Archives of Microbiology

, Volume 192, Issue 3, pp 167–174

Osmoregulated periplasmic glucans synthesis gene family of Shigella flexneri

  • Liu Liu
  • Mahesh Dharne
  • Porteen Kannan
  • Allen Smith
  • Jianghong Meng
  • Mingtao Fan
  • Tara L. Boren
  • Ryan T. Ranallo
  • Arvind A. Bhagwat
Original Paper

Abstract

Osmoregulated periplasmic glucans (OPGs) of food- and water-borne enteropathogen Shigella flexneri were characterized. OPGs were composed of 100% glucose with 2-linked glucose as the most abundant residue with terminal glucose, 2-linked and 2,6-linked glucose also present in high quantities. Most dominant backbone polymer chain length was seven glucose residues. Individual genes from the opg gene family comprising of a bicistronic operon opgGH, opgB, opgC and opgD were mutagenized to study their effect on OPGs synthesis, growth in hypo-osmotic media and ability to invade HeLa cells. Mutation in opgG and opgH abolished OPGs biosynthesis, and mutants experienced longer lag time to initiate growth in hypo-osmotic media. Longer lag times to initiate growth in hypo-osmotic media were also observed for opgC and opgD mutants but not for opgB mutant. All opg mutants were able to infect HeLa cells, and abolition of OPGs synthesis did not affect actin polymerization or plaque formation. Ability to synthesize OPGs was beneficial to bacteria in order to initiate growth under low osmolarity conditions, in vitro mammalian cell invasion assays, however, could not discriminate whether OPGs were required for basic aspect of Shigella virulence.

Keywords

Periplasmic glucans Low osmolarity Food- and water-borne Shigellosis 

Supplementary material

203_2009_538_MOESM1_ESM.pdf (133 kb)
Supplementary material 1 (PDF 133 kb)

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Liu Liu
    • 1
    • 2
    • 4
  • Mahesh Dharne
    • 2
  • Porteen Kannan
    • 2
  • Allen Smith
    • 3
  • Jianghong Meng
    • 4
  • Mingtao Fan
    • 1
  • Tara L. Boren
    • 5
  • Ryan T. Ranallo
    • 5
  • Arvind A. Bhagwat
    • 2
  1. 1.College of Food Science and TechnologyNorthwest A&F UniversityYanglingChina
  2. 2.Environmental Microbial & Food Safety Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research ServiceUSDABeltsvilleUSA
  3. 3.Diet Genomics and Immunology Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, Agricultural Research ServiceUSDABeltsvilleUSA
  4. 4.Department of Food Science and NutritionUniversity of MarylandCollege ParkUSA
  5. 5.Division of Bacterial and Rickettsial DiseasesWalter Reed Army Institute of ResearchSilver SpringUSA

Personalised recommendations