Bubonic plague, meningitis, antibiotic-resistant infections? That New York’s trains are rife with germs is no surprise, but who knew it was such a diverse thriving universe?

In a recent 18-month sample-collecting mission, researchers from Weill Cornell Medical College swabbed and dabbed surfaces from the complete set of 466 Metropolitan Transit Authority stations to map out the first genetic profile of a city’s transportation system. The data-gathering project is part of a larger effort to understand public life at the microscopic level.

"By documenting the miniature wildlife," reports The Wall Street Journal, "microbiologists hope to discover new ways to track disease outbreaks – including contagious diseases like Ebola or measles – detect bioterrorism attacks and combat the growing antibiotic resistance among microbes, which causes about 1.7 million hospital infections every year."

The team had no easy task. They sequenced more than 10 billion fragments of biochemical code and sorted it by supercomputer; the results are staggering. They detected 15,152 types of life-forms. Almost half of the DNA belonged to bacteria, but most of it harmless or in quantities that pose little human health risk. They found bacteria from food, pets, plants, shoes, trash, sneezes, and dirty hands. Along with human, mice, rat and lice DNA, they found evidence of flies and beetles, and even fish – likely there from the 14 million gallons of water that get pumped out of the subways daily.

At the South Ferry Station, which hasn’t been open since superstorm Sandy, they found bacteria that have previously only been seen in Antarctica.

Of the 562 species of bacteria they have detected so far, at least 67 of those species can make us ill, but again, were detected at such minor levels that they are unlikely to cause problems in a healthy person. According to the report, they found DNA related to strep infections at 66 stations and urinary tract infections at 192 stations. E. coli lived in 56 stations they sampled and food poisoning bacteria was found at 215 stations. In 409 stations the multidrug resistant bacterium Stenotrophomonas maltophilia, associated with respiratory ailments and hospital infections, made an appearance.

On a garbage can, a farecard vending machine and a stairway handle they found the bacteria that brings us bubonic plague. But not to worry, New Yorkers. The U.S. Centers for Disease Control and Prevention notes that it has been 12 years since a human diagnosis of plague has been reported in New York City. City slickers are tough birds.

And while all of this might sound daunting and enough to inspire the donning of hazmat suits for the morning commute, researcher Dr. Christopher Mason reminds us that everything around us – including us – is awash in bacteria. The human body is typically home to some hundred trillion microbial cells comprised of five million different genes, adding up to nearly 5 pounds of micro-organisms per person. Human cells are outnumbered by other microbes by 10 to 1.

“You are a minority party in the democracy of the body,” Mason said.

Which puts things in perspective when it comes to the subway, and really just goes to show that there is an incredibly complicated universe happening in a world too teeny for us to see. The takeaway? The world is as small as it is big, and it’s fascinating.

The subway findings might unsettle some people, Dr. Mason acknowledged, but he said they illustrate the remarkable microbial diversity of a healthy city. “I don’t want people to be terrified,” he said. “I want them to be intrigued.”

To see an interactive map of the findings, head over to The Wall Street Journal.