V parahaemolyticus
This presentation is the property of its rightful owner.
Sponsored Links
1 / 19

V. parahaemolyticus PowerPoint PPT Presentation


  • 72 Views
  • Uploaded on
  • Presentation posted in: General

V. parahaemolyticus. Sodium transport genes & Osmoregulatory pumps Andrea, Saikumar, Stacey, & Cesar. (Kozo, et. al, 2002). Intro to V . parahaemolyticus. Gram negative bacterium, curved rod shaped with single flagellum Part of bacterial Vibrionaceae family

Download Presentation

V. parahaemolyticus

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


V parahaemolyticus

V. parahaemolyticus

Sodium transport genes & Osmoregulatory pumps

Andrea, Saikumar, Stacey, & Cesar

(Kozo, et. al, 2002)


Intro to v parahaemolyticus

Intro to V. parahaemolyticus

  • Gram negative bacterium, curved rod shaped with single flagellum

  • Part of bacterial Vibrionaceae family

  • Thrives in salt water (halophilic) obligate heterotrophs

  • Found predominately in marine and estuary communities

(Research in Microbiology, 2004; http://en.wikipedia.org/wiki/Vibrio_parahemolyticus)


Pathogenesis of v parahaemolyticus

Pathogenesis of V. parahaemolyticus

  • Mutualistic state with oysters/shellfish

    • Concentrated in gills of oysters due to filtering

  • Pathogenic state with humans/mammals.

    • Causes gastrointestinal problems

    • Major cause of food poisoning from consuming raw/undercooked seafood

      (Research in Microbiology, 2004)


Genome of v parahaemolyticus

Genome of V. Parahaemolyticus

  • Genome similar to V. cholerae

  • Two chromosomes (conserved vs. non-conserved genes)

  • Where would we expect to find Na+/H+ genes and how do we determine the chromosomal location of theses genes?

  • (FEMS Microbiology Review, 2001)


Osmoregulatory pumps

Osmoregulatory Pumps

  • Specific genes that allows plasticity in marine hosts (non infectious) to human hosts (infectious)

  • Location of these genes within the genome

  • Antiporter regulation effects on virulence

  • The problem of the chicken and the egg

  • Evolutionary patterns


Na h antiporter

Na+/H+ Antiporter

  • Na+/H+ Antiporter is a transport protein used to maintain gradients across the cell membrane

http://upload.wikimedia.org/wikipedia/en/7/71/Antiporter.jpg


Location of the genes of interest

Location of the Genes of Interest

Na+/H+ are essential for survival

Expect to be found on conserved regions of the chromosome

FISH

fluorescent in situ hybridization

(http://www.genome.gov/glossary.cfm?key=fluorescence%20in%20situ%20hybridization%20%28FISH%29)


Genome map

Genome Map

  • Genes encoding sodium pumps are highly conserved closely together mostly on chromosome one

    • Gene VP2449

    • Gene VP1092

(Kozo, et. al, 2002)


Genes con t

Genes, Con’t…

If Na+/H+ antiporter genes were found on non conserved regions this would indicate that the genes were not necessary for survival

Genes evolved with a specific purpose and can be easily manipulated without killing the bacteria


Na h antiporter expression in changing environment

Na+/H+ Antiporter Expression in changing Environment

  • Experiment

    • Growing the bacteria under:

      • Optimum conditions (pH, salinity, temperature, food)

      • Decreased temperature

      • Decreased food

      • Varying pH

  • Cultures obtained and stain with the appropriate dye

  • Antiporters will be visualized and counted


  • Expected results

    Expected Results

    • Under stressful conditions

      • pH extremes and varying salinity

        – up regulation or down regulation of antiporter proteins

      • Varying Temperature and Food supply

        • Expression of antiporters would not be affected but cell proliferation would be greatly affected


    Rabbit model for pathogenicity

    Rabbit Model for Pathogenicity

    • V. parahaemolyticus collected from bivalves

    • Grown in cell broths

    • Inoculate rabbits with a fixed dosage of broth

    • Rabbits were sacrificed 24 hours post infection

    • Post mortem cell cultures Na+/H+ antiporter proteins stained

    • Cells visualized and compared with cell cultures from bivalves.

