title: High throughput phenotypic analysis of Mycobacterium tuberculosis and Mycobacterium bovis strains' metabolism using biolog phenotype microarrays.
abstract: Tuberculosis is a major human and animal disease of major importance worldwide. Genetically, the closely related strains within the Mycobacterium tuberculosis complex which cause disease are well-characterized but there is an urgent need better to understand their phenotypes. To search rapidly for metabolic differences, a working method using Biolog Phenotype MicroArray analysis was developed. Of 380 substrates surveyed, 71 permitted tetrazolium dye reduction, the readout over 7 days in the method. By looking for ≥5-fold differences in dye reduction, 12 substrates differentiated M. tuberculosis H37Rv and Mycobacterium bovis AF2122/97. H37Rv and a Beijing strain of M. tuberculosis could also be distinguished in this way, as could field strains of M. bovis; even pairs of strains within one spoligotype could be distinguished by 2 to 3 substrates. Cluster analysis gave three clear groups: H37Rv, Beijing, and all the M. bovis strains. The substrates used agreed well with prior knowledge, though an unexpected finding that AF2122/97 gave greater dye reduction than H37Rv with hexoses was investigated further, in culture flasks, revealing that hexoses and Tween 80 were synergistic for growth and used simultaneously rather than in a diauxic fashion. Potential new substrates for growth media were revealed, too, most promisingly N-acetyl glucosamine. Osmotic and pH arrays divided the mycobacteria into two groups with different salt tolerance, though in contrast to the substrate arrays the groups did not entirely correlate with taxonomic differences. More interestingly, these arrays suggested differences between the amines used by the M. tuberculosis complex and enteric bacteria in acid tolerance, with some hydrophobic amino acids being highly effective. In contrast, γ-aminobutyrate, used in the enteric bacteria, had no effect in the mycobacteria. This study proved principle that Phenotype MicroArrays can be used with slow-growing pathogenic mycobacteria and already has generated interesting data worthy of further investigation.
authors: Animal Health Veterinary Laboratories (Weybridge), Department for Bovine Tuberculosis, New Haw, Surrey, United Kingdom.
authors: Bhagwati
authors: B
authors: Khatri
authors: Mark
authors: M
authors: Fielder
authors: Gareth
authors: G
authors: Jones
authors: William
authors: W
authors: Newell
authors: Manal
authors: M
authors: Abu-Oun
authors: Paul R
authors: PR
authors: Wheeler
mesh_terms: D004396:Coloring Agents / Q000378:metabolism; D003470:Culture Media / Q000378:metabolism; D006019:Glycolysis; D006801:Humans; D006838:Hydrocarbons / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D046228:Microarray Analysis / Q000295:instrumentation* / Q000379:methods*; D009163:Mycobacterium bovis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D017672:Nitrogen Compounds / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D010641:Phenotype; D017553:Phosphorus Compounds / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D013045:Species Specificity; D013457:Sulfur Compounds / Q000378:metabolism; D013778:Tetrazolium Salts / Q000378:metabolism
chemical_list: D004396:Coloring Agents; D003470:Culture Media; D006838:Hydrocarbons; D017672:Nitrogen Compounds; D017553:Phosphorus Compounds; D013457:Sulfur Compounds; D013778:Tetrazolium Salts; D012965:Sodium Chloride