A new plasmidic cefotaximase in a clinical isolate of Escherichia coli

Infection. Sep-Oct 1990;18(5):294-8. doi: 10.1007/BF01647010.


Escherichia coli GRI was isolated from an ear exudate of a newborn. The strain was highly resistant to cefotaxime (MIC 128 mg/l). Resistance to cefotaxime and the majority of beta-lactam antibiotics was readily transferred to an Escherichia coli recipient strain. Both the wild type and the transconjugant strains are different in their resistance phenotype from TEM-3 beta-cefotaximase producers by higher MICs to the majority of beta-lactams and lower MICs to ceftazidime. The isoelectric point of the cefotaximase of E. coli GRI was 8.9 in comparison with 6.3 for TEM-3. Thus, the enzyme produced by E. coli GRI represents a new plasmidic (plasmid pMVP-3) broad spectrum beta-lactamase (CTX-M) which may not be closely related to either the TEM- oder SHV-family of extended broad spectrum beta-lactamases.

MeSH terms

  • Cefotaxime / metabolism
  • Conjugation, Genetic
  • DNA, Bacterial / analysis
  • Drug Resistance, Microbial / genetics
  • Escherichia coli / drug effects
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics
  • Escherichia coli Infections / microbiology*
  • Humans
  • Infant
  • Isoelectric Point
  • Otitis Media with Effusion / microbiology*
  • R Factors*
  • beta-Lactamases / chemistry
  • beta-Lactamases / genetics*


  • DNA, Bacterial
  • beta-Lactamases
  • Cefotaxime