Mycobacteria identification

Garcia-Fernandez E, Medrano FJ, Galan B, Garcia JL (2014) Deciphering the transcriptional regulation of cholesterol catabolic pathway in mycobacteria identification of the inducer of KstR repressor. J Biol Chem 289 17576-17588... 

Fractionation of mycobacteria resulted in the identification of two cellular immunostimulatory components, namely TDM and MDPs. Both are normally found in association with the mycobacterial cell wall. TDM is composed of a molecule of trehalose (a disaccharide consisting of two molecules of a-D-glucose linked via an a 1-1 glycosidic bond), linked to two molecules of my-colic acid (a long-chain aliphatic hydrocarbon-based acid) found almost exclusively in association with mycobacteria. TDM, although retaining its adjuvanticity, is relatively non-toxic. 

The possible role of the mycobactins in the storage of iron in the mycobacteria has been noted. Of greater significance is the identification of ferritin-like molecules in some bacteria. The cytochrome 6557.5 from Azotobacter vinelandii, known to be associated with large amounts of iron, is now known to be a ferritin, with an iron content of 13-20% and an electron-dense core of... 

Lefmann M, Honisch C, Bocker S, Storm N, von Wintzingerode F, Schlotelburg C, Moter A, van den Boom D, Gobel UB. Novel mass spectrometry-based tool for genotypic identification of mycobacteria. J Clin Microbiol 2004 42 339-346. 

Whole cell growth inhibition screens combined with subsequent target identification using molecular methods have proven viable approaches to the discovery of novel antibacterial inhibitors. Andries and colleagues (2005) at Johnson Johnson employed whole cell assays to discover a series of antimycobacterial diarylquinolines (DARQs). Chemical optimization of a lead compound led to DARQ derivatives exhibiting potent in vitro activities against several mycobacteria including Mycobacterium tuberculosis (Andries et al., 2005 Ji et al., 2006), with MICs below 0.5 pg/mL. Antimycobacterial efficacy in vivo was confirmed for three of the derivatives. 

Mycobacteria take a long time to duplicate themselves (18-24 hours compared with 30 minutes for Escherichia coli). This means it can take a long time to culture enough organisms for identification and there is a long period between infection and clinical manifestation of disease. 

The cell walls of M. lepraemurium have been harvested from the livers of moribund rats that had been infected with the above organism. The walls contained a cord factor (oa-trehalose-6,6-dimycolate) that was similar in structure to the well-characterized cord factor from M. tuberculosumThis is the first unequivocal identification of a cord factor as a product of in vivo derived mycobacteria. 

Minnikin, D.E. (ed.) (1982) Lipids Complex Lipids, Their Chemistry, Biosynthesis and Roles in the Biology of the Mycobacteria. Vol. 1, Physiology, Identification and Classification. Academic Press, New York. 

Saleeb, P.G., Drake, S.K., Murray, P.R., and Zelazny, A.M. (2011) Identification of mycobacteria in solid-culture media by matrix-assisted laser desorption ionization-time of flight mass spectrometry. J. Clin. Microbiol, 49,... 

C., Raoult, D., and Drancourt, M. (2011) Matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry identification of mycobacteria in routine clinical practice. 

Leite, C.Q.F. Desouza, C.W.O. Leite, S.R.D. Identification of mycobacteria by thin layer chromatographic analysis of mycolic acids and conventional biochemical method—four years of experience. Mem. Inst. Oswaldo Cruz 1998, 93 (6), 801 05. 

Machen A, Kobayashi M, Connelly MR, Wang YF (Wayne). Comparison of heat inactivation and cell disruption protocols for identification of mycobacteria from solid culture media by use of vitek matrix-assisted laser desorption ionization-time of flight mass spectrometry. J Clin Microbiol. 2013 51(12) 4226-9. 

Mather CA, Rivera SE, Butler-Wu SM. Comparison of the Broker Biotyper and Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry systems for identification of Mycobacteria using simplified protein extraction protocols. J Clin Microbiol. 2014 52(l) 130-8. 

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