Identification of Mycobacterium pseudoshottsii in the Eastern Mediterranean

Abstract

Mycobacterium pseudoshottsii was first detected in 1997 in the USA, infecting wild striped bass ( Morone saxatilis ). Since then, several reports from different countries worldwide have shown its capacity to become established in new regions as well as its pathogenicity to saltwater and euryhaline finfish of different genera.

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

“…All bacterial strains were genomically sequenced, and contigs of approximately 6.0‍ ‍Mb were assembled. These contig sequences were incorporated into the genome sequences of M. marinum complex strains available from the nucleotide database for a core genome ana­lysis, along with the contig sequences of three Mps strains (named as iso­lates 189, 539, and 540) isolated from the East Mediterranean Sea of Israel ( Davidovich et al , 2023 ). The core genome phylogenetic tree showed that the sequences of the two registered Mps strains (YM-3 and NJB1907-Z4) and those of the 12 strains in the present study were almost identical, whereas those of three Mediterranean strains were similar to that of the reference strain JCM 15466 ( Fig.…”

“…2 ). In contrast to these two subspecies, the number of cases of infection owing to Mps has been increasing in industrial fisheries, and there are concerns that its economic impact may be severe ( Stine et al , 2009 ; Mugetti et al , 2020 ; Davidovich et al , 2023 ). This situation led us to anticipate that controlling infection by this species in fisheries will be required in the future.…”

“…The contigs obtained were used for a core-genome ana­lysis in combination with 19 complete genome sequences of the M. marinum complex registered in the NCBI database ( Table S1 ). Short-read sequences obtained from three Mps strains reported from Israel ( Davidovich et al , 2023 ) were also downloaded from the database, assembled in the same manner as described above, and integrated into this ana­lysis. The core SNVs were retrieved using kSNP4.0, an upgraded version of kSNP3 ( Gardner et al , 2015 ).…”

“…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 ). Consequently, there is apprehension that this pathogen may be spreading surreptitiously not only in aquaculture fisheries, but also among fish bred in different facilities worldwide, based on reports of sporadic cases of its occurrence from diverse sources.…”