CFS The undetectable infection: The symbiotic relationship.
I may as well get laughed off this forum, as every doctor I have spoken to has thrown me out of my office when I present them with the argument of pathogenic normal flora!
Normally we are colonized with numerous bacteria and viruses which are both good and bad. These live in a slurry on the surface of our mucous membranes, mouth nose, throat, vagina, urinary tract, colon etc. A symbiotic relationship develops and many of these organisms are able to attach onto cell receptors so they can permanently inhabit the mucous membranes. When they live on the mucous membranes in this manner the body is protected from any virulence traits of the organism, and the organism is protected from being attacked by the bodies immune system. And in this manner, the body and organism get something from this relationship.
When an organism is pathogenic it has acquired the ability to breech the epithelial layer of the mucous membrane and then has access to the underlying cells and blood stream. This is the point where the body's immune system comes into play and it launches an attack against the invaders. All of you who have been studying the immune system can tell me more about the chemistry of the immune system but basically there are pro inflammatory enzymes (cytokines) released (this is why there is inflammation) the bodies attacking force arrives at the site of inflammation and starts fighting the invaders, and then there is an anti-inflammatory enzyme released which then turns off the inflammation. Until the invaders are destroyed, this is a continuous process. So if you are one of the 25% of people that have an interleukin 10 deficiency, you would have continuous visible inflammation. Most people who have normal interleukin 10 have inflammation initially, and then it goes away but the battle still goes on. As a result of the battle you have this cocktail of inflammatory and anti inflammatory enzymes (cytokines), dead invaders, antibodies and expressed proteins and enzymes from the invaders circulating through your blood stream. Basically we are being continuously poisoned from the battle. I reckon this alone makes us really sick ...
A bacterial pathogen has one purpose, attack at the cellular level, create pus and thus create an environment that is good for them. Viridans streptococcus however works more like guerrilla warfare. It is happy with its symbiotic relationship but also likes to launch invasive attacks, and as they are non pyogenic (don't form pus) all as you have is an inflammation. Scientists know that viridans strep species can cause infection if it is allowed to enter the bloodstream (bacteremia) scientists haven't caught on yet that some strains of viridans streptococcus and enterococcus have found the ability to breach the epithelial layer and live at the cellular level.
(I believe this is why so much time has been spent looking for viruses because there is no pus, just inflammation!!)
If I was a researcher and wanted to look at any one bug, I would start with streptococcus sanguinis/parasanguinis and I will explain why next ......