milk and risk factors assessment in Samburu East, Kenya. Six hundred and twelve camels and 48 people presumed to have tuberculosis (TB) from 86 households in Wamba and Waso regions were screened. Camels were categorized into Somali, Turkana and Rendile breeds. Single intradermal comparative tuberculin test (SICTT) was used as a herd-screening test on lactating camels and a milk sample collected from reactive camels. Sputum samples were collected from eligible members of participating households. A standard questionnaire on possible risk factors for both humans and camels was administered to respective household heads or their representatives. Total camel skin test reactors were 238/612 (38.9%). Milk and sputum samples were analysed at KEMRI/TB research laboratory for microscopy, GeneXpert® , culture and identification. Isolates were identified using 16S rRNA gene sequencing at Inqaba biotec in South Africa. Sixty-four isolates were acid-fast bacilli (AFB) positive of which M. fortuitum (3), M. szulgai (20), M. monacense (5), M. lehmanni (4), M. litorale (4), M. elephantis (3), M. duvalii (3), M. brasiliensis (1), M. arcueilense (1) and M. lentiflavum (1) were from milk; M. fortuitum (1), M. szulgai (2) and M. litorale (1) were from humans. Risk factors included the following: Turkana breed (OR = 3.4; 95% CI: 1.2-9.3), replacements from outside the County (OR = 2.1; 95% CI: 0.3-12.3), presence of other domestic species (small stock; OR = 4.6) and replacement from within the herd (OR = 3.2; 95% CI: 0.7-14.7). Zoonotic risk practices included raw milk consumption, shared housing and handling camels. Monitoring of zoonotic NTM through surveillance and notification systems is required.

Prevalence of nontuberculous mycobacteria in a tertiary hospital in Beijing, China, January 2013 to December 2018.

BACKGROUND: To investigate the species distribution of non-tuberculous mycobacteria (NTM) among tuberculosis (TB) specimens collected from January 2013 to December 2018 at Peking Union Medical Hospital (Beijing), China. NTM species identification was carried out by DNA microarray chip. RESULTS: Mycobacterial species were detected in 1514 specimens from 1508 patients, among which NTM accounted for 37.3% (565/1514), increasing from a proportion of 15.6% in 2013 to 46.1% in 2018 (P < 0.001). Among the 565 NTM positive specimens, the majority (55.2%) were from female patients. Furthermore, patients aged 45-65 years accounted for 49.6% of the total patients tested. Among 223 NTM positive specimens characterized further, the majority (86.2%) were from respiratory tract, whilst 3.6 and 3.1% were from lymph nodes and pus, respectively. Mycobacterium intracellulare (31.8%) and Mycobacterium chelonae / Mycobacterium abscessus (21.5%) were the most frequently detected species, followed by M. avium (13.5%), M. gordonae (11.7%), M. kansasii (7.6%), and others. CONCLUSION: The proportion of NTM among mycobacterial species detected in a tertiary hospital in Beijing, China, increased rapidly from year 2013 to 2018. Middle-aged patients are more likely to be infected with NTM, especially females. Mycobacterium intracellulare and Mycobacterium chelonae/ Mycobacterium abscessus were the most frequently detected NTM pathogens. Accurate and timely identification of NTM is important for diagnosis and treatment.

An overview of pulmonary infections due to rapidly growing mycobacteria in South Asia and impressions from a subtropical region.

Background: Rapidly growing mycobacteria (RGM) comprise nearly half of the validated species of nontuberculous mycobacteria (NTM) and have been reported to have a higher incidence in Asia as compared to Europe and America. There is limited information on RGM infections from South Asia. Hence, the present study aimed to ascertain the incidence of pulmonary infections due to RGM in Delhi and to review the status of available information on the prevalence of RGM in South Asia, a region endemic for tuberculosis. Methods: We analyzed 933 mycobacterial isolates obtained from pulmonary samples in Delhi and performed species identification by polymerase chain reaction (PCR)-restriction analysis (restriction fragment length polymorphism) and line probe assay. Drug susceptibility testing (DST) was performed by broth microdilution method. We also reviewed reports available on pulmonary infections in South Asia, attributed to RGM. Results: Of the 933 mycobacterial isolates studied, NTM were identified in 152 (16.3%). Of these, 65/152 (42.8%) were RGM comprising Mycobacterium fortuitum (34/65; 52.3%), Mycobacterium abscessus (25/65; 38.5%), Mycobacterium chelonae (3/65; 4.61%), Mycobacterium mucogenicum (2/65; 3.1%), and Mycobacterium smegmatis (1/65; 1.5%). On applying the American Thoracic Society/Infectious Diseases Society of America guidelines, 11/25 (44%) M. abscessus, 3/3 (100%) M. chelonae, and both isolates of M. mucogenicum were found to be clinically relevant. DST revealed that maximum susceptibility of the RGM was seen to linezolid, clarithromycin, and amikacin. Conclusions: Of the RGM isolated in the present study, 16/65 (24.6%) were found to be clinically relevant. Hence, it is important to recognize these organisms as potential pathogens to identify patients with RGM disease to initiate appropriate therapy.