Acinetobacter baumannii Resistance: A Real Challenge for Clinicians

<i>Acinetobacter baumannii</i> (named in honor of the American bacteriologists Paul and Linda Baumann) is a Gram-negative, multidrug-resistant (MDR) pathogen that causes nosocomial infections, especially in intensive care units (ICUs) and immunocompromised patients with central venous catheters. <i>A. baumannii</i> has developed a broad spectrum of antimicrobial resistance, associated with a higher mortality rate among infected patients compared with other non-<i>baumannii</i> species. In terms of clinical impact, resistant strains are associated with increases in both in-hospital length of stay and mortality. <i>A. baumannii</i> can cause a variety of infections; most involve the respiratory tract, especially ventilator-associated pneumonia, but bacteremia and skin wound infections have also been reported, the latter of which has been prominently observed in the context of war-related trauma. Cases of meningitis associated with <i>A. baumannii</i> have been documented. The most common risk factor for the acquisition of MDR <i>A baumannii</i> is previous antibiotic use, following by mechanical ventilation, length of ICU/hospital stay, severity of illness, and use of medical devices. Current efforts focus on addressing all the antimicrobial resistance mechanisms described in <i>A. baumannii</i>, with the objective of identifying the most promising therapeutic scheme. Bacteriophage- and artilysin-based therapeutic approaches have been described as effective, but further research into their clinical use is required.