Characteristics of the microbiota in patients with various clinical phenotypes of occupational COPD and chronic bronchitis

Objective. To study the characteristics of microbial landscape in patients with chronic obstructive pulmonary disease and chronic simple bronchitis of occupational etiology from mineral dust exposure (COPD OE) with different clinical phenotypes. Materials and Methods. Patients were divided into 3 groups. Group-1 – 10 patients with COPD OE, clinical phenotype “B” (GOLD II); Group-2 – 19 patients with COPD OE, clinical phenotype “E” (GOLD III-IV); Group-3 – 11 patients with chronic simple bronchitis (CSBPE). Clinical samples were inoculated on solid nutrient media; the culture was incubated under aerobic and microaerophilic conditions. The identification of grown cultures was carried out using the MALDI-ToF mass spectrometry. Antimicrobial susceptibility was determined by disk diffusion method. Results. The common characteristics of the microbiota in COPD patients with both phenotypes were: the predominance of the Firmicutes type, equal bacterial load (p = 0.48), the absence of protective commensals and microorganisms typical for COPD patients (Moraxella catarrhalis). Streptococcus pneumoniae and Hemophilus influenzae were found in only one patient (phenotype “E”). The COPD OE phenotype “E” was qualitatively different from the phenotype “B” due to the predominance of Pseudomonadota (p = 0.0005), potentially pathogenic microorganisms over non-pathogenic microorganisms (54% versus 19%, p = 0.0005), lesser quantity of Neisseriales, more antibiotic-resistant microorganisms and more Candida spp. Conclusions. The study results may indicate significant heterogeneity of the microbiota in patients with occupational COPD due to exposure to mineral dust. The common features of all phenotypes were the tendency to growth of opportunistic microbiota, presence of antibiotic-resistant isolates. Patients with frequent exacerbations had T2 endotype of inflammation, they showed more pronounced simplification of microbiota, growth of opportunistic microbiota resistant to antibiotics. Disturbances in the microbiota in patients with CPB PE indicate the involvement of microorganisms in the processes of inflammation and remodeling of airways at an early stage of the disease, which requires further research. The obtained results should be taken into account when conducting empirical antibacterial therapy of exacerbations in these patients, as well as the inclusion of vaccine prophylaxis against pneumococcus in the rehabilitation program of COPD PE and CPB PE patients