title: Emergence of multidrug-resistant Corynebacterium striatum as a nosocomial pathogen in long-term hospitalized patients with underlying diseases.
abstract: During a 53-month period (March 1994 to August 1998), 48 Corynebacterium striatum isolates recovered from clinical specimens were characterized. The organisms were identified by both phenotypic characteristics and 16S rRNA gene sequence analysis. Thirty-six (75%) were isolated from sputum/bronchial aspirates, 10 (21%) from wound exudates/pus, 1 (2%) from vaginal discharge, and 1 (2%) from an otorrheic specimen. All 48 patients had been hospitalized for treatment of an underlying disease and had received antibiotics previously. The C. striatum isolates were considered pathogenic based on their abundance within polymorphonuclear neutrophils and their dominant growth in culture. Sensitivities of isolates to 11 antibiotics were determined by broth microdilution. MIC90 values of the isolates were 1 microg/mL for vancomycin, 16 microg/mL for penicillin and ampicillin, 32 microg/mL for minocycline, and > or = 32 microg/mL for cephalosporins, imipenem, ofloxacin, and macrolides. Restriction fragment-length polymorphism analysis with pulsed-field gel electrophoresis was used to determine the clonal identity. The pulse-field gel electrophoresis profiles revealed 14 distinct patterns with 20 subtypes. The isolates for the nosocomial outbreaks of C. striatum included 3 types (A, D, and E) with 4 subtypes (A1, A2, D2, and E). All 4 genotypes had broad-spectrum resistance to antimicrobial agents. Furthermore, type E strain isolated from 3 patients in the same ward was sensitive only to vancomycin. We conclude that C. striatum should be considered an emerging multidrug-resistant nosocomial pathogen in patients hospitalized for a prolonged period and/or in immunocompromised patients with such underlying conditions as cerebrovascular disease, pulmonary disease, diabetes, or malignancy.
authors.affiliation: Department of Microbiology, Gifu University Graduate School of Medicine, Gifu 501-1194, Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Otsuka
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Ohkusu
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kawamura
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Baba
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ezaki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kimura
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D003352:Corynebacterium / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity; D003354:Corynebacterium Infections / Q000276:immunology / Q000382:microbiology*; D003428:Cross Infection / Q000276:immunology / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D021521:Ribotyping; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D012336:RNA, Ribosomal, 16S