M3: Biology of Pathogens/Bacteria I Flashcards by Heather Acuff

Major divisions of pathogens (3)

viruses

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

eukaryotes (with a nucleus)

How well did you know this?

Not at all

Perfectly

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)

smallest

none

How well did you know this?

Not at all

Perfectly

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)

prokaryotic

small

and

70S

peptidoglycan

sometimes

yes

How well did you know this?

Not at all

Perfectly

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)

eukaryotic

large

and

80S

yes

chitin

none

yes

How well did you know this?

Not at all

Perfectly

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)

eukaryotic

largest

and

80S

yes

none

usually

yes

How well did you know this?

Not at all

Perfectly

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)

obligate intracellular
replication

or (not both)

energy
protein

particular types and/or species of host cells

antibacterial/antifungal antibiotics

How well did you know this?

Not at all

Perfectly

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 _)

usually 1

70S

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

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

How well did you know this?

Not at all

Perfectly

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 _)

yes

> 1

yes

80S

yes

How well did you know this?

Not at all

Perfectly

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)

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

How well did you know this?

Not at all

Perfectly

Bacteria:

morphology (3)

arrangements (3)

cocci
rods
spirochete

diplococci
cocci in chains
cocci in clusters

How well did you know this?

Not at all

Perfectly

Bacterial Cell Components (3)

Cytoplasm
Cell envelope
External structures (if present)

How well did you know this?

Not at all

Perfectly

Bacterial Cell Components:

Cytoplasm (3)

DNA, ribosomes, metabolic enzymes

site of some antibiotic action

outer membrane (if present)

How well did you know this?

Not at all

Perfectly

Bacterial Cell Components:
Cell envelope (3)

plasma membrane

cell wall (target of some antibiotic action)

outer membrane (if present)

How well did you know this?

Not at all

Perfectly

Bacterial Cell Components:
External structures (if present) (4)

common pili

capsule

sex pilus

flagella

How well did you know this?

Not at all

Perfectly

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 _

basic life

protein synthesis
DNA replication or RNA transcription

resistance and virulence

How well did you know this?

Not at all

Perfectly

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 _)

permeability barrier and transport

osmotic lysis

permeability barrier
pumps and pores

How well did you know this?

Not at all

Perfectly

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

common pili: _

capsule: _, can result in _ formation

sex pilus: _

flagella: _

attachment to tissue

antiphagocytic
biofilm

conjugation

motility

How well did you know this?

Not at all

Perfectly

Bacterial Cell Wall Synthesis:

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

Peptidoglycan
transpeptidases
penicillin binding proteins (PBPs)

The Gram Stain:

Procedures (4)

stain
mordant
decolorize
counterstain

The Gram Stain:
Gram+ and Gram- procedure colors

Stain

Mordant

Decolorize

Counterstain

Stain: purple, purple

Mordant: purple, purple

Decolorize: purple, clear

Counterstain: purple, red

Structures/components unique to gram+ bacteria (2)

Lipoteichoic acid

Teichoic acid

Examples of medically-important gram+ bacteria (3)

Streptococcus spp.
Staphylococcus spp.
Clostridium spp.

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

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

outer membrane

enterics
lipopolysaccharide (LPS)

Structures/components unique to the Gram-negative bacteria:

LPS consists of three regions (3)

lipid A
core
O antigen

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 _

endotoxic conserved bile and complement resistance polysaccharide

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

O H K

Gram-negative antigens: O: _, _ portion of LPS H: found on _ K: _ antigen

variable, outermost flagella capsular

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.

nonenteric lipooligosaccharide (LOS) O core lipid A

Being gram- vs. gram+ Advantage: _ from the _ (including some antibiotics) Disadvantage: _ to make, hard to _ through _

Protection from the environment expensive secrete proteins through two membranes

Structures/components unique to the Gram-negative bacteria: _: channels in outer membrane, allow molecules to _ Alterations can impact _

Porins move across the outer membrane antibiotic resistance

Some examples of Gram negative pathogens (4)

Shigella spp. Salmonella spp. Vibrio cholerae E. coli

"Atypical" Myobacteria: Stain: _ Cell envelope functions (2) Cell envelope components (4)

Acid-fast resistance to desiccation & phagocytosis helps disease transmission waxy layer phenolic glycolipid mycolic acids peptidoglycan

Examples of medically-important Mycobacterium spp. (2)

Mycobacterium tuberculosis Mycobacterium leprae

"Atypical" Spirochetes: These bacteria can be visualized only by _ Examples (2)

dark-field microscopy Borrelia burgdorferi Treponema pallidum

"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 _

obligate intracellular vector-borne energy fleas, ticks, lice, etc. negative Gram-stain

Medically important Rickettsiae spp. (2)

R. rickettsii: rocky mountain spotted fever R. typhi: endemic typhi

"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

obligate intracellular reticulate elementary Energy two peptidoglycan Gram

Examples of medically important spp. (3)

Chlamydiae trachomatis: blindness, nongonococcal urethritis, pneumoniae Chlamydophila psittaci: psittacosis (a form of pneumonia) Chlamydophila pneumoniae: pneumonia

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)

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

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)

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

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)

no, except for Rochalimaea quintana yes sometimes yes yes yes and

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)

yes yes yes no yes yes and

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)

no no no no no no or

"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 _)

small cell wall sterols artificial antibiotic M. pneumoniae pneumonia