Risk assessment and photo-disinfection of antibiotic residues and antibiotic-resistant bacteria in water sources from Ede,avy Metals in Groundwater Sources from Two Rural Communities in Nigeria
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Date
2025-05-16
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Abstract
Environmental antibiotic residues (EARs) and antibiotic-resistant bacteria (ARB) are known to
contribute to global antimicrobial resistance (AMR). This study investigated EAR levels in
selected wells, river, abattoir wastewater, bottled water and sachet water from Ede, Nigeria.
Ecological risk quotient (RQ) and health risk (Hazard quotient) of the levels of these EARs, ARB
and multidrug-resistant bacteria (MDR) with their antibiotic resistance were calculated. Antibiotic residues detected included tetracycline-TET (14.2–135.8 μg/L), chloramphenicol-CHL
(6.8–224.7 μg/L), metronidazole-MET (3.7–83.8 μg/L), sulfamethoxazole-SUL (0.56–18.6 μg/
L), and ciprofloxacin-CIP (3.8–97 μg/L). Antibiotic residues in STW samples were below the
detection limit while ampicillin was not detected in any of the water samples. Chloramphenicol
posed the highest ecological risk to algae while infants were particularly at risks of ciprofloxacin
and metronidazole resistance in various water sources. No health risk due to bottled water
exposure is observed for any population group. The mean log10 bacteria count (cfu/mL) followed
the trend abattoir (5.68) > river (5.67) > hand-dug well (5.53) > sachet (5.03) > bottled (4.83).
The most occurring ARB in water samples are Bacillus spp (36.3 %) > Staphylococcus (27.5 %)
and the most dominant MDR isolate is Bacillus cereus. All isolates exhibited 62.5, 100, 31.3, 77.5,
58.8 and 33.8 % resistance to AMP, MET, CIP, TET, CHL and SUL, respectively. Visible-light
composite material (Cu/Zn-doped delaminated kaolinite) completely disinfected 12.5 and 15.8