Polymyxin-Resistant Acinetobacter baumannii: Urgent Action Needed

of America (IDSA) set the acronym ESKAPE, which lists the groups of path-ogens that pose the highest threat to pa-tients ’ safety and to public health [1], one of which is Acinetobacter baumannii [1].Acinetobacter baumannii is a particu-larly challenging pathogen because it is associated with a high degree of resis-tance [2], and it is difficult to eliminate its environmental reservoir in healthcare settings with conventional measures [3]. Carbapenems are considered first-line agents for the treatment of A. baumannii infections [4–6], and therefore the rise of infections due to carbapenem-resistant strains is of particular concern, as out-comes deteriorate significantly when isolates become resistant to all β-lactam op-tions [2, 3, 5–7]. Additionally, carbapenem-resistant A. baumannii isolates are often susceptible to only 1 or 2 agents, making them extensively drug-resistant (XDR) pathogens by definition [8]. The inci-dence of XDR A. baumannii infections is continually rising [9]. For severe XDR A. baumannii infections, polymyxins are frequently used, and are considered by most to be the drugs of choice [4]. In this issue of Clinical Infectious Diseases, Qureshi and colleagues report on a case series of patients with isolation of colistin-resistant carbapenem-resistant A. baumannii [10]. In some of the cases described by the authors, the isolates have become truly pandrug resistant (PDR) with resistance seen to all tested antimi-crobials. These infections represent a seri-ous iatrogenic complication of modern healthcare, where patients acquire infec-tions in our healthcare facilities, for which we have no treatment options