Vet Med - Czech, 2026, 71(4):156-168 | DOI: 10.17221/101/2025-VETMED

The effect of Lactiplantibacillus plantarum probiotic supplement on rainbow trout challenged with Aeromonas salmonicidaOriginal Paper

I Mikulikova ORCID...1,2, Z Lepkova ORCID...1, H Bandouchova ORCID...1, J Blahova ORCID...1, I Papezikova ORCID...1,2, H Novotna ORCID...1,2,3, I Toulova ORCID...1,2, K Kobelkova ORCID...1, K Odehnalova ORCID...4, E Postulkova ORCID...2, M Radojicic ORCID...2, J Mares ORCID...2, D Mudronova ORCID...5, M Palikova ORCID...1,2
1 University of Veterinary Sciences Brno, Brno, Czech Republic
2 Mendel University in Brno, Brno, Czech Republic
3 Veterinary Research Institute, Brno, Czech Republic
4 Czech Academy of Sciences, Brno, Czech Republic
5 University of Veterinary Medicine and Pharmacy in Ko¹ice, Ko¹ice, Slovak Republic

Two probiotic (Lactiplantibacillus plantarum) supplementation strategies (continuous and cyclic) were evaluated for their ability to enhance resistance of rainbow trout (Oncorhynchus mykiss) to Aeromonas salmonicida infection. Neither of these strategies improved post-challenge survival. Instead, cyclic administration resulted in a significantly higher mortality rate (73%) compared with continuous supplementation (52%) and the control group (46%). One week post-challenge, most haematological, plasma biochemical, and immune parameters showed no significant difference between treatments, though fish receiving cyclic supplementation did exhibit a reduced lymphocyte count. However, three weeks post-challenge, this same group showed a significant decrease in total phagocyte number and in the proportion of phagocytes within white blood cells. IgM concentrations were significantly lower in both probiotic-supplemented groups than in the control group. In the cyclic group, reductions in interleukin-10 and elevations in total protein levels were also observed. Microbiome analysis of gut content three weeks post-challenge revealed a marked decline in microbial diversity in both probiotic-treated groups. These findings indicate that, under the experimental conditions, probiotic supplementation did not provide protection against A. salmonicida infection and that cyclic administration may disrupt immune homeostasis and intestinal microbial stability, ultimately compromising host resilience.

Keywords: furunculosis; gut microbiota; lactobacilli; Oncorhynchus mykiss

Received: November 28, 2025; Revised: February 10, 2026; Accepted: February 26, 2026; Published: April 30, 2026  Show citation

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Mikulikova I, Lepkova Z, Bandouchova H, Blahova J, Papezikova I, Novotna H, et al.. The effect of Lactiplantibacillus plantarum probiotic supplement on rainbow trout challenged with Aeromonas salmonicida. Veterinární medicína. 2026;71(4):156-168. doi: 10.17221/101/2025-VETMED.
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References

