BM8300 Non-acidified Lowenstein Jensen Pyruvate Medium is an egg-based medium for the isolation and presumptive identification of Mycobacterium spp., particularly Mycobacterium bovis. BM8300 Non-acidified Lowenstein Jensen Pyruvate Medium is designed for use with sodium hydroxide (NaOH) treated samples which have been neutralised using known buffering solutions to achieve a pH of 6.8 to 7.0 and which are inoculated directly onto LJ media after concentration by centrifugation. This medium differs from E&O BM8200 Non-acidified Glycerol Lowenstein Jensen Medium in that sodium pyruvate has replaced the glycerol, which has been demonstrated to be inhibitory to some species, particularly M. bovis.
BM8300 is recommended by the UK Standards for Microbiology Investigations and tested in accordance with the principals of ISO 11133:2014.
The medium contains an egg emulsion which provides the required protein and fatty acids. Sodium pyruvate is included as an alternate to glycerol to allow favourable growth of M. bovis. The coagulation of the egg albumin during preparation also provides a solid surface for inoculation purposes. Malachite green and penicillin G are incorporated into the medium to inhibit contaminating organisms other than the mycobacteria that may still be present in the specimen in the specimen after decontamination.
Lowenstein-Jensen slopes should be inoculated with pre-treated specimens and incubated at 36 ± 1°C for 8 weeks, checking weekly for growth. Further incubation up to 12 weeks may be required for certain Mycobacterium species.
