Acinetobacter baumannii: Emergence of a Superbug, Past, Present, and Future

Abstract

By exhibiting resistance to most known antibiotics or quickly acquiring resistance to antimicrobials it was once susceptible to, Acinetobacter baumannii has attracted increasing attention worldwide since the last decades of the previous century. The resistance abilities of the bacterium were soon shown to be so advanced that it was even able to resist antibiotics that had only just been discovered and used for first time. Utilizing complex mechanisms of resistance, combining different modalities, and achieving new resistant traits established A. baumannii as one of the most clinically important and challenging pathogens of the new century, being categorized by the World Health Organization as a critical priority bacterium for which new antibiotics are urgently needed. After even last-resort, broad-spectrum antibiotics were rendered useless, the fight against this superbug began to be led by the reintroduction of once abandoned antimicrobials, new combination therapies and novel modalities of treatment. In this chapter, we will look at the history and background of Acinetobacter species and then specifically focus on A. baumannii, explaining its clinical importance in detail, reviewing the most recent findings regarding its mechanisms of resistance, latest modalities of treatment and newest areas of research towards opening new frontiers in the management of infections caused by multi-resistant strains of this bacterium.