Composition of bacterial microbiome in sputum of patients with localized forms of pulmonary tuberculosis

Abstract

Recent studies have shown that the respiratory bacterial microbiome has an impact on the development of pulmonary tuberculosis. Changes in the composition of the microbiome have been associated with the pathogenesis of Mycobacterium tuberculosis infection, response to therapy, and clinical outcomes of the disease. To date, the composition of the respiratory microbiome has not been studied in patients with localized forms of pulmonary tuberculosis. Methods. In the present study, the taxonomic composition of the sputum microbiome of 14 patients with localized forms of pulmonary tuberculosis (tuberculomas) and 14 healthy donors in the comparison group was analyzed by sequencing (NGS) of the V3 – V4 region of the bacterial gene encoding 16S rRNA. Results. The sputum microbiomes of the patients and the control group did not have significant differences in the species richness index (Shannon). However, the patients showed a decrease in the uniformity index, another parameter of alpha diversity. Bacterial community structures (beta diversity) did not differ significantly between patients with localized forms of tuberculosis and healthy subjects. In patients with limited forms of tuberculosis, contrary to the decrease in the content of representatives of the phyla Fusobacteria, TM7, Tenericutes, Spirochaetes, and SR1, and of the genera Dialister, Mycoplasma, and Filifactor in the sputum, no clear dominance of any bacterial taxon was observed. Conclusion. Certain alpha and beta diversity parameters that characterize the sputum microbiome of patients with localized forms of pulmonary tuberculosis need to be confirmed in independent large-scale studies to further understand the role of the sputum microbiota in the development of localized forms of pulmonary tuberculosis. Determination of Prevotella titers in the sputum of these patients holds promise for the diagnosis of localized forms of pulmonary tuberculosis and the search for their genomic markers.