Effects of anti-neoplastic agents on the recovery of bacteria and yeasts in an automated blood culture system.

The effects of 7 anti-neoplastic agents on the recovery of 5 aerobic gram-positive cocci, gram-negative rods and yeasts were studied in 2 different automated blood culture systems using an experimental model. In the absence of anti-neoplastic agents, the growth of gram-positive cocci was detected significantly earlier in standard than in FAN aerobic bottles. In the presence of 100 microM doxorubicin, however, the growth of gram-positive cocci was totally inhibited in standard culture conditions, while in FAN bottles the agent has no inhibitory effect. Etoposide at a concentration of 100 micromol/l also significantly delayed the growth of cocci in standard conditions. Neither the culture bottles nor the anti-neoplastic agents tested had any effect on the growth of gram-negative rods and yeasts. The results suggest that the anti-neoplastic agents present in blood might disturb the growth of gram-positive cocci in blood culture. This should be considered when validating blood culture systems and evaluating blood cultures of chemotherapy-receiving febrile patients.