MLVA genotyping of Moritella viscosa reveals serial emergence of novel, host-specific clonal complexes in Norwegian salmon farming.
J Fish Dis
; 46(5): 535-543, 2023 May.
Article
em En
| MEDLINE
| ID: mdl-36787245
ABSTRACT
A Multi-Locus Variable number of tandem repeat Analysis (MLVA) genotyping scheme was developed for the epidemiological study of Moritella viscosa, which causes 'winter ulcer' predominantly in sea-reared Atlantic salmon (Salmo salar L.). The assay involves multiplex PCR amplification of six Variable Number of Tandem Repeat (VNTR) loci, followed by capillary electrophoresis and data interpretation. A collection of 747 spatiotemporally diverse M. viscosa isolates from nine fish species was analysed, the majority from farmed Norwegian salmon. MLVA distributed 76% of the isolates across three major clonal complexes (CC1, CC2 and CC3), with the remaining forming minor clusters and singletons. While 90% of the salmon isolates belong to either CC1, CC2 or CC3, only 20% of the isolates recovered from other fish species do so, indicating a considerable degree of host specificity. We further highlight a series of 'clonal shifts' amongst Norwegian salmon isolates over the 35-year sampling period, with CC1 showing exclusive predominance prior to the emergence of CC2, which was later supplanted by CC3, before the recent re-emergence of CC1. Apparently, these shifts have rapidly swept the entire Norwegian coastline and conceivably, as suggested by typing of a small number of non-Norwegian isolates, the Northeast Atlantic region as a whole.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Salmo salar
/
Moritella
/
Doenças dos Peixes
Limite:
Animals
Idioma:
En
Revista:
J Fish Dis
Ano de publicação:
2023
Tipo de documento:
Article