Recovery of Listonella anguillarum from Diseased Pufferfish (Takifugu rubripes) in China

Abstract

In May 2016, there was a disease outbreak among pufferfish (Takifugu rubripes) in a marine farm in Tianjin municipality, with the cumulative mortality rate reaching 45% within 7 days from the beginning of the outbreak. The main symptoms of the disease were abdominal and anal swelling of the diseased fish. Significant damage was also observed histopathologically in the intestine, liver, and kidney. The strain H008 was isolated from diseased kidneys, and the challenge test revealed that the same disease was diagnosed in pufferfish which suffered similarly high mortality rates. Using physiological biochemical tests combined with 16S rDNA sequence analysis, the strain was identified as Listonella anguillarum. Antimicrobial susceptibility tests showed that H008 was resistant to 10 of 15 antimicrobial agents tested. To the best of our knowledge, this is the first report of L. anguillarum causing disease in pufferfish.