Genetic organization of the lipopolysaccharide O-antigen biosynthetic locus of Leptospira borgpetersenii serovar Hardjobovis

Kalambaheti, Thareerat; Bulach, Dieter; Rajakumar, Kumar; Adler, Ben

doi:10.1006/mpat.1999.0285

Cited by 36 publications

(65 citation statements)

References 52 publications

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“…VNTR-10 is located within the rfb locus, which encodes proteins involved in lipopolysaccharide O-antigen biosynthesis. The rfb locus has a different genetic organization in L. interrogans and L. borgpetersenii serovars (5,6,13). However, the gene organization around VNTR-10 seems to be conserved, irrespective of the serovar and the species considered.…”

Section: Discussionmentioning

confidence: 98%

Application of Multilocus Variable-Number Tandem-Repeat Analysis for Molecular Typing of the Agent of Leptospirosis

et al. 2006

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Leptospirosis is a worldwide-distributed zoonosis, endemic in tropical areas. Epidemiologic investigations of leptospirosis still rely on tedious serological identification tests. Recently, molecular typing systems based on variable-number tandem-repeat (VNTR) analysis have been described and have been used to identify Leptospira interrogans strains. Although L. interrogans is the most common Leptospira species encountered in human infections around the world, other pathogenic species, such as Leptospira kirschneri and Leptospira borgpetersenii, are also frequently associated with human leptospirosis. In this study, we aimed to extend multilocus VNTR analysis (MLVA) identification of strains to species other than L. interrogans. We designed primers for VNTR loci found in L. interrogans, L. kirschneri, and L. borgpetersenii. The discriminatory power of the redefined primers was evaluated on collection strains and then on clinical strains. We also carried out a retrospective study on 156 strains isolated from patients and animals from New Caledonia, an area of high endemicity in the South Pacific. Our results show that this simple PCR-based MLVA typing technique is a powerful methodology for the epidemiology of leptospirosis.

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Section: Discussionmentioning

confidence: 98%

Application of Multilocus Variable-Number Tandem-Repeat Analysis for Molecular Typing of the Agent of Leptospirosis

et al. 2006

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“…Electrophoretic profiles of pathogenic strains of Leptospira differ between species and typically comprise two or three major bands (7,40). The rfb locus of Leptospira has been extensively characterized (5,6,9,10,18,25). Aside from being a protective antigen against homologous challenge, LPS Oag forms the basis for the reference diagnostic assay for leptospirosis, the microscopic agglutination test, in which live leptospires representing a panel of serovars undergo reaction with patient serum samples to detect agglutinating antibodies.…”

Section: Discussionmentioning

confidence: 99%

Changes in Lipopolysaccharide O Antigen Distinguish Acute versus Chronic Leptospira interrogans Infections

et al. 2005

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Leptospirosis is the most geographically widespread zoonotic disease in the world. A severe pulmonary form of leptospirosis (SPFL) is being recognized with increased frequency. We have reported that human SPFL isolates of Leptospira cause acute lethal infection with prominent pulmonary hemorrhage in guinea pigs. We have found that the same SPFL strains cause asymptomatic infection and chronic renal shedding in rats, where infection is restricted to the renal tubules. To address the antigenic composition of host tissue-derived Leptospira (HTL), motile leptospires were purified from guinea pig liver by centrifugation on Percoll density gradients and compared to Percoll-purified in vitro-cultivated Leptospira (IVCL). The lipopolysaccharide O antigen (Oag) content of guinea pig liver-derived HTL was markedly reduced compared to that of IVCL, as demonstrated both by immunoblotting with a monoclonal antibody that was serovar specific for Oag and by periodate-silver staining. Confocal microscopy of HTL in guinea pig liver and kidney with the Oag-specific monoclonal antibody provided further evidence that diminution of the Oag content occurred in situ during lethal infection. In contrast, the Oag content of HTL in chronically infected rat renal tubules was indistinguishable from that of IVCL. These findings suggest that there may be regulation of Oag synthesis by Leptospira specific to the animal host infected. The hypothesis that the Oag content is related to whether lethal infection or chronic renal tubular colonization occurs remains to be tested.

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“…Comparative pulsedfield gel electrophoresis studies of even closely related strains reveal many large rearrangements (3,52). In addition, Leptospira species contain repetitive transposase-encoding insertion sequences (IS), some of which may play a role in producing genomic rearrangements (3,24). The mobility of one of these IS elements, IS1500, is sufficient to allow Southern blot discrimination of 15 different groups within isolates of L. interrogans serovar Pomona type kennewicki (51).…”

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confidence: 99%

“…The mobility of one of these IS elements, IS1500, is sufficient to allow Southern blot discrimination of 15 different groups within isolates of L. interrogans serovar Pomona type kennewicki (51). Evidence for horizontal transfer of DNA among Leptospira species comes from studies of the intervening sequences found within the 23S rRNA gene (37) and from the finding that the leptospiral lipopolysaccharide biosynthetic locus (rfb) is located in a genomic island that was probably acquired through horizontal transfer from a gram-negative source (24). Comparative sequence analysis of rfb loci has provided information about variability of genes involved in lipopolysaccharide biosynthesis (7).…”

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confidence: 99%

Molecular Evolution and Mosaicism of Leptospiral Outer Membrane Proteins Involves Horizontal DNA Transfer

et al. 2004

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Leptospires belong to a genus of parasitic bacterial spirochetes that have adapted to a broad range of mammalian hosts. Mechanisms of leptospiral molecular evolution were explored by sequence analysis of four genes shared by 38 strains belonging to the core group of pathogenic Leptospira species: L. interrogans, L. kirschneri, L. noguchii, L. borgpetersenii, L. santarosai, and L. weilii. The 16S rRNA and lipL32 genes were highly conserved, and the lipL41 and ompL1 genes were significantly more variable. Synonymous substitutions are distributed throughout the ompL1 gene, whereas nonsynonymous substitutions are clustered in four variable regions encoding surface loops. While phylogenetic trees for the 16S, lipL32, and lipL41 genes were relatively stable, 8 of 38 (20%) ompL1 sequences had mosaic compositions consistent with horizontal transfer of DNA between related bacterial species. A novel Bayesian multiple change point model was used to identify the most likely sites of recombination and to determine the phylogenetic relatedness of the segments of the mosaic ompL1 genes. Segments of the mosaic ompL1 genes encoding two of the surface-exposed loops were likely acquired by horizontal transfer from a peregrine allele of unknown ancestry. Identification of the most likely sites of recombination with the Bayesian multiple change point model, an approach which has not previously been applied to prokaryotic gene sequence analysis, serves as a model for future studies of recombination in molecular evolution of genes.

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Genetic organization of the lipopolysaccharide O-antigen biosynthetic locus of Leptospira borgpetersenii serovar Hardjobovis

Cited by 36 publications

References 52 publications

Application of Multilocus Variable-Number Tandem-Repeat Analysis for Molecular Typing of the Agent of Leptospirosis

Application of Multilocus Variable-Number Tandem-Repeat Analysis for Molecular Typing of the Agent of Leptospirosis

Changes in Lipopolysaccharide O Antigen Distinguish Acute versus Chronic Leptospira interrogans Infections

Molecular Evolution and Mosaicism of Leptospiral Outer Membrane Proteins Involves Horizontal DNA Transfer

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