Features of the microbial landscape of dental plaque in children and adolescents with Down syndrome

Background. The high prevalence of dental caries in children and adolescents with Down syndrome is associated with a number of factors (concomitant somatic disea-ses, special dental and psychoemotional states, etc.). Poor oral hygiene in children and adolescents with Down syndrome contributes to oral microbiocenosis disorders.Purpose – to identify the etiological structure and environmental attributes of dental plaque microflora in children and adolescents with Down syndrome.Materials and Methods. 76 children and adolescents aged 8 months to 18 years were examined, who were divided into the following groups: the main group – 21 children with Down syndrome and the control group – 55 conditionally healthy children with no history of hereditary diseases. The microbiological study materials were neck area dental plaque swabs. The pure culture was identified according to cultural, morphological, and biochemical characteristics for microbiological diagnosis. Environmental attributes of the dental plaque microbiome were tested according to the following parameters: continuous index and Berger–Parker index. Results. 141 strains of microorganisms were isolated and identified in children of the control group and 49 strains in children with Down syndrome. The vast majority of microorganisms isolated in children of the main group were C.albicans, S.pyogenes, and α-hemolytic streptococci. The proportion of nonpathogenic Neisseria spp. was significantly lower than in the control group, and they were absent in children with a permanent dentition. As opposed to the control group, other bacteria were also found, namely E.aerogenes, P.aeruginosa, K.pneumoniae, and Bacillus spp. In children of both groups, microorganisms were found in two- and three-component combinations, which included bacteria and fungi in 40% of children of the control group and in 61.9% of children of the main group.Conclusions. In children and adolescents with Down syndrome, microorganisms of the neck area dental plaque microbiome were redistributed towards the replace-ment of microorganisms of the normal microflora with allochthonous opportunistic pathogenic bacteria S.pyogenes, E.aerogenes, P.aeruginosa, K.pneumoniae, and C.albicans. The biggest C.albicans colonization was found in children with a perma-nent and mixed dentition, and beta-hemolytic streptococci were predominant in children with a temporary dentition.