Spread of resistant bacteria of anthropogenic origin in the environment of Lesvos island, Greece

Abstract

The aim of the present study was to investigate the single-drug and multidrug resistance of different environmental bacterial strains to antibiotics. All samples were collected from the island of Lesvos, Greece. The Escherichia coli and enterococci isolates came from wells, boreholes, untreated water, thermal- hot springs, farming and poultry farming, private polls, wastewater treatment plants input and output water, aquacultures, urban wastewater and hospital waste. We analyzed for antibiotic resistance of 193 strains E.coli and 97 strains enterococci. Resistance was tested against Norfloxacin, Ciprofloxacin, Levofloxacin, Amoxicillin, Cefaclor, Vancomycin, Ampicillin, Ceftazidime and Cefuroxime. Approximately 32% of the Escherichia coli strains proved resistant to at least one antibiotic, while 7% showed multiple drug resistance to two antibiotics and only 4% proved resistant to three. Respectively, among the enterococci strains only 2% proved resistant to one antibiotic, 31% showed multiple drug resistance to four antibiotics and a mere 1% was resistant to 8 antibiotics. The strains originating from drinking-water springs exhibited a generalized susceptibility. All Escherichia coli strains showed 100% resistance to Vancomycin.