Chromosomally Encoded mcr-5 in Colistin non-susceptible Pseudomonas aeruginosa

Whole genome sequencing (WGS) of historical Pseudomonas aeruginosa clinical isolates identified a chromosomal copy of mcr-5 within a Tn 3 -like transposon in P. aeruginosa MRSN 12280. The isolate was non-susceptible to colistin by broth microdilution and genome analysis revealed no mutations known to confer colistin resistance. To the best of our knowledge, this is the first report of mcr in colistin non-susceptible P. aeruginosa .