Effects of gamma-irradiation on microbial contamination and on histological changes of muscle in Poecilia reticulata.

摘要

This study was conducted to determine the effect of gamma-irradiation on the microbial skin and organ contamination and on the histological changes of fish skeletal musculature. The aquarium fish Poecilia reticulata were exposed to the radiation effect of 60Co at doses of 20 and 30 Gy (11.36 Gy/min). Frequent intravital haemorrhages were observed from day 8 after the exposure. A general long-term body fading appeared from days 10 to 30 of the experiment. Microbiological and histological examinations were done on days 7, 14, 21 and 28. Individual muscle cells were bound together into fascicles surrounded by connective tissue. No significant morphological changes were observed on skeletal muscle cells, except for more watery connective tissue. The presence of Escherichia coli and Aeromonas hydrophila was proven in the body surface samples and in aquarium water based on the microbiological test. A moderate increase of the number of E. coli and A. hydrophila was observed in the intestines in both exposed groups (20 and 30 Gy) depending on the time that elapsed from the exposure (from 1x101 to 6x103 CFU). However, the heart, liver and musculature remained sterile. No microbial contamination of musculature was found for the intravital ionizing radiation dose of 30 Gy even for the single specimen killed on day 28 from the exposure.