M3: Biology of Pathogens/Bacteria I Flashcards

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1
Q

Major divisions of pathogens (3)

A

viruses

prokaryotes (no nucleus): Bacteria and Archaea (no proven role in human disease-maybe periodontal disease?)

eukaryotes (with a nucleus)

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2
Q

Viruses:

cells (eukaryotic / prokaryotic / no)

size (smallest / small / large / largest)

nucleic acid: DNA (and / or) RNA

ribosomes (80S / 70S / no)

mitochondria (yes / no)

cell wall (peptidoglycan / chitin / none)

motility (usually / sometimes / none)

reproduction by binary fission (yes / no)

A

no

smallest

or

no

no

none

none

no

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3
Q

Bacteria:

cells (eukaryotic / prokaryotic / no)

size (smallest / small / large / largest)

nucleic acid: DNA (and / or) RNA

ribosomes (80S / 70S / no)

mitochondria (yes / no)

cell wall (peptidoglycan / chitin / none)

motility (usually / sometimes / none)

reproduction by binary fission (yes / no)

A

prokaryotic

small

and

70S

no

peptidoglycan

sometimes

yes

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4
Q

Fungi:

cells (eukaryotic / prokaryotic / no)

size (smallest / small / large / largest)

nucleic acid: DNA (and / or) RNA

ribosomes (80S / 70S / no)

mitochondria (yes / no)

cell wall (peptidoglycan / chitin / none)

motility (usually / sometimes / none)

reproduction by binary fission (yes / no)

A

eukaryotic

large

and

80S

yes

chitin

none

yes

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5
Q

Protozoa/Helminths (Parasites):

cells (eukaryotic / prokaryotic / no)

size (smallest / small / large / largest)

nucleic acid: DNA (and / or) RNA

ribosomes (80S / 70S / no)

mitochondria (yes / no)

cell wall (peptidoglycan / chitin / none)

motility (usually / sometimes / none)

reproduction by binary fission (yes / no)

A

eukaryotic

largest

and

80S

yes

none

usually

yes

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6
Q

Viruses:

(obligate/facultative) (intracellular/extracellular) pathogens (they require the host cell for _)

Have DNA (and/or) RNA.

No independent _ production or _ synthesis

Usually show selectivity for infecting _

Not sensitive to _ (e.g. penicillins)

A

obligate intracellular
replication

or (not both)

energy
protein

particular types and/or species of host cells

antibacterial/antifungal antibiotics

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7
Q

Bacteria (prokaryotes):

DNA enclosed by a nuclear membrane (yes / no)

chromosome number (usually 1 / >1)

membrane-bound organelles, e.g., mitochondria (yes / no)

ribosomes (70S / 80S)

peptidoglycan in cell wall (yes, except _ / no)

sterols in plasma membrane (yes / no, except _)

A

no

usually 1

no

70S

yes, except Mycoplasma spp. & (probably) Chlamydiae spp.

no, except Mycoplasma spp., Helicobacter pylori & Borrelia burgodorferi

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8
Q

Eukaryotes:

DNA enclosed by a nuclear membrane (yes / no)

chromosome number (usually 1 / >1)

membrane-bound organelles, e.g., mitochondria (yes / no)

ribosomes (70S / 80S)

peptidoglycan in cell wall (yes, except _ / no)

sterols in plasma membrane (yes / no, except _)

A

yes

> 1

yes

80S

no

yes

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9
Q

Bacteria:

Bacteria lack _ and _

Bacteria usually have _ made of _ (exceptions: _ and _)

Bacteria have _ ribosomes

Bacteria (and eukaryotes) have RNA (and/or) DNA, make their own _ (except for
_ and _) and have independent _ synthesis

Most Bacteria lack _ in their plasma membrane (except _, _, and _)

Bacteria are usually about 1/5th to 1/10th the size of _ (need _ to visualize)

A

nuclei and internal organelles

cell walls
peptidoglycan
Mycoplasma and Chlamydiae

70S

and
energy (Rickettsiae and Chlamydiae)
protein

sterols (Mycoplasma spp., Helicobacter pylori and Borrelia burgodorferi)

eukaryotes
oil immersion lens

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10
Q

Bacteria:

morphology (3)

arrangements (3)

