Phylogenomic and genomic analysis reveals unique and shared genetic signatures of Mycobacterium kansasii complex species.

Species belonging to the Mycobacterium kansasii complex (MKC) are frequently isolated from humans and the environment and can cause serious diseases. The most common MKC infections are caused by the species M. kansasii (sensu stricto), leading to tuberculosis-like disease. However, a broad spectrum of virulence, antimicrobial resistance and pathogenicity of these non-tuberculous mycobacteria (NTM) are observed across the MKC. Many genomic aspects of the MKC that relate to these broad phenotypes are not well elucidated. Here, we performed genomic analyses from a collection of 665 MKC strains, isolated from environmental, animal and human sources. We inferred the MKC pangenome, mobilome, resistome, virulome and defence systems and show that the MKC species harbours unique and shared genomic signatures. High frequency of presence of prophages and different types of defence systems were observed. We found that the M. kansasii species splits into four lineages, of which three are lowly represented and mainly in Brazil, while one lineage is dominant and globally spread. Moreover, we show that four sub-lineages of this most distributed M. kansasii lineage emerged during the twentieth century. Further analysis of the M. kansasii genomes revealed almost 300 regions of difference contributing to genomic diversity, as well as fixed mutations that may explain the M. kansasii's increased virulence and drug resistance.

Clinical and epidemiological characteristics of M. kansasii pulmonary infections from Rio de Janeiro, Brazil, between 2006 and 2016. / Características clínicas e epidemiológicas de casos de infecção pulmonar por Mycobacterium kansasii no Rio de Janeiro, no período de 2006 a 2016.

Objective To evaluate clinical, tomographic, and microbiological characteristics of pulmonary disease caused by M. kansasii (MKPD) in patients treated at an outpatient unit from 2006-2016. Methods We studied thirty eight patients, and analyzed socio-demographic, clinical-radiological, laboratory, and therapeutic characteristics. Results The mean age was 64 years (SD = 10.6; IIQ = 57-72; median = 65.0), and 22 (57.9%) male patients. Pulmonary comorbidity was present in 89.5% of the patients. The most frequent comorbidity was bronchiectasis (78.9%). Previous treatment for pulmonary tuberculosis (PTB) was found in 65.9%. The most used therapeutic regimen was rifampicin, isoniazid and ethambutol (44.7%). Chest tomography (CT) showed bronchiectasis (94.1%), architectural distortion (76.5%), septum thickening (67.6%), and cavities (64.7%). Disease was bilateral in 85.2%. We observed 10.7% resistance to rifampicin, 67.9% resistance to ethambutol, and sensitivity to clarithromycin. Conclusion In patients with structural lung disease, it is important to search for NTM, the main differential diagnosis with PTB. Chest CT showed different patterns that overlapped with structural disease caused by PTB or other lung diseases. We observed resistance to ethambutol, a drug component of the recommended regimen.

Pulmonary Densitovolumetry Using Computed Tomography in Patients with Nontuberculous Mycobacteria: Correlation with Pulmonary Function Tests.

BACKGROUND: Since nontuberculous mycobacterial pulmonary disease (NTM-PD) is a condition with increasing morbidity, a more detailed knowledge of radiological aspects and pulmonary function plays a relevant role in the diagnosis and appropriate therapeutic management of these patients. OBJECTIVES: The purpose of this study was to evaluate changes in lung parenchyma through computed tomography (CT) densitometry and, secondarily, to analyze its correlation with pulmonary function testing (PFT) in patients with NTM-PD. METHODS: This is a cross-sectional study in which 31 patients with NTM-PD and 27 controls matched by sex, age, and body mass index underwent CT pulmonary densitovolumetry and pulmonary function tests including spirometry and body plethysmograph. RESULTS: Based on the total lung volume (TLV) and total lung mass (TLM) measurements, the cumulative mass ratios were calculated for 3% (M3), 15% (M15), 85% (M85), and 97% (M97) of the TLV. We also calculated the complement, which is represented by TLM (100%) minus the mass of 15% (C85) or 3% (C97) of the TLV. Patients with NTM-PD presented lower values of M3 and M15 than controls, with greater significant differences in the apical third and middle third measurements. Compared to controls, patients with NTM-PD showed higher values of C85 and C97, although significant differences were observed only in the basal third measurements. There were negative correlations of total lung capacity with M3 and M15 in the middle third and apical third measurements. There were positive correlations of residual volume and airway resistance with M3 at the apical third measurement. CONCLUSIONS: Patients with NTM-PD show reduced lung mass and increased lung mass in the apical and basal regions of the lungs, respectively. Furthermore, there is a relationship between lung mass measurements and pulmonary function parameters.

Whole genome sequence of Mycobacterium kansasii isolates of the genotype 1 from Brazilian patients with pulmonary disease demonstrates considerable heterogeneity.

Mycobacterium kansasii is an opportunistic pathogen and one of the most commonly encountered species in individuals with lung disease. We here report the complete genome sequence of 12 clinical isolates of M. kansasii from patients with pulmonary disease in Brazil.

