Antibiotic resistance is one of the major health problems of the 21st century. The development and spread of antibiotic resistance is influenced by human, animal and environmental reservoirs. Little is known in Slovenia about the presence of bacteria with reduced sensitivity to antibiotics in the non-hospital environment. Among the major resistant bacteria that pose a threat to human health are bacteria with genes for the enzymes ESBL and carbapenemase. The aim of the study was to isolate bacteria that are phenotypically resistant to betalactams with extended spectrum and carbapenem from surface and groundwater associated with the selected landfill and genotypic definition of phenotypic resistance based on the secretion of enzymes for betalactamase (ESBL) and carbapenemases. Bacteria from groundwater and surface water samples were isolated by three specific selective-differential media and identified using MALDI-TOF. ESBL enzymes and carbapenemases were first confirmed by phenotypic tests (combined disk method to confirm ESBL and CIM tests), then their genes were determined by commercially available kits. Surface water isolates were found to be resistant to more antibiotics than groundwater isolates. Molecular tests confirmed the presence of resistance genes in two isolates isolated from surface waters. In the case of Klebsiella oxytoca isolate (ZZV20-11045) isolated from surface rainwater, the gene for the enzyme CTXM-1 and the gene for the enzyme OXA-48 were confirmed. In the isolate of Pseudomonas aeruginosa (ZZV20-11064), which was isolated from surface leachate, the presence of the gene for the enzyme from the VIM group was confirmed. More betalactam and carbapenem resistant bacteria were isolated from surface waters than in groundwater. In both resistant microorganisms, the presence of genes for ESBL and carbapenemase enzymes were confirmed (genes blaVIM, blaCTXM-1 and blaOXA-48 were detected).
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