Disseminated pneumonia caused by Mycobacterium fortuitum group
Background: Mycobacterium fortuitum group (MFG) species are generally associated with low virulence, however, reports of invasive MFG infections are emerging. Multiple ESX complexes, which are type VII secretion systems, are present in all Mycobacteria. Their composition plays a key role in virulence. Here, we evaluate the phylogenetics and ESX-complexes of UMCGMFG1: an MFG blood culture isolate from an immunocompetent patient with life-threatening pneumonia associated with late-onset achalasia, as well as bloodstream dissemination and lymphadenopathy.   Methods: Short-read sequencing was performed using Illumina. Phylogenetics were analysed by TYGS, and annotation by RAST with manual amendments. Hypothetical proteins were not shown in genetic maps.  Results: The whole genome-based phylogeny presented in figure 1 shows that UMCGMFG1 is most closely related to the bovine pathogen M. farcinogenes DSM 43637 at the subspecies level. However, the GC-content, genome size, and identity to housekeeping genes, presented in the table, indicate a closer genetic relationship to the human pathogen M. houstonense ATCC 49403.  Conclusion: This study reveals the distinct ESX-complexes, including novel EspA/EspE-family effectors, of an invasive MFG species that clusters with M. farcinogenes and M. houstonense. Pneumonia associated with late-onset achalasia due to MFG species is reported as a disease entity. Molecular evaluation of future MFG isolates from similar cases could help determine whether this M. houstonense pathovar is more often associated with this specific disease presentation.