Cleaner environments have more-resistant microbes

Abstract

Trying to control the microbial population in settings such as hospitals may have unintended negative consequences. A new study reports that the microbiomes in such highly controlled environments are much less diverse but have a broader arsenal of resistance mechanisms than the microbiomes in less tightly controlled ones (Nat. Commun. 2019, DOI: 10.1038/s41467-019-08864-0). These trends suggest we need to rethink how we manage microbial diversity in hospitals to slow the spread of resistant bacteria. Alexander Mahnert, a postdoctoral researcher at Graz University of Technology, and coworkers collected samples from surfaces in a variety of buildings. They sequenced bacterial DNA in the samples and used computational methods to reconstruct the genomes of individual microbial species present. The researchers found that more-controlled environments had just as many bacteria as less-controlled environments but fewer species of bacteria. The cleaner an environment was, the more the microbial population tended toward gram-negative bacteria, the researchers