Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea) is the causative agent of proliferative kidney disease (PKD), which affects both wild and farmed salmonid fish. The objective of this study was to outline differences in susceptibility to PKD in different salmonid species, hybrids and breeding lineages. Susceptibility to T. bryosalmonae infection was established based on cumulative mortality, pathological findings and detection of T. bryosalmonae in the kidney using immunohistochemistry and molecular methods. Determination of pure and hybrid individuals of different species in the genus Salvelinus, and dissimilarity of rainbow trout lineages, was performed using traditional polymerase chain reaction (PCR) and microsatellite analyses. Rainbow trout displayed higher disease severity compared with brook trout and Alsatian charr. Moreover, the results indicated differences in infection susceptibility, not only among different salmonid species but also among different lineages of charr and rainbow trout. Our study indicated that some salmonid species and even different lineages of the same species are more suitable for farming under PKD pressure.

• Klíčová slova
• Tetracapsuloides bryosalmonae, Alsatian charr, brook trout, genetic lineage, rainbow trout,
• MeSH
• imunohistochemie veterinární   MeSH
• mikrosatelitní repetice MeSH
• Myxozoa genetika   patogenita   MeSH
• nemoci ledvin patologie   MeSH
• nemoci ryb patologie   MeSH
• Oncorhynchus mykiss parazitologie   MeSH
• parazitární nemoci u zvířat patologie   MeSH
• polymerázová řetězová reakce veterinární   MeSH
• pstruh parazitologie   MeSH
• vodní hospodářství MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Proliferative kidney disease (PKD) is an endoparasitic disease of salmonid fish caused by Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea). This study presents a comprehensive view on PKD development in rainbow trout (Oncorhynchus mykiss) reared at an intensive fish breeding facility, with focus on mortality, pathology/histopathology, haematological findings and immune functions. Diseased and reference fish were sampled monthly and time course of natural infection was followed up from the onset of clinical signs (September 2014) to full recovery (January 2015). PKD- associated cumulative mortality was 30% with a peak value in October, while immunohistochemical testing indicated a continuous significant decrease in T. bryosalmonae numbers from September to December; with no parasites detected in January. During peak clinical infection, a significant decrease in red blood cell counts, haematocrit values, haemoglobin concentration, along with a reduction in lymphocytes and a significant phagocyte elevation corresponding with an increase in phagocyte oxidative burst were measured in comparison to control animals. Complement activity and total immunoglobulin plasma concentrations were also elevated, though only during the initial monitoring period (September). Individuals surviving PKD, recovered and were able to fully regenerate both renal structure and haematopoietic parameters to normal levels. Changes in the red blood cell parameters indicate anaemia and a decreased oxygen transportation capacity during the clinical disease phase. Together with an increased oxygen demand at higher temperatures and decreased oxygen solubility this could lead to decompensation and elevated mortality. The stimulation of immune parameters, and especially oxidative phagocytic burst, is likely to have had a strong effect on both, regeneration and elimination of the pathogenic agent.

• Klíčová slova
• Complement activity, Histology, Immunohistochemistry, Oxidative burst, Proliferative kidney disease, Rainbow trout, Total immunoglobulins,
• MeSH
• epidemický výskyt choroby veterinární   MeSH
• Myxozoa fyziologie   MeSH
• náchylnost k nemoci veterinární   MeSH
• nemoci ledvin patologie   veterinární   MeSH
• nemoci ryb parazitologie   MeSH
• Oncorhynchus mykiss parazitologie   MeSH
• parazitární nemoci u zvířat parazitologie   MeSH
• teplota MeSH
• vodní hospodářství MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH