Co-occurrence of carbapenemase encoding genes in Acinetobacter baumannii, a dream or reality?

Background Acinetobacter baumannii is an important opportunistic pathogen that is rapidly evolving towards multidrug resistance and is responsible for life-threatening infections. Carbapenems are commonly used to treat A. baumannii infections but the emergence of carbapenemase encoding genes, such as blaOXA-23-like, blaOXA-24-like, blaOXA-58-like, and blaNDM has been reported. Moreover, several studies have reported the co-occurrence of two distinct carbapenemases in some isolates. The aim of the present study is to demonstrate whether the phenomenon of co-occurrence of two distinct carbapenemase encoding genes in a single isolate still exists.