With an outbreak of “nightmare bacteria” in a Chicago suburb hospital that has infected 40 people in the last year, the threat of drug-resistant bacteria is growing.

The bug, known as carbapenem-resistant enterobacteriaceae (CRE), bears a rare enzyme that breaks down antibiotics. According to The Centers for Disease Control and Prevention (CDC), 2 million people have been infected and 23,000 have died from various kinds of drug-resistant bacteria over the last year.