Bacterial Protein Signatures Identified inPorphyromonas gingivalisContaining-Autophagic Vacuoles Reveal Co-Evolution Between Oral Red/Orange Complex Bacteria and Gut Bacteria

Abstract

Oral bacterial species have evolved in humans to enable the colonization of a diversity of commensals and opportunistic pathogens likePorphyromonas gingivalis. Due to the communalistic survival mechanism shared amongst oral bacteria and gut bacteria, these bacteria have likely evolved together to establish in the human oral cavity and transfer genetic information. Our liquid-chromatography with tandem-mass-spectrometry (LC-MS-MS) analysis has revealed protein signatures, Elongation Factor Tu, RagB/SusD nutrient uptake outer membrane protein and DnaK, specifically fromP. gingivalis-containing autophagic vacuoles isolated from the infected primary gingival epithelial cells. Interestingly, our Mass-Spectrometry analysis reported similar proteins from closely related oral bacteria,Tannerella forsythiaandPrevotella intermedia. In our phylogenetic study of these key protein signatures, we have established that pathogenic oral bacteria share extensive relatedness to each other and gut resident bacteria. We have shown that virulence factors, Elongation Factor Tu and DnaK, there are several structural similarities and conservation with proteins from pathogenic oral bacteria. We have also shown that the RagB/SusD nutrient uptake These findings may highlight the shared virulence mechanisms not only amongst oral bacterial pathogens but gut bacteria and their evolution in the human host.