Multidrug-resistant Gram-negative bacteria (MDR-GNB)

Multidrug-resistant Gram-negative bacteria (MDR-GNB) are a group of bacterial pathogens characterized by their resistance to multiple classes of antimicrobial agents, posing a significant challenge to modern medicine (WHO, 2017). This category includes critical-priority pathogens such as Acinetobacter baumannii, Pseudomonas aeruginosa, and various Enterobacteriaceae that have developed resistance to carbapenems and third-generation cephalosporins (CDC, 2019). Their resistance is often mediated by a combination of enzymatic degradation (e.g., carbapenemases), decreased outer membrane permeability, and active efflux of drugs (Nature Reviews Microbiology, 2017). MDR-GNB are primarily responsible for severe healthcare-associated infections, including pneumonia, bloodstream infections, and surgical site infections (NIH, 2020). Because MDR-GNB are whole organisms rather than single molecular targets, they possess a multitude of essential biological processes that can be targeted by different antibiotic classes. The management of these infections often necessitates the use of last-line antibiotics, which may be associated with significant toxicity and declining efficacy (StatPearls, 2023).

Other names

Multi-drug resistant Gram-negative bacteriaMDR Gram-negative bacteriaCarbapenem-resistant EnterobacteriaceaeCRECarbapenem-resistant Acinetobacter baumanniiCRABCarbapenem-resistant Pseudomonas aeruginosaCRPAESBL-producing Gram-negative bacteria

Antibiotics targeting these bacteria utilize various mechanisms including inhibition of cell wall synthesis (beta-lactams), disruption of the outer membrane (polymyxins), inhibition of protein synthesis (tetracyclines, aminoglycosides), and inhibition of nucleic acid synthesis (fluoroquinolones) (Nature Reviews Microbiology, 2017; StatPearls, 2023).