A “PathoMap,” a New York City-wide subway system microbiome map, has been published by study investigators from Weill Cornell Medical College. The study has been published in Cell Systems.

Over a period of 17 months, the study team used nylon swabs to collect DNA from turnstiles, wooden and metal benches, stairway hand railings, trashcans, and kiosks in all open subway stations for 24 subway lines across the five boroughs. Samples were also collected from train seats, doors, poles, and handrails. The team was able to sequence and analyze 1,457 samples out of the >4,200 collected.

Experiments showed live bacteria were present at all the subway sites tested. Bacteria was the most commonly found organism (46.9%), of which the majority (57%) were found on subway surfaces that have never been linked to human disease; viruses only made up 0.032% of the samples.

The microbes that reside in the New York City subway systems have been deemed mostly harmless, though some samples included drug-resistant bacteria (27%) and DNA fragments associated with anthrax (Bacillus anthracis) and Bubonic plague (Yersinia pestis); culture experiments of these DNA fragments did not show they were alive. The majority of the bacterial, viral, fungal, and animal species detected were non-pathogenic and represented typical bacteria present on human skin and body.

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The study also revealed that about half (48.3%) of the DNA sequences collected did not match any organism known to the National Center for Biotechnology Information or the Centers for Disease Control and Prevention. These undiscovered organisms highlight the potential for further scientific research.

The study’s senior investigator, Dr. Christopher E. Mason, assistant professor in Weill Cornell’s Department of Physiology and Biophysics, stated that repeat sampling could assist in long-term disease surveillance, mitigation of bioterrorism, and large scale health management for New York. Researchers are still analyzing more samples collected during all four seasons to assess the microbiome’s temporal dynamics.

For more information visit Weill.Cornell.edu.