Host-Parasite Relationships Flashcards
Exotoxins
bacterial products that directly harms tissue of leads to destructive biologic activites
Adhesion
binding of the bacterial adhesin to the host cell surface
Ways bacteria adhere
invasion into cells
dissemination
invasion into cells
hijack host cell machinery
modulate maturation of the phagosome to promote survival
Dissemination
cause pathology due to toxin production of through thte original lesion
Ways pathogens use to evade clearance by phagocytosis
- Inhibit opsonization
- Inhibit chemotaxis
- Kill phagocyte
- Inhibit lysosomal fusion
- Escape from lysosome
- Resistant antibacterial lysosomal action
Superantigens
bind both T cell receptor and MHCII without a requiring antigen
Acitvation of large number of T-cells triggers a cytokine storm
Encapsulation
generally a poor antigen
makes more antigenic epitopes on bacterial
surface
prevents binding of antibody or compliment
Microbiota found on teeth
a. Streptoccus
Microbiota found in throat
a. Strep viridans, pyogenes, and pneumoniae
b. Neisseria
c. Straphloccus epidermis
d. Haemophiliz influenza
Microbiota found on skin
a. Staph epidermidis
b. Staph. Aureus
c. Diptheroids
d. Streptococci
e. Pseudomonas aeruginosea
f. Anaerobes, candida turlopsis pitrosporum
Microbiota found in nose
a. Staph aureus
b. Staph epidermidis
c. Diptheroids
d. Streptococci
Microbiota found in mouth
a. Strep mitis and other streptoccci
b. Trichomonas tenax
c. candida
Microbiota found in urethra/vagina
a. Staphylococcus epidermidis
b. Diptheroids
c. Streptoccic
d. Gram neg. rods
Microbiota found in esophagus and stomach
lactobacilli
MIcrobiota found in small bowel
i. Lactobacilli
ii. Streptocci
iii. Enterobacteria
iv. Bacteoids spp
Microbiota found in large bowel
i. Bacterises spp.
ii. Fusobacterium spp.
iii. Strep faecalis
iv. E. coli
v. Lactobacillus
vi. Staph aures
vii. Clostrium spp
viii. Enterobacteria
ix. Klebsiella spp
x. Eubacteria
xi. Streptococci
xii. Pseuodomas
xiii. Salmonella
Microbiota found in fecal matter
i. Bacteroids spp.
ii. Bifidobacteria
iii. Eubacteria
iv. Coliforms
v. Strep faecalis
Pathogen
any microorganism that has the capacity to cause disease
strict pathogens
organism always associated with disease
opportunistic pathogens
tend to be members of normal microbiota
take advantages of pre-existing conditions
most infections of humans are caused by these
Pathogenicity
ability of a microorganism to cause disease
virulence
measurement of pathogenicity
Major sites of pathogen entry into the human body
- Transplacental
- Secretions
- Stool to oral
- Skin
- Blood
- Zoonotic
- Arthropod
Biofilm
bacteria encased in a exopolymeric substance of their own making. Found on wet surfaces
Characteristics of biofilm
i. Slowed metabolism
ii. Increased resistance to antibiotics
iii. Increased genetic exchange -> increased likelihood of antibiotic resistance transfer
iv. Resistant to disinfection – decreased diffusion, increased organic matter
