title: Restoring methicillin-resistant Staphylococcus aureus susceptibility to β-lactam antibiotics.
abstract: Despite the need for new antibiotics to treat drug-resistant bacteria, current clinical combinations are largely restricted to β-lactam antibiotics paired with β-lactamase inhibitors. We have adapted a Staphylococcus aureus antisense knockdown strategy to genetically identify the cell division Z ring components-FtsA, FtsZ, and FtsW-as β-lactam susceptibility determinants of methicillin-resistant S. aureus (MRSA). We demonstrate that the FtsZ-specific inhibitor PC190723 acts synergistically with β-lactam antibiotics in vitro and in vivo and that this combination is efficacious in a murine model of MRSA infection. Fluorescence microscopy localization studies reveal that synergy between these agents is likely to be elicited by the concomitant delocalization of their cognate drug targets (FtsZ and PBP2) in MRSA treated with PC190723. A 2.0 Å crystal structure of S. aureus FtsZ in complex with PC190723 identifies the compound binding site, which corresponds to the predominant location of mutations conferring resistance to PC190723 (PC190723(R)). Although structural studies suggested that these drug resistance mutations may be difficult to combat through chemical modification of PC190723, combining PC190723 with the β-lactam antibiotic imipenem markedly reduced the spontaneous frequency of PC190723(R) mutants. Multiple MRSA PC190723(R) FtsZ mutants also displayed attenuated virulence and restored susceptibility to β-lactam antibiotics in vitro and in a mouse model of imipenem efficacy. Collectively, these data support a target-based approach to rationally develop synergistic combination agents that mitigate drug resistance and effectively treat MRSA infections.
authors.affiliation: Infectious Diseases, Merck Research Laboratories, Kenilworth, NJ 07033, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Tan
authors.forename: Alex G
authors.initials: AG
authors.lastname: Therien
authors.forename: Jun
authors.initials: J
authors.lastname: Lu
authors.forename: Sang H
authors.initials: SH
authors.lastname: Lee
authors.forename: Alexandre
authors.initials: A
authors.lastname: Caron
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Gill
authors.forename: Christian
authors.initials: C
authors.lastname: Lebeau-Jacob
authors.forename: Liliana
authors.initials: L
authors.lastname: Benton-Perdomo
authors.forename: João M
authors.initials: JM
authors.lastname: Monteiro
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Pereira
authors.forename: Nathaniel L
authors.initials: NL
authors.lastname: Elsen
authors.forename: Jin
authors.initials: J
authors.lastname: Wu
authors.forename: Kathleen
authors.initials: K
authors.lastname: Deschamps
authors.forename: Mihai
authors.initials: M
authors.lastname: Petcu
authors.forename: Simon
authors.initials: S
authors.lastname: Wong
authors.forename: Etienne
authors.initials: E
authors.lastname: Daigneault
authors.forename: Susanne
authors.initials: S
authors.lastname: Kramer
authors.forename: Lianzhu
authors.initials: L
authors.lastname: Liang
authors.forename: Eugene
authors.initials: E
authors.lastname: Maxwell
authors.forename: David
authors.initials: D
authors.lastname: Claveau
authors.forename: John
authors.initials: J
authors.lastname: Vaillancourt
authors.forename: Kathryn
authors.initials: K
authors.lastname: Skorey
authors.forename: John
authors.initials: J
authors.lastname: Tam
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Meredith
authors.forename: Susan
authors.initials: S
authors.lastname: Sillaots
authors.forename: Lisa
authors.initials: L
authors.lastname: Wang-Jarantow
authors.forename: Yeeman
authors.initials: Y
authors.lastname: Ramtohul
authors.forename: Eric
authors.initials: E
authors.lastname: Langlois
authors.forename: France
authors.initials: F
authors.lastname: Landry
authors.forename: John C
authors.initials: JC
authors.lastname: Reid
authors.forename: Gopal
authors.initials: G
authors.lastname: Parthasarathy
authors.forename: Sujata
authors.initials: S
authors.lastname: Sharma
authors.forename: Anastasia
authors.initials: A
authors.lastname: Baryshnikova
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Lumb
authors.forename: Mariana G
authors.initials: MG
authors.lastname: Pinho
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Soisson
authors.forename: Terry
authors.initials: T
authors.lastname: Roemer
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D018360:Crystallography, X-Ray; D003598:Cytoskeletal Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism; D004195:Disease Models, Animal; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D004357:Drug Synergism; D053263:Gene Regulatory Networks / Q000235:genetics; D006153:Guanosine Diphosphate; D015378:Imipenem / Q000494:pharmacology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000166:cytology / Q000187:drug effects* / Q000472:pathogenicity; D051379:Mice; D008826:Microbial Sensitivity Tests; D009154:Mutation / Q000235:genetics; D017433:Protein Structure, Secondary; D021381:Protein Transport / Q000187:drug effects; D011725:Pyridines / Q000737:chemistry / Q000494:pharmacology; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology; D013844:Thiazoles / Q000737:chemistry / Q000494:pharmacology; D014774:Virulence / Q000187:drug effects; D047090:beta-Lactams / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; C531944:PC190723; D011725:Pyridines; D013844:Thiazoles; D047090:beta-Lactams; D006153:Guanosine Diphosphate; D015378:Imipenem