Inside the Secret Microbial World of Bat Wings

Inside the Secret Microbial World of Bat Wings

Think of wildlife microbiomes, and you probably picture forests, wetlands, or soils teeming with life. But what about the delicate skin on a bat’s wings? It turns out these thin membranes host a surprisingly diverse community of bacteria and fungi—and cracking their secrets could help us protect bats from devastating diseases like white-nose syndrome (WNS).

A recent paper by Insuk et al. (2024) in Microbial Ecology set out to map exactly what microbes live on bat wings in Lillooet, British Columbia—a region not yet touched by WNS.

Why Bat-Wing Microbes Matter

Healthy wings are essential for bats’ survival and reproduction. Their wing-skin microbiome can help fend off pathogens, tune their immune responses, and even influence how they resist WNS—the fungus-driven disease that has killed millions of North American bats. By cataloguing the “normal” microbial residents, scientists can spot which bacteria or fungi might be recruited as natural defenders should WNS arrive in Western Canada.

Big brown bat (Eptesicus fuscus): In BC’s Okanagan Valley, maternity colonies of up to ~200 individuals nest in cavities of dead Ponderosa pines and rock crevices. They hibernate from November–April in buildings or mines, yet coastal populations may rouse on mild winter nights.

DNA Extraction & DNA Metabarcoding: Study Workflow

Extracting DNA from bat wings is no easy feat: wings yield very few microbial cells, and skin oils, salts, and debris can jam up PCR and sequencing. Insuk and colleagues tackled this with a kit to pull out DNA—even from those ultra-low-biomass swabs.

  1. Careful Sampling: Sterile swabs rolled over both sides of each wing, stored frozen within hours.
  2. Powerful DNA Cleanup: Vortexing plus the Sox kit’s spin-column chemistry stripped away blockers like lipids and salts.
  3. Dual-Marker Sequencing: Bacterial 16S (V4) and fungal ITS1 regions were amplified in triplicate, pooled, and sequenced on Illumina MiSeq.
  4. High-Resolution Analysis: DADA2 denoised the data into thousands of exact sequence variants (ASVs), then SILVA and UNITE databases assigned taxonomy.

Yuma myotis (Myotis yumanensis): In British Columbia, this little 6 g bat is limited to low‐elevation coastal forests, Ponderosa Pine/Douglas‐fir woodlands, and arid grasslands—and in summer, huge maternity colonies (1,500–4,100 adults) cluster under bridges and in buildings right next to open water.

DNA Metabarcoding of Bat Wings: Key Microbiome Discoveries

  • Massive Diversity: Over 3.2 million bacterial reads yielded 4,167 ASVs across 27 phyla and 639 genera; 3.1 million fungal reads gave 11,722 ASVs across 16 phyla and 806 genera.
  • Key Bacterial Players: Proteobacteria dominated—especially Delftia tsuruhatensis, found on every bat wing (22–67% relative abundance). This species is seldom reported on bats elsewhere, making its prevalence here particularly intriguing.
  • Fungal Front-Runners: Ascomycota led the fungal charge, with Cladosporium and Aspergillus present on almost all individuals.
  • Site & Species Signatures: Big brown bats (Eptesicus fuscus) carried richer bacterial communities than the two Myotis species, and different field sites—grasslands vs. riparian forests vs. rocky valleys—each had distinct microbial “fingerprints.”
  • No WNS Pathogen Detected: Although some Pseudogymnoascus sequences showed up (~27% of bats), none matched P. destructans, and targeted qPCR confirmed the WNS-causing fungus was absent.
  • Linked Diversity: Samples with high bacterial richness tended to have high fungal richness too (Spearman’s ρ≈0.32, P=0.006), hinting at interwoven bacterial–fungal networks on bat skin.

Little brown myotis (Myotis lucifugus): Occupying Thompson, Okanagan and Kootenay regions, these 6–9 g bats use abandoned mines and dark caves as their “frost‐free” winter hibernacula—and in early summer females choose cellars, caves or unoccupied buildings for maternity roosts, where pups fledge in just 3–5 weeks.

Applying Bat Wing Microbiome Insights for WNS Control

By defining the baseline wing microbiome of bats in a WNS-naïve region, this study lays the groundwork for probiotic or biocontrol approaches: researchers can now hunt for those native bacteria, like certain Pseudomonas species, with proven anti-P. destructans activity and consider them as living shields. At the same time, discovering highly abundant but little-known microbes (e.g., Delftia tsuruhatensis) opens doors to uncovering new antimicrobial compounds. In short, bat wings aren’t just flight surfaces—they’re miniature ecosystems full of allies we may one day harness to safeguard these essential, insect-eating mammals.

🔬 Interested in tackling challenging environmental DNA samples yourself? Check out our Sox DNA Extraction Kit for reliable, inhibitor-resistant DNA preps from low-biomass, high-inhibitor samples—perfect for wildlife microbiome work (or any tough sample).

Insuk, C., Cheeptham, N., Lausen, C., & Xu, J. (2024). DNA metabarcoding analyses reveal fine-scale microbiome structures on Western Canadian bat wings. Microbiology Spectrum, 12(12), e00376-24. https://doi.org/10.1128/spectrum.00376-24

Keywords: bat wing microbiome, white-nose syndrome, inhibitor-resistant DNA extraction, DNA extraction, DNA metabarcoding

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