Francisellosis in fish: an emerging challenge

Francisellosis is a bacterial disease with increasing economic impacts in the culture of tilapia and Atlantic cod since emerging in 1992. Two main strains – Francisella noatunensis subsp. orientalis (Fno) and F. noatunensis subsp. noatunensis (Fnn), have been identified, causing both acute and chron...

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Bibliographic Details
Main Author: Chong, Roger
Format: Article in Journal/Newspaper
Language:unknown
Published: 2016
Subjects:
Online Access:http://era.daf.qld.gov.au/id/eprint/5438/
Description
Summary:Francisellosis is a bacterial disease with increasing economic impacts in the culture of tilapia and Atlantic cod since emerging in 1992. Two main strains – Francisella noatunensis subsp. orientalis (Fno) and F. noatunensis subsp. noatunensis (Fnn), have been identified, causing both acute and chronic granulomatous systemic disease. The piscine host range is increasing and Francisella culture should be included in routine diagnosis. Differentiation from the major zoonotic F. tularensis and opportunistic zoonotic F. philomiragia when dealing with environmental soil and water samples from fish farms is important. Diagnosis can be challenging but presentation of granulomatous pathology in fish should require use of cysteine supplemented selective media, culture at 15–28°C or culture in fish cell lines and specific PCR to exclude piscine Fno or Fnn. Control of infections in fish rely on appropriate antibiotic selection although in the long term an effective commercial vaccine that includes the pathogenic species of Francisella is required.