Potential selection and maintenance of manure-originated multi-drug resistant plasmids at sub-clinical concentrations for tetracycline family antibiotics.

The goal of this study was to (a) determine the minimum selection concentrations of tetracycline family antibiotics necessary to maintain plasmids carrying tetracycline-resistant genes and (b) correlate these results to environmental hotspot concentrations reported in previous studies. This study used two plasmids (pT295A and pT413A) originating from dairy manure in a surrogate host CV601. The minimum selection concentrations of antibiotics tested in nutrient-rich medium were determined as follows: 0.