title: Phage pattern-specific oxacillin-resistant and borderline oxacillin-resistant Staphylococcus aureus in U.S. hospitals: epidemiological significance.
abstract: For a 13-year period (1978 through 1990), oxacillin-resistant (MIC, greater than 4 micrograms/ml) Staphylococcus aureus (ORSA) strains were collected from Clinical Center (National Institutes of Health) patients and patients from five other U.S. hospitals. From Clinical Center patients, 251 of 253 isolates (99%) were bacteriophage typed as phage group III. Five other hospitals contributed 203 ORSA strains, of which 188 (93%) were group III. The group III ORSA strains predominantly included a characteristic core pattern of phages, 7/47/53/54/75/77. For the low-level (borderline) oxacillin-resistant strains (MIC, 2 to 4 micrograms/ml), amoxicillin-clavulanic acid combination (Augmentin) testing disclosed 62 hyper-beta-lactamase producers, of which 59 (95%) were of a separate, distinct S. aureus strain, with the phage pattern 92/94/96/292/D-11 (group V). Thus, ORSA and hyper-beta-lactamase producing S. aureus are distinct epidemic strains.
authors.affiliation: Clinical Pathology Department, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: C H
authors.initials: CH
authors.lastname: Zierdt
authors.forename: I K
authors.initials: IK
authors.lastname: Hosein
authors.forename: R
authors.initials: R
authors.lastname: Shively
authors.forename: J D
authors.initials: JD
authors.lastname: MacLowry
mesh_terms: D001434:Bacteriophage Typing; D003428:Cross Infection / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D010068:Oxacillin / Q000494:pharmacology*; D010403:Penicillin Resistance; D013211:Staphylococcus aureus / Q000145:classification* / Q000187:drug effects / Q000201:enzymology; D014481:United States / Q000453:epidemiology; D001618:beta-Lactamases / Q000096:biosynthesis
chemical_list: D001618:beta-Lactamases; D010068:Oxacillin