Tn6553, a Tn7-family transposon encoding putative iron uptake functions found in Acinetobacter

Acinetobacter baumannii is an opportunistic pathogen that has become difficult to eradicate mainly because of its high level of antibiotic resistance. Other features that contribute to this organism's success are the ability to compete for nutrients and iron. Recently, several novel Tn7-family transposons that encode synthesis and transport of siderophore and iron uptake systems were characterised. Here, another Tn7-type transposon (named Tn6553) is described. Tn6553 contains a set of iron utilisation genes with a transposition module related to Tn7. Tn7-family transposons that carry iron uptake systems facilitate the spread of these functions in Acinetobacter strains. Given that Tn7 is known to transpose efficiently into its preferred target site, finding siderophore functions on Tn7 family transposons is important in the context of dissemination of virulence genes amongst Acinetobacter strains.