Antibiotic Treatment of Commercial Broiler Flocks: Incidence and Mechanisms of Fluoroquinolone Resistance in Campylobacter

The aims of this study were to isolate campylobacter from commercial broiler flocks and their environment before, during and after treatment with a fluoroquinolone that was administered to treat a clinically relevant infection.<P>
The overall objectives were to determine whether (i) fluoroquinolones select resistant campylobacter from poultry, (ii) these bacteria spread throughout the flock, due to the selection of one, or a few resistant clones or multiple clones, (iii) the types of fluoroquinolone-resistant campylobacter that emerge in poultry were similar to, or the same as, those isolated from infected humans, (iv) the mechanisms of resistance in the campylobacter isolated from commercial poultry flocks were the same as those already determined for human isolates, and (v) the mechanisms of resistance give rise to bacteria resistant to clinically achievable concentrations of fluoroquinolone in man, i.e. full clinical resistance.
Project Objectives: <OL> <LI> To identify broiler flocks colonised with Campylobacter spp. and which will be treated with fluoroquinolone antibiotics.
<LI>To set up systems with the collaborating poultry companies to enable them to (i) alert the research groups when flocks will be treated with antibiotics, and (ii) to keep an accurate record of antibiotic use.
<LI>To agree and use sensitive isolation and enumeration techniques for Campylobacter spp. and which will enable the detection of antibiotic-resistant organisms.
<LI> To collect faecal and environmental samples from poultry flocks before, during and after antibiotic treatment.
<LI> To analyse collected organisms for resistance to fluoroquinolones and to determine the mechanisms of resistance.
<LI>Using DHPLC to analyse isolates of Campylobacter spp for resistance to fluoroquinolones and to determine the mechanisms of resistance.
<LI> To use the knowledge gained from 5 to develop molecular screening methods for specific resistance genotypes.
<LI>To type the campylobacter isolated and determine the epidemiology of antibiotic-resistant isolates.
<LI>To use the above information to inform DEFRA and the food industry of appropriate treatment and withdrawal regimens which will best protect the public health.