Стан системи антиоксидантного захисту у гепатопанкреасі коропів за асоційованої інфекції аеромонозу з сапролегніозом

Abstract

Bacterial diseases are responsible for heavy mortality in both wild and cultured fish. Co-infections are very common in nature and occur when hosts are infected by two or more different pathogens either by simultaneous or secondary infections so that two or more infectious agents are active together in the same host. Associative infections pose a significant threat to fish farming, so it is necessary to develop effective means of prevention and treatment of these infections; it is advisable to study in detail their impact on various fish. The aim of the study was to determine the intensity of lipid peroxidation processes and the activity of the antioxidant defense system in the body of carp suffering from aeromonosis and the associated infection of aeromonosis with saprolegniosis. The research was conducted at the Lviv Research Station of the Institute of Fisheries of NAAS. There were three groups of fish, 5 in each. The control group consisted of clinically healthy fish, the first experimental group (D1) – carps affected by Aeromonas hydrophila infection, the second experimental group (D2), which consisted of carps affected by associative Aeromonas hydrophila infection with Saprolegnia Sp. The results of studies have shown that carp with associative infection ‒ of Aeromonas hydrophila infection with Saprolegnia Sp. leads to the activation of lipid peroxidation processes, especially the primary product of LPO. Thus, in the hepatopancreas of fish there was an increase of 1.4 (p <0.05) in the reasonable content of diene conjugates and there was a tendency to increase the content of TBA-active products. At the same time, the inhibitory effect of pathogenic factors of this disease on the activity of the enzymatic link of the antioxidant defense system was stated. In particular, carp patients with associative infection ‒ of Aeromonas hydrophila infection with Saprolegnia Sp. had higher catalase and superoxide dismutase activity, respectively, 1.3 (p <0.05) and 2.3 (p <0.01) times. The results of experimental studies made it possible to expand and deepen the mechanisms of the pathogenesis of the co-infection of Aeromonas hydrophila infection with Saprolegnia Sp. and to use the data to develop effective treatments.