A

cocci
rods
spirochete

diplococci
cocci in chains
cocci in clusters

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11
Q

Bacterial Cell Components (3)

A

Cytoplasm
Cell envelope
External structures (if present)

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12
Q

Bacterial Cell Components:

Cytoplasm (3)

A

DNA, ribosomes, metabolic enzymes

site of some antibiotic action

outer membrane (if present)

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13
Q
Bacterial Cell Components:
Cell envelope (3)
A

plasma membrane

cell wall (target of some antibiotic action)

outer membrane (if present)

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14
Q
Bacterial Cell Components:
External structures (if present) (4)
A

common pili

capsule

sex pilus

flagella

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15
Q

Role of Bacterial Cell Components:
Cytoplasm:

DNA, ribosomes, metabolic enzymes: _ processes

site of some antibiotic action (e.g., _ inhibitors, antibiotics affecting _ or _)

plasmids: antibiotic _ and _

A

basic life

protein synthesis
DNA replication or RNA transcription

resistance and virulence

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16
Q

Role of Bacterial Cell Components:
Cell envelope:

plasma membrane: _ and _

cell wall (target of some antibiotic action): resists _

outer membrane (if present): _ (but contains _ and _)

A

permeability barrier and transport

osmotic lysis

permeability barrier
pumps and pores

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17
Q
Role of Bacterial Cell Components:
External structures (if present):

common pili: _

capsule: _, can result in _ formation

sex pilus: _

flagella: _

A

attachment to tissue

antiphagocytic
biofilm

conjugation

motility

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18
Q

Bacterial Cell Wall Synthesis:

_ crosslinking is carried out by _ (also known as _).

A

Peptidoglycan
transpeptidases
penicillin binding proteins (PBPs)

19
Q

The Gram Stain:

Procedures (4)

A

stain
mordant
decolorize
counterstain

20
Q

The Gram Stain:
Gram+ and Gram- procedure colors

Stain

Mordant

Decolorize

Counterstain

A

Stain: purple, purple

Mordant: purple, purple

Decolorize: purple, clear

Counterstain: purple, red

21
Q

Structures/components unique to gram+ bacteria (2)

A

Lipoteichoic acid

Teichoic acid

22
Q

Examples of medically-important gram+ bacteria (3)

A

Streptococcus spp.
Staphylococcus spp.
Clostridium spp.

23
Q

Structures/components unique to the gram-bacteria include the _

Some gram-s (e.g. the _) contain _

A

outer membrane

enterics
lipopolysaccharide (LPS)
24
Q

Structures/components unique to the Gram-negative bacteria:

LPS consists of three regions (3)

A

lipid A
core
O antigen

25
Q

Structures/components unique to the Gram-negative bacteria:

LPS consists of three regions:

lipid A: has _ activity

a core: _

O antigen: important for _ and _, very variable _

A

endotoxic

conserved

bile and complement resistance
polysaccharide

26
Q

Gram-negatives can be stereotyped for their antigens (3)

A

O
H
K

27
Q

Gram-negative antigens:

O: _, _ portion of LPS

H: found on _

K: _ antigen

A

variable, outermost

flagella

capsular

28
Q

Some (mostly _) Gram-negative bacteria have an LPS-like molecule in their outer membrane instead of true LPS.

This molecule, _, lacks the _ antigen but retains the _ and _ regions of LPS.

A

nonenteric

lipooligosaccharide (LOS)

O
core
lipid A

29
Q

Being gram- vs. gram+

Advantage: _ from the _ (including some antibiotics)

Disadvantage: _ to make, hard to _ through _

A

Protection from the environment

expensive
secrete proteins through two membranes

30
Q

Structures/components unique to the Gram-negative bacteria:

_: channels in outer membrane, allow molecules to _

Alterations can impact _

A

Porins
move across the outer membrane

antibiotic resistance

31
Q

Some examples of Gram negative pathogens (4)

A

Shigella spp.
Salmonella spp.
Vibrio cholerae
E. coli

32
Q

“Atypical” Myobacteria:

Stain: _

Cell envelope functions (2)

Cell envelope components (4)

A

Acid-fast

resistance to desiccation & phagocytosis
helps disease transmission

waxy layer
phenolic glycolipid
mycolic acids
peptidoglycan

33
Q

Examples of medically-important Mycobacterium spp. (2)

