The quantitative measurement of antimicrobial resistance in Escherichia coli at the meta-population level (meta-population analysis).
OBJECTIVE
To define a method that describes antimicrobial resistance of meta-populations of bacteria in both a quantitative and biologically meaningful way.


RESULTS
Using spiral plating and colony counting technology we obtained, from animal faecal samples, the density of Escherichia coli that grow at different concentrations of antibiotic. A mathematical description of this dose-response curve fitted the data well. The parameters of this model have biological meaning and the model allowed subtle differences between meta-populations to be detected.


CONCLUSIONS
This method, termed MPA (meta-population analysis), is practical and provides a useful quantitative description of antimicrobial resistance in a bacterial meta-population.


CONCLUSIONS
This study shows that resistance can be defined quantitatively. The method may be used in many epidemiological and clinical studies of antimicrobial resistance in animals and humans.
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002417:Cattle; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development; D005243:Feces / Q000382:microbiology; D008826:Microbial Sensitivity Tests / Q000379:methods*; D015233:Models, Statistical; D017063:Outcome Assessment, Health Care; D013552:Swine
D000900:Anti-Bacterial Agents; D003470:Culture Media