Outer membrane protein CD of Branhamella catarrhalis: sequence conservation in strains recovered from the human respiratory tract

Microb Pathog. 1995 Oct;19(4):215-25. doi: 10.1016/s0882-4010(95)90272-4.


Branhamella catarrhalis causes lower respiratory tract infections in patients with chronic obstructive pulmonary disease. The outer membrane protein CD (OMP-CD) of B. catarrhalis is a major, heat-modifiable OMP. The goals of this study are to characterize the degree of conservation of OMP-CD among strains and to investigate if OMP-CD maintains its homogeneity under the effect of host immune selective pressure. Isolates of B. catarrhalis were collected prospectively from patients with bronchiectasis and chronic bronchitis. We studied the OMP-CD gene by analysis of PCR restriction fragment length polymorphisms (PCR-RFLP) and further determined DNA sequence of the CD gene of eight selected isolates. Five patterns of PCR-RFLP of the OMP-CD gene were observed among all isolates when the gene was digested with Sau3AI. The sequence analysis revealed a high degree of homogeneity in OMP-CD among strains of B. catarrhalis. Three regions of OMP-CD with minimal sequence heterogeneity were identified. The sequences of the OMP-CD gene of isolates collected from patients colonized with the same strain for up to 6 months was identical. These observations establish that the OMP-CD of B. catarrhalis recovered from clinical isolates is highly conserved among strains.

Publication types

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

MeSH terms

  • Bacterial Outer Membrane Proteins / genetics*
  • Base Sequence
  • Bronchiectasis / microbiology
  • Bronchiectasis / pathology
  • Bronchitis / microbiology
  • Bronchitis / pathology
  • Conserved Sequence / genetics*
  • DNA, Bacterial / genetics*
  • Genes, Bacterial / genetics*
  • Humans
  • Longitudinal Studies
  • Molecular Sequence Data
  • Moraxella catarrhalis / chemistry
  • Moraxella catarrhalis / genetics*
  • Moraxella catarrhalis / isolation & purification
  • Polymerase Chain Reaction
  • Polymorphism, Restriction Fragment Length
  • Prospective Studies
  • Respiratory System / microbiology
  • Respiratory System / pathology
  • Sequence Homology, Nucleic Acid


  • Bacterial Outer Membrane Proteins
  • CD protein, Branhamella
  • DNA, Bacterial