Periodontal pathogens and antibiotic resistance genes in individuals with chronic generalized periodontitis

Abstract

Relevance. Considering the role of personalized medicine in dental practice, the accumulation of knowledge about the genetic determinants of bacterial resistance and the use of antibacterial drugs, the learning of periodontal microbiota, sensitivity to antimicrobial drugs, the identification of key periodontal pathogens will allow predicting the development mechanisms of inflammatory periodontal diseases and monitoring and prescribing effective antibacterial therapy.Aim. The study aimed to determine the prevalence of pathogens and the occurrence of antibiotic resistance genes in individuals with chronic generalized periodontitis (CGP).Materials and methods. Clinical and laboratory examinations studied 163 subjects aged 18 to 45 years, of which there were 100 patients with inflammatory periodontal diseases and 63 subjects with intact periodontium. The study obtained periodontal pocket and gingival crevice swabs. The real-time PCR isolated marker bacteria and resistance genes to glycopeptide and β-lactam antibiotics.Results. The patients with chronic periodontitis demonstrated a periodontal pathogen detection rate of 96.4 %. Among the isolated periodontal pathogens, bacteria of the red complex were the most common: T. forsythia (81%; p < 0.001), T. denticola (63%; p = 0.054) and P. gingivalis (69%; p < 0.001). In healthy individuals with intact periodontium, P. gingivalis (12.7%), T. denticola (47.62%), and T. forsythia (36.51%) prevailed in the studied material, i.e., gingival fluid. The mean ratio of bone loss in relation to the root length (the Fuchs Index) was 0.83 ± 0.03 in patients with mild CGP and 0.71 ± 0.05 with moderate CGP. The β-lactam antibiotic resistance genes appeared to occur frequently (%). So, TEM and SHV genes were in 72% and 26%. The control group demonstrated the TEM gene in 41.27% (p < 0.001) and the SHV gene in 4.76% (p < 0.001).The group with CGP appeared to have resistance genetic markers: MecA to cephalosporins (15%) and OXA-51 to carbapenems (9%). The control group detected MecA (6.35%; p = 0.0948), while OXA-51 markers were absent (p = 0.014). Both groups did not show resistance genes to other antibiotic groups (AB).Conclusion. The "red complex" microorganisms T. forsythia, T. denticola and P. gingivalis, which were the most frequent during the progression of bone destruction, appeared to play the leading role in the onset and progression of inflammatory periodontal diseases.The oral microbiome can serve as a reservoir for the transfer of resistance genes: the study results indicate a high incidence rate (%) of β-lactam antibiotic resistance genes in the group of patients with chronic periodontitis. The group with chronic periodontitis revealed TEM and SHV genes in 72% and 26%, respectively. The group with intact periodontium also demonstrated a high occurrence rate of the TEM gene in 58.3 % of cases.