Identification of potential tobramycin-resistant mutagenesis of Escherichia coli strains after spaceflight

Background: This study aimed to explore potential tobramycin-resistant mutagenesis of Escherichia coli (E. coli) strains after spaceflight. Methods: A spaceflight-induced mutagenesis of multi-drug resistant E.coli strain (T1_13) on the outer space for 64 days (ST5), and a ground laboratory with the same conditions (GT5) were conducted. Both whole-genome sequencing and RNA-sequencing were performed. Results: A total of 75 SNPs and 20 InDels were found to be associated with the resistance mechanism. Compared to T1_13, 1242 genes were differentially expressed in more than 20 of 38 tobramycin-resistant E. coli isolates while not in GT5. Function annotation of these SNPs/InDels related genes and differentially expressed genes was performed. Conclusion: This study provided clues for potential tobramycin-resistant spaceflight-induced mutagenesis of E. coli. Overall design: RNA-sequencing of one GT5 isolate, and 39 ST5 isolates were performed on IlluminaHiSeq PE150.