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Gene Review

ampC  -  beta-lactamase

Escherichia coli O157:H7 str. EDL933

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Disease relevance of ampC


High impact information on ampC

  • Addition of the muropeptide, anhMurNAc-tripeptide, which accumulates in beta-lactamase-overproducing mutants, counteracts the negative effect of UDP-MurNAc-pentapeptide, restoring the innate ability of AmpR to induce ampC expression in vitro [6].
  • The murein precursor, UDP-MurNAc-pentapeptide, decreases AmpR-mediated transcriptional activation in vitro, but has no effect on an AmpR(G102E) mutant that mediates constitutive activation of ampC in vivo [6].
  • We have isolated on a plasmid a segment of chromosomal DNA carrying multiple ampC repeats, and compared the nucleotide sequence of the region joining repeat units to the sequence of the DNA segments that fused to create the joint [7].
  • Ampicillin resistance is strictly related to ampC gene copy number thus we have been able to isolate ampicillin-resistant mutants carrying multiple ampC repeats [7].
  • Six mutants with a 21-fold increase in promoter strength compared with the wild-type were mutated in the -35 promoter region from TTGTCA to the consensus sequence TTGACA . The -10 region sequence TACAAT was mutated to the consensus sequence TATAAT in three mutants exhibiting an ampC promoter seven times stronger than the wild-type [1].

Chemical compound and disease context of ampC


Biological context of ampC


Anatomical context of ampC

  • The phenotypes of these mutants support a model in which formation of a ribosome initiation complex at a level increasing with the growth rate inhibits termination of transcription at the ampC attenuator [16].

Associations of ampC with chemical compounds


Other interactions of ampC

  • Mutations within the structural gene of ampD can lead to AmpC overproduction and increases in beta-lactam MICs in organisms with an inducible ampC [20].

Analytical, diagnostic and therapeutic context of ampC


  1. Sequence elements determining ampC promoter strength in E. coli. Jaurin, B., Grundström, T., Normark, S. EMBO J. (1982) [Pubmed]
  2. ampR gene mutations that greatly increase class C beta-lactamase activity in Enterobacter cloacae. Kuga, A., Okamoto, R., Inoue, M. Antimicrob. Agents Chemother. (2000) [Pubmed]
  3. Chromosomally encoded ampC-type beta-lactamase in a clinical isolate of Proteus mirabilis. Bret, L., Chanal-Claris, C., Sirot, D., Chaibi, E.B., Labia, R., Sirot, J. Antimicrob. Agents Chemother. (1998) [Pubmed]
  4. Membrane topology of the Escherichia coli AmpG permease required for recycling of cell wall anhydromuropeptides and AmpC beta-lactamase induction. Chahboune, A., Decaffmeyer, M., Brasseur, R., Joris, B. Antimicrob. Agents Chemother. (2005) [Pubmed]
  5. Isolation and characterization of a penicillinase from Pseudomonas cepacia 249. Prince, A., Wood, M.S., Cacalano, G.S., Chin, N.X. Antimicrob. Agents Chemother. (1988) [Pubmed]
  6. Cytosolic intermediates for cell wall biosynthesis and degradation control inducible beta-lactam resistance in gram-negative bacteria. Jacobs, C., Frère, J.M., Normark, S. Cell (1997) [Pubmed]
  7. Recombination between short DNA homologies causes tandem duplication. Edlund, T., Normark, S. Nature (1981) [Pubmed]
  8. Naturally occurring extended-spectrum cephalosporinases in Escherichia coli. Mammeri, H., Poirel, L., Fortineau, N., Nordmann, P. Antimicrob. Agents Chemother. (2006) [Pubmed]
  9. Beta-lactam resistance in clinical isolates of Escherichia coli caused by elevated production of the ampC-mediated chromosomal beta-lactamase. Bergström, S., Normark, S. Antimicrob. Agents Chemother. (1979) [Pubmed]
  10. Wide geographic spread of diverse acquired AmpC {beta}-lactamases among Escherichia coli and Klebsiella spp. in the UK and Ireland. Woodford, N., Reddy, S., Fagan, E.J., Hill, R.L., Hopkins, K.L., Kaufmann, M.E., Kistler, J., Palepou, M.F., Pike, R., Ward, M.E., Cheesbrough, J., Livermore, D.M. J. Antimicrob. Chemother. (2007) [Pubmed]
  11. Interference with murein turnover has no effect on growth but reduces beta-lactamase induction in Escherichia coli. Kraft, A.R., Prabhu, J., Ursinus, A., Höltje, J.V. J. Bacteriol. (1999) [Pubmed]
  12. Molecular mechanisms of cefoxitin resistance in Escherichia coli from the Toronto area hospitals. Forward, K.R., Willey, B.M., Low, D.E., McGeer, A., Kapala, M.A., Kapala, M.M., Burrows, L.L. Diagn. Microbiol. Infect. Dis. (2001) [Pubmed]
  13. GcvA, a LysR-type transcriptional regulator protein, activates expression of the cloned Citrobacter freundii ampC beta-lactamase gene in Escherichia coli: cross-talk between DNA-binding proteins. Everett, M., Walsh, T., Guay, G., Bennett, P. Microbiology (Reading, Engl.) (1995) [Pubmed]
  14. Extended-spectrum-beta-lactamase-producing Escherichia coli strains isolated from farm animals from 1999 to 2002: report from the Japanese Veterinary Antimicrobial Resistance Monitoring Program. Kojima, A., Ishii, Y., Ishihara, K., Esaki, H., Asai, T., Oda, C., Tamura, Y., Takahashi, T., Yamaguchi, K. Antimicrob. Agents Chemother. (2005) [Pubmed]
  15. Molecular genetic analysis of cephalosporinase production and its role in beta-lactam resistance in clinical isolates of Enterobacter cloacae. Nicolas, M.H., Honore, N., Jarlier, V., Philippon, A., Cole, S.T. Antimicrob. Agents Chemother. (1987) [Pubmed]
  16. Initiation of translation makes attenuation of ampC in E. coli dependent on growth rate. Grundström, T., Normark, S. Mol. Gen. Genet. (1985) [Pubmed]
  17. High-level expression of ampC beta-lactamase due to insertion of nucleotides between -10 and -35 promoter sequences in Escherichia coli clinical isolates: cases not responsive to extended-spectrum-cephalosporin treatment. Siu, L.K., Lu, P.L., Chen, J.Y., Lin, F.M., Chang, S.C. Antimicrob. Agents Chemother. (2003) [Pubmed]
  18. Detection of multiple cephalosporin-resistant Escherichia coli from a cattle fecal sample in Great Britain. Batchelor, M., Clifton-Hadley, F.A., Stallwood, A.D., Paiba, G.A., Davies, R.H., Liebana, E. Microb. Drug Resist. (2005) [Pubmed]
  19. Characterisation of CTX-M and AmpC genes in human isolates of Escherichia coli identified between 1995 and 2003 in England and Wales. Hopkins, K.L., Batchelor, M.J., Liebana, E., Deheer-Graham, A.P., Threlfall, E.J. Int. J. Antimicrob. Agents (2006) [Pubmed]
  20. Model system to evaluate the effect of ampD mutations on AmpC-mediated beta-lactam resistance. Schmidtke, A.J., Hanson, N.D. Antimicrob. Agents Chemother. (2006) [Pubmed]
  21. Comparison of two RT-PCR methods for quantifying ampC specific transcripts in Escherichia coli strains. Corvec, S., Caroff, N., Espaze, E., Marraillac, J., Drugeon, H., Reynaud, A. FEMS Microbiol. Lett. (2003) [Pubmed]
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