title: Phylogeny of the genus Haemophilus as determined by comparison of partial infB sequences.
abstract: A 453 bp fragment of infB, the gene encoding translation initiation factor 2, was sequenced and compared from 66 clinical isolates and type strains of Haemophilus species and related bacteria. Analysis of the partial infB sequences obtained suggested that the human isolates dependent on X and V factor, H. influenzae, H. haemolyticus, H. aegyptius and some cryptic genospecies of H. influenzae, were closely related to each other. H. parainfluenzae constituted a heterogeneous group within the boundaries of the genus, whereas H. aphrophilus/paraphrophilus and Actinobacillus actinomycetemcomitans were only remotely related to the type species of the genus Haemophilus H. parahaemolyticus and H. paraphrohaemolyticus took up an intermediary position and may not belong in the genus Haemophilus sensu stricto. Ambiguous results were obtained with seven isolates tentatively identified as H. segnis, which fell into two discrete clusters. The delineation of 'Haemophilus sensu stricto' as suggested by infB analysis supports previous results obtained by DNA hybridization, in contrast to the delineation inferred from 16S rRNA sequence comparison.
authors.affiliation: Departments of Molecular and Structural Biology1 and Medical Microbiology and Immunology4, University of Aarhus, DK-8000 Aarhus C, Denmark.
authors.forename: Jakob
authors.initials: J
authors.lastname: Hedegaard
authors.affiliation: Departments of Clinical Biochemistry2 and Clinical Microbiology5, Aalborg Hospital, DK-9000 Aalborg, Denmark.
authors.forename: Henrik
authors.initials: H
authors.lastname: Okkels
authors.affiliation: Department of Clinical Microbiology, Statens Serum Institut, DK-2300 Copenhagen S, Denmark3.
authors.forename: Brita
authors.initials: B
authors.lastname: Bruun
authors.affiliation: Departments of Molecular and Structural Biology1 and Medical Microbiology and Immunology4, University of Aarhus, DK-8000 Aarhus C, Denmark.
authors.forename: Mogens
authors.initials: M
authors.lastname: Kilian
authors.affiliation: Departments of Molecular and Structural Biology1 and Medical Microbiology and Immunology4, University of Aarhus, DK-8000 Aarhus C, Denmark.
authors.forename: Kim K
authors.initials: KK
authors.lastname: Mortensen
authors.affiliation: Departments of Clinical Biochemistry2 and Clinical Microbiology5, Aalborg Hospital, DK-9000 Aalborg, Denmark.|Department of Clinical Microbiology, Statens Serum Institut, DK-2300 Copenhagen S, Denmark3.
authors.forename: Niels
authors.initials: N
authors.lastname: Nørskov-Lauritsen
mesh_terms: D000188:Actinobacillus / Q000145:classification / Q000235:genetics; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006190:Haemophilus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006193:Haemophilus influenzae / Q000145:classification / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D010325:Pasteurella / Q000145:classification / Q000235:genetics; D010448:Peptide Initiation Factors / Q000235:genetics*; D010641:Phenotype; D010802:Phylogeny; D039881:Prokaryotic Initiation Factor-2; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D010448:Peptide Initiation Factors; D039881:Prokaryotic Initiation Factor-2; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S