Bacterial Protein Signatures Identified in Porphyromonas gingivalis Containing-Autophagic Vacuoles Reveal Evolutionary History Between Oral Red/Orange Complex Bacteria and Gut Resident Bacteria.

Oral bacterial species have evolved in humans to enable the colonization of a diversity of commensals and opportunistic pathogens like Porphyromonas 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 from P. 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 forsythia and Prevotella 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.