Ph.D.
Sittichoke Ketkaeo
Department of Microbiology, Faculty of Medicine, Khon Kaen University
Title: Ecological Structuring of Airborne Viromes Reveals Bacteriophage-Mediated Antimicrobial Resistance Signals in Northern Thailand
Name(s): Sittichoke Ketkaeo1, Tipaya Ekalaksananan1, Hans J. Overgaard2,3, Thawaree Nukpook1, Watcharapong Panthong1, Sirinart Aromseree1, Supranee Phanthanawiboon1, Jirayu Nuadthaisong1, Sirada Patthawaro1, Sutharini Rakkiattikhun1, Narathit Chanraeng1, Jittraporn kitwetchakun1 and Chamsai Pientong1*
1Department of Microbiology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
2Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway
3Department of Microbiology and Tropical Disease Research Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
*Corresponding author: chapie@kku.ac.th
Antimicrobial resistance (AMR) in ambient air remains poorly characterized, despite growing recognition of aerosol-mediated transmission pathways. Bacteriophages, which dominate environmental viromes, have emerged as potential vehicles for horizontal ARG transfer; yet their ecological distribution in outdoor air and contribution to airborne AMR remain poorly understood.
This study characterized the ecological structure of airborne bacteriophage communities across three habitat types and two seasons, and examined their role as reservoirs of clinically relevant ARGs in Chiang Rai Province, northern Thailand. Air samples were collected from twelve sites including temple/village, agriculture/forest, and dumpsite habitats during dry and wet seasons. Viral nucleic acids were extracted, sequenced on the Illumina platform, assembled, and taxonomically classified using BLASTx; bacteriophage contigs were screened for ARGs with CARD-RGI.
Metagenomic analysis yielded 22.4 million viral reads, with bacteriophages dominating the airborne virome (85.9%; 485 unique species); Acinetobacter-targeting phages (35%) and Escherichia-targeting phages (31%) were the predominant host groups. ARGs were identified in 64 of 1,120 phage sequences (5.7%; 75 hits spanning 21 antibiotic classes), including last-resort agents such as colistin and carbapenems. Dry season samples carried markedly more ARGs than wet season (49 vs. 26 hits; 65.3% vs. 34.7%), with all six colistin resistance determinants detected exclusively during the dry season. Temple/village habitats harbored the greatest ARG burden (45%; 34/75), followed by agriculture/forest (31%; 23/75) and dumpsite (24%; 18/75), while Acinetobacter phages accounted for 61% of all ARG hits (46/75), a 1.7-fold enrichment relative to their virome representation. These results identify airborne bacteriophages as ecologically structured AMR reservoirs, with season as the primary determinant of ARG burden and human-influenced habitats as key accumulation sites. Integrating phage-inclusive virome surveillance into AMR monitoring frameworks may be essential for capturing the full scope of environmental resistance dissemination.
Biography of the presenting author
Dr. Sittichoke Ketkaeo holds a Ph.D. in Bioscience and Technology from Kagoshima University. Currently a Postdoctoral Researcher at Department of Microbiology, Faculty of Medicine, Khon Kaen University, his research focuses on environmental virology, molecular epidemiology, and bioinformatics. He is part of the PANDASIA (Pandemic Literacy and Viral Zoonotic Spillover Risk at the Frontline of Disease Emergence in Southeast Asia to Improve Pandemic Preparedness) project, investigating viral emergence risks and environmental surveillance of viral pathogens in Southeast Asia.
Presenting author details
Full name: Dr. Sittichoke Ketkaeo
Contact number: +66 61 389 0922
Email: sittichoke.kk@gmail.com
ORCID: 0009-0006-2494-7129
Website: www.pandasia-project.com
Session name/ number: Environmental Microbiology
Category: Oral presentation