title: Comparative analysis of lipopolysaccharides of pathogenic and intermediately pathogenic Leptospira species.
abstract: BACKGROUND
  Lipopolysaccharides (LPS) are complex, amphipathic biomolecules that constitute the major surface component of Gram-negative bacteria. Leptospira, unlike other human-pathogenic spirochetes, produce LPS, which is fundamental to the taxonomy of the genus, involved in host-adaption and also the target of diagnostic antibodies. Despite its significance, little is known of Leptospira LPS composition and carbohydrate structure among different serovars.
  
  
  RESULTS
  LPS from Leptospira interrogans serovar Copenhageni strain L1-130, a pathogenic species, and L. licerasiae serovar Varillal strain VAR 010, an intermediately pathogenic species, were studied. LPS prepared from aqueous and phenol phases were analyzed separately. L. interrogans serovar Copenhageni has additional sugars not found in L. licerasiae serovar Varillal, including fucose (2.7%), a high amount of GlcNAc (12.3%), and two different types of dideoxy HexNAc. SDS-PAGE indicated that L. interrogans serovar Copenhageni LPS had a far higher molecular weight and complexity than that of L. licerasiae serovar Varillal. Chemical composition showed that L. interrogans serovar Copenhageni LPS has an extended O-antigenic polysaccharide consisting of sugars, not present in L. licerasiae serovar Varillal. Arabinose, xylose, mannose, galactose and L-glycero-D-mannoheptose were detected in both the species. Fatty acid analysis by gas chromatography-mass spectrometry (GC-MS) showed the presence of hydroxypalmitate (3-OH-C16:0) only in L. interrogans serovar Copenhageni. Negative staining electron microscopic examination of LPS showed different filamentous morphologies in L. interrogans serovar Copenhageni vs. L. licerasiae serovar Varillal.
  
  
  CONCLUSIONS
  This comparative biochemical analysis of pathogenic and intermediately pathogenic Leptospira LPS reveals important carbohydrate and lipid differences that underlie future work in understanding the mechanisms of host-adaptation, pathogenicity and vaccine development in leptospirosis.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Biomedical Research Facility, University of California San Diego, 9500 Gilman Drive, BRF 2, Room 5220, La Jolla, 92093-0760, California, USA. kpatra@ucsd.edu.
authors.forename: Kailash P
authors.initials: KP
authors.lastname: Patra
authors.affiliation: Glycotechnology Core Resources, University of California San Diego, 9500 Gilman Drive, BRF 2, Room 4243, La Jolla, 92093-0687, California, USA. bchoudhury@ucsd.edu.
authors.forename: Biswa
authors.initials: B
authors.lastname: Choudhury
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Biomedical Research Facility, University of California San Diego, 9500 Gilman Drive, BRF 2, Room 5220, La Jolla, 92093-0760, California, USA. mmatthias@ucsd.edu.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Matthias
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Biomedical Research Facility, University of California San Diego, 9500 Gilman Drive, BRF 2, Room 5220, La Jolla, 92093-0760, California, USA. sbaga@ucsd.edu.
authors.forename: Sheyenne
authors.initials: S
authors.lastname: Baga
authors.affiliation: Glycotechnology Core Resources, University of California San Diego, 9500 Gilman Drive, BRF 2, Room 4243, La Jolla, 92093-0687, California, USA. kbandyopadhya@ucsd.edu.
authors.forename: Keya
authors.initials: K
authors.lastname: Bandyopadhya
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Biomedical Research Facility, University of California San Diego, 9500 Gilman Drive, BRF 2, Room 5220, La Jolla, 92093-0760, California, USA. jvinetz@ucsd.edu.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Vinetz
mesh_terms: D002241:Carbohydrates / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005227:Fatty Acids / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D007919:Leptospira / Q000737:chemistry* / Q000472:pathogenicity / Q000648:ultrastructure; D008070:Lipopolysaccharides / Q000032:analysis*; D046529:Microscopy, Electron, Transmission; D008970:Molecular Weight
chemical_list: D002241:Carbohydrates; D005227:Fatty Acids; D008070:Lipopolysaccharides