title: Comparative genomics of Neisseria meningitidis: core genome, islands of horizontal transfer and pathogen-specific genes.
abstract: To better understand Neisseria meningitidis genomes and virulence, microarray comparative genome hybridization (mCGH) data were collected from one Neisseria cinerea, two Neisseria lactamica, two Neisseria gonorrhoeae and 48 Neisseria meningitidis isolates. For N. meningitidis, these isolates are from diverse clonal complexes, invasive and carriage strains, and all major serogroups. The microarray platform represented N. meningitidis strains MC58, Z2491 and FAM18, and N. gonorrhoeae FA1090. By comparing hybridization data to genome sequences, the core N. meningitidis genome and insertions/deletions (e.g. capsule locus, type I secretion system) related to pathogenicity were identified, including further characterization of the capsule locus, bioinformatics analysis of a type I secretion system, and identification of some metabolic pathways associated with intracellular survival in pathogens. Hybridization data clustered meningococcal isolates from similar clonal complexes that were distinguished by the differential presence of six distinct islands of horizontal transfer. Several of these islands contained prophage or other mobile elements, including a novel prophage and a transposon carrying portions of a type I secretion system. Acquisition of some genetic islands appears to have occurred in multiple lineages, including transfer between N. lactamica and N. meningitidis. However, island acquisition occurs infrequently, such that the genomic-level relationship is not obscured within clonal complexes. The N. meningitidis genome is characterized by the horizontal acquisition of multiple genetic islands; the study of these islands reveals important sets of genes varying between isolates and likely to be related to pathogenicity.
authors.affiliation: The Institute for Genomic Research, 9712 Medical Center Dr, Rockville, MD 20850, USA.
authors.forename: Julie C Dunning
authors.initials: JCD
authors.lastname: Hotopp
authors.affiliation: Novartis Vaccines and Diagnostics Ltd, Via Fiorentina 1, 53100 Siena, Italy.
authors.forename: Renata
authors.initials: R
authors.lastname: Grifantini
authors.affiliation: The Institute for Genomic Research, 9712 Medical Center Dr, Rockville, MD 20850, USA.
authors.forename: Nikhil
authors.initials: N
authors.lastname: Kumar
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30322 and Research Service, VA Medical Center, Decatur, GA 30033, USA.
authors.forename: Yih Ling
authors.initials: YL
authors.lastname: Tzeng
authors.affiliation: The Institute for Genomic Research, 9712 Medical Center Dr, Rockville, MD 20850, USA.
authors.forename: Derrick
authors.initials: D
authors.lastname: Fouts
authors.affiliation: Novartis Vaccines and Diagnostics Ltd, Via Fiorentina 1, 53100 Siena, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Frigimelica
authors.affiliation: Novartis Vaccines and Diagnostics Ltd, Via Fiorentina 1, 53100 Siena, Italy.
authors.forename: Monia
authors.initials: M
authors.lastname: Draghi
authors.affiliation: Novartis Vaccines and Diagnostics Ltd, Via Fiorentina 1, 53100 Siena, Italy.
authors.forename: Marzia Monica
authors.initials: MM
authors.lastname: Giuliani
authors.affiliation: Novartis Vaccines and Diagnostics Ltd, Via Fiorentina 1, 53100 Siena, Italy.
authors.forename: Rino
authors.initials: R
authors.lastname: Rappuoli
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30322 and Research Service, VA Medical Center, Decatur, GA 30033, USA.
authors.forename: David S
authors.initials: DS
authors.lastname: Stephens
authors.affiliation: Novartis Vaccines and Diagnostics Ltd, Via Fiorentina 1, 53100 Siena, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Grandi
authors.affiliation: The Institute for Genomic Research, 9712 Medical Center Dr, Rockville, MD 20850, USA.
authors.forename: Hervé
authors.initials: H
authors.lastname: Tettelin
mesh_terms: D016667:Bacterial Capsules / Q000235:genetics; D001692:Biological Transport / Q000235:genetics; D016000:Cluster Analysis; D004251:DNA Transposable Elements; D022761:Gene Transfer, Horizontal; D016680:Genome, Bacterial; D044404:Genomic Islands; D023281:Genomics; D020071:Interspersed Repetitive Sequences; D042804:Neisseria cinerea / Q000235:genetics; D009344:Neisseria gonorrhoeae / Q000235:genetics; D042806:Neisseria lactamica / Q000235:genetics; D009345:Neisseria meningitidis / Q000235:genetics* / Q000472:pathogenicity; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D039002:Prophages / Q000235:genetics; D026801:Synteny; D014774:Virulence / Q000235:genetics
chemical_list: D004251:DNA Transposable Elements