Journal of Research in Environmental Health

Journal of Research in Environmental Health

Isolation and Identification of Municipal Excess Sludge and Investigation of Its Resistance to Amoxicillin and Gentamicin

Document Type : Research article

Authors
Elahe khayyami 1
Roya Mafigholami 2
Saviz, Shahrooz 3
, Hadi Farsiani 4
Amir Hossein Sari, 5
1 - PhD. Student, Department of Environment, West Tehran Branch, Azad Islamic University, Tehran, Iran
2 Associate Professor, Department of Water and Wastewater Environment, West Tehran Branch, Azad Islamic University, Tehran, Iran
3 Professor, Plasma Physics Research Center, Science and Research Branch, Azad Islamic University, Tehran, Iran
4 Assistant Professor, Department of Microbiology & Virology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
5 Assistant Professor, Quantum Technologies Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran
10.22038/jreh.2026.28094
Abstract
Background and Objective: Sustainable Municipal Sewage Sludge Management (MSS ) and its stabilization to reduce pathogens and unpleasant odors are critical environmental imperatives. However, the influx of antibiotic residues into wastewater systems can affect the diversity and function of microbial communities, posing new challenges for biological stabilization processes. Consequently, the present study was designed to isolate and identify bacterial strains from municipal excess sludge samples and analyze their resistance patterns against amoxicillin and gentamicin, in order to evaluate the impact of these compounds on the performance of these strains.

Materials and Methods: In this descriptive-analytical study, bacterial strains were isolated from municipal waste activated sludge. The strains were identified via biochemical tests, and their antibiotic resistance patterns against amoxicillin and gentamicin were evaluated using the disk diffusion method.

Results: The results demonstrated a significantly high level of antibiotic resistance among the bacterial agents isolated from the waste activated sludge. Among the antibiotics studied, the highest resistance was observed toward amoxicillin.

Conclusion: The findings indicate that the excessive and improper use of antibiotics in healthcare has led to increased microbial resistance within sewage treatment environments. Consequently, it is recommended to revise protocols for managing unused medications and optimize sludge stabilization methods by considering the influence of antibiotics.

Open Access Policy: This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/
Keywords
Waste Activated Sludge
Municipal Sewage
Stabilizing Bacteria
Antibiotic
Antibiotic Resistance
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