The study shows that restoration of OAg production in E. coli K-12 increases susceptibility to vancomycin in the presence of bile salts, and that disruption of OAg biogenesis leads to increased resistance to vancomycin and bile salts. Mutations in genes involved in OAg synthesis and processing, such as wbbL, waaU, rmlA, rmlB, rmlC, wbbI, yfdI, wzy, wzz, and dacA, were identified as contributing to this resistance.