Whole genome sequence of Mycobacterium kansasii isolates of the genotype 1 from Brazilian patients with pulmonary disease demonstrates considerable heterogeneity

Mycobacterium kansasii is an opportunistic pathogen and one of the most commonly encountered species in individuals with lung disease. We here report the complete genome sequence of 12 clinical isolates of M. kansasii from patients with pulmonary disease in Brazil.

Pulmonary infection caused by Mycobacterium kansasii: findings on computed tomography of the chest.

OBJECTIVE: To describe the main tomography findings in patients diagnosed with pulmonary infection caused by Mycobacterium kansasii. MATERIALS AND METHODS: Retrospective study of computed tomography scans of 19 patients with pulmonary infection by M. kansasii. RESULTS: Of the 19 patients evaluated, 10 (52.6%) were male and 9 (47.4%) were female. The mean age of the patients was 58 years (range, 33-76 years). Computed tomography findings were as follows: architectural distortion, in 17 patients (89.5%); reticular opacities and bronchiectasis, in 16 (84.2%); cavities, in 14 (73.7%); centrilobular nodules, in 13 (68.4%); small consolidations, in 10 (52.6%); atelectasis and large consolidations, in 9 (47.4%); subpleural blebs and emphysema, in 6 (31.6%); and adenopathy, in 1 (5.3%). CONCLUSION: There was a predominance of cavities, as well as of involvement of the small and large airways. The airway disease was characterized by bronchiectasis and bronchiolitis presenting as centrilobular nodules.

OBJETIVO: Descrever os achados tomográficos de pacientes com diagnóstico de infecção pulmonar pelo Mycobacterium kansasii. MATERIAIS E MÉTODOS: Estudo retrospectivo dos exames de tomografia computadorizada do tórax de 19 pacientes com infecção pulmonar pelo M. kansasii. RESULTADOS: Dos 19 pacientes avaliados, 10 (52,6%) eram do sexo masculino e 9 (47,4%) eram do sexo feminino. A média de idade do grupo foi 58 anos, com variação entre 33 e 76 anos. As alterações encontradas nos exames de tomografia computadorizada foram distorção arquitetural em 17 pacientes (89,5%), opacidades reticulares e bronquiectasias em 16 (84,2%), cavidades em 14 (73,7%), nódulos centrolobulares em 13 (68,4%), pequenas consolidações em 10 (52,6%), atelectasias e grandes consolidações em 9 (47,4%), bolhas subpleurais e enfisema em 6 (31,6%) e linfonodomegalias em 1 paciente (5,3%). CONCLUSÃO: Houve predomínio de cavidades e do padrão de acometimento de pequenas e grandes vias aéreas. A doença de vias aéreas foi caracterizada por bronquiectasias e bronquiolites que se manifestaram como nódulos centrolobulares.

Pulmonary infection caused by Mycobacterium kansasii: findings on computed tomography of the chest / Alterações na tomografia computadorizada do tórax em pacientes com infecção pulmonar por Mycobacterium kansasii

Abstract Objective: To describe the main tomography findings in patients diagnosed with pulmonary infection caused by Mycobacterium kansasii. Materials and Methods: Retrospective study of computed tomography scans of 19 patients with pulmonary infection by M. kansasii. Results: Of the 19 patients evaluated, 10 (52.6%) were male and 9 (47.4%) were female. The mean age of the patients was 58 years (range, 33-76 years). Computed tomography findings were as follows: architectural distortion, in 17 patients (89.5%); reticular opacities and bronchiectasis, in 16 (84.2%); cavities, in 14 (73.7%); centrilobular nodules, in 13 (68.4%); small consolidations, in 10 (52.6%); atelectasis and large consolidations, in 9 (47.4%); subpleural blebs and emphysema, in 6 (31.6%); and adenopathy, in 1 (5.3%). Conclusion: There was a predominance of cavities, as well as of involvement of the small and large airways. The airway disease was characterized by bronchiectasis and bronchiolitis presenting as centrilobular nodules.

Resumo Objetivo: Descrever os achados tomográficos de pacientes com diagnóstico de infecção pulmonar pelo Mycobacterium kansasii. Materiais e Métodos: Estudo retrospectivo dos exames de tomografia computadorizada do tórax de 19 pacientes com infecção pulmonar pelo M. kansasii. Resultados: Dos 19 pacientes avaliados, 10 (52,6%) eram do sexo masculino e 9 (47,4%) eram do sexo feminino. A média de idade do grupo foi 58 anos, com variação entre 33 e 76 anos. As alterações encontradas nos exames de tomografia computadorizada foram distorção arquitetural em 17 pacientes (89,5%), opacidades reticulares e bronquiectasias em 16 (84,2%), cavidades em 14 (73,7%), nódulos centrolobulares em 13 (68,4%), pequenas consolidações em 10 (52,6%), atelectasias e grandes consolidações em 9 (47,4%), bolhas subpleurais e enfisema em 6 (31,6%) e linfonodomegalias em 1 paciente (5,3%). Conclusão: Houve predomínio de cavidades e do padrão de acometimento de pequenas e grandes vias aéreas. A doença de vias aéreas foi caracterizada por bronquiectasias e bronquiolites que se manifestaram como nódulos centrolobulares.