Genetic Diversity and Local Prevalence of Porphyromonas gingivalis and Prevotella intermedia Among Periodontal Patients in Diwaniyah, Iraq

Abstract

This study aimed to investigate the prevalence of Porphyromonas gingivalis and Prevotella intermedia in gingivitis and periodontitis patients in Diwaniyah, and to analyze their virulence genes (fimA and adpC) using real-time PCR and sequencing. A total of 120 clinical isolates were obtained from patients aged 16–65 years with suspected gingivitis or periodontitis. Samples were analyzed by quantitative real-time PCR for detection of P. gingivalis and P. intermedia, followed by sequencing of fimA and adpC genes for phylogenetic analysis. Statistical tests (Pearson correlation and ANOVA) were used to evaluate associations between bacterial loads, clinical parameters, and demographic factors. P. intermedia was detected in 78.33% of patients, while P. gingivalis was present in 37.5%. Sequencing revealed significant genetic diversity among isolates, with multiple genotypes identified for both species. Phylogenetic analysis indicated local clustering of some strains, while others formed independent evolutionary lineages, suggesting possible new variants. The high prevalence of P. intermedia compared to P. gingivalis highlights its prominent role in the studied population. Genetic heterogeneity of virulence genes suggests ongoing bacterial adaptation, which may contribute to disease severity. Real-time PCR and molecular typing provide reliable tools for early detection and epidemiological tracking of periodontal pathogens. Download Full Text