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Gene Review

bla  -  beta-lactamase

Mycobacterium tuberculosis CDC1551

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Disease relevance of bla


High impact information on bla

  • While clavulanate is a mechanism-based inhibitor to class A beta-lactamase with high potency (typically K(i) < 0.1 microM), it is a relatively poor inhibitor of the M. tuberculosis BlaC (K(i) = 2.4 microM) [1].
  • However, they are ineffective against Mycobacterium tuberculosis, due to the production of a beta-lactamase enzyme encoded on the chromosome of M. tuberculosis that degrades these antibiotics [1].
  • A sequence analysis identified it as a class A beta-lactamase whose expression correlated with the increased resistance phenotype [6].
  • The presence of membrane-associated beta-lactamase precluded the use of membranes for assaying the binding affinities of beta-lactam antibiotics [7].
  • Resistance could be reversed with the beta-lactamase inhibitors clavulanate or sulbactam or could be circumvented by the use of a beta-lactamase-stable drug, imipenem, indicating that mycobacterial beta-lactamase, probably in conjunction with slow penetration, is a major determinant of M. tuberculosis resistance to beta-lactam antibiotics [7].

Chemical compound and disease context of bla


Biological context of bla

  • We hypothesized that characterizing additional mutants (derived from beta-lactamase deletion mutants) that are hypersusceptible to beta-lactam antibiotics might reveal novel genes involved with other mechanisms of beta-lactam resistance, peptidoglycan assembly, and cell envelope physiology [9].
  • Twelve of the beta-lactamase gene fusions conferred high levels of Ampr (up to 1 mg ampicillin ml-1); insert sizes ranged from 350 to 3000 bp [2].
  • DESIGN: Cell-associated beta-lactamase was measured by nitrocefin disc method. beta-lactamases obtained from some mycobacteria were studied for their substrate specificity, metal ion-dependency and isoelectric focusing (IEF) patterns [10].

Anatomical context of bla

  • Optimum activity was observed at 100 mg/l which killed 58-97% of the mycobacteria within macrophages, as determined by the CFU. beta-Lactam/beta-lactamase-inhibitors, especially ampicillin/sulbactam, might provide an effective alternative therapy against infections caused by mycobacteria resistant to other drugs [11].

Associations of bla with chemical compounds


Analytical, diagnostic and therapeutic context of bla


  1. Crystal structure and activity studies of the Mycobacterium tuberculosis beta-lactamase reveal its critical role in resistance to beta-lactam antibiotics. Wang, F., Cassidy, C., Sacchettini, J.C. Antimicrob. Agents Chemother. (2006) [Pubmed]
  2. Identification of Mycobacterium tuberculosis signal sequences that direct the export of a leaderless beta-lactamase gene product in Escherichia coli. Chubb, A.J., Woodman, Z.L., da Silva Tatley, F.M., Hoffmann, H.J., Scholle, R.R., Ehlers, M.R. Microbiology (Reading, Engl.) (1998) [Pubmed]
  3. PCR amplification on a microarray of gel-immobilized oligonucleotides: detection of bacterial toxin- and drug-resistant genes and their mutations. Strizhkov, B.N., Drobyshev, A.L., Mikhailovich, V.M., Mirzabekov, A.D. BioTechniques (2000) [Pubmed]
  4. Beta-lactamases of Mycobacterium tuberculosis and Mycobacterium kansasii. Segura, C., Salvadó, M. Microbiologia (1997) [Pubmed]
  5. New experimental drugs for the treatment of tuberculosis. Parenti, F. Rev. Infect. Dis. (1989) [Pubmed]
  6. Cloning and sequence analysis of a class A beta-lactamase from Mycobacterium tuberculosis H37Ra. Hackbarth, C.J., Unsal, I., Chambers, H.F. Antimicrob. Agents Chemother. (1997) [Pubmed]
  7. Can penicillins and other beta-lactam antibiotics be used to treat tuberculosis? Chambers, H.F., Moreau, D., Yajko, D., Miick, C., Wagner, C., Hackbarth, C., Kocagöz, S., Rosenberg, E., Hadley, W.K., Nikaido, H. Antimicrob. Agents Chemother. (1995) [Pubmed]
  8. Comparison of four beta-lactamase inhibitors in combination with ampicillin against Mycobacterium tuberculosis. Sorg, T.B., Cynamon, M.H. J. Antimicrob. Chemother. (1987) [Pubmed]
  9. Characterization of novel Mycobacterium tuberculosis and Mycobacterium smegmatis mutants hypersusceptible to beta-lactam antibiotics. Flores, A.R., Parsons, L.M., Pavelka, M.S. J. Bacteriol. (2005) [Pubmed]
  10. Distribution and characterization of beta-lactamases of mycobacteria and related organisms. Kwon, H.H., Tomioka, H., Saito, H. Tuber. Lung Dis. (1995) [Pubmed]
  11. Bactericidal action of ampicillin/sulbactam against intracellular mycobacteria. Prabhakaran, K., Harris, E.B., Randhawa, B. Int. J. Antimicrob. Agents (1999) [Pubmed]
  12. Susceptibility of multidrug-resistant strains of Mycobacterium tuberculosis to amoxycillin in combination with clavulanic acid and ethambutol. Abate, G., Miörner, H. J. Antimicrob. Chemother. (1998) [Pubmed]
  13. Characterization of the twin-arginine translocase secretion system of Mycobacterium smegmatis. Posey, J.E., Shinnick, T.M., Quinn, F.D. J. Bacteriol. (2006) [Pubmed]
  14. Amoxicillin-clavulanic acid for treating drug-resistant Mycobacterium tuberculosis. Nadler, J.P., Berger, J., Nord, J.A., Cofsky, R., Saxena, M. Chest (1991) [Pubmed]
  15. The vitro efficacy of beta-lactam and beta-lactamase inhibitors against multidrug resistant clinical strains of Mycobacterium tuberculosis. Dinçer, I., Ergin, A., Kocagöz, T. Int. J. Antimicrob. Agents (2004) [Pubmed]
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