Acinetobactin is a bifunctional siderophore secreted by Acinetobacter baumannii that competitively binds ferric iron ions. Acinetobactin supplies A. baumannii by sequestering host-sequestered Fe 3+, while competitively depriving skin and respiratory commensal bacteria of iron resources, thereby exerting growth-inhibitory effects on Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus haemolyticus, and Corynebacterium striatum. The synthesis and transport of Acinetobactin enhance the intracellular epithelial colonization ability of A. baumannii, induce apoptosis of host epithelial cells, and simultaneously improve the survival and invasion capabilities of the bacterium in Galleria mellonella and mouse sepsis models. Acinetobactin can be used in A. baumannii -related research [1] [2] [3].
In Vivo, Acinetobactin (1 × 102 - 1 × 105 CFU; injected into the hemocoel of the last left proleg of final-instar Galleria mellonella larvae) mediates an intact iron uptake pathway that is required for full virulence of Acinetobacter baumannii ATCC 19606T in larvae. Disruption of either biosynthetic or transport functions of this system drastically reduces bacterial persistence and host mortality, and such virulence defects can be rescued by exogenous iron supplementation[2]. Acinetobactin (1.7 × 106 - 3.1 × 106 CFU; intraperitoneal injection) mediates an intact iron uptake system that acts as a core essential component for Acinetobacter baumannii ATCC 19606T to colonize and induce lethal infection in a mouse sepsis model; impaired biosynthesis of acinetobactin reduces virulence, while impaired transport function abolishes lethal virulence at high inoculum doses[2].
In Vitro, Acinetobactin is produced by Acinetobacter baumannii 17978, and specifically diffuses into the inhibition zone of Staphylococcus epidermidis ATCC 12228 only under iron-limiting conditions. It inhibits the growth of Corynebacterium striatum ATCC 6940 and Staphylococcus hominis, exhibits iron ion dependence, and forms a significantly larger inhibition zone under iron-limiting conditions[1]. Acinetobactin is a key factor mediating the inhibition of human Staphylococcus and Corynebacterium striatum ATCC 6940 by Acinetobacter baumannii AB5075 under iron-limiting conditions[1]. Acinetobactin-mediated iron uptake (5 × 103 bacterial cells; 3 h) enables A. baumannii ATCC 19606T to survive within human alveolar epithelial cell line A549, with intracellular CFU counts of the biosynthesis-deficient (s1) and transport-deficient (t6) mutant strains reduced by 2.7-fold and 12-fold, respectively[2]. Acinetobactin-mediated iron uptake is essential for the colonization and survival of A. baumannii ATCC 19606T in the cytoplasm of human alveolar epithelial cell line A549[2]. Acinetobactin-mediated iron uptake enables A. baumannii ATCC 19606T to induce apoptosis in human alveolar epithelial cell line A549[2].
References:
[1]. Knauf GA, et al. Acinetobactin-Mediated Inhibition of Commensal Bacteria by Acinetobacter baumannii. mSphere. 2022 Feb 23;7(1):e0001622.
[2]. Gaddy JA, et al. Role of acinetobactin-mediated iron acquisition functions in the interaction of Acinetobacter baumannii strain ATCC 19606T with human lung epithelial cells, Galleria mellonella caterpillars, and mice. Infection and immunity. 2012 Mar;80(3):1015-24.
[3]. Yamamoto S, et al. Isolation and structure elucidation of acinetobactin, a novel siderophore from Acinetobacter baumannii. Archives of microbiology. 1994;162(4):249-54.
In Vivo, Acinetobactin (1 × 102 - 1 × 105 CFU; injected into the hemocoel of the last left proleg of final-instar Galleria mellonella larvae) mediates an intact iron uptake pathway that is required for full virulence of Acinetobacter baumannii ATCC 19606T in larvae. Disruption of either biosynthetic or transport functions of this system drastically reduces bacterial persistence and host mortality, and such virulence defects can be rescued by exogenous iron supplementation[2]. Acinetobactin (1.7 × 106 - 3.1 × 106 CFU; intraperitoneal injection) mediates an intact iron uptake system that acts as a core essential component for Acinetobacter baumannii ATCC 19606T to colonize and induce lethal infection in a mouse sepsis model; impaired biosynthesis of acinetobactin reduces virulence, while impaired transport function abolishes lethal virulence at high inoculum doses[2].
In Vitro, Acinetobactin is produced by Acinetobacter baumannii 17978, and specifically diffuses into the inhibition zone of Staphylococcus epidermidis ATCC 12228 only under iron-limiting conditions. It inhibits the growth of Corynebacterium striatum ATCC 6940 and Staphylococcus hominis, exhibits iron ion dependence, and forms a significantly larger inhibition zone under iron-limiting conditions[1]. Acinetobactin is a key factor mediating the inhibition of human Staphylococcus and Corynebacterium striatum ATCC 6940 by Acinetobacter baumannii AB5075 under iron-limiting conditions[1]. Acinetobactin-mediated iron uptake (5 × 103 bacterial cells; 3 h) enables A. baumannii ATCC 19606T to survive within human alveolar epithelial cell line A549, with intracellular CFU counts of the biosynthesis-deficient (s1) and transport-deficient (t6) mutant strains reduced by 2.7-fold and 12-fold, respectively[2]. Acinetobactin-mediated iron uptake is essential for the colonization and survival of A. baumannii ATCC 19606T in the cytoplasm of human alveolar epithelial cell line A549[2]. Acinetobactin-mediated iron uptake enables A. baumannii ATCC 19606T to induce apoptosis in human alveolar epithelial cell line A549[2].
References:
[1]. Knauf GA, et al. Acinetobactin-Mediated Inhibition of Commensal Bacteria by Acinetobacter baumannii. mSphere. 2022 Feb 23;7(1):e0001622.
[2]. Gaddy JA, et al. Role of acinetobactin-mediated iron acquisition functions in the interaction of Acinetobacter baumannii strain ATCC 19606T with human lung epithelial cells, Galleria mellonella caterpillars, and mice. Infection and immunity. 2012 Mar;80(3):1015-24.
[3]. Yamamoto S, et al. Isolation and structure elucidation of acinetobactin, a novel siderophore from Acinetobacter baumannii. Archives of microbiology. 1994;162(4):249-54.