[Intestinal Microbiota in Migrating Barn Swallows around Osaka]

Area of Science:

• Microbiology
• Ornithology
• Ecology

Background:

• Migratory birds, like barn swallows (Hirundo rustica), can transmit infectious diseases over vast distances.
• The gastrointestinal microbiota of barn swallows is not well-understood, despite their significant migratory populations.

Purpose of the Study:

• To characterize the fecal bacterial community in barn swallows during their spring migration to Japan.
• To identify potentially pathogenic bacteria within the barn swallow fecal microbiota.

Main Methods:

• 16S rRNA gene metagenomic sequencing of fecal samples collected from barn swallows in Osaka.
• Quantification of total bacteria and analysis of bacterial community composition.
• Detection and identification of potentially pathogenic bacterial genera.

Main Results:

• The total bacterial count was approximately 2.1(±3.4)×10^8 per gram of feces.
• Bacterial communities were dominated by families including Enterobacteriaceae, Pseudomonadaceae, and Mycoplasmataceae.
• Potentially pathogenic bacteria, such as Pseudomonas spp., Escherichia/Shigella spp., and Enterococcus spp., were detected at rates >0.1%.

Conclusions:

• Barn swallows harbor a diverse fecal microbiota, including potentially pathogenic bacteria.
• These migratory birds play a significant role in the long-distance transmission of various bacterial genera.