Induction of beta-lactamase production in Aeromonas hydrophila is responsive to beta-lactam-mediated changes in peptidoglycan composition

Microbiology. 2010 Aug;156(Pt 8):2327-2335. doi: 10.1099/mic.0.035220-0. Epub 2010 Apr 29.

Abstract

We have studied the mechanism by which beta-lactam challenge leads to beta-lactamase induction in Aeromonas hydrophila through transposon-insertion mutagenesis. Disruption of the dd-carboxypeptidases/endopeptidases, penicillin-binding protein 4 or BlrY leads to elevated monomer-disaccharide-pentapeptide levels in A. hydrophila peptidoglycan and concomitant overproduction of beta-lactamase through activation of the BlrAB two-component regulatory system. During beta-lactam challenge, monomer-disaccharide-pentapeptide levels increase proportionately with beta-lactamase production and beta-lactamase induction is inhibited by vancomycin, which binds muro-pentapeptides. Taken together, these data strongly suggest that the Aeromonas spp. beta-lactamase regulatory sensor kinase, BlrB, responds to the concentration of monomer-disaccharide-pentapeptide in peptidoglycan.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aeromonas hydrophila / enzymology*
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / metabolism
  • Mutagenesis, Insertional
  • Peptidoglycan / chemistry*
  • Vancomycin / pharmacology
  • beta-Lactamases / biosynthesis*
  • beta-Lactams / pharmacology*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Peptidoglycan
  • beta-Lactams
  • Vancomycin
  • beta-Lactamases