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 antibiotic resistance bacteria (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 faecal 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
upregulation 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 with 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.