title: High-Level Resistance of Staphylococcus aureus to β-Lactam Antibiotics Mediated by Penicillin-Binding Protein 4 (PBP4).
abstract: Penicillin-binding protein 4 (PBP4), a nonessential, low-molecular-weight penicillin-binding protein ofStaphylococcus aureus, has been implicated in low-level resistance to β-lactam antibiotics, although the mechanism is unknown. Mutations in PBP4 and its promoter were identified in a laboratory-generated mutant strain, CRB, which expresses high-level resistance to β-lactams, including resistance to the new-generation cephalosporins active against methicillin-resistant strains ofS. aureusThese mutations did not appreciably alter the β-lactam antibiotic binding affinity of purified recombinant mutant PBP4 compared to that of wild-type PBP4. Compared to the susceptible parent strain, COLnex, the CRB strain produces a highly cross-linked cell wall peptidoglycan, indicative of increased transpeptidase activity. Thepbp4promoter mutation of CRB was associated with greatly increased amounts of PBP4 in membranes compared to those in the COLnex parent. Replacement of the native promoter of COLnex with the mutant promoter of CRB resulted in increased amounts of PBP4 in membranes and a highly cross-linked cell wall. PBP4 can be repurposed to provide essential transpeptidase activityin vivoand confer high-level resistance to β-lactam antibiotics, such as ceftobiprole and ceftaroline.
authors.affiliation: Division of Infectious Disease, Department of Medicine, San Francisco General Hospital, San Francisco, California, USA.
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: Hamilton
authors.affiliation: Department of Biochemistry and Molecular Biology and the Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: J Andrew N
authors.initials: JAN
authors.lastname: Alexander
authors.affiliation: Division of Infectious Disease, Department of Medicine, San Francisco General Hospital, San Francisco, California, USA.|Division of Infectious Diseases, Soonchunhyang University, Bucheon, Republic of Korea.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Choo
authors.affiliation: Division of Infectious Disease, Department of Medicine, San Francisco General Hospital, San Francisco, California, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Basuino
authors.affiliation: Division of Infectious Disease, Department of Medicine, San Francisco General Hospital, San Francisco, California, USA.|Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Thaina M
authors.initials: TM
authors.lastname: da Costa
authors.affiliation: Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, New York, New York, USA.
authors.forename: Anatoly
authors.initials: A
authors.lastname: Severin
authors.affiliation: Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, New York, New York, USA.
authors.forename: Marilyn
authors.initials: M
authors.lastname: Chung
authors.affiliation: Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, New York, New York, USA.
authors.forename: Sandra
authors.initials: S
authors.lastname: Aedo
authors.affiliation: Department of Biochemistry and Molecular Biology and the Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Natalie C J
authors.initials: NCJ
authors.lastname: Strynadka
authors.affiliation: Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, New York, New York, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Tomasz
authors.affiliation: Division of Infectious Disease, Department of Medicine, San Francisco General Hospital, San Francisco, California, USA.
authors.forename: Som S
authors.initials: SS
authors.lastname: Chatterjee
authors.affiliation: Division of Infectious Disease, Department of Medicine, San Francisco General Hospital, San Francisco, California, USA hchambers@medsfgh.ucsf.edu.
authors.forename: Henry F
authors.initials: HF
authors.lastname: Chambers
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D002511:Cephalosporins / Q000494:pharmacology / Q000627:therapeutic use; D016106:Methicillin Resistance / Q000235:genetics; D046915:Penicillin-Binding Proteins / Q000235:genetics / Q000378:metabolism; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects*; D047090:beta-Lactams / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D046915:Penicillin-Binding Proteins; D047090:beta-Lactams; C443755:ceftobiprole
keywords: PBP4; Staphylococcus aureus; ceftaroline; ceftobiprole; drug resistance mechanisms; mechanisms of resistance; penicillin-binding protein 4; penicillin-binding proteins; β-lactam antibiotics; β-lactams