A case of mycobacteriosis associated with <i>Mycobacterium pseudoshottsii</i> in aquarium-reared fish in Japan

Abstract

In 2019, several aquarium-reared fish died at a sea life park in Japan.Necropsy revealed micronodules on the spleen in the dotted gizzard shad (Konosirus punctatus). Seven of 16 fish exhibited microscopic multifocal granulomas associated with acid-fast bacilli in the spleen, kidney, liver, alimentary tract, mesentery, gills, and/or heart. Bacterial cultures yielded isolates from the dotted gizzard shad and a Japanese sardine (Sardinops melanostictus). Microbiological and molecular biological examinations revealed the isolates asMycobacterium pseudoshottsii. To our knowledge, this is the first isolation of M. pseudoshottsii from aquarium-reared fish.

Retrospective identification of pathogenic mycobacterial species in fish: Mycobacterium pseudoshottsii YM-3, isolated from a yellowtail fish in 1986 in Kochi, Japan

“…Mycobacterium pseudoshottsii , a subspecies of Mycobacterium marinum , can cause mycobacteriosis in both farmed and wild fish ( 1 – 5 ). Genetically, M. pseudoshottsii is highly conserved with M. marinum and related species, including Mycobacterium ulcerans , which is a causative agent of Buruli ulcer ( 6 – 9 ).…”

Complete Genome and Partial Megaplasmid Sequences of Mycobacterium pseudoshottsii Strain NJB1907-Z4, Isolated from an Aquarium-Reared Japanese Sardine (Sardinops melanostictus) in Japan

“…A Japanese sardine ( Sardinops melanostictus ) was randomly sampled from a tank at the Tokyo Sea Life Park in which mycobacteriosis occurred in 2019. The liver was collected from the fish and subjected to mycobacterial culture, resulting in the isolation of M. pseudoshottsii strain NJB1907-Z4 ( 7 ). After the strain was streaked onto two 2% Ogawa slants (Kyokuto Pharmaceutical Industrial Co., Ltd., Japan) and cultivated for 4 weeks at 25°C, DNA was extracted from colonies on each slant.…”

Application of Genomic Epidemiology of Pathogens to Farmed Yellowtail Fish Mycobacteriosis in Kyushu, Japan

“…Another report was documented in 2020, describing cases of infected farmed fish in Italy ( Mugetti et al , 2020 ). In 2022, the organism was detected in sardines held in aquariums in Japan ( Komine et al , 2022 ). In 2020–2021, this organism caused many cases of infection in an aquaculture facility in Israel raising imported food fish from the United States ( Davidovich et al , 2023 ).…”