University Of Tehran Press Pollution 2383-451X 11 4 2025 10 01 Antibiotic Resistance in Wastewater: Contamination Sources, Multidrug-Resistant Bacteria, and Treatment Impact in Southern Vietnam 1216 1226 103798 10.22059/poll.2025.388840.2753 EN Minh Trong Quang Department of Microbiology - Parasitology, School of Pharmacy, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam Thuy Thi Thu Mai Department of Microbiology - Parasitology, School of Pharmacy, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam Dieu Mai Xuan Do Department of Microbiology - Parasitology, School of Pharmacy, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam Huy Thanh Nguyen Department of Microbiology - Parasitology, School of Pharmacy, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam Thai Minh Nguyen Department of Microbiology - Parasitology, School of Pharmacy, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam Journal Article 2025 01 16 Antimicrobial resistance (AMR) poses a critical global challenge, and wastewater is a significant reservoir for antibiotic-resistant bacteria and resistance genes. This study investigates bacterial contamination and antibiotic resistance in wastewater from Southern Vietnam, specifically from the regions of Dong Nai, Binh Duong, Tay Ninh, and Ho Chi Minh City, by analyzing 105 samples of treated and untreated wastewater from healthcare, industrial, pharmaceutical, livestock, food production, and residential sources. Bacterial contamination was observed in 33.3% of samples, with untreated wastewater exhibiting higher contamination rates (38.6%) than treated wastewater (29.5%). The pharmaceutical and industrial wastewaters exhibited the highest contamination rates of 100% and 39.4%, respectively. Among the 51 bacterial isolates, Pseudomonas (27.5%), Burkholderia (23.5%), and Enterobacter (21.6%) were the predominant genera. Antibiotic susceptibility testing revealed high resistance rates, with 66.7% of isolates resistant to tetracycline, 33.3% resistant to sulfamethoxazole/trimethoprime, and 28.2% resistant to ciprofloxacin. Multidrug resistance (MDR) was observed in 25.5% of the isolates, with the highest MDR rates recorded in pharmaceutical (100%) and industrial (68.3%) wastewaters. These findings emphasize the need for stricter regulations on wastewater discharge, particularly from the pharmaceutical and industrial sectors, alongside the implementation of advanced wastewater treatment technologies and routine surveillance programs to mitigate the spread of AMR. This study highlights the regional dynamics of AMR in Vietnam and contributes to the global understanding of wastewater’s role in AMR dissemination, providing a foundation for targeted interventions to protect public health and the environment. https://jpoll.ut.ac.ir/article_103798_832bbec09a0b0adf4a2d41a93333b2aa.pdf