Controlled comparison of the BACTEC high-blood-volume fungal medium, BACTEC Plus 26 aerobic blood culture bottle, and 10-milliliter isolator blood culture system for detection of fungemia and bacteremia

Abstract

The BACTEC high-blood-volume fungal medium (HBV-FM) (Becton Dickinson Diagnostic Instrument Systems, Sparks, Md.) was compared with the Isolator (IS) tube and the BACTEC Plus 26 (BP26) blood culture bottle for the ability to recover fungi from the blood of adult patients suspected of having fungemia. A total of 6,836 blood culture sets that fulfilled criteria for inclusion in the study were received. Three separate comparisons were performed: 4,907 HBV-FM versus IS, 4,886 BP26 versus HBV-FM, and 4,949 BP26 versus IS. For the HBV-FM versus IS comparison, 218 isolates were recovered: 125 (57.3%) were bacteria and 93 (42.7%) were fungi. HBV-FM was comparable to IS for recovery of yeasts, but IS was superior for recovery of Histoplasma capsulatum (25 versus 0 isolates recovered [P < 0.001]). Growth of Torulopsis glabrata was detected earlier (P < 0.05) in HBV-FM bottles. For the BP26 versus HBV-FM comparison, 229 isolates were recovered: 161 (70.3%) were bacteria, and 68 (29.7%) were fungi. HBV-FM was superior for recovery of T. glabrata (P < 0.025) and all fungi combined (P < 0.025). There were no statistically significant differences in the speed of detection of microbial growth. For the BP26 versus IS comparison, 251 isolates were recovered: 165 (65.7%) were bacteria, and 86 (34.2%) were fungi. IS was superior for recovery of H. capsulatum (P < 0.001), T. glabrata (P < 0.05), and fungi other than H. capsulatum (P < 0.025).

Growth inhibition of pathogenic yeasts by Pseudomonas aeruginosa in vitro: clinical implications in blood cultures

“…However, in all cases, early diagnosis and treatment are of vital importance. These findings underline the possible advantages of using, in parallel on standard medium, a selective medium for fungal recovery for an accurate diagnosis of bacteraemia-fungaemia associations [22]. Some of our observations (unpublished data) in patients with polymicrobial septicaemia support this concept.…”

Controlled evaluation of BacT/Alert standard aerobic and FAN aerobic blood culture bottles for detection of bacteremia and fungemia

“…One could also speculate that the charcoal or other components in the Ecosorb supplement might bind inhibitory factors in blood, thereby enhancing microbial recovery. Regardless of the explanation, the improved yield of yeasts may represent a potential advantage of the BacT/Alert system over other blood culture systems that require separate fungal medium formulations that do not support bacterial growth (13).…”

Update on detection of bacteremia and fungemia.

“…In automated systems with newer medium formulations, particularly the resin-containing, nonradiometric media for the BACTEC 660 instrument, Candida spp. have been recovered as well as in the lysis-centrifugation system, but the recovery of Cryptococcus neoformans and dimorphic moulds is less satisfactory than by lysis-centrifugation (205).…”

“…For patients with culture-negative endocarditis, a better practice is to use another blood culture method designed to improve the recovery of rare or fastidious microorganisms such as fungi or Legionella or Brucella spp. (33,142,205,207). Subcultures.…”