Major Mechanisms of Pathogenicity Flashcards
colonization is a way for a bacteria to be forced into an environment and is important for adherence and partial adherence.
What are structures that help adherence in gram positive and gram negative organisms?
pilli/fimbriae (gram negative)
teichoic acids (gram positive)
adhesions (pertussis toxin and hemagglutins)
IgA proteases ( to attach to mucosal surfaces)
what structure can give partial adherence to inert materials
biofilms (slime laters which give resistance and act as tight connections between bacteria through glycoproteins)
bacteria with a capsules have anti _ properties
what are the most common encapsulated organisms
antiphagocytic
Please SHINE my SKiS
pseudomonas, streptococcus pneumonia, haemophilus, neisseria, e. coli , salmonella, klebsiella, step (group B)
what fungus is encapsulated
cryptococcous neoformans
surface components are also anti-phagocytic along with capsules
surface component of s. pyogenes:
surface component of N. gonorrhea:
surface component of S. Aureus:
surface component of s. pyogenes: M protein
surface component of N. gonorrhea: pili
surface component of S. Aureus: A protein
what is antigenic variation
change in surface antigens to avoid immune detection
antigenic variation in gonorrheae:
change in pill and outer membrane proteins
antigenic variation in T. Bruce rhodesiense and T. Bruce gambiense:
phase variation
antigenic variation in enterobacteriaceae:
capsular and flagellar antigens
antigenic variation in HIV and influenze:
antigenic drift
variations in HIV
gp120 and gp40
variations in influenzae
neurominadase
hemagluttanin
how can bacteria survive intracellularly
evasion of intracellular killing, invasions, damage secondary to intracellular replication
M tuberculosis has _ that inhibit phagosome-lysosome fusion
sulfatides
listeria monocytogenes escapees from the _ before phagosome-lysosome fusion
phagosome
Yersinia pseudotuberculosis surface proteins allow organisms to bind to and infect normally _ _ cells
non-phagocytic cells
examples of ways bacteria damage cells secondarily to intracellular replication
lysis, transformation, and latency
what is molecular mimicry
- results in immune mediated damage/inflammation from bacteria
cross reaction of bacteria induced antibodies with tissue antigens (like in rheumatic fever)- type two hypersensitivity
delayed hypersensitivity and granulomatous response is usually triggered by _ (intracellular/extracellular) bacteria or systemic _
intracellular
mycoses
granulomatous response and delayed hypersensitivity is a type _ HSR
4
large fragments of _ can cause immune mediated damage or inflammation. They work as structural toxins that are released from gram + organisms and serve as chemoattractants for _
peptidoglycan-teichoic acid
neutrophils
toxins aid in invasion, damage cells and inhibit cellular processes or trigger an immune response and damage. What are the 2 types of toxins?
structural toxins and exotoxins
structural toxins are found within the _ of gram positive and gram negative bacteria
envelope
exotoxins are _ toxins secreted into the environment by gram positive and gram negative bacteria
protein
