Bacterial resistance and genotoxicity of wastewater in a Lebanese University hospital

Abstract

Hospital wastewater is a major source of micropollutants and toxic chemicals, which have a hazardous effect on the environment. The aim of the study is to assess the genotoxicity of wastewater in a university hospital in a rural area of Lebanon and to evaluate the presence of multidrug resistant bacteria in wastewater. The samples were taken on a five day period, twice per day morning and afternoon, from four different pits, from different departments of the hospital. Bacteria were isolated from the samples; they were identified along with their resistant β- lactamases enzymes. Genotoxicity was evaluated using the SOS-Chromotest with the Escherichia coli PQ37 and the Ames Fluctuation Test with Salmonella typhimurium TA 98, with and without metabolic activation According to the samples collected, around 67.5% of the strains were Extended spectrum β-lactamases (ESBL) procedures, 25% were AmpC producers and 3 other strains were divided between AmpC/ESBL producers, Inhibitor resistant TEM (IRT) procedure and IRT/ESBL. The SOS Chromotest showed slightly or no genotoxicity at the concentrations tested. In the Ames Fluctuation test, 62.5% of the pits were non-genotoxic, 31.25% were slightly genotoxic and 6.25% were moderately genotoxic at the (x1) concentration. Moreover, an increase in genotoxicity was observed in the Ames Fluctuation test after metabolic activation. However, genotoxicity was much lower in this study compared to our previous work in a central university hospital.