title: Failure to detect capsule gene bexA in Haemophilus influenzae types e and f by real-time PCR due to sequence variation within probe binding sites.
abstract: Detection of the conserved capsule gene bexA is used to distinguish capsulate from non-capsulate Haemophilus influenzae. While developing a real-time PCR assay to detect bexA, it was found that bexA probes produced a detectable signal for H. influenzae types a to d, but failed to do so for H. influenzae types e and f. Sequencing revealed differences compared with H. influenzae types a to d within probe binding sites. To prevent misclassification of strains as non-capsulate, assays must detect all capsular types.
authors.affiliation: Health Protection Agency London, Department of Virology, King's College Hospital (Dulwich site), Dulwich Hospital, East Dulwich Grove, London SE22 8QF, UK.
authors.forename: I-C
authors.initials: IC
authors.lastname: Sam
authors.affiliation: Health Protection Agency London, Department of Virology, King's College Hospital (Dulwich site), Dulwich Hospital, East Dulwich Grove, London SE22 8QF, UK.
authors.forename: M
authors.initials: M
authors.lastname: Smith
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D015342:DNA Probes; D005798:Genes, Bacterial; D014644:Genetic Variation; D006193:Haemophilus influenzae / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D015342:DNA Probes; C068101:bexA protein, Haemophilus influenzae