Propionibacterium acnes: Time-to-Positivity in Standard Bacterial Culture From Different Anatomical Sites.
BACKGROUND
Propionibacterium acnesinfections are likely under-recognized and underreported. This is partly because of low clinical suspicion, perceived non-pathogenicity, or lack of adequate culture incubation time. We conducted a study to assess the optimal incubation period to recoverP. acnesfrom specimens acquired during the workup of suspected clinical infections.


METHODS
A 5-year retrospective chart review was conducted between January 2010 and December 2014 at a single tertiary-care hospital. All patient cases from whichP. acneswas recovered were included for analysis. Source of infection, antibiotic use, and culture time-to-positivity (TTP) were recorded.


RESULTS
Implanted devices comprised the single most common source ofP. acnesinfection. In the majority of cases,P. acneswas the only organism identified. The mean incubation TTP for all isolates was 5.73 days.


CONCLUSIONS
Standard 5-day culture incubation periods are insufficient to recoverP. acnes. As a result,P. acnesis likely a much more common etiology of a variety of clinical infections than previously reported.
Division of Infectious Diseases, Allegheny General Hospital, 420 East North Ave., Pittsburgh, PA 15212, USA.
Rasha
R
Abdulmassih
Division of Infectious Diseases, Allegheny General Hospital, 420 East North Ave., Pittsburgh, PA 15212, USA.
Jina
J
Makadia
Division of Infectious Diseases, Allegheny General Hospital, 420 East North Ave., Pittsburgh, PA 15212, USA.
James
J
Como
Division of Infectious Diseases, Allegheny General Hospital, 420 East North Ave., Pittsburgh, PA 15212, USA.
Michelle
M
Paulson
Division of Infectious Diseases, Allegheny General Hospital, 420 East North Ave., Pittsburgh, PA 15212, USA.
Zaw
Z
Min
Division of Infectious Diseases, Allegheny General Hospital, 420 East North Ave., Pittsburgh, PA 15212, USA.
Nitin
N
Bhanot
Implanted electronic cardiac device infection; Propionibacterium acnes; Prosthetic joint infection; Time-to-positivity