Ecotoxicology of some Antibiotics (Ciprofloxacin, Penicillin G and Tylosin) and Their Mixture on Cyanobacteria Mats Collected from Wadi Gaza, Palestine

Abstract

The extensive use of the antibiotics for human and animals health creates many environmental problems. The present study aimed to investigate the growth inhibition effect of Penicillin G, Ciprofloxacin, and Tylosin as single and mixtures to non-target microorganism cyanobacterial mats collected from Wadi Gaza - Palestine. Toxicity of antibiotics to cyanobacterial mats was tested at various concentrations. Concentrations of the tested antibiotics were as follows: Penicillin G and Tylosin from 0-80 mg/l and Ciprofloxacin was 0-1 mg/l. Single toxicity tests showed that EC50 of Penicillin, Ciprofloxacin and Tylosin were 0.13, 0.71, 5.28 mg/l respectively. Relative toxicity showed that Penicillin and Ciprofloxacin were more toxic to cyanobacterial mats than the standard toxic material which is Diuron. Binary mixtures have toxicity values 0.077, 0.103, 0.292 TU, for (Penicillin+Tylosin), (Ciprofloxacin+Tylosin) and (Ciprofloxacin+ Penicillin) respectively. Tertiary mixture showed toxicity higher than binary mixtures and has EC50 0.034 TU. Potential antagonistic effects between tested compounds in binary and tertiary mixtures were observed. Statistical analysis of the results indicated significant differences between the toxic effects of compounds and mixtures to cyanobacterial mats. The toxic effects over the time indicated that cyanobacterial mats were able to overcome the toxic effects after, approximately 72h of exposure time. From these results we can conclude that the antibiotics exert dangerous toxic effects to the environment. This study recommend the rational use of the antibiotics for human and animals. To the best of our knowledgment this results are considered the first results that demonstrate the toxic effects of antibiotics in Palestine and may be in the Arab world.