Daphnia as a refuge for an antibiotic resistance gene in an experimental freshwater community

Mechanisms that enable the maintenance of antibiotic resistance genes in the environment are still greatly unknown.
Here we show that the tetracycline resistance gene tet(A) is largely removed from the pelagic aquatic
bacterial community through filter feeding by Daphnia obtusa while it becomes detectable within the
microbiome of the daphniids themselves, where it was not present prior to the experiment. We moreover
show that a multitude of Daphnia-associated bacterial taxa are potential carriers of tet(A) and postulated that
the biofilm-like structures,where bacteria growin,may enable horizontal transfer of such genes. This experiment
highlights the need to take ecological interactions and a broad range of niches into consideration when studying
and discussing the fate of antibiotic resistance genes in nature.