Administration of Clinical COVID-19 Mouthwashing Protocol and Potential Modulation of Pediatric Oral Bacterial Prevalence of Selenomonas noxia: A Pilot Study

Abstract

Dental office protocols to combat the SARS-CoV-2 (COVID-19) pandemic include mouth washing for an extended 60 s, thereby reducing detectable oral virus. However, it is unclear whether this protocol has any effects on the newly identified periodontal pathogen and obesity-related bacterium often found among pediatric patients, Selenomonas noxia. To determine if the mouthwash protocol has any measurable effect on S. noxia amongst pediatric patients, clinical pediatric saliva samples were obtained from pediatric patients during routine visits for clinical care and treatment. Using an approved protocol, two saliva samples were collected on the same visit before and after chlorhexidine mouthwash (Sample A, Sample B). The third sample (Sample C) was taken at the recall appointment—usually between two and eight weeks later. A total of n = 97 pre-mouthwash samples, and an equal number of matching post-mouthwash samples (n = 97) were collected, with a small number of matching recall samples (n = 36) that were subsequently collected and identified. The demographic composition of the study sample was analyzed using Chi square statistics. Sample DNA from the matching pre-, post-, and recall collections (Sample A, Sample B, and Sample C) was isolated and screened using qPCR and validated primers, which revealed that 11.1% (n = 4/36) from Sample A tested positive for S. noxia with 0% (n = 0/36) of Sample B testing positive and 13.9% (n = 5/36) of the recall (Sample C) testing positive. In addition, comparative analysis of the qPCR cycle threshold data revealed relatively lower expression (quantity) of S. noxia DNA among the recall samples, as determined by two-tailed t-tests (p=0.004). These data and results provide new evidence for the oral prevalence of S. noxia among pediatric patients, while also demonstrating that the COVID-19 protocol of mouth washing prior to clinical treatment for periods extending up to 60 s may be sufficient to reduce the levels of detectable S. noxia—at least temporarily. More research will be needed to determine whether these effects may be limited to the short- or may exhibit more lasting effects in the long-term.

Higher Prevalence of the Periodontal Pathogen Selenomonas noxia among Pediatric and Adult Patients May Be Associated with Overweight and Obesity

“…Many other studies have found significant differences between males and females with respect to the development and progression of periodontal disease and the prevalence of specific periodontal pathogens [ 36 , 37 , 38 ]. The lack of sex-specific associations with this organism is consistent with other recent studies that have included both pediatric and adult patient populations, strongly suggesting that the traditional risk factors of sex and age may not be the most important factors to determine which patients harbor Selenomonas [ 24 , 25 ].…”

“…The samples were then processed to isolate DNA, as previously described [ 24 , 25 , 26 ]. In brief, the TRizol reagent from Fisher Scientific (Fair Lawn, NJ, USA) was used to perform DNA extractions from each sample according to the manufacturer’s recommendations.…”

“…The chi-square statistic (X 2 ), degrees of freedom (d.f. ), and appropriate probability ( p ) values were calculated [ 24 , 25 , 26 ]. In addition, the odds ratio (OR) or odds of occurrence within a particular group, and the relative risk (RR) or risk of risk of occurrence in one group relative to another, were also calculated using a 95% confidence interval by utilizing the online GraphPad Prism 9 software (San Diego, CA, USA).…”

“…However, recent evidence has now suggested that a particular periodontal pathogen, Selenomonas noxia , may be capable of digesting cellulose and other normally non-digestible fibers that significantly increase calorie extraction from normal dietary intake compared with healthy-weight adults who do not harbor this pathogen [ 22 , 23 ]. Although Selenomonas has been identified in periodontal disease and obesity studies in adults, more recent studies from this institution have demonstrated that this organism may also be present in saliva from a significant percentage of pediatric patients [ 24 , 25 , 26 ]. These observations suggest that Selenomonas may be systemically present in pediatric patients and may influence the development and progression of obesity over time—although no comparative studies of Selenomonas among adult and pediatric overweight and obese patients has yet been conducted.…”

Screening for Selenomonas noxia in a Pediatric and Adolescent Patient Population Reveals Differential Oral Prevalence across Age Groups

“…However, recent studies from this group have revealed that some pediatric patients, with and without orthodontic brackets, also harbor this organism [14,15]. This may be of particular concern as this gram-negative anaerobe typically found in periodontitis may also colonize the gastrointestinal tract and has been strongly associated with overweight and obese adults [16,17].…”