title: Initial concentration of Staphylococcus epidermidis in simulated pediatric blood cultures correlates with time to positive results with the automated, continuously monitored BACTEC blood culture system.
abstract: The relationship of initial concentration of Staphylococcus epidermidis in blood cultures and time to positivity (TTP) in an automated, continuously monitored blood culture system was assessed. Blood and 1 to 1,000 CFU of S. epidermidis per ml in stationary or exponential phase were inoculated in BACTEC Pediatric Plus F bottles and incubated. The TTP was inversely proportional to the initial inoculated concentration. Blood culture bottles with initial bacterial densities of <10 CFU/ml had a TTP of >20 h (upper limit of 95% prediction interval, 20.7 h) and bottles with initial bacterial densities of > or =50 CFU/ml had a TTP of < or =15 h (lower limit of 95% prediction interval, 13.4 h).
authors.affiliation: Department of Pediatrics, Schneider Children's Hospital, Long Island Jewish Medical Center of the North Shore-Long Island Jewish Health System, New Hyde Park, New York, USA.
authors.forename: Yishai
authors.initials: Y
authors.lastname: Haimi-Cohen
authors.forename: Ernestine M
authors.initials: EM
authors.lastname: Vellozzi
authors.forename: Lorry G
authors.initials: LG
authors.lastname: Rubin
mesh_terms: D016470:Bacteremia / Q000382:microbiology*; D002648:Child; D006801:Humans; D013212:Staphylococcus epidermidis / Q000302:isolation & purification*; D013997:Time Factors