The vir locus affects the response of Bordetella pertussis to antibiotics: phenotypic tolerance and control of autolysis

J Infect Dis. 1990 Aug;162(2):560-3. doi: 10.1093/infdis/162.2.560.


Eradication of Bordetella pertussis from the respiratory tract occurs slowly even when bactericidal antibiotics are used. The rate of killing of B. pertussis was found to be proportional to growth rate: virulent, slowly growing strains were killed over days, while rapidly growing strains (either avirulent or virulent modulated by growth conditions to avirulent) were killed over hours. Minimum inhibitory concentrations and binding of antibiotics to membrane targets were equivalent in virulent and avirulent cells, suggesting differences in antibiotic response might reflect differences in activities of the autolytic cascade. This was supported by the finding that cell wall degradation was less than 40% per day in virulent strains and greater than 70% per day in avirulent strains. Penem antibiotics, known to rapidly kill even slowly growing bacteria, demonstrated a more-than-twofold greater rate of killing of slowly growing virulent strains compared with ampicillin or erythromycin. This suggests the potential for improved therapeutic efficacy in vivo. Thus, the vir locus, which determines phase transition in B. pertussis, is apparently the first example of a sensor-transducer system controlling phenotypic tolerance and antibiotic-induced autolytic activity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Anti-Bacterial Agents / metabolism
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins*
  • Bacteriolysis / drug effects*
  • Bordetella pertussis / drug effects*
  • Bordetella pertussis / pathogenicity
  • Bordetella pertussis / ultrastructure
  • Carrier Proteins / analysis
  • Carrier Proteins / metabolism
  • Cell Wall / drug effects
  • Cell Wall / metabolism
  • Densitometry
  • Hexosyltransferases*
  • Humans
  • Lactams
  • Microscopy, Electron
  • Molecular Weight
  • Muramoylpentapeptide Carboxypeptidase / analysis
  • Muramoylpentapeptide Carboxypeptidase / metabolism
  • Penicillin-Binding Proteins
  • Peptidoglycan / metabolism
  • Peptidyl Transferases*
  • Phenotype
  • Virulence


  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Carrier Proteins
  • Lactams
  • Penicillin-Binding Proteins
  • Peptidoglycan
  • Peptidyl Transferases
  • Hexosyltransferases
  • Muramoylpentapeptide Carboxypeptidase