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29 Cards in this Set
- Front
- Back
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List three components of the bacterial envelope.
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Capsule/cell wall and membrane
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Bacterial capsules are made from what substance?
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Polysaccharides(sugar monomers)
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List 2 functions of the bacterial capsule.
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They are considered virulence factors, that protect the bacterium from phagocytosis. They aid bacteria in attaching to host surfaces.
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How does one test for capsule identification?
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The quellung test. It employs capsular antibodies that bind and induce swelling of the capsule, which is then seen via light microscopy. It has been used for Strep pneumoniae.
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Capsules have polysaccharides that can be used for the development of vaccines. TRUE/FALSE
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TRUE. S. pneumoniae and Haemophilus influenzae type B are 2 examples.
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Bacterial cell walls are comprised of what?
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Murein. It is a peptidoglycan(a molecule of peptides and sugars).
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What color are Gram + bacteria?
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They appear blue, because they effectively absorb the crystal violet stain.
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What color are Gram neg bacteria?
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They appear pink because theu use the crystal violet dye when treated with red safranin counter-stain.
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Are the peptidoglycan layers structurally different between Gram+ and Gram- bacteria?
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Yes.Gram + have a thicker peptidoglycan cell wall. Gram negative bacteria have thinner walls and a periplasmic space.
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Where is Beta lactamase found?
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It is found in the periplasmic space of Gram negative bacteria.
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Which type of Gram staining bacteria has techoic and lipotechoic acid?
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Gram positive bacteria.
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What type of bacteria have lipopolysaccharide endotoxins?
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Gram negative.
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What are some of the harmful effects of techoic acid and LPS.
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Both produce cytokine production(TNF-alpha and interleukin 1. These activate the inflammatory, complimentary and coagulation pathways that may lead to septic shock.
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LPS/endotoxin has three components. What are they?
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1. O-antigen(outer polysaccharide, major antigen).
2. Middle core polysaccharide 3. Inner lipid A(phospholipid that causes the pathogenic effect). |
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Are there any Gram + organisms that have endotoxins?
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Listeria monocytogenes
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How do the cell walls of Mycobacteria differ from Gram stained bacteria?
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Mycobacteria cell walls have mycolic acids which cannot absorb Gram stain. They stain instead with carbolfuchsin and are referred to as acid fast.
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List 6 other type of bacteria that do not take up Gram stain?
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Treponema(fluorescent antibody staining)
Borrelia(Giemsa stain) Legionella(Silver stain) Mycobacteria(Ziehl- Neelsen) Rickettsia(Giemsa stain) Chlamydia(Giemsa, iodide, and fluorescent) |
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Mycoplasma species have a standard cell wall. TRUE/FALSE
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False. Mycoplasma do not possess a cell wall.
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Do bacterial cell membranes differ from mammalian cell membranes>
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Bacterial membranes lack sterols, except for the Mycoplasma species.
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If bacteria lack organelles such as mitochondria, do they possess an electron transport chain?
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Yes. In the bacterial cell membrane.
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List 2 bacteria that have a single polar flagellae.
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Vibrio cholerae/Campylobacter jejuni.
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What 2 bacteria have multiple flagella?
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E. coli/proteus mirabilis
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What are the two types of pili?
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Common pili(fimbriae), mediate bacterial adhesion and sex pili, for exchange of genetic material.
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List 6 types of bacteria with pili.
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E. coli/Neisseria gonorrhea/C. jejuni/Bordetella pertussis/V. cholerae.
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Glycocalyx is made of what macromolecule?
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Polysaccharides. If it is tightly associated with the cell wall, it is a capsule. When loosely attached, it is a slime layer.
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List some pathogenic bacteria that use a slime layer glycocalyx for infection.
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Strep. mutans(teeth)
Strep. sanguis(heart valves) Staph. epidermidis(catheters) |
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List some pathogenic bacteria that use a slime layer glycocalyx for infection.
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Strep. mutans(teeth)
Strep. sanguis(heart valves) Staph. epidermidis(catheters) |
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What 2 chemical features of spores allow for resistance to environmental stresses?
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A keratin like coat and dipocolinic acid(core)
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Bacillus and Clostridium are the two important spore forming Gram+ rods. TRUE/FALSE
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TRUE.
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