Dynamics of microecological indicators of the respiratory tract in patients with cystic fibrosis using targeted therapy

Cystic fibrosis (CF) is a chronic genetic disease in which life expectancy and prognosis are largely determined by the severity of the respiratory infection caused by the microbiological status. A breakthrough in the treatment of this disease is the introduction of targeted therapy, which opens up new prospects for increasing life expectancy and quality of life. The purpose of this study is to evaluate the dynamics of the species diversity of the microbiota, as well as the nature of the intermicrobial interactions of species colonizing the respiratory tract of patients with CF in the Samara region, against the background of the use of targeted therapy drugs. Depending on the type of the treatment received, the patients were divided into three groups: group 1 – elexacaftor/ tezacaftor/ ivacaftor + ivacaftor therapy, group 2 – ivacaftor+lumacaftor, and group 3, patients who were transferred from ivacaftor+lumacaftor therapy to elexacaftor/ tezacaftor/ ivacaftor +ivacaftor therapy due to the low clinical efficacy of the drug treatment. During the three-year follow-up period, representatives of 154 species of microorganisms were isolated from 23 patients with CF. The species diversity of representatives of the permanent, additional and accidental microbiota of the respiratory tract was assessed before the start of therapy and at different times using the coefficient of constancy C. To assess the degree of conjugacy of individual species, and, as a result, the nature of their symbiotic interactions, the Jaccard similarity coefficient was applied. In order to further assess the degree of biological diversity and microecology of the respiratory tract of patients with CF, calculations of the Shannon, Simpson and Richness indices were performed. It was found that the microbiota of the respiratory tract of patients with CF undergoes significant changes while receiving targeted therapy. There is a decrease in the prevalence of key pathogens due to an increase in representatives of the normal microbiota, as well as a change in the nature of inter-microbial interactions.

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