Do we have any leverage against drug-resistant organisms? Our post on the Wellcome Trust blog explores the importance of the “fitness cost of drug resistance”.
Two studies in 2013 gave notice that our normal expectation — that drug-resistant populations will revert to sensitivity when the selective environment is removed — doesn’t hold true for all pathogens.
In mouse and guinea pig models, oseltamivir-resistant H7N9 influenza viruses showed no detectable differences in replication or transmission from their sensitive counterparts. And one of our studies showed that 6 out of 11 fluoroquinolone-resistant Salmonella Typhi genotypes showed fitness benefits when compared to wild-type in an in vitro assay.
Hai et al, Nature Communications, 2013