University Of Tasmania
Ghosh_et_al - 2018 - (Preprint) Accepted Manuscript - Non-invasive quantitative Y. ruckeri detection in fish faeces.pdf (712.31 kB)

A highly sensitive, non-invasive qPCR-based strategy for direct quantification of Yersinia ruckeri in fish faeces

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posted on 2023-05-19, 18:13 authored by Bikramjit GhoshBikramjit Ghosh, Crosbie, PBB, Barbara NowakBarbara Nowak, Andrew Bridle
Finfish with asymptomatic Yersinia ruckeri infections pose a major risk as they can transmit the pathogen and cause clinical outbreaks in stock populations. Current tools have insufficient quantitative ability for accurately detecting the trace levels of Y. ruckeri typically associated with asymptomatic infection, necessitate invasive or lethal sampling, or require long processing times. This study presents a highly sensitive qPCR-based method, targeting part of the Y. ruckeri 16S rRNA sequence, that is capable of detecting extremely low levels of Y. ruckeri in non-invasively collected faecal samples. Quantitative precision and accuracy of faecal sample analysis was consistent, despite the complexity of the faecal matrix. The assay demonstrated linearity over a 6 log-wide dynamic range. Its limit of detection (LOD) and limit of quantification (LOQ) were 4 and 10 copies of the target sequence, respectively. Sensitivity of the assay was comparable to other qPCR-based methods without requiring invasive or lethal sampling. Applicability as a screening strategy was tested using passively collected faecal samples. Asymptomatic Y. ruckeri infection was detected in all samples, though none of the fish exhibited overt infection. This method will be beneficial for finfish disease management if developed further as a non-invasive, screening tool against asymptomatic Y. ruckeri infection.


Publication title

Journal of Fish Diseases










Institute for Marine and Antarctic Studies


Blackwell Publishing Ltd

Place of publication

9600 Garsington Rd, Oxford, England, Oxon, Ox4 2Dg

Rights statement

Copyright 2018 John Wiley & Sons Ltd. This is the peer reviewed version of the following article: A highly sensitive, non-invasive qPCR-based strategy for direct quantification of Yersinia ruckeri in fish faeces, which has been published in final form at This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions

Repository Status

  • Restricted

Socio-economic Objectives

Control of pests, diseases and exotic species in coastal and estuarine environments

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