Evidence of dissemination of a clc-type integrative and conjugative element to Stenotrophomonas maltophilia, mediating acquisition of sul1 and other resistance determinants

A Stenotrophomonas maltophilia strain positive for the blaVIM-1 metallobeta-lactamase gene and resistant to trimethoprim-sulfamethoxazole was unexpectedly isolated from a surveillance rectal swab. The characterization of the strain revealed carriage of a 91 kb integrative and conjugative element (ICE) harboring several resistance determinants [sul1, blaVIM-1, aac(6')-Ib, aac(6')-31, qacE∆1, cld, and merEDAPTR], closely related with a group of clc-type ICEs widespread among Pseudomonas aeruginosa and other pseudomonads. Results highlighted the possible spreading of similar elements to S. maltophilia, mediating the acquisition of relevant resistances.