http://www.newsweek.com/scientists-track-how-antibiotic-resistant-genes-can-hitch-rides-subway-1066205

Microbes live all around us. They thrive in our guts and propagate on our skin. They also ride the subway.

Some microbes can lead to illnesses like stomach bugs that are easily treated, but others are far worse. Antibiotic resistant bacteria are so resilient they can sometimes kill their human hosts. This is why one team of scientists at the University of Hong Kong wanted to better understand how dangerous pathogens travel through cities and move through populations.