Molecular Identification of Entamoeba gingivalis and Its Association with Periodontitis in Diabetic Patients: A PCR-Based Study Targeting the ITS2 Region

Entamoeba gingivalis is an anaerobic protozoan increasingly associated with periodontitis, particularly in individuals with systemic conditions such as diabetes mellitus. This cross-sectional study investigated the prevalence of E. gingivalis in 160 Thai patients with periodontitis and analyzed associated risk factors. Microscopy detected the parasite in 15.0% of patients, PCR in 25.6%, and sequencing confirmed the infection in 22.5%, all of which were Subtype 1. Infection was significantly more common among diabetic patients (41.3%) than non-diabetics (3.8%) (P<0.001). Multivariate analysis identified type 2 diabetes (adjusted OR = 20.77; 95% CI: 5.39–80.09), alcohol use (adjusted OR = 3.72; 95% CI: 1.01–13.68), and other underlying diseases (adjusted OR = 1.49; 95% CI: 1.07–2.06) as independent risk factors. PCR demonstrated superior diagnostic performance compared to microscopy. These findings support a potential pathogenic role of E. gingivalis in periodontitis, especially among patients with type 2 diabetes or behavioral risk factors.