Variations of AbaR4-type resistance islands in Acinetobacter baumannii isolates from South Korea.

AbaR resistance islands in Acinetobacter baumannii isolates from South Korea were investigated. AbaR4-type resistance islands, including bla(OXA-23)-containing Tn2006, interrupted the comM gene in A. baumannii ST75 isolates. However, Tn2006 was not identified within AbaR resistance islands of ST138 isolates, although the bla(OXA-23) gene was detected in them. The similar structures of resistance islands suggest that most carbapenem-resistant A. baumannii isolates in South Korea have originated from the same ancestor with a globally disseminated clone, GC II.