Coculturing with Streptococcus anginosus alters Staphylococcus aureus transcriptome when exposed to tonsillar cells

Better understanding of S. aureus throat colonization in the presence of other competing/coexisting microbes may provide insight into S. aureus adaptation to the human throat and recurrence of infection. In this work, we explore the responses triggered by the encounter between two common throat bacteria, S. aureus and S. anginosus, in the presence of human tonsillar epithelial cells. We performed an in vitro coculture experiment followed by RNA sequencing. A total of 332 and 279 significant DEGs with p-value < 0.05 and Log2 fold change > |2| were identified after 1 h and 3 h of post-infection, respectively. Our study identified several transcripts in S. aureus that might be important when facing a potential competitor during throat colonization. These transcripts may be useful in the development of treatments against S. aureus throat colonization and could be further investigated to better understand their roles in the immune response. The study involved co-culturing of S. aureus with S. anginosus, and both being exposed with/without HTEpiC at 1 h and 3 h of interaction with the host. We performed RNA sequencing to identify interaction-induced transcriptional alterations, visualization of differentially expressed genes (DEGs), and gene enrichment analysis to identify important gene ontology (GO) terms involved by those DEGs.