title: Genetic diversity of three lgt loci for biosynthesis of lipooligosaccharide (LOS) in Neisseria species.
abstract: Lipooligosaccharide (LOS) is a major virulence factor of the pathogenic Neisseria. Nine lgt genes at three chromosomal loci (lgt-1, 2, 3) encoding the glycosyltransferases responsible for the biosynthesis of LOS oligosaccharide chains were examined in 26 Neisseria meningitidis, 51 Neisseria gonorrhoeae and 18 commensal Neisseria strains. DNA hybridization, PCR and nucleotide sequence data were compared to previously reported lgt genes. Analysis of the genetic organization of the lgt loci revealed that in N. meningitidis, the lgt-1 and lgt-3 loci were hypervariable genomic regions, whereas the lgt-2 locus was conserved. In N. gonorrhoeae, no variability in the composition or organization of the three lgt loci was observed. lgt genes were detected only in some commensal Neisseria species. The genetic organization of the lgt-1 locus was classified into eight types and the lgt-3 locus was classified into four types. Two types of arrangement at lgt-1 (II and IV) and one type of arrangement at lgt-3 (IV) were novel genetic organizations reported in this study. Based on the three lgt loci, 10 LOS genotypes of N. meningitidis were distinguished. Phylogenetic analysis revealed a gene cluster, lgtH, which separated from the homologous genes lgtB and lgtE. The lgtH and lgtE genes were mutually exclusive and were located at the same position in lgt-1. The data demonstrated that pathogenic and commensal Neisseria share a common lgt gene pool and horizontal gene transfer appears to contribute to the genetic diversity of the lgt loci in Neisseria.
authors.affiliation: Division of Bacterial, Parasitic and Allergenic Products1 and Division of Viral Products2, Center for Biologics Evaluation and Research, FDA, 8800 Rockville Pike, Bethesda, MD 20892, USA.
authors.forename: Peixuan
authors.initials: P
authors.lastname: Zhu
authors.affiliation: Division of Bacterial, Parasitic and Allergenic Products1 and Division of Viral Products2, Center for Biologics Evaluation and Research, FDA, 8800 Rockville Pike, Bethesda, MD 20892, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Klutch
authors.affiliation: Division of Bacterial, Parasitic and Allergenic Products1 and Division of Viral Products2, Center for Biologics Evaluation and Research, FDA, 8800 Rockville Pike, Bethesda, MD 20892, USA.
authors.forename: Margaret C
authors.initials: MC
authors.lastname: Bash
authors.affiliation: National Microbiology Laboratory, Population and Public Health Branch, Health Canada, Canada3.
authors.forename: Raymond S W
authors.initials: RSW
authors.lastname: Tsang
authors.affiliation: National Microbiology Laboratory, Population and Public Health Branch, Health Canada, Canada3.
authors.forename: Lai-King
authors.initials: LK
authors.lastname: Ng
authors.affiliation: Division of Bacterial, Parasitic and Allergenic Products1 and Division of Viral Products2, Center for Biologics Evaluation and Research, FDA, 8800 Rockville Pike, Bethesda, MD 20892, USA.
authors.forename: Chao-Ming
authors.initials: CM
authors.lastname: Tsai
mesh_terms: D005798:Genes, Bacterial / Q000235:genetics*; D014644:Genetic Variation / Q000235:genetics*; D005838:Genotype; D016695:Glycosyltransferases / Q000235:genetics; D008070:Lipopolysaccharides / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics; D009345:Neisseria meningitidis / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D010802:Phylogeny; D011110:Polymorphism, Genetic / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D008070:Lipopolysaccharides; C023023:lipid-linked oligosaccharides; D016695:Glycosyltransferases; D017351:N-Acetylglucosaminyltransferases