Comment by anotherpaul
1 day ago
"The most unique finding in our study was that viridans streptococci seemed to colonize the lipid core and wall of an atheroma as a biofilm and that this biofilm was not recognized by cells of the innate immune system. "
This is a pretty cool finding. Biofilms are also beyond reach of antibacterials usually. And seing a commensal become a problem due to "location, location, location" is also cool.
Nice article. Cool leads
Streptococcus pyogenes (group A streptococci) are well known for being able to form this kind of biofilm [1] and stay hidden from the immune system.
Chronic strep throat (sometimes leading to guttate psoriasis) are thought to be due to this feature. The bacteria can form these biofilms in many places, including the tonsils. It's implicated in things like periodontitis. (Another streptococcus, S. mutans, causes cavities.)
They're very sneaky bacteria, due to what's called molecular mimicry. The bacterial surface has a protein called M protein, and some of this protein's epitopes (stretches of amino acids) are the same or similar to human proteins like myosin, similar enough that antibodies cause cross-reactivity with human tissue. This is why strep bacteria can cause rheumatic fever and some other diseases.
Strep has also been implicated in psoriasis; we have good evidence that the cross-reactivity is what kick-starts the disease and is in some way responsible for why it's chronic.
[1] https://www.ncbi.nlm.nih.gov/books/NBK587105/