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The conventional assumption is that antibiotic resistance comes at a substantial fitness cost, so in the absence of selective pressure, susceptible bacteria wil
by Fomite 10y ago
The conventional assumption is that antibiotic resistance comes at a substantial fitness cost, so in the absence of selective pressure, susceptible bacteria will out compete them.
This is a nice, clear, elegant theory.
It hasn't worked in practice. Community-acquired MRSA rates have risen, even as the selective pressure from antibiotics has declined, and the general observation is that the fitness cost is nowhere near as big as we assumed it would be.
- jakobegger 10y agoInteresting. I didn't know about Community-acquired MRSA. From some googling, it sounds like its spread is currently still limited to at-risk communities (athletes that share equipment, kids in daycare). There still has to be a substantial selective cost, otherwise the resistant strain would quickly spread through the whole population, right?
- Fomite 10y agoWe honestly don't have a great handle on it's prevalence. It would only spread quickly through the population of there was also a lot of selective pressure from antibiotics in the community. There's definitely some selective cost to multi-drug resistance, but it's proving to not be nearly as big a hurdle as conventional wisdom suggested it would be.