Effect of Polymyxins on the Lipopolysaccharide-Defective Mutants of Proteus Mirabilis

Microbios. 1990;61(246):23-32.


The effects of polymyxins (Pmx) B and E on smooth and rough Proteus mirabilis strains were investigated. P. mirabilis mutant R4/028 which completely lacked 4-amino-4-deoxy-L-arabinose was sensitive towards both polymyxins, and the other P. mirabilis strains investigated were resistant. Lipopolysaccharide (LPS) from Pmx-sensitive R4/028 strain, binds 50% more Pmx B than LPS derived from resistant P. mirabilis strains. The presence of iodoacetamide, N-ethylmaleimide and chloramphenicol rendered the Pmx-resistant P. mirabilis strains sensitive towards both polymyxins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chloramphenicol / pharmacology
  • Drug Resistance, Microbial
  • Ethylmaleimide / pharmacology
  • Iodoacetamide / pharmacology
  • Lipopolysaccharides / metabolism*
  • Mutation
  • Polymyxin B / metabolism
  • Polymyxin B / pharmacology*
  • Polymyxins / metabolism
  • Polymyxins / pharmacology*
  • Proteus mirabilis / drug effects*
  • Proteus mirabilis / genetics


  • Lipopolysaccharides
  • Polymyxins
  • Chloramphenicol
  • Polymyxin B
  • Ethylmaleimide
  • Iodoacetamide