Trans-isolate medium: a new medium for primary culturing and transport of Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae.

A diphasic medium, Trans-Isolate medium, was developed for the transport of primary cultures of cerebrospinal fluids from patients with bacterial meningitis. It consists of a charcoal-starch agar slant and soybean-casein digest-gelatin broth buffered at pH 7.2 with 0.1 M 3-(N-morpholino)propanesulfonic acid buffer. In the laboratory, this medium supported the growth and survival of stock cultures of Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae for at least 3 months. Under field conditions in Africa, cerebrospinal fluids from patients suspected of having bacterial meningitis were inoculated directly onto plates of chocolate agar medium and into bottles of Trans-Isolate medium. An etiological agent was isolated from 52 spinal fluids by direct plating. After shipment to Atlanta, Ga., 2 to 4 weeks later, the same etiological agents were recovered from 38 bottles of Trans-Isolate medium.