0000000000003817
AUTHOR
Päivi Pylkkö
Atypical Aeromonas salmonicida -infection as a threat to farming of Arctic charr (Salvelinus alpinus L.) and European grayling (Thymallus thymallus L.) and putative means to prevent the infection
Päivi Pylkön väitöskirjatutkimus osoittaa harjuksen ja nieriän olevan lohikaloista herkimpiä epätyyppisen Aeromonas salmonicida (aAS)–bakteerin aiheuttamalle tulehdukselle. Tautia esiintyy vuosittain useimmilla harjusta ja nieriää viljelevillä laitoksilla. Laitoskasvatus on ensiarvoista vaarantuneiden harjus- ja erittäin uhanalaisten nieriäkantojen säilymiselle. This review summarizes the results of studies on atypical Aeromonas salmonicida (aAS) -infection among farmed Arctic charr (Salvelinus alpinus) and European grayling (Thymallus thymallus) (later referred as charr and grayling, respectively). Specifically, I aimed to characterize the causative agent of aAS -infection, to describe put…
Glutathione-dependent defence system and monooxygenase enzyme activities in Arctic charr Salvelinus alpinus (L.) exposed to ozone
Abstract One of the major obstacles of the increasing usage of ozone in aquaculture is the lack of relevant risk assessment in culture conditions. Before the apparent advantages of ozonation can be utilised efficiently, the safety margins and biological basis of ozone toxicity should be assessed. In this research, 1-year-old Arctic charr ( Salvelinus alpinus (L.)) were exposed to an ozone concentration high enough to inactivate Aeromonas sp. bacteria in freshwater, but too low to be directly lethal to the fish themselves. The effects of ozone exposure on the activity of glutathione-dependent antioxidant enzymes and monooxygenase reactions were studied in blood and in liver. The fish were ac…
Evidence of enhanced bacterial invasion during Diplostomum spathaceum infection in European grayling, Thymallus thymallus (L.)
Farmed grayling, Thymallus thymallus (L.), are susceptible to atypical Aeromonas salmonicida (aAS) infections. Interactions between bacteria and parasites were studied using grayling subjected to concomitant exposure to aAS bacteria and the digenean parasite Diplostomum spathaceum. Atypical AS was detected from fish by a combination of bacterial cultivation and polymerase chain reaction techniques. A detection level of 17 aAS cells per 100 mg intestine tissue sample was obtained. Concomitant bacterial exposure did not enhance the severity of grayling eye rupture and nuclear extrusion induced by D. spathaceum, but D. spathaceum invasion into grayling increased the proportion of fish carrying…