Screening and quantitative analysis of antibiotic resistance genes in hospital and aquaculture effluent in Sri Lanka as an emerging environmental contaminant

Hospital and aquaculture wastewaters play an important role in the evolution and spread of antibiotic resistance genes. In the present study, nine Antibiotic Resistance Genes (ARGs) were screened, which belong to two common groups of antibiotics: penicillin – OPR D, bla TEM, bla OXA, amp a, and amp b, and tetracycline – tet A, tet M, tet B, and tet S. The highest number of hospital wastewater sample locations were positive for bla TEM (51%) gene, followed in descending order by amp a (15%), bla OXA (14%), OPR D (5%) and amp b (1%). The highest number of positive sample locations for tet (M) genes was detected in aquaculture sampling sites (82%), followed by tet (A), tet (S), and tet (B) were 53%, 35%, and 18% respectively. A significant positive correlation (p = 0.001) between the concentrations of penicillin (0.001–0.024 μg/mL) and bla TEM gene (7.56 × 105–9.8 copies/mL) was found. The average concentrations of the OPR D and amp a was in the range 1.2–1.56 × 102 copies/mL, 1.2–6.56 × 105 copies/mL in hospital wastewater, whereas tet M and tet A in aquaculture effluent water was in the range 1.1–9.23 × 105 copies/mL and 1.3–4.56 × 104 copies/mL, respectively. The penicillin group (AMX, AMP, CLOX) in hospital wastewater effluent and tetracycline (TET, OTC) in aquaculture wastewater effluent were found to be important point sources of antibiotic pollution in their respective environments.

University of Sri Jayewardenepura; The Centre
for Water Quality and Algae Research and Department of Microbiology, University of Sri Jayewardenepura