Direct visualization of the novel pathogen, Spiroplasma eriocheiris, in the freshwater crayfish Procambarus clarkii (Girard) using fluorescence in situ hybridization. Issue 9 (29th August 2014)

• Record Type: Journal Article
• Authors: Ding, Z F; Xia, S Y; Xue, H; Tang, J Q; Ren, Q; Gu, W; Meng, Q G; Wang, W
• Is Part Of: Journal of fish diseases. Volume 38:Issue 9(2015:Sep.)
• Page Start: 787
• Page End: 794
• Publication Date: 2014-08-29
• Subjects: Fishes -- Diseases -- Periodicals; 639.3
• DOI: 10.1111/jfd.12287
• Languages: English
• ISSNs: 0140-7775

Abstract

<abstract abstract-type="main" id="jfd12287-abs-0001"> <title>Abstract</title> <p> <italic>Spiroplasma eriocheiris</italic> is the first spiroplasma strain known to be pathogenic to freshwater crustaceans. It has caused considerable economic losses both in the freshwater crayfish <italic>Procambarus clarkii</italic> (Girard) and in some other crustaceans. The monitoring of the pathogen in crustacean populations and study of its behaviour in the laboratory require the development of reliable diagnostic tools. In this article, we improved microscopic identification of <italic>S. eriocheiris</italic> by combining <italic>in situ</italic> hybridization with specific fluorescently labelled oligonucleotide probes. The established fluorescence <italic>in situ</italic> hybridization (FISH) allowed simultaneous visualization, identification and localization of <italic>S. eriocheiris</italic> in the tissues of diseased crayfish <italic>P. clarkii</italic> and exhibited low background autofluorescence and ideal signal‐to‐noise ratio. With the advantages of better tissue penetration, potentially more specific and stable, we designed three species‐specific oligonucleotide probes utilizing the sequences of 16S‐23S rRNA intergenic spacer regions (ISRs) of <italic>S. eriocheiris</italic>. Positive hybridization signals were visualized in haemocytes and connective tissues of hepatopancreas, cardiac muscle and gill from diseased crayfish. This unique distribution pattern matched the pathological changes when diagnosed by H&E staining and indicated that <italic>S. eriocheiris</italic> probably spread throughout the tissues in <italic>P. clarkii</italic> by hemokinesis. This assay will facilitate our understanding of the pathogenesis of <italic>S. eriocheiris</italic> and enhance the early diagnosis of the novel pathogen.</p> </abstract>