Orth Lab

Research

Bacterial adhesion

The initial binding of bacteria to host cells is crucial for the delivery of virulence factors and thus a key determinant for a pathogen’s success. We have recently discovered a multivalent adhesion molecule (MAM7) that enables a wide range of Gram-negative pathogens to establish high affinity binding to host cells during the early stages of infection. MAM7 binds to the host by engaging in both protein-protein (with fibronectin) and protein-lipid (with phosphatidic acid) interactions with the host cell membrane. MAM7 expression on the outer membrane of a Gram-negative pathogen is necessary for virulence in a nematode infection model and for efficient killing of cultured mammalian host cells. Expression of MAM7 on a non-pathogenic strain resulted in a tool that could be used to impede infection by Gram-negative bacterial pathogens. Targeting or exploiting MAM7 might provide a valuable tool for combating Gram-negative bacterial infections and we are currently exploring applications of MAM7 as an antimicrobial agent.

Cultured human cells infected with Yersinia pseudotuberculosis without (left) or with (right) protection of cells with non-pathogenic bacteria expressing MAM7. Pre-treatment with the competing strain inhibits cell killing by Yersinia.

 

Publications on bacterial adhesion