The physiology and pathogenicity of Mycobacterium tuberculosis grown under controlled conditions in a defined medium.
A chemically-defined culture medium was developed which supported batch growth of Mycobacterium tuberculosis, strain H37Rv, at a minimum doubling time of 14.7 h. This medium also facilitated chemostat culture of M. tuberculosis at a constant doubling time of 24 h. Chemostat growth was optimized at a dissolved oxygen tension of 20% (v/v) and 0.2% (v/v) Tween-80. Chemostat cultures were dispersed suspensions of single bacilli (1.5-3 microm long), or small aggregates, at a mean density of log10 8.3 cfu ml-1. A limited number of amino acids was utilized (alanine, asparagine, aspartate and serine were depleted by >50%; glycine, arginine, isoleucine, leucine and phenylalanine, by approximately 40%). Chemostat-grown cells were pathogenic in aerosol-infected guinea pigs, producing disseminated infection similar to that caused by plate-grown cells. Cells from chemostat culture were significantly more invasive for J774A.1 mouse macrophages than agar- or batch-grown cells. This study demonstrates the suitability of chemostat culture for the growth of pathogenic mycobacteria in a defined physiological state with potential applications for the controlled production of mycobacterial components for therapeutic and vaccine applications.
James
B W
BW
Centre for Applied Microbiology and Research, Salisbury, UK. brian.james@camr.org.uk
Williams
A
A
Marsh
P D
PD
D000818:Animals; D002460:Cell Line; D003470:Culture Media; D006168:Guinea Pigs; D008264:Macrophages / Q000382:microbiology; D051379:Mice; D009169:Mycobacterium tuberculosis / Q000254:growth & development / Q000472:pathogenicity* / Q000502:physiology
D003470:Culture Media