If there is anything I try to convey to anyone who will listen: never underestimate the intelligence of bacteria. A new case-in-point was published in the journal Infection and Immunity (Abstract only- Paywall) from researchers in Buffalo, New York to back up my claim. Former knowledge from two pathogens that cause strep throat, ear infections, and colds suggested they did not survive long outside the human body. However, a new study about Streptococcus pyogenes and Streptococcus pneumoniae suggests we were wrong and the bacteria were right.
Previous studies used unnatural conditions; i) cells grown in broth media and ii) free-living cells. These both are not encountered by bacteria which invade a human host. S. pyogenes and S. pneumoniae both infect humans as biofilms; very resistant, closely-connected bacterial communities. The present study used biofilm bacteria to test how long these bacteria could survive outside the body and still infect mice.
To drive the message home, researchers tested a day-care center for S. pyogenes and S. pneumoniae living on surfaces and capable of causing infection. Results indicate these bacteria were found at high levels and viable even after surfaces were cleaned before sampling.
Let me re-iterate: bacteria know survival. Don’t underestimate their ability to evade our most clever defenses and come out on top while we lay in bed recovering.
- Biofilm bacteria linger on toys, books, cribs (futurity.org)