Bacteria may readily swap beneficial genes
Much as people can exchange information instantaneously in the digital age, bacteria associated with humans and their livestock appear to freely and rapidly exchange genetic material related to human disease and antibiotic resistance through a mechanism called horizontal gene transfer (HGT). In a paper appearing in Nature online Oct. 30, researchers — led by Eric Alm of MIT’s Department of Civil and Environmental Engineering and Department of Biological Engineering — say they’ve found evidence of a massive network of recent gene exchange connecting bacteria from around the world: 10,000 unique genes flowing via HGT among 2,235 bacterial genomes. HGT is an ancient method for bacteria from different lineages to acquire and share useful genetic information they didn’t inherit from their parents. Scientists have long known about HGT and known that when a transferred gene confers a desirable trait, such as antibiotic resistance or pathogenicity, that gene may undergo positive selection...