(a) Three distinct MGB strains, isolated from in vitro conjugations between E. coli pGT donors and mouse fecal bacteria, were analyzed by whole-genome sequencing. MGB4 and MGB9 appear to be the same strain isolated from separate experiments with different pGT vectors transferred. Sequencing of (b) MGB4/9 and (c) MGB3 revealed the presence of genes involved in conjugation and genetic transfer. However, only MGB4/9 strains that shared homology with the pECO-fce plasmid were observed to transfer their pGT vectors to E. coli during in vitro conjugations. (d) PCR confirmation of pGT vector transfer from MGB4 to an E. coli recipient following in vitro conjugation. The conjugation was performed 3 times, with similar results; 5 individual transconjugants were assessed by colony PCR.