Streptomyces sp. TR1341 was isolated from the sputum of a man with a history of lung and kidney tuberculosis, recurrent respiratory infections, and COPD. It produces secondary metabolites associated with cytotoxicity and immune response modulation. In this study, we complement our previous results by identifying the genetic features associated with the production of these secondary metabolites and other characteristics that could benefit the strain during its colonization of human tissues (virulence factors, modification of the host immune response, or the production of siderophores). We performed a comparative phylogenetic analysis to identify the genetic features that are shared by environmental isolates and human respiratory pathogens. The results showed a high genomic similarity of Streptomyces sp. TR1341 to the plant-associated Streptomyces sp. endophyte_N2, inferring a soil origin of the strain. Putative virulence genes, such as mammalian cell entry (mce) genes were not detected in the TR1341's genome. The presence of a type VII secretion system, distinct from the ones found in Mycobacterium species, suggests a different colonization strategy than the one used by other actinomycete lung pathogens. We identified a higher diversity of genes related to iron acquisition and demonstrated that the strain produces ferrioxamine B in vitro. These results indicate that TR1341 may have an advantage in colonizing environments that are low in iron, such as human tissue.

Faculty of Fisheries and Protection of Waters University of South Bohemia Zátiší 728 2 38925 Vodňany Czech Republic

Faculty of Science University of South Bohemia Branišovská 1645 31a 37005 České Budějovice Czech Republic

Institute of Immunology and Microbiology 1st Faculty of Medicine Charles University Studničkova 7 12800 Prague 2 Czech Republic

Institute of Soil Biology Biology Centre Academy of Sciences of The Czech Republic Na Sádkách 702 7 37005 České Budějovice Czech Republic

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