In vitro comparison of fluid blood culture media.

Eight fluid blood culture media from different manufacturers were compared with regard to their ability to culture fastidious microorganisms. In turbidity measurements following inoculation with different bacteria, the media differed with respect to the duration of the lag phase and the log phase of bacterial growth. Similar differences were observed with small inocula in original blood culture bottles (commercially available). Fastidious microorganisms grew better in Supplemented Peptone Broth II (Becton-Dickinson), BHI Roche and BHI bioMérieux. Meningococci could only be cultured in four of the eight media tested, and pneumococci in seven of the eight media (with different velocities of growth). Haemophilus influenzae showed the best results after adding blood or IsoVitalex BBL.