title: Pseudo-outbreak of Actinomyces graevenitzii associated with bronchoscopy.
abstract: Outbreaks and pseudo-outbreaks of infection related to bronchoscopy typically involve Gram-negative bacteria, Mycobacterium species or Legionella species. We report an unusual bronchoscopy-related pseudo-outbreak due to Actinomyces graevenitzii. Extensive epidemiological and microbiological investigation failed to identify a common source. Strain typing revealed that the cluster was comprised of heterogeneous strains of A. graevenitzii. A change in laboratory procedures for Actinomyces cultures was coincident with the emergence of the pseudo-outbreak, and we determined that A. graevenitzii isolates more readily adopted a white, dry, molar tooth appearance on anaerobic colistin nalidixic acid (CNA) agar which likely facilitated its detection and identification in bronchoscopic specimens. This unusual pseudo-outbreak was related to frequent requests of bronchoscopists for Actinomyces cultures combined with a change in microbiology laboratory practices.
authors.affiliation: Yale-New Haven Hospital, New Haven, Connecticut, USA Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Peaper
authors.affiliation: Yale-New Haven Hospital, New Haven, Connecticut, USA.
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Havill
authors.affiliation: Yale-New Haven Hospital, New Haven, Connecticut, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Aniskiewicz
authors.affiliation: Yale-New Haven Hospital, New Haven, Connecticut, USA.
authors.forename: Deborah
authors.initials: D
authors.lastname: Callan
authors.affiliation: Yale University School of Medicine, New Haven, Connecticut, USA.
authors.forename: Olivia
authors.initials: O
authors.lastname: Pop
authors.affiliation: Yale-New Haven Hospital, New Haven, Connecticut, USA.
authors.forename: Dana
authors.initials: D
authors.lastname: Towle
authors.affiliation: Yale-New Haven Hospital, New Haven, Connecticut, USA Yale University School of Medicine, New Haven, Connecticut, USA John.Boyce@ynhh.org.
authors.forename: John M
authors.initials: JM
authors.lastname: Boyce
mesh_terms: D000190:Actinomyces / Q000145:classification* / Q000235:genetics; D000196:Actinomycosis / Q000453:epidemiology* / Q000382:microbiology*; D058491:Bacterial Load; D001999:Bronchoscopy / Q000009:adverse effects*; D016022:Case-Control Studies; D003428:Cross Infection; D004196:Disease Outbreaks; D004866:Equipment Contamination; D006801:Humans; D016133:Polymerase Chain Reaction; D062606:Tertiary Care Centers