title: Molecular epidemiology of a nosocomial outbreak due to SHV-4-producing strains of Citrobacter diversus.
abstract: Over a 6-month period, eight strains of Citrobacter diversus (Citrobacter koseri) resistant to extended-spectrum cephalosporins and monobactams were isolated from seven colonized and/or infected patients from the same intensive care unit. All strains harbored a single large conjugative plasmid which mediated an extended-spectrum beta-lactamase of the SHV-4 type (ceftazidimase phenotype; enzyme pI, 7.8; plasmid DNA hybridization with a blaSHV-specific probe). All strains were characterized by antibiotic resistance pattern analysis, beta-lactamase content analysis, plasmid profiling, ribotyping with EcoRI, and arbitrarily primed (AP)-PCR with primers O8 and O12. Among the eight C. diversus strains, strains Cd5 to Cd12, six isolates (isolates Cd6 to Cd11) were identical by all markers; one strain (strain Cd5) differed by two markers (antibiotype and AP-PCR pattern with primer O8), and the remaining strain (strain Cd12) differed by two other markers (ribotype and AP-PCR pattern with primer O12). Our results suggest that six of the eight SHV-4-producing C. diversus strains studied (strains Cd6 to Cd11) were a single epidemic strain. Strain Cd5 could be related to the epidemic strain; the origin of strain Cd12 remains uncertain.
authors.affiliation: Laboratoire de Microbiologie, Hôpital Robert Boulin, Libourne, France.
authors.forename: Z
authors.initials: Z
authors.lastname: El Harrif-Heraud
authors.forename: C
authors.initials: C
authors.lastname: Arpin
authors.forename: S
authors.initials: S
authors.lastname: Benliman
authors.forename: C
authors.initials: C
authors.lastname: Quentin
mesh_terms: D015373:Bacterial Typing Techniques; D002954:Citrobacter; D003428:Cross Infection / Q000453:epidemiology*; D004196:Disease Outbreaks; D004756:Enterobacteriaceae Infections / Q000453:epidemiology*; D005602:France / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D007362:Intensive Care Units; D017720:Molecular Epidemiology; D009493:Neurosurgery; D010641:Phenotype; D010957:Plasmids; D016133:Polymerase Chain Reaction; D013045:Species Specificity; D018440:beta-Lactam Resistance; D001618:beta-Lactamases
chemical_list: D001618:beta-Lactamases