A study of microbial diversity could help lower rates of hospital infection

"Before it opened, the hospital had a relatively low diversity of bacteria," study author Jack Gilbert, director of the Microbiome Center at the University of Chicago, told the Chicago Tribune. Once the people arrived, "the bacteria from their skin took over."

On a patient's first day, germs tended to move from surfaces to the patient, but after that germs moved from the patient to the room, with a patient's germ makeup overtaking the room in 24 hours. The study also found that the longer a patient was in a room the more drug-resistant germs became.

Two findings were unexpected. In the heat and humidity of summer, staff members shared more bacteria with each other. Second, the effect of treatments—antibiotics, chemotherapy or surgery—was minimal.

Intravenous or oral antibiotics had little effect on the skin microbiome, Gilbert told UChicagoNews. "But when a patient received a topical antibiotic, then, as expected, it wiped out the skin microbes."

The study, published in May in the journal Science Translational Medicine, "may provide context to future studies of the transmission of hospital-acquired infections," the authors said.