Antibiotic resistant bacteria in surface waters in Slovakia

This work deals with the occurrence of selected antibiotic resistant bacteria in Slovak surface waters. Total and antibiotic resistant coliform bacteria, enterococci and coagulase positive staphylococci were determined in 34 samples of surface water from rivers and still waters (dams, natural lakes, thermal bath) some of them used for recreational swimming. Sampling was performed during summer season 2017 (July and August). The number of total coliforms ranged from 1.74 log CFU/10 mL to 3.69 log CFU/10 mL. Coliform bacteria were registered in each tested sample. The highest number was observed in the sample from river Hron. Majority of samples contained ampicillin and tetracycline resistant bacteria. Enterococci were determined in 70 % of samples ranging from 0.78 log CFU/10 mL to 3.81 log CFU/10 mL. The highest number of enterococci was observed in river Váh. Ampicillin and vancomycin resistance prevailed over ciprofloxacin and gentamicin resistance. Coagulase positive staphylococci were present in 91 % of samples in the range of 0.70—3.03 log CFU/10 mL. Antibiotic resistant coagulase positive staphylococci were observed only in 32 % of samples, predominantly from rivers. In these samples, chloramphenicol resistance predominated. In three samples of water used for recreational purposes, the limit value for enterococci and E. coli according to Slovak legislation (Decree no. 308/2012 Coll.) for the quality of water in natural swimming pools during bathing season was exceeded.