Antibiotic Resistance Levels of Pathogens Isolated from Medical Wastewater in Urumqi

Objective To detect the levels of bacteria resistance to antibiotics in hospital wastewater in Urumqi.

Methods Wastewater samples were collected from the inlets and outlets of wastewater treatment systems in four general hospitals in Urumqi. The resistance level of pathogenic bacteria and contamination levels of antibiotic resistant bacteria in hospital wastewater were detected by heterotrophic plate counts. The detection of antibiotic resistant genes(ampC, tetO, tetW, sul1, sul2, qnrD, and qnrS) in antibiotic resistant pathogens was illustrated by PCR.

Results The resistance rates of isolated bacteria to ampicillin, tetracycline, sulfadiazine, and ciprofloxacin were 47.1%, 63.4%, 53.4% and 42.4%, respectively. In addition, the detection rates of seven antibiotic resistant genes ranged from 66.7% to 100.0% in the corresponding resistant bacteria. However, after sewage treatment, the concentrations of antibiotic resistant bacteria were 1.01×10⁸-1.39×10⁸ CFU/mL in the effluent samples, which were released to natural environment.

Conclusion The hospital wastewater in Urumqi is polluted with antibiotic resistant bacteria and has become one of the reservoirs and contamination sources of antibiotic resistant bacteria.