| Abstract [eng] |
Aquatic oomycetes (Latin: Oomycota) are freshwater fungus-like stramenopiles, also known as water molds. Oomycetes are distinct because of their multinucleated hyphae, heterokont zoospores and the formation of sexual structures - oogonia with oospores and antheridia. These organisms also do not have chitin in their cell wall structure but have cellulose and glycans. Most aquatic oomycetes belong to the order Saprolegniales (phylum Oomycota, kingdom Stramenopila) and usually live as saprotrophs, decomposing plant matter and participating in the water self - purification process, however, some species can change the saprotrophic lifestyle to pathogenic and infect various fish, crustaceans, amphibians. High ecological plasticity, morphological variability and genetic variability can complicate the identification of these organisms. In addition to the difficulties in identifying oomycetes, other difficulties have arisen, especially in fish farms and natural aquaculture, since there are no methods for treating or preventing mycoses caused by this fish pathogen - saprolegniosis. Oomycete colonies isolated from water samples from lotic freshwater bodies were identified by morphology and their identity was confirmed by a molecular method based on the analysis of rDNA ITS region sequences. In this work, the effect of the bacterial experimental preparation M20G, temperature and electroporation on oomycetes of the Saprolegniales order was studied. It was found that amphotericin B, itraconazole, nystatin, griseofulvin and the experimental M20G agent are potentially effective drugs in the treatment of saprolegniosis. When examining the effect of temperature on the growth rate of oomycetes, it was determined that cultures grown at 5 ºC grew the slowest, especially D. monosporus, while at 15 ºC and 20 ºC they grew faster and there were small differences between genera. In experiments with electroporation of oomycete oogonia, it was found that after exposing them to 20 kV/cm power, 5 µs width and 120 pulses, they were torn open and new colonies no longer formed. |
