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

Abstract

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.

A Murine Model of Mycobacterium kansasii Infection Reproducing Necrotic Lung Pathology Reveals Considerable Heterogeneity in Virulence of Clinical Isolates

“…These genes were conserved in all genomes of the Brazilian M. kansasii isolates, although some of the isolates exhibited heterogeneity in copy number (data not shown) and numerous SNPs in these genes. However, we observed identical SNPs in gene MKAN_07615, encoding for ESX secretion-associated protein EspG, in several geographically distant isolates, such as Pernambuco (strains 8835, 8837, and 8839) and Rio de Janeiro (strains 1580, 3657, and 4404) ( Machado et al, 2018 ). Besides the possible influence of presence, absence, or copy number of specific genes, the presence of SNPs can also interfere with virulence phenotype.…”

“…In the present study, we analyzed eleven strains of M. kansasii : the reference strain ATCC 12478 and ten clinical isolates obtained from Brazilian patients with pulmonary disease ( Machado et al, 2018 ). The diagnosis of pulmonary disease caused by NTM was performed generally following the Brazilian Ministry of Health guidelines and an official statement by the American Thoracic Society/Infectious Diseases Society of America ( Griffith et al, 2007 ), based on respiratory symptoms, image findings (e.g., nodular or cavitary opacities on X-rays or multifocal bronchiectasis and multiple small nodules), and positive culture for NTM in sputum or BAL fluid specimens, or a positive tissue culture following lung biopsy.…”

“…Considering the role of the virulence of M. tuberculosis isolates in the severity of experimental TB ( Ribeiro et al, 2014 ), we anticipated that the M. kansasii clinical isolates, exhibiting a higher degree of virulence compared to the reference strain 12478, might induce more severe lung pathology and disease in C57BL/6 mice. To verify this hypothesis, we first tested the virulence–associated features of M. kansasii strains from our collection of genetically well-characterized clinical isolates ( Machado et al, 2018 ), employing the model of macrophage infection in vitro , then selecting five strains with different degrees of predicted virulence (high, intermediate, and low) for studies in mice. Our results demonstrate that isolates exhibiting high or intermediate degrees of in vitro virulence, when intratracheally inoculated at a relatively low dose of 5.0 × 10 4 bacilli/mouse, could induce progressive lung disease, resulting in formation of large encapsulated caseous granulomas in 4–5 months post-infection; in contrast, the low-virulence strain was eliminated from the lungs in 40 days.…”

Comparative Genomic and Transcriptomic Analyses of Mycobacterium kansasii Subtypes Provide New Insights Into Their Pathogenicity and Taxonomy

“…These strains were collected from Radboud UMC Center of Infectious Diseases in the Netherlands. The isolates we collected were subtyped using the hsp65 gene as discussed before (Telenti et al, 1993) and subtype I-V were found, which are mostly isolated in many clinical cases (Taillard et al, 2003;Houben et al, 2012;Borówka et al, 2017;Machado et al, 2018) and no subtype VI and VII was detected.…”

“…In addition to systemic infection, M. kansasii also causes lung, cervical lymph node, and skin infections (Breathnach et al, 1995). Seven major subtypes have been described based on PCR-restriction fragment length polymorphism (RFLP) of hsp65 and internal transcribed spacer (ITS) (Taillard et al, 2003), while subtype I remains the most commonly isolated from clinical environments (Taillard et al, 2003;Borówka et al, 2017;Machado et al, 2018). A recent study proposed that the "subspecies" of M. kansasii should be considered as new species (Tagini et al, 2019).…”