AUTHOR=Shi Jingchao , Cheng Jianghao , Liu Shourong , Zhu Yufeng , Zhu Mingli 

TITLE=Acinetobacter baumannii: an evolving and cunning opponent

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1332108

DOI=10.3389/fmicb.2024.1332108

ISSN=1664-302X

ABSTRACT=<p><italic>Acinetobacter baumannii</italic> is one of the most common multidrug-resistant pathogens causing nosocomial infections. The prevalence of multidrug-resistant <italic>A. baumannii</italic> infections is increasing because of several factors, including unregulated antibiotic use. <italic>A. baumannii</italic> drug resistance rate is high; in particular, its resistance rates for tigecycline and polymyxin—the drugs of last resort for extensively drug-resistant <italic>A. baumannii</italic>—has been increasing annually. Patients with a severe infection of extensively antibiotic-resistant <italic>A. baumannii</italic> demonstrate a high mortality rate along with a poor prognosis, which makes treating them challenging. Through carbapenem enzyme production and other relevant mechanisms, <italic>A. baumannii</italic> has rapidly acquired a strong resistance to carbapenem antibiotics—once considered a class of strong antibacterials for <italic>A. baumannii</italic> infection treatment. Therefore, understanding the resistance mechanism of <italic>A. baumannii</italic> is particularly crucial. This review summarizes mechanisms underlying common antimicrobial resistance in <italic>A. baumannii</italic>, particularly those underlying tigecycline and polymyxin resistance. This review will serve as a reference for reasonable antibiotic use at clinics, as well as new antibiotic development.</p>