The state of the nasopharyngeal microbiome in healthy people and in patients with chronic nasopharyngitis

Topicality: The chronic nasopharyngitis (CNP) morbidity rate tends to increase in childhood and adenoid removal is one of the most common of all surgeries in children. The state of the nasopharyngeal microbiome plays the significant role in the development of inflammatory processes of nasopharynx and adenoid hypertrophy and it is considered that the great progress can be made through its correction in conservative treatment and prevention of recurrence after surgery. Traditional cultural studies which reflect only a small proportion of bacteria present in the nasopharynx cannot describe the real state of microbiome. Therefore, the study of its quantitative and qualitative composit ion is essent ial for justified treatment. Aim: to examine the state of the nasopharyngeal microbiome in patients with CNP associated with EpsteinBarr virus and compare its characteristics with the severity of disease. Material and methods: 20 healthy persons and 32 patients diagnosed with CNP associated with EpsteinBarr virus have been included in the study. The qualitative composition of nasopharyngeal microflora and its quantitative characteristics have been studied by determining t itres of colony-forming units (CFU). The findings have been compared with the features of the clinical course of disease. Results: The healthy individuals of the control group have Lactobacillus spp. and Bifidobacterium spp., aerobic S. salivarius, which belong to commensal microorganisms, as the basis of the nasopharyngeal microbiome. There has been seen the preservation of the population level of commensal flora: lactobacilli, bifidobacteria, salivary streptococci and appearance of opportunistic flora (Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Escherichia coli) in small titres in the patients with mild CNP. During the moderate/severe course, there has been observed a sharp decline in the population level of commensal flora and an increase in the titer of opportunistic flora to the population level of commensals. In severe cases, the preservation of high titers of opportunistic flora, complete absence of commensal one and emergence of pathogenic microflora (Pneumococcus pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa and yeast-like fungi of the Candida type) can be seen. All patients have been observed the presence of microbiome disorders, regardless of its quantitative and qualitative changes, which are accompanied by hypertrophy of the pharyngeal tonsil. Conclusions: Dysfunction of the microbiome, i.e. changes in the quantitative and qualitative composition of microorganisms in patients with CNP, is important in the course of disease. Minor changes that are determined by a reduced level of commensal flora are associated with the mild disease course. If there is a significant reduction in the levels of commensals and emergence of opportunistic flora, the moderate/severe disease course can be observed. The complete absence of commensal flora, high titers of opportunistic pathogens and emergence of pathogenic flora including Candida albicans are characterized by a severe disease course.