Costs of fluoroquinolone resistance in clinical E. coli: a potential explanation for similarities in resistance between the UK and Canada

BBSRC : Rosie Clover : BB/M011208/1

The ability of some bacteria to counteract the effects of antibiotics (antibiotic resistance) has become an extensive global health issue. Understanding the effects of antibiotic resistance on bacterial growth in the absence of antibiotics is vital. Previous research has suggested that resistance reduces bacterial growth in the absence of antibiotics, leading to the widely accepted concept that suggest a reduction in antibiotic therapies will reduce the emergence and spread of resistant bacteria. However, the majority of this research has been conducted on laboratory organisms. To understand whether reducing antibiotic therapies is an effective strategy, these mechanisms need to be considered in clinical organisms.

To address the current gap in research, we will study the effects of resistance to a commonly-prescribed class of antibiotics (fluoroquinolones) in clinical Escherichia coli. Use of fluoroquinolones differs between Canada and the UK. Canada tends to use fluoroquinolone as a common treatment for urinary tract infections, whereas the UK preferentially opts for other antibiotic classes. Yet the rates of fluoroquinolone resistance are similar, making it unclear whether the fluoroquinolone prescribing influences the rate of resistance. In common laboratory organisms, fluoroquinolone resistance is associated with extensively reduced bacterial growth. However, differences in the effects of resistance on growth between laboratory organisms and clinical organisms may explain why resistance rates in clinical organisms are similar despite different rates of prescription. If fluoroquinolone resistance does not reduce the growth of clinical organisms in the absence of antibiotics, this could help to explain why rates of resistance in Canada and the UK are similar despite their different prescribing practises.