title: Outer membrane protein CD of Branhamella catarrhalis: sequence conservation in strains recovered from the human respiratory tract.
abstract: 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.
authors.affiliation: Division of Infectious Diseases, State University of New York at Buffalo, USA.
authors.forename: C B
authors.initials: CB
authors.lastname: Hsiao
authors.forename: S
authors.initials: S
authors.lastname: Sethi
authors.forename: T F
authors.initials: TF
authors.lastname: Murphy
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001483:Base Sequence; D001987:Bronchiectasis / Q000382:microbiology / Q000473:pathology; D001991:Bronchitis / Q000382:microbiology / Q000473:pathology; D017124:Conserved Sequence / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics*; D006801:Humans; D008137:Longitudinal Studies; D008969:Molecular Sequence Data; D001936:Moraxella catarrhalis / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011446:Prospective Studies; D012137:Respiratory System / Q000382:microbiology / Q000473:pathology; D012689:Sequence Homology, Nucleic Acid
chemical_list: D001425:Bacterial Outer Membrane Proteins; C090131:CD protein, Branhamella; D004269:DNA, Bacterial