Mice live where we live, so it can be easy for whatever germs they carry to be transferred to us. A new, year-long assessment of mice in New York City discovered an amazing six new viruses, as well as antibiotic-resistant bacteria.

The study collected 416 mice in the city over a year period, and then analyzed their droppings for bacteria and viruses. Running genetic tests, the researchers found 149 species of bacteria. Included were the most common causes of gastrointestinal problems: Salmonella, Shigella, E. coli, and C. difficile. Salmonella alone causes 1.2 million reported cases in the US each year, including 450 deaths.

Also alarming was that the genes indicated antimicrobial resistance to several common antibiotics, meaning the mouse droppings contained bacteria that would be difficult to treat with common antibiotics. There were also 36 different viruses in the droppings, including six new viruses never seen before. Fortunately, none of the known viruses were known to affect humans, but it is not known if the new viruses can infect humans