Effects of doxycycline hydrochloride and enrofloxacin on intestinal microbial community of Paphia amabilis

【Objective】To provide a reference basis for the healthy breeding of Paphia amabilis，the effects of doxycycline hydrochloride and enrofloxacin on the intestinal microbial community of P. amabilis were studied.【Method】The diversity and composition of intestinal microbial community of P. amabilis were analyzed by PacBio high-throughput fulllength 16S rRNA gene sequencing technology after being exposed with doxycycline hydrochloride and enrofloxacin respectively at a concentration of 10.0 mg/L for 1 d.【Result】Results indicated that there was no significant difference in α- diversity index of intestinal microbial community between antibiotics treatment group and control group（CK）（P>0.05）. At the phylum level，the dominant intestinal microbial community in P. amabilis were Proteobacteria and Bacteroidetes. In addition，Campylobacter decreased significantly in the two antibiotic treatment groups（P<0.05，the same below）. At the genus level，the main dominant bacteria of CK were Malacioactor，Roseimarinus，Poseidonibacter and Klebsiella，and in the doxycycline hydrochloride treatment group were Alteromonas，Rubritalea and Colwellia，while in the enrofloxacin treatment group were Polaribacter，Aurantivirga and Pseudofulvibacter. The dominant bacteria in the intestinal microbial community of the three treatments were different；antibiotics exposure decreased significantly the relative abundances of Malaciobacter，Roseimarinus，Poseidonibacter and Halarcobacter.【Conclusion】The study shows that there is no significant change on the abundance and diversity of intestinal microbial community under the short-term exposure to 10.0 mg/L doxycycline hydrochloride and 10.0 mg/L enrofloxacin，but it changes the structure and composition of intestinal microbial community. Meanwhile，the treatment of antibiotics reduce the relative abundance of some harmful bacteria in the intestine of P. amabilis.