title: Linezolid-resistant Staphylococcus epidermidis associated with long-term, repeated linezolid use in a pediatric patient.
abstract: We report an 8-year-old patient with catheter-related bacteremia caused by linezolid-resistant Staphylococcus epidermidis that was isolated after the long-term, repeated use of linezolid. Three S. epidermidis strains isolated from this patient were bacteriologically analyzed. While the strain isolated prior to linezolid initiation was susceptible to linezolid, two strains after linezolid therapy displayed low-level linezolid susceptibility (MIC, 4 mg/L) and linezolid resistance (MIC, 16 mg/L). T2500A mutation in two copies and G2575T mutations in three copies of 23S rRNA were detected in the low-susceptible strain and the resistant strain, respectively. Linezolid-resistant S. epidermidis infection is rare, but may occur with the long-term administration of linezolid.
authors.affiliation: Department of Infectious Diseases, Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan. Electronic address: ishiwada@faculty.chiba-u.jp.
authors.forename: Naruhiko
authors.initials: N
authors.lastname: Ishiwada
authors.affiliation: Department of Microbiology and Molecular Genetics, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Takaya
authors.affiliation: Department of Microbiology and Molecular Genetics, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan.
authors.forename: Asahi
authors.initials: A
authors.lastname: Kimura
authors.affiliation: Division of Laboratory Medicine, Chiba University Hospital, Chiba 260-8677, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Pediatrics, Chiba University Hospital, Chiba 260-8677, Japan.
authors.forename: Moeko
authors.initials: M
authors.lastname: Hino
authors.affiliation: Department of Pediatrics, Chiba University Hospital, Chiba 260-8677, Japan.
authors.forename: Hidemasa
authors.initials: H
authors.lastname: Ochiai
authors.affiliation: Department of Bacteriology II, National Institute of Infectious Diseases, Musashimurayama, Tokyo 208-0011, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Matsui
authors.affiliation: Department of Bacteriology II, National Institute of Infectious Diseases, Musashimurayama, Tokyo 208-0011, Japan.
authors.forename: Keigo
authors.initials: K
authors.lastname: Shibayama
authors.affiliation: Department of Infectious Diseases, Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan; Department of Microbiology and Molecular Genetics, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D002648:Child; D024881:Drug Resistance, Bacterial / Q000187:drug effects* / Q000235:genetics; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000150:complications; D000069349:Linezolid / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests; D013203:Staphylococcal Infections / Q000150:complications / Q000188:drug therapy / Q000382:microbiology; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D000069349:Linezolid
keywords: Children; Linezolid; Long-term use; Resistance; Staphylococcus epidermidis