title: Isolation of Enterobacter aerogenes susceptible to beta-lactam antibiotics despite high level beta-lactamase production.
abstract: This report describes a patient with nosocomial meningitis from whom four distinct isolates of Enterobacter aerogenes were recovered over a complicated course of chemotherapy. The initial isolate was susceptible to expanded spectrum beta-lactams despite constitutive production of high levels of beta-lactamase. Resistant isolates recovered during antibiotic therapy had lost a 42,000 outer membrane protein. These data suggest that b-lactam susceptibility in the original isolate was due to "hyperpermeability" mediated by the 42,000 Dalton protein.
authors.affiliation: Veterans Administration Medical Center, Section of Infectious Diseases, Omaha, Nebraska 68105.
authors.forename: M A
authors.initials: MA
authors.lastname: Mellencamp
authors.forename: J S
authors.initials: JS
authors.lastname: Roccaforte
authors.forename: L C
authors.initials: LC
authors.lastname: Preheim
authors.forename: C C
authors.initials: CC
authors.lastname: Sanders
authors.forename: C A
authors.initials: CA
authors.lastname: Anene
authors.forename: M J
authors.initials: MJ
authors.lastname: Bittner
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D004352:Drug Resistance, Microbial / Q000502:physiology; D004754:Enterobacter / Q000187:drug effects* / Q000201:enzymology / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000382:microbiology*; D006801:Humans; D008297:Male; D008581:Meningitis / Q000382:microbiology*; D008875:Middle Aged; D001618:beta-Lactamases / Q000096:biosynthesis*; D047090:beta-Lactams
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D047090:beta-Lactams; D001618:beta-Lactamases