expression in saliva of patients with COVID-19 and its association with and .

A relationship between oral microbiota and susceptibility to SARS-CoV-2 infection has been extensively studied. However, the relationship between oral commensal flora and expression of angiotensin-converting enzyme 2 ( ) remains to be established. In this observational study, we collected saliva from patients with COVID-19 and evaluated the relationship between expression and as well as with selected gram-negative bacteria ( , , and ). We investigated how this may be directly or indirectly involved in oral dysbiosis in patients with COVID-19. We included 23 hospitalized patients admitted to Universitas Indonesia Hospital with PCR-confirmed COVID-19, with six healthy participants serving as controls. Saliva and tongue surface swabs were collected from patients with diabetes (DG) and without diabetes (NDG) and subject controls. Using quantitative PCR (qPCR) we assessed the mRNA expression of , the abundance of , and the transcription levels of its biofilm-associated genes, agglutinin-like protein 3 ( ), hyphal wall protein 1 ( ), and yeast-form wall protein 1 ( ). We also counted the relative proportion of the three selected gram-negative oral bacteria in saliva. All analyses were performed to determine the relationship between expression and and gram-negative bacteria. mRNA expression was significantly higher in tongue swab samples than in saliva. However, no significant difference was observed between the patient groups. Conversely, DG patients had a significantly higher abundance of in saliva compared to NDG patients and control group patients. The correlation and sensitivity/specificity relationship between expression and or the selected oral bacteria were also observed. The data show that expression can be detected in saliva of patients with COVID-19 and its association with and gram-negative oral bacteria might contribute toward developing an oral dysbiosis based predictor for prognosis of COVID-19 severity.