Inducible or constitutive expression of resistance in clinical isolates of streptococci and enterococci cross-resistant to erythromycin and lincomycin

J Antimicrob Chemother. 1999 Apr;43(4):559-62. doi: 10.1093/jac/43.4.559.


Thirty-five of 40 clinical isolates of enterococci and streptococci cross-resistant to erythromycin and lincomycin and harbouring erm genes were inducibly resistant to these drugs, suggesting that ribosomal methylation is predominantly inducibly expressed in these bacterial genera. Regulatory regions located upstream of the erm genes of four inducible and three constitutive strains were amplified and sequenced. Expression of constitutive resistance in two strains of Streptococcus pneumoniae and Enterococcus faecalis could be accounted for by a large deletion or a DNA duplication within the regulatory regions, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Base Sequence
  • Drug Resistance, Microbial / genetics
  • Drug Resistance, Multiple / genetics
  • Enterococcus / drug effects*
  • Erythromycin / pharmacology*
  • Gene Expression Regulation, Bacterial
  • Genes, Bacterial
  • Gram-Positive Bacterial Infections / microbiology
  • Humans
  • Lincomycin / pharmacology*
  • Methyltransferases / genetics
  • Molecular Sequence Data
  • Regulatory Sequences, Nucleic Acid
  • Ribosomes / metabolism
  • Streptococcal Infections / microbiology
  • Streptococcus / drug effects*


  • Anti-Bacterial Agents
  • Erythromycin
  • Lincomycin
  • Methyltransferases