title: Efficacy of Artilysin Art-175 against Resistant and Persistent Acinetobacter baumannii.
abstract: Bacteriophage-encoded endolysins have shown promise as a novel class of antibacterials with a unique mode of action, i.e., peptidoglycan degradation. However, Gram-negative pathogens are generally not susceptible due to their protective outer membrane. Artilysins overcome this barrier. Artilysins are optimized, engineered fusions of selected endolysins with specific outer membrane-destabilizing peptides. Artilysin Art-175 comprises a modified variant of endolysin KZ144 with an N-terminal fusion to SMAP-29. Previously, we have shown the high susceptibility of Pseudomonas aeruginosa to Art-175. Here, we report that Art-175 is highly bactericidal against stationary-phase cells of multidrug-resistant Acinetobacter baumannii, even resulting in a complete elimination of large inocula (≥10(8) CFU/ml). Besides actively dividing cells, Art-175 also kills persisters. Instantaneous killing of A. baumannii upon contact with Art-175 could be visualized after immobilization of the bacteria in a microfluidic flow cell. Effective killing of a cell takes place through osmotic lysis after peptidoglycan degradation. The killing rate is enhanced by the addition of 0.5 mM EDTA. No development of resistance to Art-175 under selection pressure and no cross-resistance with existing resistance mechanisms could be observed. In conclusion, Art-175 represents a highly active Artilysin against both A. baumannii and P. aeruginosa, two of the most life-threatening pathogens of the order Pseudomonadales.
authors.affiliation: Centre of Microbial and Plant Genetics, Department of Microbial and Molecular Systems, KU Leuven, Heverlee, Belgium.
authors.forename: Valerie
authors.initials: V
authors.lastname: Defraine
authors.affiliation: Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Heverlee, Belgium.
authors.forename: Joris
authors.initials: J
authors.lastname: Schuermans
authors.affiliation: Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Heverlee, Belgium.
authors.forename: Barbara
authors.initials: B
authors.lastname: Grymonprez
authors.affiliation: Laboratory of Food Microbiology, Department of Microbial and Molecular Systems, KU Leuven, Heverlee, Belgium.
authors.forename: Sander K
authors.initials: SK
authors.lastname: Govers
authors.affiliation: Laboratory of Food Microbiology, Department of Microbial and Molecular Systems, KU Leuven, Heverlee, Belgium.
authors.forename: Abram
authors.initials: A
authors.lastname: Aertsen
authors.affiliation: Centre of Microbial and Plant Genetics, Department of Microbial and Molecular Systems, KU Leuven, Heverlee, Belgium.
authors.forename: Maarten
authors.initials: M
authors.lastname: Fauvart
authors.affiliation: Centre of Microbial and Plant Genetics, Department of Microbial and Molecular Systems, KU Leuven, Heverlee, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Michiels
authors.affiliation: Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Heverlee, Belgium.
authors.forename: Rob
authors.initials: R
authors.lastname: Lavigne
authors.affiliation: Laboratory of Gene Technology, Department of Biosystems, KU Leuven, Heverlee, Belgium Laboratory of Applied Biotechnology, Department of Applied Biosciences, Ghent University, Ghent, Belgium yves.briers@ugent.be.
authors.forename: Yves
authors.identifier: 0000-0001-7723-1040
authors.initials: Y
authors.lastname: Briers
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D054804:Cathelicidins / Q000494:pharmacology*; D024901:Drug Resistance, Multiple, Bacterial; D004492:Edetic Acid / Q000494:pharmacology; D010450:Endopeptidases / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D046210:Microfluidic Analytical Techniques; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D054804:Cathelicidins; D011993:Recombinant Fusion Proteins; D004492:Edetic Acid; D010450:Endopeptidases; C000601046:Art-175; C001143:endolysin