Characterisation of a Novel Tigecycline Resistance Gene tet(X22) and its Coexistence with blaNDM-1 in a Pseudomonas caeni Isolate

•The novel tigecycline resistance gene tet(X22) was first identified.•There was coexistence of tet(X22) with blaNDM-1 in a novel species Pseudomonas caeni.•Tet(X22) confers resistance to tetracyclines, including tigecycline.•The tet(X) variant has adapted to new hosts and may widely spread to further expand the host range.