Antibiotic resistance pattern and prevalence of qacEΔ1 and sul1 genes in Pseudomonas aeruginosa from hospital wastewater

Introduction: Hospital effluents may pose great environmental risk due to the presence of pathogenic microorganisms, drugs and chemical components. Pseudomonas aeruginosa is an opportunistic pathogen frequently found in hospital environment. Objective: To evaluate the resistome of P. aeruginosa from the hospital wastewater treatment plant (HWTP) in a hospital complex of Rio de Janeiro city. Method: Twenty isolates from the five stages of the HWTP were identified as P. aeruginosa by 16S rRNA gene sequencing analysis. Susceptibility to antibiotics was determined according to CLSI and qacEΔ1 and sul1 genes were detected by PCR. Sulphonamide residues were investigated by high performance liquid chromatography coupled to sequential mass spectrometry. Results: The sulfamethoxazole has been demonstrated at a level below 50 ng L-1. Sulfonamide resistance (80%) has been demonstrated followed by quinolone class (50%) and 13 susceptibility patterns to antimicrobials. The qacEΔ1-sul1 genes were detected in 100% of isolates suggesting the presence of class 1 integrons in the whole HWTP. Conclusions: The results signalized limitations of HWTP and propagation of resistance genes in all stages of the HWTP. These data also contribute to the environmental sanitary surveillance in the design of prevention actions against negative impact on the public health