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Publication Abstract from PubMed

Carbapenem-resistant Acinetobacter baumannii infections have limited treatment options. Synthesis, transport and placement of lipopolysaccharide or lipooligosaccharide (LOS) in the outer membrane of Gram-negative bacteria are important for bacterial virulence and survival. Here we describe the cerastecins, inhibitors of the A. baumannii transporter MsbA, an LOS flippase. These molecules are potent and bactericidal against A. baumannii, including clinical carbapenem-resistant Acinetobacter baumannii isolates. Using cryo-electron microscopy and biochemical analysis, we show that the cerastecins adopt a serpentine configuration in the central vault of the MsbA dimer, stalling the enzyme and uncoupling ATP hydrolysis from substrate flipping. A derivative with optimized potency and pharmacokinetic properties showed efficacy in murine models of bloodstream or pulmonary A. baumannii infection. While resistance development is inevitable, targeting a clinically unexploited mechanism avoids existing antibiotic resistance mechanisms. Although clinical validation of LOS transport remains undetermined, the cerastecins may open a path to narrow-spectrum treatment modalities for important nosocomial infections.

Cerastecins inhibit membrane lipooligosaccharide transport in drug-resistant Acinetobacter baumannii.,Wang H, Ishchenko A, Skudlarek J, Shen P, Dzhekieva L, Painter RE, Chen YT, Bukhtiyarova M, Leithead A, Tracy R, Babaoglu K, Bahnck-Teets C, Buevich A, Cabalu TD, Labroli M, Lange H, Lei Y, Li W, Liu J, Mann PA, Meng T, Mitchell HJ, Mulhearn J, Scapin G, Sha D, Shaw AW, Si Q, Tong L, Wu C, Wu Z, Xiao JC, Xu M, Zhang LK, McKenney D, Miller RR, Black TA, Cooke A, Balibar CJ, Klein DJ, Raheem I, Walker SS Nat Microbiol. 2024 Apr 22. doi: 10.1038/s41564-024-01667-0. PMID:38649414^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.