In one study, which has implications for space microbiology, a non-pathogenic strain "E. coli" MG1655 was exposed to trace levels of the broad spectrum antibiotic chloramphenicol, under simulated microgravity (LSMMG, or, Low Shear Modeled Microgravity) over 1000 generations. The adapted strain acquired resistance to not only chloramphenicol, but also cross-resistance to other antibiotics; this was in contrast to the observation on the same strain, which was adapted to over 1000 generations under LSMMG, but without any antibiotic exposure; the strain in this case did not acquire any such resistance. Thus, irrespective of where they are used, the use of an antibiotic would likely result in persistent resistance to that antibiotic, as well as cross-resistance to other antimicrobials.