• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/31

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

31 Cards in this Set

  • Front
  • Back
Microbial substances or organelles that are involved in adherence are known as what?
adhesins
3 examples of gram (-) bacterial adhesins:
1. pili (fimbriae)
2. surface proteins (nonfimbrial)
3. capsules
These adhesion receptors are primarily involved in other processes, such as the adherence of WBCs to endothelial surfaces.
integrins
This protein normally coats the mucosal surfaces of epithelial cells and is the receptor for certain gram (+) bacteria.
fibronectin
T/F Both adhesins and receptors are usually highly specific for the species of microbes and the host.
True. The greater incidence of pneumonia caused by gram (-) bacteria in hospitalized patients can be explained in part by such adherence specificity.
The increase of iron-binding proteins in plasma and tissue fluids is due to what property of bacterial growth?
The lack of free iron significantly limits the growth of bacteria in the body, because bacteria need iron for the synthesis of their cytochromes and other enzymes.
LPS of gram - bacteria, teichoic acids of gram + bacteria, and other structural components of microbes are potential complement activators. Bacteria such as meningococci and pneumococci prevent complement activation by masking these activators by the secretion of what?
capsules
What is the purpose of sialic acid in host cells and some bacteria?
it is a sugar that inhibits complement activation
Meningococci become coated with this, a class of immunoglobulins that do not activate the complement cascade.
circulating IgA antibodies
What is the mechanisms by which herpes simplex virus (HSV) inhibits activation by the alternative pathway?
the presence of an envelope glycoprotein that binds complement component C3b
"Smooth" strains of Salmonella and E. coli do not prevent formation of the complement membrane attack complex, but rather hinder its access to its target, the bacterial outer membrane by the presence of what?
long O-antigen polysaccharide chains. Notice that these organisms defend themselves better agaisnt the more immediate host defense, activation of complement by the alternative pathway, than against later events, the formation of antibodies.
What is the effect of group A streptococci produced C5a peptidase?
it specifically inactivates this (C5a) chemotactic product of the complement cascade.
These exotoxins are produced by bacteria to kill neutrophils and macrophages.
leukocidins
What is the function of protein A, a surface component produced by staphylococci, streptococci, and probably other bacteria?
it binds to IgG molecules by the "wrong" end, the Fc portion.
Name four methods in which microbes survive inside phagocytes:
1. inhibition of lysosome fusion with phagosomes
2. escape into the cytoplasm
3. resistance to lysosomal enzymes
4. inhibition of the phagocytes' oxidative pathway
This bacteria secretes a pore forming toxin, listeriolysin, which is required for phagosomal escape.
Listeria monocytogense
This protozoa's resistance to lysosomal enzymes may be a result of resistant cell surfaces and to the excretion of enzyme inhibitors
Leishmania
This microbe inhibits the hexosemonophosphate shunt and oxygen consumption in neutrophils, thus reducing the respiratory burst.
Legionella
Name 3 viruses that spread by causing infected cells to fuse with uninfected, neighboring cells. Notable for the formation of syncytia and multinucleated giant cells.
herpes simplex virus, varicella zoster virus, and respiratory syncytial virus
These viruses and microbes cause immune depression by impairing the function of lymphoid or myeloid cells without causing major structural changes.
measles virus, tuberculosis, hepatitis B and influenza
Mycobacteria, certain viruses, and some multicellular parasites have been shown to affect different steps in the _______ cascade.
cytokine
What is the mechanisms of action for superantigens?
They bind directly to both the MHC molecule (but not at the antigen-binding groove) and the T-cell receptor (but not at the antigen recognition sites). Because it is not dependent on specific antigen recognition, superantigen binding occurs on the surface of many more APCs than usual and leads to the diversion of these cells to nonproductive uses.
Trypanosomes are covered with a thick protein coat called ______, which undergoes periodic antigenic changes during the infection.
variable surface glycoprotein
These bacteria undergo periodic changes in pilin.
gonococci
Antigenic change in the influenza virus involves two surface proteins known as what?
hemagglutinin that serves to bind to cell surface receptors and a neuraminidase that changes these receptors
Minor antigenic changes that occur every 2-3 years:
antigenic drift
Major antigenic changes taking place every 10 years or so:
antigenic shift
staphylokinase
cleaves host plasminogen into plasmin at the bacterial cell surface. Then it degrades both IgG and C3b which enables the microbe to avoid opsonization and phagocytosis.
The cleavage of IgA, in which the antigen-binding fragment remains attached is known as what?
fabulation
A virus in this state is not affected by antibodies, cell-mediated immunity, or interferon and can survive for a long time in an immunocompetent host.
latent
This bacteria causes gastric ulcers and probably is responsible for gastric adenocarcinomas.
Helicobacter pylori