Data from: Aquatic animals promote antibiotic resistance gene dissemination in water via conjugation: role of different regions within the zebra fish intestinal tract, and impact on fish intestinal microbiota

The aqueous environment is one of many reservoirs of
antibiotic resistance genes (ARGs). Fish, as important aquatic animals
which possess ideal intestinal niches for bacteria to grow and
multiply, may ingest antibiotic resistance bacteria from aqueous
environment. The fish gut would be a suitable environment for conjugal
gene transfer including those encoding antibiotic resistance. However,
little is known in relation to the impact of ingested ARGs or ARB on
gut microbiota. Here, we applied the cultivation method, qPCR, nuclear
molecular genetic marker and 16S rDNA amplicon sequencing technologies
to develop a plasmid-mediated ARG transfer model of zebrafish.
Furthermore, we aimed to investigate the dissemination of ARGs in
microbial communities of zebrafish guts after donors carrying
self-transferring plasmids that encode ARGs were introduced in
aquaria. On average, 15% of fecal bacteria obtained ARGs through
RP4-mediated conjugal transfer. The hindgut was the most important
intestinal region supporting ARG dissemination, with concentrations of
donor and transconjugant cells almost 25 times higher than those of
other intestinal segments. Furthermore, in the hindgut where conjugal
transfer occurred most actively, there was remarkable up-regulation of
the mRNA expression of the RP4 plasmid regulatory genes, trbBp
and trfAp. Exogenous bacteria seem to alter bacterial
communities by increasing Escherichia and Bacteroides
species, while decreasing Aeromonas compared to control groups.
We identified the composition of transconjugants and abundance of both
cultivable and uncultivable bacteria (the latter accounted for
90.4-97.2% of total transconjugants). Our study suggests that aquatic
animal guts contribute to the spread of ARGs in water environments.