Wplyw beta[1,3]-D-glukanu i lipopolisacharydu na odpornosc karpi przeciwko Aeromonas hydrophila

The effects of β-glucan, lipopolisaccharide (LPS) and cells of pathogenic Aeromonas hydrophila were studied on survival in carp, Cyprinus carpio, that were infected by the pathogen A. hydrophila. Beta-glucan from barley, LPS from Serratia marcescens and the virulent for carp A. hydrophila were used in this study. Immunostimulants were injected intramuscularly in the dorsolateral region of fish. Fish were divided into groups as follows: fish from group I (β-glucan, 50 mg kg⁻¹ i.m.), fish from group II (LPS, 50 mg kg⁻¹ i.m.), fish from group III (LPS, 50 mg kg⁻¹ i.m. and β-glucan, 50 mg kg⁻¹ i.m.), fish from group IV (killed cells of A. hydrophila, 0.1 ml), fish from group V - control (0.1 ml PBS i.m.). Control and test fish were challenged by intraperitoneal injections of A. hydrophila on days 7, 14 and 21. The cases od mortality were recorded for 7 days and the relative percent of survival (RPS) was calculated. The RPS in group I was 83%, 66% and 44%; in group II it was 42%, 55% and 63%; in group III it was 50%, 55% and 97%; in group IV it was 33%, 40% and 56% in the challenge test on the 7th, 14th and 21st days, respectively. It may be concluded that intramuscular injections of β-glucan and LPS mixture in carp could enhance resistance to an infection by A. hydrophila.