Related Experiment Video
Updated: Jun 19, 2026
Avian Influenza Surveillance with FTA Cards: Field Methods, Biosafety, and Transportation Issues Solved
Published on: August 2, 2011
Winter migratory birds may carry diverse antimicrobial resistance genes into Japan
1Biodiversity Division, Biodiversity Resource Conservation Office, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305- 8506, Japan. nabeshima.kei@nies.go.jp.
Background:
Environmental surveillance of antimicrobial resistance (AMR) in wildlife remains limited, despite increasing recognition that resistance determinants can circulate across human, livestock, and natural ecosystems. Migratory waterbirds move long distances and aggregate at shared stopover and wintering sites, potentially facilitating the acquisition and redistribution of antimicrobial resistance genes (ARGs) across regions. However, nationwide evidence describing the breadth of ARGs carried by winter migratory birds in Japan is scarce. We assessed the diversity and distribution of ARGs in pooled fecal samples from winter migratory birds across Japan.
Methods:
We analyzed pooled fecal DNA collected at migratory bird habitats across 12 local governments during the 2021-2022 and 2022-2023 winter seasons (24 pools). Avian host origin was inferred by DNA metabarcoding, and ARGs were profiled by probe-based target enrichment with read-based detection (ARG detected at ≥ 10 reads).
Results:
Ducks (Anas spp. and Mareca spp.) were the predominant inferred hosts. ARGs were detected in all areas and included genes associated with resistance to multiple antibiotic classes used in livestock production. Across the two seasons, genes associated with resistance to gentamicin, cephalosporins, macrolides, tetracyclines, fosfomycin, clindamycin, penicillins, streptogramins, sulfonamides/trimethoprim, colistin, erythromycin, chloramphenicol, rifampicin, and isoniazid were detected in all 12 areas in at least one season. Genes associated with resistance to agents restricted for use in Japanese livestock production, including colistin, erythromycin, chloramphenicol, and rifampicin, were also detected in all 24 pools. Isoniazid-, gentamicin-, meropenem-, and tigecycline-associated genes were detected in 23/24, 20/24, 11/24, and 9/24 pools, respectively.
Conclusions:
These data indicate widespread environmental occurrence of diverse ARGs and support the possibility that migratory birds could contribute to long-distance dispersal of ARGs. Culture-based isolation, phenotypic testing, and quantitative analyses will be needed to identify host bacteria and assess clinical relevance.
Insights
Migratory birds in Japan carry diverse antimicrobial resistance genes (ARGs), including those linked to restricted livestock antibiotics. This highlights their potential role in the long-distance spread of ARGs across ecosystems.
Area of Science:
- Environmental microbiology
- Wildlife ecology
- Genomics
Background:
- Limited data exists on antimicrobial resistance (AMR) in wildlife, yet resistance genes circulate among human, livestock, and natural environments.
- Migratory birds are potential vectors for AMR gene dissemination due to their extensive travel and aggregation patterns.
- Nationwide data on AMR genes in Japanese winter migratory birds is scarce.
Purpose of the Study:
- To assess the diversity and distribution of antimicrobial resistance genes (ARGs) in fecal samples from winter migratory birds across Japan.
- To investigate the role of migratory birds in the environmental spread of ARGs.
Main Methods:
- Analysis of pooled fecal DNA from migratory bird habitats across 12 Japanese local governments over two winter seasons (2021-2023).
- Inference of avian host origin using DNA metabarcoding.
- Profiling of ARGs via probe-based target enrichment and read-based detection.
Main Results:
- Ducks were the predominant inferred hosts.
- ARGs were detected in all surveyed areas, indicating widespread environmental presence.
- Genes conferring resistance to multiple antibiotic classes, including those restricted in Japanese livestock (colistin, erythromycin, chloramphenicol, rifampicin), were prevalent in all samples.
Conclusions:
- Widespread occurrence of diverse ARGs in migratory birds suggests their potential contribution to long-distance ARG dispersal.
- Further research, including culture-based isolation and quantitative analyses, is necessary to identify host bacteria and assess clinical relevance.
Related Concept Videos
01:30Development of Antibiotic Resistance
00:53Migration
01:25Clinical Significance of Antibiotic Resistance
01:25Mechanism of Antibiotic Resistance in MRSA
02:39Gene Flow
01:19Conjugation