Pyrosequencing Revealed Oropharyngeal Microbial risk indicators of Secondary Bacterial lung Infections in Patients with Avian-origin H7N9 Virus Infection. Pyrosequencing Revealed Oropharyngeal Microbial risk indicators of Secondary Bacterial lung Infections in Patients with Avian-origin H7N9 Virus Infection

Secondary bacterial lung infection (SBLI) was one of serious complications in patients with H7N9 virus infection, which increased disease severity. Oropharyngeal (OP) microbiome acts as a gatekeeper and plays important roles in resistance to colonization of respiratory pathogens. Herein, we are the first time to investigate OP microbiome of H7N9 patients with or without secondary bacterial pneumonia based on 16S ribosomal RNA (rRNA) gene sequencing. After strict inclusion and exclusion criteria, 81 OP swap microbiome from 51 H7N9 patients (21with SBLI and 30 without SBLI) and from 30 matched healthy controls (HC) were used for subsequent composition, diversity, and richness of microbial communities comparisons analysis between the three groups. OP Microbiome was significantly distinguished all H7N9 patients from healthy subjects by principal coordinates analysis. And microbiome diversity of OP in patients with SBLI was significantly increased shown by Shannon, impson, invsimpson, OBS, ICE and Chao 1 indexes. Lineardiscriminant analysis (LDA) effect size (LEfSe) reveals significant microbial dysbiosis of OP microbiome in patients, which mainly embodied in overwhelming abundance of the genera of Leptotrichia, Oribacterium, Streptococcus, Atopobium, Eubacterium, Solobacterium and Rothia in patients with SBLI; Filifactor, Megasphaera and Leptotrichia in patients without SBLI when compared to HC. Strikingly, Haemophilus and Bacteroides were found to be enriched in HC OP microbiota. These findings firstly identify OP microbiota dysbiosis in H7N9 patients, and may providing novel and non-invasive potential diagnostic biomarkers for early microbiota-targeted prophylaxis therapies for SBLI prevention.