Culture-based study on the development of antibiotic resistance in a biological wastewater system treating stepwise increasing doses of streptomycin.

The effects of streptomycin (STM) on the development of antibiotic resistance in an aerobic-biofilm reactor was explored by stepwise increases in STM doses (0-50 mg L), over a period of 618 days. Totally 191 bacterial isolates affiliated with 90 different species were harvested from the reactor exposed to six STM exposures. Gammaproteobacteria (20-31.