Fig. 4

Genetic structures of tet(X)-positive plasmids and chromosomes. a Sketch maps of the tet(X3)-, tet(X4)-, tet(X5.2)-, and tet(X5.3)-positive Acinetobacter spp. strains. Bacterial species, isolation sources, and tet(X) variants are illustrated. b, c Structures of the tet(X3)-harboring plasmid p10FS3-1-3 (b) and the tet(X3)- and tet(X5.3)-co-harboring plasmid pYH12207-2 (c). GC skew and GC content are indicated from the inside out. The arrows represent the positions and transcriptional directions of the ORFs. Δ symbol indicates the truncated gene. d, e Putative integration processes of tet(X)-carrying composite transposons in Clade_U1 YH12138 (d), A. piscicola YH12207 (d), and A. indicus Q186-3 (e). The replication initiation site oriIS and replication termination site terIS of the ISCR2 element are also indicated