Journal Article

Occurrence of antibiotics and antibiotic-resistant bacteria in the Lebanese polluted Litani River

Borjac, Jamilah M., Baydoun, Safaa A., Mounzer, Carine K., Amer, Ranya A.

2024

Overview

Antibiotic contamination in polluted rivers is well recognized as an environmental and public health challenge. In this study, the occurrence, distribution, and ecological risk assessment of three commonly used antibiotics (amoxicillin, ciprofloxacin, and azithromycin) were assessed in the Litani River, the most important and highly polluted river in Lebanon. Physicochemical and microbiological water quality parameters including the antibiotic-resistant ones were in parallel determined in the same sites. Water samples from five sites stretching across the river upper basin were analyzed for the antibiotics under study using high-performance liquid chromatography, with both fluorometric and UV detectors post-extraction using a solid-phase method with a hydrophilic-lipophilic balance cartridges. The disc diffusion method and standardized water quality methods were used for antibiotic-resistant bacteria and water quality assessment, respectively. Amoxicillin and ciprofloxacin were found at concentrations of 250 ng/L and 107.2 ng/L, while azithromycin was not detected in any of the sites under study. Varying levels of antibiotic resistance were detected with the isolated Escher ichia coli ( E. coli ) and Pseudomonas aeruginosa ( P. aeruginosa ) while the total coliforms showed resistance to multiple antibiotics. COD, TP, PO43-, TN, NO3-, NH4 + , E. coli , total coliform, P. aeruginosa , and Cd levels surpassed permissible levels. Correlation analysis with water quality parameters (COD, total phosphate, phosphate, total nitrogen, and cadmium) showed a significant positive correlation with ciprofloxacin (r > 0.5, p value < 0.05). Also, the resistant P. aeruginosa showed a significant positive correlation with cadmium ( r  > 0.5, p value < 0.05) while the resistant E. coli was positively correlated with total nitrogen, nitrate, and lead levels ( r  > 0.5, p value < 0.05). The ecological risk assessment revealed that all the tested antibiotics pose low risks (ecological risk quotient RQ < 0.1) except ciprofloxacin, which could pose a medium risk (0.1 < RQ < 1). Future research concerning the long-term assessment of antibiotics’ residues and the identification of resistance genes in the river is recommended.

• Publisher: Springer International Publishing,Springer Nature B.V
• Subject: Amoxicillin / Anti-Bacterial Agents - pharmacology / Antibiotic resistance / Antibiotics / Azithromycin / Bacteria / basins / Cadmium / Chromatography / Ciprofloxacin / Ciprofloxacin - pharmacology / coliform bacteria / Coliforms / Contamination / Correlation analysis / Detectors / Disease resistance / Drug resistance / E coli / Earth and Environmental Science / Ecological risk assessment / Ecology / Ecotoxicology / Environment / environmental assessment / Environmental impact / Environmental Management / Environmental Monitoring / Escherichia coli / fluorometry / Genes / Heavy metals / High-performance liquid chromatography / HPLC / Lead / Lebanon / Lipophilic / Liquid chromatography / Monitoring/Environmental Analysis / Nitrates / Nitrogen / Parameters / Penicillin / Phosphates / Pollutants / Pseudomonas aeruginosa / Public health / Quality assessment / Quality control / relative risk / Risk assessment / Rivers / Solid phases / total nitrogen / Ultraviolet detectors / Water analysis / Water pollution / Water quality / Water quality assessments / Water sampling