Oral colonization by Entamoeba gingivalis and Trichomonas tenax: PCR-based study in health, gingivitis, and periodontitis

ABSTRACT The etiology of periodontitis needs further investigation, as is the place of gingivitis in its pathophysiology. A few studies linked the oral colonization by parasites ( Entamoeba gingivalis and Trichomonas tenax ) to the disease and its severity. The aim of this study was to estimate the prevalence of these oral parasites among healthy individuals, gingivitis and periodontitis patients in Jordan. The study was conducted by active enrolment of participants at Jordan University Hospital. The participants answered a questionnaire that included items related to possible risk factors for periodontal disease. Saliva and dental plaque samples were collected. The detection of oral parasites was done using conventional PCR and microscopic examination of wet mounts. The study population comprised a total of 237 individuals divided into three groups: healthy (n=94), gingivitis (n=53), and periodontitis (n=90). PCR results revealed that the overall prevalence of E. gingivalis was 71.7% compared to 12.2% for T. tenax . The periodontal disease group had higher prevalence of E. gingivalis and T. tenax compared to the healthy group (p<0.001). Increasing age was associated with higher prevalence of E. gingivalis (p=0.008) and T. tenax (p=0.019), in the entire study population. The number of cases of colonization detected by microscopic observation was lower for any of the oral parasites, as compared to diagnosis by PCR (40.7% vs. 71.7%, p<0.001 for E. gingivalis and 4.3% vs. 12.2%, p=0.007 for T. tenax ). The higher prevalence of oral parasites among patients with periodontal disease might point to their potential contribution in the disease and its severity. IMPORTANCE Periodontal disease has a high prevalence globally, with adverse effects on the quality of life for affected individuals. Despite the presence of several studies that investigated the role of oral parasites in periodontal disease, reliable conclusions about this matter remained elusive mainly due to utilization of microscopy in parasite detection. The current study provides new insights into the epidemiology and prevalence of the two oral parasites ( Entamoeba gingivalis and Trichomonas tenax ) in patients with various stages of periodontal disease in comparison to healthy adults. In addition, we describe the potential role of oral colonization by parasites as a risk factor for development of periodontal disease and its severity using a molecular-based approach.