A swine probiotic candidate that tests resistant to erythromycin and carries three copies of a vancomycin resistance gene looks like a strain to discard. That is the first reading of the data on a newly characterized bacteriocin producing isolate taken from the pig gut. and it is the wrong reading. Where those genes sit matters more than whether they are present. In this isolate, every resistance and virulence determinant found was on the chromosome. None were on the plasmids. and plasmids are the part of a bacterial genome that moves between strains. That distinction is the whole argument for doing genomic safety screening properly instead of chasing gene names. A…