State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
Sichuan Center for Disease Control and Prevention, Chengdu, 610041, China.
BMC Microbiol. 2021 Oct 11;21(1):277. doi: 10.1186/s12866-021-02336-6.
Fusobacterium nucleatum (F. n) is an important opportunistic pathogen causing oral and gastrointestinal disease. Faecalibacterium prausnitzii (F. p) is a next-generation probiotic and could serve as a biomarker of gut eubiosis/dysbiosis to some extent. Alterations in the human oral and gut microbiomes are associated with viral respiratory infection. The aim of this study was to characterise the oral and fecal bacterial biomarker (i.e., F. n and F. p) in COVID-19 patients by qPCR and investigate the pharyngeal microbiome of COVID-19 patients through metagenomic next-generation sequencing (mNGS).
Pharyngeal F. n was significantly increased in COVID-19 patients, and it was higher in male than female patients. Increased abundance of pharyngeal F. n was associated with a higher risk of a positive SARS-CoV-2 test (adjusted OR = 1.32, 95% CI = 1.06 ~ 1.65, P < 0.05). A classifier to distinguish COVID-19 patients from the healthy controls based on the pharyngeal F. n was constructed and achieved an area under the curve (AUC) of 0.843 (95% CI = 0.688 ~ 0.940, P < 0.001). However, the level of fecal F. n and fecal F. p remained unaltered between groups. Besides, mNGS showed that the pharyngeal swabs of COVID-19 patients were dominated by opportunistic pathogens.
Pharyngeal but not fecal F. n was significantly increased in COVID-19 patients, clinicians should pay careful attention to potential coinfection. Pharyngeal F. n may serve as a promising candidate indicator for COVID-19.
具核梭杆菌（F. n）是一种重要的机会性病原体，可引起口腔和胃肠道疾病。普拉梭菌（F. p）是一种新一代益生菌，在某种程度上可以作为肠道菌群正常/失调的生物标志物。人类口腔和肠道微生物组的改变与病毒呼吸道感染有关。本研究旨在通过 qPCR 对 COVID-19 患者的口腔和粪便细菌生物标志物（即 F. n 和 F. p）进行特征分析，并通过宏基因组下一代测序（mNGS）研究 COVID-19 患者的咽微生物组。
COVID-19 患者咽部分离的 F. n 显著增加，且男性患者高于女性患者。咽部分离的 F. n 丰度增加与 SARS-CoV-2 检测阳性的风险增加相关（调整后的 OR=1.32，95%CI=1.061.65，P<0.05）。基于咽 F. n 构建的区分 COVID-19 患者和健康对照者的分类器，曲线下面积（AUC）为 0.843（95%CI=0.6880.940，P<0.001）。然而，两组间粪便 F. n 和粪便 F. p 水平无变化。此外，mNGS 显示 COVID-19 患者咽拭子中以机会性病原体为主。
COVID-19 患者咽部分离的 F. n 显著增加，而粪便 F. n 无明显变化，临床医生应密切注意潜在的合并感染。咽 F. n 可能成为 COVID-19 的一个有前景的候选指标。
