Dissemination of a Carbapenem-Resistant Acinetobacter baumannii Strain Belonging to International Clone II/Sequence Type 2 and Harboring a Novel AbaR4-Like Resistance Island in Latvia

An outbreak of hospital-acquired Acinetobacter baumannii infections, caused by a bla(OXA-23)-positive carbapenem-resistant strain belonging to international clone II/ST2, was detected in Latvia. The strain was partially equipped with the armA gene and the intI1-aacA4-catB8-aadA1-qacEΔ1 class 1 integron. In addition, the strain carried AbaR25, a novel AbaR4-like resistance island of ~46,500 bp containing structures similar to the previously described AbaR22 and Tn6167 islands. AbaR25 was characterized by the occurrence of a second copy of Tn6022a interrupted by Tn2006 carrying the bla(OXA-23) gene.