  1. Bartkova S, Kokotovic B, Dalsgaard I. Infection routes of Aeromonas salmonicida in rainbow trout monitored in vivo by real-time bioluminescence imaging. J Fish Dis. 2017 Jan;40(1):73-82. Go to original source... Go to PubMed...
  2. Benzie IF, Strain JJ. The ferric reducing ability of plasma (FRAP) as a measure of "antioxidant power": The FRAP assay. Anal Biochem. 1996 Jul 15;239(1):70-6. Go to original source... Go to PubMed...
  3. Bogwald J, Dalmo RA. Review on immersion vaccines for fish: An update 2019. Microorganisms. 2019 Nov 29;7(12):627. Go to original source... Go to PubMed...
  4. Carru C, Zinellu A, Sotgia S, Serra R, Usai MF, Pintus GF, Pes GM, Deiana L. A new HPLC method for serum neopterin measurement and relationships with plasma thiols levels in healthy subjects. Biomed Chromatogr. 2004 Jul;18(6):360-6. Go to original source...
  5. Ceron JJ, Martinez-Subiela S. An automated spectrophotometric method for measuring canine ceruloplasmin in serum. Vet Res. 2004 Nov-Dec;35(6):671-9. Go to original source... Go to PubMed...
  6. Cingelova Maruscakova I, Schusterova P, Popelka P, Gancarcikova S, Csank T, Feckaninova A, Ratvaj M, Mudronova D. Effect of autochthonous lactobacilli on immunologically important molecules of rainbow trout after bacterial infection studied on intestinal primoculture. Fish Shellfish Immunol. 2021 Dec;119:379-83. Go to original source... Go to PubMed...
  7. Costa G, Danz H, Kataria P, Bromage E. A holistic view of the dynamisms of teleost IgM: A case study of Streptococcus iniae vaccinated rainbow trout (Oncorhynchus mykiss). Dev Comp Immunol. 2012 Feb;36(2):298-305. Go to original source... Go to PubMed...
  8. Feckaninova A, Koscova J, Mudronova D, Schusterova P, Cingelova Maruscakova I, Popelka P. Characterization of two novel lactic acid bacteria isolated from the intestine of rainbow trout (Oncorhynchus mykiss, Walbaum) in Slovakia. Aquaculture. 2019 May;506:294-301. Go to original source...
  9. Fijan S. Probiotics and their antimicrobial effect. Microorganisms. 2023 Feb 19;11(2):528. Go to original source... Go to PubMed...
  10. Gudding R, Van Muiswinkel WB. A history of fish vaccination: Science-based disease prevention in aquaculture. Fish Shellfish Immunol. 2013 Dec;35(6):1683-8. Go to original source...
  11. Haluzova I, Modra H, Blahova J, Marsalek P, Siroka Z, Groch L, Svobodova Z. Effects of subchronic exposure to Spartakus (prochloraz) on common carp Cyprinus carpio. Neuro Endocrinol Lett. 2010 Dec;31(Suppl_2):105-13.
  12. Harun NO, Costa MM, Secombes CJ, Wang T. Sequencing of a second interleukin-10 gene in rainbow trout Oncorhynchus mykiss and comparative investigation of the expression and modulation of the paralogues in vitro and in vivo. Fish Shellfish Immunol. 2011 Jul;31(1):107-17. Go to original source... Go to PubMed...
  13. Hoseinifar SH, Ashouri G, Marisaldi L, Candelma M, Basili D, Zimbelli A, Notarstefano V, Salvini L, Randazzo B, Zarantoniello M, Pessina A, Sojan JM, Vargas A, Carnevali O. Reducing the use of antibiotics in European aquaculture with vaccines, functional feed additives and optimization of the gut microbiota. J Mar Sci Eng. 2024 Jan;12(2):204. Go to original source...
  14. Irianto A, Austin B. Use of probiotics to control furunculosis in rainbow trout, Oncorhynchus mykiss (Walbaum). J Fish Dis. 2002 Jun;25(6):333-42. Go to original source...
  15. Jun JW, Kang JW, Giri SS, Kim SW, Kim SG, Kwon J, Lee SB, Jung WJ, Lee YM, Jo SJ, Park SC. Preventive effect of starch hydrogel-based oral vaccine against Aeromonas salmonicida infection in rainbow trout (Oncorhynchus mykiss). Aquaculture. 2022 Jun;555:738202. Go to original source...
  16. Menanteau-Ledouble S, Kumar G, Saleh M, El-Matbouli M. Aeromonas salmonicida: Updates on an old acquaintance. Dis Aquat Organ. 2016 Jun 15;120(1):49-68. Go to original source... Go to PubMed...
