Fecal indicators resistance to antimicrobial agents present in municipal wastewater

In this study removal rate of six antimicrobial compounds (belonging to folate pathway inhibitors and macrolides class) was analyzed in processes of local Wastewater Treatment Plant (WWTP) together with susceptibility patterns of Erythromycin (E) resistant Enterococcus spp. and trimethoprim/ Sulfamethoxazole (SXT) resistant Escherichia coli. According to the obtained data, six of tested antimicrobial agents, namely erythromycin, clarithromycin, trimethoprim, roxithromycin, sulfamethoxazole and N-acetyl-sulfamethoxazole were detected in both raw and treated wastewater samples. Among tested E. coli resistance to SXT was highly correlated with resistance to penicillins as well as to tetracycline (88% and 75%, respectively) while E-resistant E. faecalis and E. faecium showed significant differences in resistance patterns. Among tested isolates of wastewater origin resistance phenotype of clinical importance were detected. Thus, further study is needed to evaluate dissemination of antimicrobial resistance via treated wastewater.