Construction of a severely attenuated mutant of Mycobacterium tuberculosis for reducing risk to laboratory workers.
The ability to construct defined deletions of Mycobacterium tuberculosis has allowed many genes involved in virulence to be identified. Deletion of nutritional genes leads to varying levels of attenuation, presumably reflecting the need for a particular molecule, and the availability (or lack) of that molecule in vivo. We have previously shown that M. tuberculosis mutants lacking either the trpD or ino1 gene are highly attenuated in mouse models of infection, but can grow when supplemented with tryptophan or inositol, respectively. In this paper we have constructed a double Delta trpDDelta ino1 mutant, and show that this is severely attenuated in SCID mouse and guinea pig models. As the strain will grow in the presence of supplements, we propose that this strain could be used for research and antigen preparative purposes, with reduced risks to laboratory workers.
Movahedzadeh
Farahnaz
F
Department of Pathology and Infectious Diseases, Royal Veterinary College, Royal College Street, London, UK. movahed@uic.edu
Williams
Ann
A
Clark
Simon
S
Hatch
Graham
G
Smith
Debbie
D
ten Bokum
Annemieke
A
Parish
Tanya
T
Bacon
Joanna
J
Stoker
Neil
N
D000818:Animals; D002478:Cells, Cultured; D003470:Culture Media; D004252:DNA Mutational Analysis / Q000379:methods; D004195:Disease Models, Animal; D005260:Female; D017353:Gene Deletion; D006168:Guinea Pigs; D006801:Humans; D008168:Lung / Q000382:microbiology; D051379:Mice; D016513:Mice, SCID; D016297:Mutagenesis, Site-Directed / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000472:pathogenicity*; D007296:Myo-Inositol-1-Phosphate Synthase / Q000235:genetics / Q000302:isolation & purification*; D009784:Occupational Diseases / Q000517:prevention & control*; D016273:Occupational Exposure / Q000517:prevention & control*; D014397:Tuberculosis, Pulmonary / Q000235:genetics / Q000517:prevention & control*; D014774:Virulence / Q000235:genetics
D003470:Culture Media; D007296:Myo-Inositol-1-Phosphate Synthase