  17. Mikulikova I, Radojicic M, Bandouchova H, Blahova J, Maly O, Papezikova I, Novotna H, Postulkova E, Lepkova Z, Toulova I, Odehnalova K, Mares J, Mudronova D, Palikova M. The effect of continuous and pulse feeding Lactiplantibacillus plantarum on growth performance, gut microbiota, immunological, haematological and plasma biochemical parameters of rainbow trout Oncorhynchus mykiss. Ital J Anim Sci. 2025 Jan;24(1):424-39. Go to original source...
  18. Montero R, Chan JTH, Muller C, Just PN, Ostermann S, Overland M, Maisey K, Korytar T, Kollner B. Variations in rainbow trout immune responses against A. salmonicida: Evidence of an internal seasonal clock in Oncorhynchus mykiss. Biology (Basel). 2022 Jan 21;11(2):174. Go to original source... Go to PubMed...
  19. Moreau E, Pineau L, Bachelet F, Rostang A, Oberle K, Calvez S. Time effect of experimental infection on Rainbow trout (Oncorhynchus mykiss) by immersion with Aeromonas salmonicida subsp. salmonicida. Fish Shellfish Immunol. 2023 Apr;135:108664. Go to original source...
  20. Nguyen NV, Onoda S, Khanh TV, Hai PD, Trung NT, Hoang L, Koshio S. Evaluation of dietary heat-killed Lactobacillus plantarum strain L-137 supplementation on growth performance, immunity and stress resistance of Nile tilapia (Oreochromis niloticus). Aquaculture. 2019 Jan;498:371-9. Go to original source...
  21. Papezikova I, Mares J, Vojtek L, Hyrsl P, Markova Z, Simkova A, Bartonkova J, Navratil S, Palikova M. Seasonal changes in immune parameters of rainbow trout (Oncorhynchus mykiss), brook trout (Salvelinus fontinalis) and brook trout × Arctic charr hybrids (Salvelinus fontinalis × Salvelinus alpinus alpinus). Fish Shellfish Immunol. 2016 Oct;57:400-5. Go to original source... Go to PubMed...
  22. Romstad AB, Reitan LJ, Midtlyng P, Gravningen K, Evensen O. Antibody responses correlate with antigen dose and in vivo protection for oil-adjuvanted, experimental furunculosis (Aeromonas salmonicida subsp. salmonicida) vaccines in Atlantic salmon (Salmo salar L.) and can be used for batch potency testing of vaccines. Vaccine. 2013 Jan 21;31(5):791-6. Go to original source... Go to PubMed...
  23. Shieh HS, Maclean JR. Blood changes in brook trout induced by infection with Aeromonas salmonicida. J Wildl Dis. 1976 Jan;12(1):77-82. Go to original source... Go to PubMed...
  24. Soltani M, Pakzad K, Taheri-Mirghaed A, Mirzargar S, Shekarabi SPH, Yosefi P, Soleymani N. Dietary application of the probiotic Lactobacillus plantarum 426951 enhances immune status and growth of rainbow trout (Oncorhynchus mykiss) vaccinated against Yersinia ruckeri. Probiotics Antimicrob Proteins. 2019 Mar;11(1):207-19. Go to original source...
  25. Soto-Davila M, Hossain A, Chakraborty S, Rise ML, Santander J. Aeromonas salmonicida subsp. salmonicida early infection and immune response of Atlantic cod (Gadus morhua L.) primary macrophages. Front Immunol. 2019 Jun 4;10:1237. Go to original source... Go to PubMed...
  26. Svobodova Z, Pravda D, Modra H. Metody hematologickeho vysetrovani ryb [Methods of haematological examination of fish]. Edition of methods, vol. 122. Vodòany: Research Institute of Fish Culture and Hydrobiology; 2012. 38 p. Czech.
  27. Talwar C, Nagar S, Lal R, Negi RK. Fish gut microbiome: Current approaches and future perspectives. Indian J Microbiol. 2018 Dec;58(4):397-414. Go to original source...
  28. Vasquez I, Cao T, Hossain A, Valderrama K, Gnanagobal H, Dang M, Leeuwis RHJ, Ness M, Campbell B, Gendron R, Kao K, Westcott J, Gamperl AK, Santander J. Aeromonas salmonicida infection kinetics and protective immune response to vaccination in sablefish (Anoplopoma fimbria). Fish Shellfish Immunol. 2020 Sep;104:557-66. Go to original source... Go to PubMed...

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