Effect of volume of blood cultured on detection of bacteremia

The rates of recovery of bacteria from vented vacuum blood culture bottles containing 50 and 100 ml of a soybean-casein digest broth were compared. Overall, more isolates were recovered from the larger bottle; moreover, gram-negative bacilli and especially Pseudomonas aeruginosa were recovered significantly more frequently (P less than 0.01) from the 100-ml bottle.