Ask a Microbiologist: A series on the creepy-crawlies of BJJ.

So back in September, I conducted a really fun interview with a microbiologist friend of mine. Since then, there have been a few additional questions, not to mention some questionable advice popping up in forums across the internet. So...Brea has been kind enough to lend her services to any questions people want to send here. If you have any, post a comment here, or shoot it over here.

Here's a quick repeat of her background (in her words):

• PhD in 2010 from Emory University in Microbiology and Molecular Genetics 
• Dissertation on antimicrobial resistance in S. aureus (she used a MRSA strain)  
• Postdoc at the USDA Agricultural Research Service in Athens, GA a part of NARMS (National Antimicrobial Resistance Monitoring Service). They monitor, characterize, and describe antimicrobial resistance in the food chain. They also are involved in foodborne illness outbreak responses.

So first let me just say that my bias is definitely in thinking of bacteria in terms of communities. I did a postbac at the NIH in a lab that studied how bacteria build communities (aka biofilms) on your body. We used dental plaque as a model. What you have to understand is that you have basically three kinds of bacteria, and this can go for fungi as well, living on you: ones that are beneficial, ones that cause you to get sick, and ones that CAN cause you to get sick given the chance. There’s this beautiful and important balance that occurs when one is healthy. When one is sick and the proportion of the latter two categories overwhelm the beneficial bacteria, then you have problems. The other part of that is that many pathogenic bacteria are really only “visiting”. They live on you, but not all the time. If you have MRSA on you now, it doesn’t mean you will be colonized with it if you were checked in a month or so. We call that being transiently colonized, and about 30% of people are at any given time transiently colonized with MRSA. Doesn’t mean they get sick. So, from what I can tell, much of this antimicrobial craze is aimed at getting rid of the “visiting” bacteria before they try to make your body a more permanent residence.