This paper attempts to show genomic differences between a Klebsiella pneumoniae strain that was incubated in the Shenzhou VIII unmanned spacecraft for 17 days and a control that remained on Earth. The reported differences between the two strains are large and include a 200 kbp difference in genome size and the acquisition of several antibiotic resistance genes and plasmids (some of enterococcal origin). These data are highly unlikely because when strains are grown in isolation, they should not be able to acquire foreign DNA from the medium. The authors do not explain these observations and simply claim that this is a result of spaceflight. In my opinion it is more likely that strains have been mixed-up or a contaminant has been sequenced. I also note that the manuscript contains several errors (including a reported %GC of 84.42% for one of the strains) and unsubstantiated claims.