    (Lexomboon 2000)


    Expected results1

    Expected Results

    • Original hypothesis: Due to a change in environmental conditions, there should be an up regulation of Na+/H+ antiporter proteins

    • The number of Na+/H+ antiporter proteins will remain relatively constant.

    • Side note:

      • This antiporter uses H+ concentrations to maintain Na+ gradients.

      • The digestive systems of animals have a high concentration of H+, thus enabling the antiporter to create a greater Na+ gradient causing osmotic diarrhea.


    Evolutionary patterns

    Evolutionary Patterns

    • Environmental conditions

      • Oxygen, temperature, and salinity have significant affects on virulence

        • Higher salinity increases virulence towards shrimp

    • Composition and metabolism of V. parahaemolyticus

      • Altered for adaptation

      • Results in increased pathogenicity


    Evolutionary patterns con t

    Evolutionary Patterns Con’t…

    • Outer membrane proteins (OMP)

      • Play key role in adaptation to changes in external environment

      • Osmolarity location is outermost part of cell.

    • Synthesis of OMPs

      • Regulation when V. parahaemolyticus is transferred to different salinity environments


    Did pathogenesis evolve from a mutualist or vice versa

    Did Pathogenesis Evolve from a Mutualist or Vice-Versa?

    • Specific virulence factors exhibited in colonization by V. parahaemolyticus

    • May be required for colonization

    • Defense mechanisms of host must be conquered in either case


    The problem of the chicken and the egg

    The problem of the Chicken and the egg

    • One view:

      • Pathogenicity evolve prior to mutualistic associations

    • Common ancestral origin of many characteristics of host-tissue colonization?

    • Most sensible for pathogen to lead to symbiont: allows host and attacker to survive.

    • V. parahaemolyticus pathogenicity islands (PAI) on chromosomeII: 80kb of DNA.

    (http://jb.asm.org/cgi/reprint/190/5/1835.pdf)


    A different view

    A Different View

    • Human host gives V. parahaemolyticus perfect environment

      • Optimal temperature and nutrition allow for increase in proliferation and environment exploitation.

    • Virulence results from a “perfect” host


    References

    References

    • C. Xu, H. Ren, S. Wang, and X. Peng. “Proteomic analysis of salt-sensitive outer membrane proteins of Vibrio parahaemolyticus.” Research in Microbiology 155 (2004) 835-842.

    • “Vibrio parahaemolyticus” Obtained from <http://en.wikipedia.org/wiki/Vibrio_parahemolyticus.>

    • Kozo Makimo, et. al. “Genomic Map of V. parahaemolyticus.” “V. Parahaemolyticus Image” July 2004.

      <http://images.google.com/imgres?imgurl=http://genome.naist.jp/bacteria/vpara/images/vpem.jpg&imgrefurl=http://genome.naist.jp/bacteria/vpara/index.html&h=540&w=600&sz=51&hl=en&start=1&um=1&usg=__EzFOOX4e2KQnHXnW7NqCC8ifylM=&tbnid=B1q8ILaobUJhkM:&tbnh=122&tbnw=135&prev=/images%3Fq%3Dv.%2Bparahaemolyticus%26um%3D1%26hl%3Den%26sa%3DN.>

    • R. Sleator, and Colin Hill. “Bacterial osmoadaptation: the role of osmolytes in bacterial stress and virulence.” FEMS Microbiology Reviews 26 (2001). 49-71.

    • Lexomboon, Udom. “The Infant Rabbit as a Model of Pathogenicity for Vibrio parahaemolyticus”, 2000, http://www.afrims.org/weblib/eapr/1971/APR71p178-181.pdf.

    • T.Sugiyama, T.Iida, K.Izutsu, K.Park and T.Honda. “ Precise region and character of the pathogenecity island in clinical Vibrio parahaemolyticus strains.” Journal of Bacteriology 190(2007)1835-1837.


  • Login