Bacteria that cause infections in hospitals are increasingly becoming resistant to antibiotics, and a group of bacterial species called Enterobacterales that are able to fend off a type of antibiotic called carbapenems are a particular problem. They cause difficult-to-treat, often fatal, infections, and can spread between patients within hospital settings, creating outbreaks that can be hard to contain.
A group led by Ashlee Earl, an institute scientist and senior group leader of the Bacterial Genomics group (BGG) at the Broad Institute of MIT and Harvard, and including BGG-affiliated scientists Rauf Salamzade, Abby Manson, Bruce Walker, and Colin Worby, along with Roby Bhattacharyya, an associate member of the Broad and assistant professor at Massachusetts General Hospital and Harvard Medical School, investigated the spread of carbapenem-resistant Enterobacterales (CRE) in four hospitals. They developed a new computational method for analyzing the genomes of CRE isolated from patients. Using that method, the scientists were able to track the movement of key genes across different CRE species over time and space, revealing many more connections between patient infections than expected based on standard methods. Their study was recently published in Genome Medicine.
“This new approach changed the picture,” said Earl. “While we expected to find examples of gene sharing, the results from Rauf’s method started to suggest that there is a veritable interstate highway for antibiotic resistance genes to move between bacteria in hospital environments and for a very long time.”
