A1 Journal article (refereed)
Glochidial infection by the endangered Margaritifera margaritifera (Mollusca) increased survival of salmonid host (Pisces) during experimental Flavobacterium disease outbreak (2021)

Chowdhury, M. M., Roy, A., Auvinen, K., Pulkkinen, K., Suonia, H., & Taskinen, J. (2021). Glochidial infection by the endangered Margaritifera margaritifera (Mollusca) increased survival of salmonid host (Pisces) during experimental Flavobacterium disease outbreak. Parasitology Research, 120(10), 3487-3496. https://doi.org/10.1007/s00436-021-07285-7

JYU authors or editors

Chowdhury, Motiur
Auvinen, Kalle
Pulkkinen, Katja
Suonia, Hanna
Taskinen, Jouni

Publication details

All authors or editors: Chowdhury, M. Motiur, R.; Roy, Amitav; Auvinen, Kalle; Pulkkinen, Katja; Suonia, Hanna; Taskinen, Jouni

Journal or series: Parasitology Research

ISSN: 0932-0113

eISSN: 1432-1955

Publication year: 2021

Publication date: 24/08/2021

Volume: 120

Issue number: 10

Pages range: 3487-3496

Publisher: Springer

Publication country: Germany

Publication language: English

DOI: https://doi.org/10.1007/s00436-021-07285-7

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/77605

Abstract

Co-infections are common in host-parasite interactions, but studies about their impact on the virulence of parasites/diseases are still scarce. The present study compared mortality induced by a fatal bacterial pathogen, Flavobacterium columnare between brown trout infected with glochidia from the endangered freshwater pearl mussel, Margaritifera margaritifera, and uninfected control fish during the parasitic period and after the parasitic period (i.e. glochidia detached) in a laboratory experiment. We hypothesised that glochidial infection would increase host susceptibility to and/or pathogenicity of the bacterial infection. We found that the highly virulent strain of F. columnare caused an intense disease outbreak, with mortality reaching 100% within 29 h. Opposite to the study hypothesis, both fresh ongoing and past infection (14 months post-infection) with glochidia prolonged the fish host’s survival statistically significantly by 1 h compared to the control fish (two-way ANOVA: fresh-infection, F1, 82 = 7.144, p = 0.009 and post-infection, F1, 51 = 4.227, p = 0.044). Furthermore, fish survival time increased with glochidia abundance (MLR: post-infection, t = 2.103, p = 0.045). The mechanism could be connected to an enhanced non-specific immunity or changed gill structure of the fish, as F. columnare enters the fish body mainly via the gills, which is also the glochidia’s attachment site. The results increase current knowledge about the interactions between freshwater mussels and their (commercially important) fish hosts and fish pathogens and also emphasise the importance of (unknown) ecosystem services (e.g., protection against pathogens) potentially associated with imperilled freshwater mussels.

Keywords: brown trout (lacustine); fish diseases; resistance (medicine); pathogens; virulence; Margaritana margaritifera; larvae; parasitism