Sludge Watch ==> Some S. aureus escape immune recognition thus cause infections

[maureen.reilly at sympatico.ca]

Sludgewatch Admin:

Hmmm...just why are so many people near sludge sites getting S.aureus 
infections?
I wonder if the sewage treatment plant generates S.aureus mutations that 
then escape
detection by the human immune system.


........................................................................
Host defenses against Staphylococcus aureus infection require recognition of 
bacterial lipoproteins
04.sep.06
PNAS Online
Proceedings of the National Academy of Sciences (PNAS)


Juliane Bubeck Wardenburg et al
http://www.pnas.org/cgi/content/abstract/0603072103v1

Toll-like receptors and other immune-signaling pathways play important roles 
as sensors of bacterial pattern molecules, such as peptidoglycan, 
lipoprotein, or teichoic acid, triggering innate host immune responses that 
prevent infection. Immune recognition of multiple bacterial products has 
been viewed as a safeguard against stealth infections; however, this 
hypothesis has never been tested for Staphylococcus aureus, a frequent human 
pathogen.

By generating mutations that block the diacylglycerol modification of 
lipoprotein precursors, we show here that S. aureus variants lacking 
lipoproteins escape immune recognition and cause lethal infections with 
disseminated abscess formation, failing to elicit an adequate host response.

Thus, lipoproteins appear to play distinct, nonredundant roles in pathogen 
recognition and host innate defense mechanisms against S. aureus infections.