Bacteria Evasion techniques and Dissemination Flashcards
How does Legionella pneumophila prevent phagolysomal fusion
prevents phagolysosomal fusion
removes the LAMP-1 and LAMP-2 proteins that are necessary fro membrane fusion with the phagosome
Describe the process that Legionella pneumophila prevents phagolysomal fusion
- bacteria is taken up into the phagosome
- bacteria removes necessary proteins for membrane fusion with the phagosome, these are LAMP-1 and LAMP-2
- phagosome does not fuse with the lysosome
- phagosome surrounded by ER studded with ribosomes
- bacteria multiply in the phagosome
- phagosome ruptures and the bacteria are released inside the cytoplasm of the cell
What bacteria turns off the LAMP proteins to prevent phagolysomal fusion
Legionella pneumophila
How does Salmonella Typhimurium prevent phagosomal fusion
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
What bacteria uses the actin in the cells cytoskeleton to create its own vesicle inside the cell
Salmonella Typhimurium
How does Mycobacterium tuberculosis prevent phagolysomal fusion
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
What bacteria used TACO to prevent phagolysomal fusion
mycobacterium tuberculosis
uses host protein TACO to coat the phagosome
How does Brucella abortus prevent phagolysomal fusion
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
What bacteria prefers fusion of the lysosome and the phagosome
Brucella abortus
Coxiella prefers acidification to replicate inside of a cell in compartmentalized vacuoles
How does Chlamydia live inside the cell
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
What types of bacteria must be inside of compartmentalized vacuoles to replicate
Chlamydia and Coxiella
How does Coxiella live inside the cell
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
How do bacteria cope with resisting reactive oxygen species
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
What enzymes can bacteria produce to neutralize oxygen radicals
Catalase
H2O2–>O2+H2O
superoxide dismutase
O2–> O2+H2O2, Salmonella SodCl enzyme is phage encoded
What is NO and how do bacteria cope with this
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)
