The goal is to evaluate the use of DNA probes for transient RNA molecules in testing the susceptibility of Mycobacterium tuberculosis to antibiotics. We will evaluate two types of transient RNA as indicators of antibiotic-resistant metabolic activity in cultures or clinical samples challenged briefly with antibiotics. First, we will clone, sequence, and develop DNA probes for M. tuberculosis ribosomal RNA (rRNA) precursor sequences. Second, we will use differential or subtractive screening techniques to identify specific messenger RNA (mRNA) sequences which, due to regulatory response to antibiotic challenge and mRNA turnover, are depleted in susceptible cells exposed to isoniazid, ethambutol, or streptomycin. DNA probes for these mRNAs will be developed and tested. Probes for both types of transient RNA will be combined with probes for species-specific nucleic acid sequences to result in assays that can rapidly and simultaneously detect M. tuberculosis and test its susceptibility to antibiotics. As a functional assay for antibiotic effectiveness, this general approach will be able to detect antibiotic resistance rapidly and specifically, regardless of the genetic basis for resistance. This work will also provide us with useful data on the biology of growth and ribosome assembly in M. tuberculosis, and may add to our understanding of the modes of action of important antituberculosis drugs.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI035280-02
Application #
2070848
Study Section
Special Emphasis Panel (SRC (36))
Project Start
1993-09-30
Project End
1995-02-28
Budget Start
1994-09-01
Budget End
1995-02-28
Support Year
2
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Epoch Biosciences, Inc.
Department
Type
DUNS #
City
Bothell
State
WA
Country
United States
Zip Code
98021
Cangelosi, G A; Hamlin, A M; Marin 3rd, R et al. (1997) Detection of stable pre-rRNA in toxigenic Pseudo-nitzschia species. Appl Environ Microbiol 63:4859-65
Cangelosi, G A; Brabant, W H (1997) Depletion of pre-16S rRNA in starved Escherichia coli cells. J Bacteriol 179:4457-63
Cangelosi, G A; Brabant, W H; Britschgi, T B et al. (1996) Detection of rifampin- and ciprofloxacin-resistant Mycobacterium tuberculosis by using species-specific assays for precursor rRNA. Antimicrob Agents Chemother 40:1790-5
Britschgi, T B; Cangelosi, G A (1995) Detection of rifampin-resistant bacteria using DNA probes for precursor rRNA. Mol Cell Probes 9:19-24
Anderberg, R J; Strachan, J A; Cangelosi, G A (1995) Purification of DNA from Mycobacterium species without sonication or phenol. Biotechniques 18:217-9