The Protozoome of the Periodontal Sulcus: From Health to Disease

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

“…The copyright holder for this preprint this version posted July 18, 2020. ; https://doi.org/10.1101/2020.07.16.20155861 doi: medRxiv preprint 13 to improving the sensitivity of detection as oral parasites can be found in either one of these sites (50). Also, we relied on contemporaneous use of the two reference methods currently applied for oral parasite detection (34,43). In addition, we tried to improve the sensitivity of molecular detection in this study through using silica column-based DNA extraction method, which can help to remove PCR inhibitors and we adopted sensitive PCR protocols that were previously validated (34,51,52).…”

“…For T. tenax, the estimates were much lower and significant differences were found moving from 3.2% in the healthy group to 18.2% among individuals with periodontal disease. To assess reproducibility of these results, a limited number of studies were found (34,36,43,53,54). The comparisons were further complicated by the reliance of a majority of the previous studies on microscopic detection methods (examination of wet mounts or permanent stained smears) (35,(37)(38)(39)(40)(41).…”

“…In the oral microbiome, the role of the bacterial fraction in periodontitis has been studied extensively with accumulating evidence pointing to its contribution to the etiology of the disease (45). However, the minority fraction of protozoa was not studied to a similar level compared to its bacterial counterpart (32, 43, 46, 47). Thus, more studies are warranted to evaluate the potential role of the human oral “protozoome” in health and disease.…”

“…Second, some key elements regarding the etiology and pathophysiology of periodontal disease have not been disentangled yet, hence more research is needed to decipher these unresolved elements (5, 7, 23). Third, despite the uncertainties regarding the specific roles of different microorganisms in periodontal disease, the accumulating evidence points to conspicuous differences in the oral microbiome between health and disease and the role of oral parasites in both states is yet to be clearly delineated (43). Fourth, a few studies on the epidemiology of oral parasites originated from the Middle East and North Africa (MENA) region, including studies from Egypt, Iran, Iraq and Saudi Arabia, without relying on molecular detection for estimating the burden of these oral parasites in the countries of the region (35, 37-39, 48, 49).…”

“…Several studies aimed to investigate parasitic oral colonization among healthy individuals and those with periodontal disease with remarkably variable results (34)(35)(36)(37)(38)(39)(40)(41). Such variability can be related to adoption of different approaches for parasite detection, the existence of previously unknown genetic variants of oral parasites, in addition to limitations of small sample sizes, and possible bias in selection of study subjects among others as reviewed recently (42,43).…”