Bacteriome Analysis of -JP2 Genotype-associated Grade C Periodontitis in Moroccan Adolescents

Background: Grade C (previously aggressive) periodontitis (GCP) in adolescents is prevalent in certain parts of Africa where it is associated with JP2 genotype, a highly virulent strain of . The aim of this study was to characterize the subgingival bacteriome in Moroccan subjects with GCP positive to JP2 genotype.

Methods: Subgingival plaque samples were collected from shallow and deep pockets of 8 subjects with GCP (17.2 ± 1.5 years) and from gingival sulci of 13 controls with no periodontitis (14.6 ± 1.1 years). Identification and genotyping of was performed using PCR analysis of the operon, while bacteriome profiling was done by 16S rRNA gene sequencing (V1-V3 region). Groups were compared in terms of microbial diversity, abundances, and dysbiosis.

Results: The shallow and deep pocket sites from GCP cases had a significantly altered microbial composition compared to controls. Species associated with health included and While known periodontal pathogens, including , , and , were significantly enriched in GCP, non-conventional taxa, including and were more abundant and showed stronger association with the disease. Less significant differences in abundances of individual taxa were observed between shallow and deep pockets. Overall dysbiosis measured in terms of Subgingival Microbial Dysbiosis Index (SMDI) differentiated between GCP and no-periodontitis with 95% accuracy.

Conclusions: The results suggest that several periodontal pathogens involved in the adult-type periodontitis also play a role in JP2 genotype-associated GCP. The potential role of non-conventional taxa in the pathogenesis of GCP warrants further investigation.