RT Journal Article
T1 Immune profiling of rainbow trout (Oncorhynchus mykiss) exposed to Lactococcus garvieae: Evidence in asymptomatic versus symptomatic or vaccinated fish
A1 Khalil, Sarker Mohammed Ibrahim
A1 Bulfon, Chiara
A1 Galeotti, Marco
A1 Acutis, Pier Luigi
A1 Altinok, Ilhan
A1 Kotzamanidis, Charalampos
A1 Vela Alonso, Ana Isabel
A1 Fariano, Lucio
A1 Prearo, Marino
A1 Colussi, Silvia
A1 Volpatti, Donatella
AB Lactococcosis, caused by the Gram-positive bacterium Lactococcus garvieae, is a major concern in rainbow trout (Oncorhynchus mykiss) farms, which are regularly affected by outbreaks especially during the summer/fall months. In these farms, unvaccinated healthy and symptomatic fish can coexist with vaccinated fish. In the present study, innate (leukogram, serum lysozyme activity, peroxidase activity, antiprotease activity, bactericidal activity, total IgM and total proteins), and specific immune parameters (serum antibodies to L. garvieae) were assessed in unvaccinated adult rainbow trout naturally exposed to the pathogen, with or without evidence of clinical signs, or subjected to vaccination. Blood was drawn from all three groups, and blood smears were prepared. Bacteria were found in the blood smears of 70% of the symptomatic fish but not in any of the asymptomatic fish. Symptomatic fish showed lower blood lymphocytes and higher thrombocytes than asymptomatic fish (p ≤ .05). Serum lysozyme and bactericidal activity did not vary substantially among groups; however, serum antiprotease and peroxidase activity were significantly lower in the unvaccinated symptomatic group than in the unvaccinated and vaccinated asymptomatic groups (p ≤ .05). Serum total proteins and total immunoglobulin (IgM) levels in vaccinated asymptomatic rainbow trout were significantly higher than in unvaccinated asymptomatic and symptomatic groups (p ≤ .05). Similarly, vaccinated asymptomatic fish produced more specific IgM against L. garvieae than unvaccinated asymptomatic and symptomatic fish (p ≤ .05). This preliminary study provides basic knowledge on the immunological relationship occurring between the rainbow trout and L. garvieae, potentially predicting health outcomes. The approach we proposed could facilitate infield diagnostics, and several non-specific immunological markers could serve as reliable indicators of the trout's innate ability to fight infection.
SN 0140-7775
SN 1365-2761
YR 2023
FD 2023-03-21
LK https://hdl.handle.net/20.500.14352/107605
UL https://hdl.handle.net/20.500.14352/107605
LA eng
NO Khalil, S. M. I., Bulfon, C.,Galeotti, M., Acutis, P. L., Altinok, I., Kotzamanidis, C., Vela,A. I., Fariano, L., Prearo, M., Colussi, S., & Volpatti, D. (2023).Immune profiling of rainbow trout (Oncorhynchus mykiss)exposed to Lactococcus garvieae: Evidence in asymptomaticversus symptomatic or vaccinated fish. Journal of FishDiseases, 46, 731–741. https://doi.org/10.1111/jfd.13782
NO AU T H O R CO N T R I B U T I O N S: All authors have confirmed to submit the manuscript.DATA AVA I L A B I L I T Y S TAT E M E N T: The data that support the findings of this study are available fromthe corresponding author upon reasonable request.
NO University of Udine
DS Docta Complutense
RD 25 abr 2025