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Molecular evidence of release of Tetracapsula bryosalmonae , the causative organism of proliferative kidney disease from infected salmonids into the environment
Author(s) -
Morris D C,
Morris D J,
Adams A
Publication year - 2002
Publication title -
journal of fish diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 85
eISSN - 1365-2761
pISSN - 0140-7775
DOI - 10.1046/j.1365-2761.2002.00352.x
Subject(s) - stirling engine , aquaculture , library science , fishery , fish <actinopterygii> , biology , engineering , computer science , mechanical engineering
Keywords: Bryozoa, polymerase chain reaction, pro-liferative kidney disease, Tetracapsula bryosalmonae,transmission.Tetracapsula bryosalmonae is the malacosporeanparasite that causes the commercially importantproliferative kidney disease (PKD) in culturedsalmonids (Canning, Curry, Feist, Longshaw O Kent, Khattra, Hervio & Devlin1998; Morris, Adams & Richards 1999). However,because of the lack of hard spore valves and theinammatory nature of the disease it was widelyconsidered that the observed spores were not viable(Kent & Hedrick 1986). The discovery that speciesof freshwater bryozoans could be infected withT. bryosalmonae demonstrated that within thesehosts the parasite formed spores that did not possesshard spore valves (Canning et al. 1999). Tetracap-sula bryosalmonae stages obtained from bryozoanswere subsequently proven to be able to infectrainbow trout, Oncorhynchus mykiss (Walbaum),resulting in clinical PKD. This suggested that thespore stages observed in the bryozoan hosts wereviable and capable of transmitting the parasite(Feist, Longshaw, Canning & Okamura 2001).It is well documented that the sporogonic stagesof T. bryosalmonae can persist in the tubulelumens of salmonids many months after the shhave recovered from clinical PKD (Kent H Kent et al. 1998; Morris, Adams,Feist, McGeorge & Richards 2000). This has ledto suggestions that the T. bryosalmonae sporestages observed in salmonids are viable andcapable of infecting bryozoan hosts (Kent,Khattra, Hedrick & Devlin 2000). Limited workhas been performed examining the release of sporestages from infected salmonid species. Kent &Hedrick (1986) examining 10 rainbow troutcollected from a hatchery in North Americaenzootic for PKD reported the presence of asmall number of sporoblasts in the urine of one ofthe sh which were presumed to be T. bryosal-monae. However, so far T. bryosalmonae spores orsporogonic stages have yet to be identied incollecting ducts, ureters or the urinary bladder ofany salmonid sh.This short communication describes bothmolecular evidence conrming that T. bryosalmonaeis released from salmonids into the freshwaterenvironment and the results of a preliminaryexperiment to transmit T. bryosalmonae from browntrout, Salmo trutta L., to a freshwater bryozoan.