Acinetobacter baumannii cell envelope

The Acinetobacter baumannii cell envelope is a complex, multi-layered structure that serves as the primary interface between the bacterium and its environment. It consists of an inner cytoplasmic membrane, a periplasmic space containing a thin peptidoglycan layer, and a highly asymmetric outer membrane composed of phospholipids and lipopolysaccharides (LPS) [4, 5]. This envelope acts as a formidable permeability barrier, which is a major factor in the pathogen's multi-drug resistance (MDR) and its ability to survive in harsh clinical environments [5]. Therapeutic strategies targeting this structure include the use of polymyxins, which disrupt membrane stability by binding to LPS, and novel inhibitors like zosurabalpin, which block the essential transport of LPS to the cell surface [1, 2]. Because the envelope is vital for structural integrity and protection against host immune defenses, it remains a critical target for the development of new antibiotics against carbapenem-resistant strains [2, 5]. Citations: [1] Clinical Microbiology Reviews (2017) doi:10.1128/CMR.00064-16; [2] Nature (2024) doi:10.1038/s41586-023-06873-0; [3] Drugs (2019) doi:10.1007/s40265-019-01188-7; [4] Frontiers in Microbiology (2019) doi:10.3389/fmicb.2019.02183; [5] International Journal of Molecular Sciences (2021) doi:10.3390/ijms22168828.

Other names

Acinetobacter baumannii outer membraneA. baumannii cell wallAcinetobacter baumannii envelopeGram-negative cell envelope

Drugs targeting the Acinetobacter baumannii cell envelope act through several distinct mechanisms: polymyxins (Colistin, Polymyxin B) bind to the lipid A component of lipopolysaccharides (LPS), displacing divalent cations and disrupting the physical integrity of the outer membrane [1]; zosurabalpin inhibits the LptB2FGC complex, which is responsible for transporting LPS from the inner membrane to the outer membrane, leading to LPS accumulation in the periplasm and bacterial death [2]; and beta-lactams like carbapenems inhibit penicillin-binding proteins (PBPs) involved in peptidoglycan synthesis within the cell envelope [5].