Evaluation of DNA damage by means of the comet assay and micronucleus test in erythrocytes of Prussian carp (Carassius auratus gibelio) infected with ulcerative disease

Abstract

The influence of ulcerative disease infection on the level of DNA damage was assessed in erythrocytes of Prussian carp (Carassius auratus gibelio). Microbiological examination of the experimental fish revealed the presence of Aeromonas and Pseudomonas bacteria in infected fish. Ten blood samplings were performed with the same fish individuals before and after i. p. injections of antibiotic oxytetracycline (OTC). The comet tail moment (CTM), the frequencies of micronucleated (MN) and amitotic (AM) erythrocytes were evaluated. The level of CTM in infected fish was higher than in controls (p < 0.0001) and significantly decreased after OTC injections (p < 0.0001). The frequency of MN erythrocytes was systematically higher in infected fish (p = 0.003) and did not decrease after OTC injections (p = 0.918). Thus, infection triggered DNA damage in fish erythrocytes. The levels of amitotically dividing erythrocytes were elevated in all individuals, and there were no significant difference between the infected and control groups (p = 0.8). Probably both infection and repeated blood sampling were the reasons for amitotic division of erythrocytes. Key words: micronuclei, comet assay, genotoxicity, amitosis Keywords: micronuclei, comet assay, genotoxicity, amitosis, erythrocytes, bacterial infection, Carassius auratus gibelio