Characterization of Encapsulated and Noncapsulated Haemophilus influenzae and Determination of Phylogenetic Relationships by Multilocus Sequence Typing
- 1 April 2003
- journal article
- research article
- Published by American Society for Microbiology in Journal of Clinical Microbiology
- Vol. 41 (4), 1623-1636
- https://doi.org/10.1128/jcm.41.4.1623-1636.2003
Abstract
A multilocus sequence typing (MLST) scheme has been developed for the unambiguous characterization of encapsulated and noncapsulated Haemophilus influenzae isolates. The sequences of internal fragments of seven housekeeping genes were determined for 131 isolates, comprising a diverse set of 104 serotype a, b, c, d, e, and f isolates and 27 noncapsulated isolates. Many of the encapsulated isolates had previously been characterized by multilocus enzyme electrophoresis (MLEE), and the validity of the MLST scheme was established by the very similar clustering of isolates obtained by these methods. Isolates of serotypes c, d, e, and f formed monophyletic groups on a dendrogram constructed from the differences in the allelic profiles of the isolates, whereas there were highly divergent lineages of both serotype a and b isolates. Noncapsulated isolates were distinct from encapsulated isolates and, with one exception, were within two highly divergent clusters. The relationships between the major lineages of encapsulated H. influenzae inferred from MLEE data could not be discerned on a dendrogram constructed from differences in the allelic profiles, but were apparent on a tree reconstructed from the concatenated nucleotide sequences. Recombination has not therefore completely eliminated phylogenetic signal, and in support of this, for encapsulated isolates, there was significant congruence between many of the trees reconstructed from the sequences of the seven individual loci. Congruence was less apparent for noncapsulated isolates, suggesting that the impact of recombination is greater among noncapsulated than encapsulated isolates. The H. influenzae MLST scheme is available at www.mlst.net , it allows any isolate to be compared with those in the MLST database, and (for encapsulated isolates) it assigns isolates to their phylogenetic lineage, via the Internet.Keywords
This publication has 39 references indexed in Scilit:
- High rates of recombination in otitis media isolates of non-typeable Haemophilus influenzaeInfection, Genetics and Evolution, 2003
- Limited Genetic Diversity of Recent Invasive Isolates of Non-Serotype b Encapsulated Haemophilus influenzaeJournal of Clinical Microbiology, 2002
- Immunological Characterization of ConjugatedHaemophilus influenzaeType b Vaccine Failure in InfantsClinical Infectious Diseases, 2001
- Multilocus Sequence Typing ofStreptococcus pyogenesand the Relationships betweenemmType and CloneInfection and Immunity, 2001
- Clinical and Immunological Risk Factors Associated withHaemophilus influenzaeType b Conjugate Vaccine Failure in ChildhoodClinical Infectious Diseases, 2000
- A multilocus sequence typing scheme for Streptococcus pneumoniae: identification of clones associated with serious invasive diseaseMicrobiology, 1998
- Invasive Disease Due to Haemophilus influenzae Serotype f: Clinical and Epidemiologic Characteristics in the H. influenzae Serotype b Vaccine EraClinical Infectious Diseases, 1996
- Epidemiology of invasiveHaemophilus influenzaeinfections in England and Wales in the pre-vaccination era (1990–2)Epidemiology and Infection, 1995
- Whole-Genome Random Sequencing and Assembly of Haemophilus influenzae RdScience, 1995
- Brazilian Purpuric Fever: Evolutionary Genetic Relationships of the Case Clone of Haemophilus influenzae Biogroup Aegyptius to Encapsulated Strains of Haemophilus influenzaeThe Journal of Infectious Diseases, 1990