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

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 ≥50 CFU/ml had a TTP of ≤15 h (lower limit of 95% prediction interval, 13.4 h)

Emergence of Candida parapsilosis as the predominant species causing candidemia in children.

An increase in the rate of isolation of Candida parapsilosis, relative to other Candida species, in our children\u27s hospital led us to analyze the clinical and epidemiological variables associated with candidemia. We sought to determine if these variables are different for patients infected with C. parapsilosis. All episodes of candidemia occurring over a 7-year period were analyzed retrospectively. Of 81 episodes in 80 patients, 35 (43%) were in neonates, and 46 (57%) were in nonneonates. C. parapsilosis was isolated in 40 episodes (49%). C. parapsilosis was significantly more likely than non-C. parapsilosis species to be associated with prematurity (P = .001), presence of a central venous catheter (P = .002), and use of total parenteral nutrition (P = .03). C. parapsilosis has emerged as the predominant species in our children\u27s hospital. The mortality rate associated with candidemia in children is lower than previously reported and may be associated with the high rate of isolation of C. parapsilosis