Free Republic

The highest resolution snapshots yet showing how bacteria adapt to survive treatment with quinolone drugs are giving drug makers an additional weapon in the fight against antibiotic resistance. Scientists at King's College London and St. George's, University of London, have shown exactly how quinolones, which are the second line of defence against diseases like pneumonia and meningitis, interact with their topoisomerase IV enzyme target. The researchers captured detailed crystal structures using high power x-rays produced at the Diamond synchrotron in the UK and its French counterpart, Soleil. From these images the team has been able to identify the amino acids that mutate...

It seems like a peculiar case of genomic overkill: a single-celled bacterium has been found that keeps tens of thousands of copies of its genome. The finding sets a record for most genomes per cell, but also poses an obvious question: what could be the advantage of stashing away as much as 200,000 copies of your genome? The number of genome copies in each cell varies by species. Many bacteria have only one copy; most cells in the human body contain two. Plants are notorious for being genomically promiscuous, picking up extra genomes then losing them again in a cycle...