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Možnosti léčby smíšených infekcí ryb
KOCOUR, Jakub
Fish diseases can be one of the factors slowing down the current development of aquaculture. Frequent causes of these diseases are pathogenic bacteria and parasites. The aim of this study was to test the effects of peracetic acid (PAA) and hydrogen peroxide (H2O2) on haematological and biochemical indicators as well as on the bacterial and parasitic load in fish. Common carp (Cyprinus carpio L.) were exposed to PAA (1.5 mg?l-1 ) and H2O2 (5 mg?l-1 ) for a period of 4 days. After the test ended, blood was collected from the fish to determine haematological and biochemical indicators, and swabs from gills and skin were taken for bacterial and parasitological examination. Haematologically, the following were determined: haematocrit (PCV), haemoglobin content (Hb), mean erythrocyte count (RBC), mean erythrocyte volume (MCV), erythrocyte haemoglobin (MCH), and mean corpuscular haemoglobin concentration (MCHC). From the blood plasma, the following biochemical indicators were assessed: glucose (GLU), total protein (TP), albumin (ALB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), inorganic phosphate (PHOS), calcium (Ca), triglycerides (TRIG), and globulins (GLOB). The haematological examination showed a statistically significant difference only in the mean erythrocyte volume (P<0.05), with an increase in MCV for the tested substances. Biochemical examination revealed statistically significant (P<0.01) increases in GLU, ALT, ALP, and PHOS levels. In TRIG, a statistically significant increase (P<0.05) occurred only in the group of fish exposed to H2O2. The last statistically significant (P<0.05) difference was observed in GLOB, with a decrease in the group of fish exposed to PAA and an increase in those exposed to H2O2. Bacteriological examination showed a statistically significant (P<0.05) difference in the reduction of bacterial counts on the skin of the fish for both tested substances. Parasitological examination revealed a statistically significant (P<0.05) effect of PAA on the occurrence of Trichodina sp., leading to the complete elimination of these parasites on both the skin and gills. The results showed that the haematological and biochemical indicators were only slightly altered compared to the control. It can be inferred that the application of PAA and H2O2 at the tested concentrations does not significantly stress the fish organism. It was also confirmed that PAA has antibacterial and antiparasitic effects, while H2O2 has only antibacterial effects.
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Possibilities of the use of peracetic acid in therapy of grass carp (Ctenopharyngodon idella)
ŠAUER, Pavel
The aim of the present study was to assess an influence of two different therapeutical concentrations of peracetic acid on selected haematological and biochemical parameters in grass carp (Ctenopharyngodon idella). Fish were radomly distributed to aquaria and exposed to concentrations of 0 mg.l-1 PAA (control group), 1.0 mg.l-1 PAA (P1 group), 3.0 mg.l-1 PAA (P2 group). Almost total mortality of fish was observed in the concentration 3.0 mg.l-1 PAA during the treatment comparing with the P1 group and untreated control where no mortality was observed. After the end of the experimental exposure of fish to peracetic acid, the sampling of blood has been realised. The samples of the blood were examined in order to determine haematological and biochemical parameters. Consequently, there were no significant differences (p<0.05) in a haematological profile of fish exposed to concentration of 1.0 mg.l-1 PAA. Goblet cells count and size have risen, that caused exposure of fish to peracetic acid. In the biochemical profile of fish, significant changes (p<0.01) in three parameters were found after exposure of fish to peracetic acid in concentration 1.0 mg.l-1. Changed parameters were: aspartate aminotransferase, creatine kinase and lactate dehydrogenase. The changes were moderate and it can be supposed that these changes are reversible. No significant change (p<0.05) in haematological parameters points out to the minimum negative influence of recommended therapeutical concntration (1.0 mg.l-1 PAA) to the health of C. idella.
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