Bacteria Evasion techniques and Dissemination Flashcards

1
Q

How does Legionella pneumophila prevent phagolysomal fusion

A

prevents phagolysosomal fusion

removes the LAMP-1 and LAMP-2 proteins that are necessary fro membrane fusion with the phagosome

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2
Q

Describe the process that Legionella pneumophila prevents phagolysomal fusion

A
  1. bacteria is taken up into the phagosome
  2. bacteria removes necessary proteins for membrane fusion with the phagosome, these are LAMP-1 and LAMP-2
  3. phagosome does not fuse with the lysosome
  4. phagosome surrounded by ER studded with ribosomes
  5. bacteria multiply in the phagosome
  6. phagosome ruptures and the bacteria are released inside the cytoplasm of the cell
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3
Q

What bacteria turns off the LAMP proteins to prevent phagolysomal fusion

A

Legionella pneumophila

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4
Q

How does Salmonella Typhimurium prevent phagosomal fusion

A

triggers actin rearrangements forming a SCV, salmonella containing vesicle that the host doesn’t recognize as bacteria

hijacks cells actin cytoskeleton to create its own space makes a SCV

bacteria remodel the vacuoles creating a growth conductive environment allowing the bacteria to grow

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5
Q

What bacteria uses the actin in the cells cytoskeleton to create its own vesicle inside the cell

A

Salmonella Typhimurium

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6
Q

How does Mycobacterium tuberculosis prevent phagolysomal fusion

A

recruits host protein TACO to coat the phagosome it is inside of so the lysosome and phagosome do not fuse

uses host protein TACO to coat the phagosome

bacteria bind to CR3 on surface of macrophage and this is what allows the bacteria to be taken up in the vesicle

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7
Q

What bacteria used TACO to prevent phagolysomal fusion

A

mycobacterium tuberculosis

uses host protein TACO to coat the phagosome

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8
Q

How does Brucella abortus prevent phagolysomal fusion

A

allows for fusion of the lysosome and phagosome

it will only replicate upon acidification of the vacuole

the acidification of the vacuole directs it to the ER to escape from inside the host cell

not a common pathogen

prefers the fusion of the lysosome to replicate

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9
Q

What bacteria prefers fusion of the lysosome and the phagosome

A

Brucella abortus

Coxiella prefers acidification to replicate inside of a cell in compartmentalized vacuoles

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10
Q

How does Chlamydia live inside the cell

A

obligate intracellular pathogen that lives inside of compartmentalized vacuoles

chlamydia is unable to replicate outside of the cell so the EB form enters the cell and then turns into RB which is the replicative from and then Chlamydia replicated and forms RB and EB forms

the EB forms leave the cell and go to infect different cells

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11
Q

What types of bacteria must be inside of compartmentalized vacuoles to replicate

A

Chlamydia and Coxiella

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12
Q

How does Coxiella live inside the cell

A

obligate intracellular pathogen that lives inside of compartmentalized vacuoles

coxiella is unable to replicate outside of the cell so the SCV form enters the cell and promotes upon acidification turns into LCV which is the replicative from and then coxiella is replicated and forms SCV and LCV forms

the SCV form leave the cell and go to infect different cells

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13
Q

How do bacteria cope with resisting reactive oxygen species

A

reactive oxygen species are the primary way the oxidative burst kills bacteria

some bacteria can produce enzymes that neutralize oxygen radicals

catalase
H2O2–>O2+H2O

superoxide dismutase
O2- –> O2+H2O2 is used by Salmonella SodCl enzyme is phage encoded

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14
Q

What enzymes can bacteria produce to neutralize oxygen radicals

A

Catalase
H2O2–>O2+H2O

superoxide dismutase
O2–> O2+H2O2, Salmonella SodCl enzyme is phage encoded

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15
Q

What is NO and how do bacteria cope with this

A

Nitric Oxide which is a reactive nitrogen compound

Neisseria meningitidis produces nitric oxide reductase converts NO to N2O (laughing gas) which is less toxic

E. coli uses nitric oxide deoxygenase to convert NO to NO3- (nitrate)

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16
Q

How does Neisseria meningitidis and E.Coli deal with NOs

A

Neisseria meningitidis produces nitric oxide reductase converts NO to N2O (laughing gas) which is less toxic

E. coli uses nitric oxide deoxygenase to convert NO to NO3- (nitrate)

17
Q

How does streptococcus pyogenes cope with the adaptive immune response

A

Protein G

surface protein that binds the antibody backwards

binds the Fc regions of the antibodies and bind the antibodies so they are facing outward

18
Q

What bacteria produces nitric oxide reductase converts NO to N2O (laughing gas) which is less toxic

A

Neisseria meningitidis

19
Q

What bacteria uses nitric oxide deoxygenase to convert NO to NO3- (nitrate)

A

E. coli

20
Q

What bacteria uses protein G to bind antibodies backwards

A

Streptococcus pyogenes

21
Q

How does Staphylococcus aureus cope with the adaptive immune response

A

Protein A

surface protein that binds the antibody backwards

binds the Fc regions of the antibodies and bind the antibodies so they

22
Q

What are ECM proteins the are used to cope with the adaptive immune response

A

extracellular matrix proteins

bind collagen, fibronectin, fibrinogen to the outside of the bacterial cell

Host mimicry
if they use these ECM proteins on their surface the host views the bacteria as one of its own cells and doesn’t emit an immune response

23
Q

How do bacteria disseminate through the body

A

cell to cell spread it one way for bacteria to spread to new parts of the body

breakdown pus from neutrophil reaction: pus is full of proteins, dead cells, and DNA

secrete spreading factors to break down substances

secrete blood thinners to escape blood clots

24
Q

How do bacteria break down pus

A

neutrophil reaction: pus is full of proteins, dead cells, and DNA

bacteria secrete DNases to thin it

25
Q

What are types of spreading factors that bacteria use to help them spread within the body

A

bacteria secrete collagenases, elastases, hyaluronidases and other proteases that break down connective tissue and other ECM proteins

26
Q

How do bacteria escape from blood clots

A

secrete blood thinners such as streptokinase which degrades fibrin