Recovery of Mycobacterium avium complex organisms from 412 lysis-centrifugation (Isolator) concentrates of blood specimens obtained from human immunodeficiency virus-positive individuals was attempted with the following media (and Isolator concentrate inoculum volumes): BACTEC 12B broth (0.2 and 1.0 ml), Lowenstein-Jensen slants (0.1 ml), and Middlebrook 7H10/11 agar (0.1 ml). A total of 42 M. ...

The recovery of Streptococcus pneumoniae from the Isolator lysis-centrifugation blood culture has been low in many studies. The poor survival of pneumococci was not due to toxicity of the Isolator medium but to autolysis before plating. This autolysis was completely inhibited by adding 10 mM phosphorylcholine to the Isolator medium.