Effects of erythromycin on Euglena gracilis as a model for testing the toxicity of antibacterial drugs.

Based on the main physiological and ultrastructural effects induced in Euglena gracilis by erythromycin, one of the least toxic of the commonly used antibiotics that specifically inhibit protein synthesis on 70S ribosomes of prokaryotic organisms, a symptomatologic picture is outlined which could be useful for the preliminary evaluation of the toxicity of antibacterial agents.