[A cytogenetic study of the Chinese hamster lung cell line V-79 infected with Mycoplasma arginini and decontaminated using ciprofloxacin].

Karyotypic variability has been studied in a line of the Chinese hamster cells artificially contaminated with Mycoplasma arginini. The contaminated cultures differed from mycoplasma-free cells in cell distribution for chromosome number. The frequency of cells with modal chromosome number 21 decreased, while that of cells with 20 chromosomes increased. Decontamination of cell culture with ciprofloxacin (10 mg/ml) and a subsequent cultivation of cell in the antibiotic-free medium did not restore the original cell distribution for chromosome number. In-53--131 days after infection, the increased frequency of chromosomal aberrations was registered. Eradication of Mycoplasma by ciprofloxacin and a long-term cultivation in antibiotic-free medium restored the frequency of chromosomal aberrations to the control level corresponding to mycoplasma-free cultures. In contaminated cultures no cyto- or genotoxic effect of ciprofloxacin was observed. These data, together with the previous ones, enable the authors to recommend ciprofloxacin to make cell cultures free from mycoplasmas with minimal risk to change the original properties of cell lines.