A

Mycobacterium tuberculosis

Mycobacterium leprae

34
Q

“Atypical” Spirochetes:

These bacteria can be visualized only by _

Examples (2)

A

dark-field microscopy

Borrelia burgdorferi
Treponema pallidum

35
Q

“Atypical” Rickettsiae spp.:

Distinguishing features: (facultative/obligate) (intracellular/extracellular) bacteria that are _

Rickettsiae spp. generate some _ but probably need to get some from host cell

Can be transmitted by _

Have typical Gram(+/-) envelope, but too small to _

A

obligate intracellular
vector-borne

energy

fleas, ticks, lice, etc.

negative
Gram-stain

36
Q

Medically important Rickettsiae spp. (2)

A

R. rickettsii: rocky mountain spotted fever

R. typhi: endemic typhi

37
Q

“Atypical” Chlamydiae and Chlamydophila spp.:

These are (facultative/obligate) (intracellular/extracellular) bacteria with a complex life cycle (_ bodies and _ bodies)

_ parasites

Have (#) membranes like Gram-negatives, but no _

Too small to see by _ stains

A

obligate intracellular
reticulate
elementary

Energy

two
peptidoglycan

Gram

38
Q

Examples of medically important spp. (3)

A

Chlamydiae trachomatis: blindness, nongonococcal urethritis, pneumoniae

Chlamydophila psittaci: psittacosis (a form of pneumonia)

Chlamydophila pneumoniae: pneumonia

39
Q

Chylamydiae:

Can grow outside host cell (yes / yes, except / no / no, except)

Have independent protein synthesis (yes / no)

Generate metabolic energy (yes / no / sometimes)

Shown to have peptidoglycan-containing cell wall (yes / no / no except)

Susceptible to antibiotics (yes / no)

Reproduced by binary fission (yes / no)

Nucleic acids (DNA and / or RNA)

A

no

yes

no

no, except Chlamydiae have two membranes (like gram-negative bacteria) but have not been shown to have a peptidoglycan

yes

yes

and

40
Q

Typical bacteria:

Can grow outside host cell (yes / yes, except / no / no, except)

Have independent protein synthesis (yes / no)

Generate metabolic energy (yes / no / sometimes)

Shown to have peptidoglycan-containing cell wall (yes / no / no except)

Susceptible to antibiotics (yes / no)

Reproduced by binary fission (yes / no)

Nucleic acids (DNA and / or RNA)

A

yes, except for a few obligate intracellular pathogens, e.g., Mycobacterium leprae

yes

yes

yes

yes

yes

and

41
Q

Rickettsiae:

Can grow outside host cell (yes / yes, except / no / no, except)

Have independent protein synthesis (yes / no)

Generate metabolic energy (yes / no / sometimes)

Shown to have peptidoglycan-containing cell wall (yes / no / no except)

Susceptible to antibiotics (yes / no)

Reproduced by binary fission (yes / no)

Nucleic acids (DNA and / or RNA)

A

no, except for Rochalimaea quintana

yes

sometimes

yes

yes

yes

and

42
Q

Mycoplasma:

Can grow outside host cell (yes / yes, except / no / no, except)

Have independent protein synthesis (yes / no)

Generate metabolic energy (yes / no / sometimes)

Shown to have peptidoglycan-containing cell wall (yes / no / no except)

Susceptible to antibiotics (yes / no)

Reproduced by binary fission (yes / no)

Nucleic acids (DNA and / or RNA)

A

yes

yes

yes

no

yes

yes

and

43
Q

Virus:

Can grow outside host cell (yes / yes, except / no / no, except)

Have independent protein synthesis (yes / no)

Generate metabolic energy (yes / no / sometimes)

Shown to have peptidoglycan-containing cell wall (yes / no / no except)

Susceptible to antibiotics (yes / no)

Reproduced by binary fission (yes / no)

Nucleic acids (DNA and / or RNA)

A

no

no

no

no

no

no

or

44
Q

“Atypical” Mycoplasma spp.:

Very (large/small), lack a _, and have _ in their
plasma membranes

Can be (slowly) grown on _ media

The absence of a cell wall affects _ sensitivity

The major pathogenic Mycoplasma spp. is _ (causes an atypical _)

A

small
cell wall
sterols

artificial

antibiotic

M. pneumoniae
pneumonia