Phagocytosis in the Fish Oreochromis Niloticus against the Background of Candidaemia Development under Aquarium Conditions

In recent years, pathogenic forms of Candida albicans have been activated and isolated in aquariums of commercially valuable fish and in closed water systems (CWIs). They largely colonise the digestive tube and lead to the death of 95‑100% of fish. Treatment methods for aquarium fish bred for food purposes are ecologically and economically unjustified, as the preparations retain a certain toxicity. In this regard, it is necessary to search for environmentally friendly methods of prevention and therapy of candidaemiasis in aquariums and CWIs. It was found that propolis in complex with methylene blue promotes complete elimination of toxicity and suppressive action of sensitizers, inhibition of increased reproduction of Candida in the organism of Oreochromis niloticus, strengthening of haematopoiesis processes, increase of neutrophils, monocytes and activation of phagocytosis. In comparison with the data of the infected fish of group 2, the level of neutrophils increased by 1.63, 1.6, 1.82 and 1.67 times, monocytes by 1.94, 2.58, 3.08 and 3.1 times on the 7th, 14th, 21st and 30th day of the experiment. This contributed to the restoration of the functional activity of cells and phagocytic reactions in the organism of O. niloticus, increasing the ecological environment, productivity and quality of the obtained dietary protein, meat rich in essential fatty acids omega‑3 and -6.