Data from: Minor environmental concentrations of antibiotics can modify bacterial virulence in co-infection with a non-targeted parasite

Leakage of medical residues into the environment can significantly impact
natural communities. For example, antibiotic contamination from
agriculture and aquaculture can directly influence targeted pathogens, but
also other non-targeted taxa of commensals and parasites that regularly
co-occur and co-infect the same host. Consequently, antibiotics could
significantly alter interspecific interactions and epidemiology of the
co-infecting parasite community. We studied how minor environmental
concentration of antibiotic affects the coinfection of two parasites, the
bacterium Flavobacterium columnare and the fluke Diplostomum
pseudospathaceum, in their fish host. We found that antibiotic in feed,
and particularly the minute concentration in water, significantly
decreased bacterial virulence and changed the infection success of the
flukes. These effects depended on the level of antibiotic resistance of
the bacterial strains. Antibiotic, however, did not compensate for the
higher virulence of co-infections. Our results demonstrate that even very
low environmental concentration of antibiotic can influence ecology and
epidemiology of diseases in co-infection with non-targeted parasites.
Leakage of antibiotics into the environment may thus have more complex
effects on disease ecology than previously anticipated.