Urban Transit System Microbial Communities Differ by Surface Type and Interaction with Humans and the Environment

Area of Science:

• Environmental microbiology
• Urban microbiome studies
• Metagenomics and amplicon sequencing

Background:

• Public transit systems offer unique environments for studying urban microbiomes and microbial transfer.
• Previous studies on subway microbiomes are limited and have yielded varied conclusions.
• The Boston subway system provides a high-traffic environment relevant for public health microbial research.

Purpose of the Study:

• To profile microbial communities on various surfaces within the Boston metropolitan transit system.
• To identify determinants of microbial community structure and function.
• To assess the presence of antimicrobial resistance and virulence genes in the transit environment.

Main Methods:

• Utilized 16S amplicon and shotgun metagenomic sequencing.
• Sampled multiple transit surfaces across different train lines and stations.
• Performed functional profiling of microbial communities.

Main Results:

• Microbial community structure was primarily determined by surface type, not geographic location or demographics.
• Human skin and oral commensals (e.g., Propionibacterium, Staphylococcus) dominated all surfaces.
• No significant reservoir of antimicrobial resistance or virulence genes was detected.

Conclusions:

• Transit surface microbiomes are shaped by human commensals and environmental generalists.
• Enrichments in microbial pathways correlate with local human interactions and environmental exposures.
• Understanding transit microbiomes is crucial for public health surveillance and designing healthier public spaces.