Infections caused by multidrug-resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacteria (GNB), including
carbapenem-resistant (CR) Enterobacterales (CRE; harboring mainly blaKPC, blaNDM, and blaOXA-48-like genes), CR- or MDR/XDR-Pseudomonas aeruginosa (production of VIM,
IMP, or NDM carbapenemases combined with
porin alteration), and Acinetobacter baumannii complex (producing mainly OXA-23, OXA-58-like carbapenemases), have gradually worsened and become a major challenge to public health because of limited
antibiotic choice and high case-fatality rates. Diverse MDR/XDR-GNB isolates have been predominantly cultured from inpatients and
hospital equipment/settings, but CRE has also been identified in community settings and
long-term care facilities. Several CRE outbreaks cost hospitals and healthcare institutions huge economic burdens for disinfection and containment of their disseminations. Parenteral
polymyxin B/E has been observed to have a poor pharmacokinetic profile for the treatment of CR- and XDR-GNB. It has been determined that
tigecycline is suitable for the treatment of
bloodstream infections owing to GNB, with a minimum inhibitory concentration of ≤ 0.5 mg/L.
Ceftazidime-avibactam is a last-resort
antibiotic against GNB of Ambler class A/C/
D enzyme-producers and a majority of CR-P. aeruginosa isolates. Furthermore,
ceftolozane-tazobactam is shown to exhibit excellent in vitro activity against CR- and XDR-P. aeruginosa isolates. Several pharmaceuticals have devoted to exploring novel
antibiotics to combat these troublesome XDR-GNBs. Nevertheless, only few
antibiotics are shown to be effective in vitro against CR/XDR-A. baumannii complex isolates. In this era of
antibiotic pipelines, strict implementation of antibiotic stewardship is as important as in-time isolation cohorts in limiting the spread of CR/XDR-GNB and alleviating the worsening trends of resistance.