similar transfer between bacterial strains cultured together in flasks or dishes, and concluded that the capacity for multiple resistance was passed by conjugation. Yes, a sizable packet of genes, not just one bit of DNA, was moving across. And the exchange wasn’t limited to Shigella and Escherichia. Further research showed that the packet could cross boundaries between other species, even from genus to genus, among almost every group in the enteric bacteria, a large family of bugs that live within human bellies.
