Adhesion of bacteria to host cells is always the first and one of the most crucial steps in the development of infection. The purpose of this adhesion of infectious agents is first to colonize the host organism and then to trigger an infection. A thorough understanding of bacterial adhesion to host cells is therefore essential to find therapeutic alternatives that block this critical interaction at the earliest stage of infection.
A critical interaction with the human protein fibronectin
The study: Scientists from the University Hospital Frankfurt and the Goethe University are decoding the mechanism of bacterial adhesion by working on the human pathogenic bacterium Bartonella henselae. This pathogen causes “cat scratch disease”, a disease that can be transmitted from animals to humans. To do this, the team uses a combination of in vitro adhesion assays and high-throughput proteomics (or studying proteins).
A key mechanism revealed: Bacterial adhesion to host cells is attributed to the interaction of a class of adhesins (trimeric autotransport adhesins), including fibronectin, a protein commonly present in human tissues. Adhesins are components on the surface of bacteria that allow the pathogen to adhere to the biological structures of the host. Homologues of the adhesin identified here as critical are also present in many other human pathogenic bacteria, such as the multi-resistant Acinetobacter baumannii.
The hope of “anti-ligand” antibiotics
Identify the exact points of interaction between proteins: By identifying these key points and blocking the process of bacterial adhesion at these sites, the scientists manage to block the infection: this is a promising therapeutic alternative, in which a new class of antibiotics (known as “antiligands”) holds promise multidrug resistant bacteria.