Pathogenicity

Last update by billock.2 on 11/30/2012
7033 People have viewed this Quiz
  • Share

common routes of entry of pathogens into humans

Answer:

· Common routes of entry of pathogens into humans include the oral portal, respiratory tract, parenteral route of entry, wounds and needles, and the conjunctiva, mucosa, and genital and urinary tracts.

View Pathogenicity as Flashcard Deck

Related Quiz Content
  • billock 2
    Answered in Pathogenicity
    virulence factors

    · Virulence factors – structures and products/secretions that enhance the disease causing capability of a pathogen. Encoded by virulence genes. Include toxins, fimbrae, pili, and capsules.

  • billock 2
    Answered in Pathogenicity
    pathogen reservoir

    · Pathogen reservoir – animal, bird, or insect that normally harbors the pathogen

  • billock 2
    Answered in Pathogenicity
    pathogenicity islands
    Pathogenicity islands – large block of DNA that increases virulence that is acquired or inserted into the chromosome by horizontal gene transfer. Have a different GC content and are often linked to a tRNA gene and flanked by phage or plasmid genes
  • billock 2
    Answered in Pathogenicity
    adhesins, pili, and fimbrae

    · Bacterial cells use adhesins, pili or fimbrae to attach to a host cell.

    · Adhesins – any microbial factor that promotes attachment. Nonpilus attachment proteins or molecules, often on cell or viral surface.

    · Pili or fimbrae – hai appendages whose tips contain receptors for mammalian cell structure surface.

  • billock 2
    Answered in Pathogenicity
    Type I and type IV pili

    · Type I pili adhere to mannose residues on host cell surface (static binding) assembled by growing from the outer membrane with subunits adding at the base.

    · Type 4 pili are mannose resistant pili assembled on the cell surface via a different pathway than type I. Involved in twitching motility.

  • billock 2
    Answered in Pathogenicity
    exo and endo-toxins

    · Exotoxins – protein toxins secreted by bacteria following attachment, subvert host function. Cell membrane disrupters, protein synthesis disrupters, second messenger pathway disrupters, superantigens, and proteases.

    · Endotoxins – nonprotein toxin produced by Gram negative bacteria. Includes Lipid A, released from lipopolysaccharide, which hyperactivates host immune systems to harmful levels.

  • billock 2
    Answered in Pathogenicity
    AB ribosylating toxins

    · AB ribosylating toxins – A subunit and pentameric B complex

    o Corynebacterium diptheriae – diptheria toxin, ribosylates elongation factor 2, blocks ribosome function and cell dies

    o Vibrio cholerae – cholera toxin, ribosylates a G protein that leads to overactivation of adenylate cyclase, high cAMP levels activate ion transport; water follows out of cell, leads to diarrhea

  • billock 2
    Answered in Pathogenicity
    bacillus anthracis toxins

    · Bacillus anthracis toxin – protective antigen, edema factor (EF) and lethal factor (LF). LF is a protease that cleaves host protein kinase kinases resulting in immune response signal failures

  • billock 2
    Answered in Pathogenicity
    type I secretory system

    · Type 1 secretory system – ATP binding cassette (ABC) transporters, outer membrane factors (OMFs), and membrane fusion proteins (MFPs) connecting the inner and outer membranes. Ex. E. coli hemolytic toxin HlyA.

  • billock 2
    Answered in Pathogenicity
    type 2 secretory system

    · Type 2 secretory system – use a pilus-like extraction/retraction mechanism to push proteins out of the cell. Genes for the T2 pilus related to those of the type 4 system.

  • billock 2
    Answered in Pathogenicity
    T3SS

    · Type 3 secretory system – use a molecular syringe to inject proteins from the bacterial cytoplasm directly into the host cell. Genes encoding the T3SS are related to the flagellar genes. Genes on pathogenicity islands.