Next Generation Sequencing

An old Danish proverb says that when then the manger is empty the horses bite each other. This idea has now been put to use by Anthony Sinskey’s research group at MIT and is described in a report by the MIT Technology Review. Sinskey’s group had previously produced the genome sequence of the soil-dwelling bacteria known as Rhodococcus fascians. Looking at the genome, they were surprised to find that this organism, not known for its antibiotic-producing powers, harbored a number of genes involved in the metabolism of antibiotic-like compounds. However, none of these genes seemed to be expressed when the bacteria was grown in the lab. To bring out the worst in the bacteria, the group decided to grow the bacteria in competition with a Streptomyces bacteria. After performing selection experiments, one strain of the Rhodococcus bacteria was shown to excrete a novel antibiotic compound, dubbed rhodostreptomycin, which belongs to the same class of antibiotics as streptomycin, a tuberculosis drug.

The inference of the exact molecular mechanisms responsible for the new compound are still under way, but one fascinating preliminary finding is that the selected Rhodococcus strain seem to have assimilated a large chunk of DNA from the competing Streptomyces strain.

This is a fascinating example of the new picture of bacterial genomics that is emerging as a result of improved sequencing technology - for an introduction, I recommend this review by Raskin et al.