July 12 Weapons of the Invaders

Topic 6: Weapons of the Invaders

Understanding Disease:  The Great Battle
The Battleground - Your Body
Invading forces:  Pathogens
Strategies for _ENTRY, avoiding capture, gaining control, using resources_____________________________
Defenders of the castle:  Your Body
Outer perimeter defenses -level one
Within the wall defenses -level 2
Final defenses (throughout) -level 3

How the pathogens attack your body:

Correct entry:portal of entry, dose
Must come in at the right ___________________, and the correct _________ must be present.

(PRINT OUT and complete comparison chart in review materials)

Physical weapons:

Ligands (Fig. 14.5)

 fimbrae

capsules (Fig. 14.5 and 14.6)
 *neutralize drugs
* avoid phagocytosis
* delay immune response to pathogen

Chemical weapons:

Enzymes of Pathogens: alter substrate in host tissue     (Fig. 14.9a)       
(Affect location of pathogen)

invasins- _Flagella_, along with invasin enzymes, allow___penetrate into tissue__

                                Ex.___Borrelia in Lyme disease________________
coagulase – forms clots

(helps pathogen form ___localized__________________ infections)

(strepto)kinase – dissolves clots

(helps pathogen become_____septicemia (spread into bloodstream_________________)

hyaluronidase-dissolves cell cement, “spread factor”

collagenase- breaks down collagen

(work together to allow _____spread of organism through tissue_______________________________)

**** draw picture***  hyaluronidase dissolvs cell cement between cells, collagenas breaks down collagen between layers of cells and it allow spread of organisms through tissue of organism ***

(Affect blood cells)

leucocidin –   kills white blood cells

(contributes to formation of____pus_____________)

M-protein – prevents White Blood Cells (WBC) phagocytosis

(prevents: _____WBC from eating bacteria_____________________  )

Example: streptococcus pneumoniae……

*****strep. Pyogenes virulence factors Box p. 545 (pus forming strep throat)*****

hemolysins –  rupture red blood cells

(two benefits)

1-      Reduces oxygen and increase carbon dioxide for microaerophiles

2-      Releases protein, iron for nutrients

Pathogens use you as food source:

digestive enzymes - proteases, lipases, amylases, etc.
***** necrotoziers fasciitis (eat through your tissues… they can spread 2 mm per hour under the skin**** if she had waited to 3 hours she would have died::: picture of a girl drug user Friday to Sunday morning….

Catch it early before it spreads:

http://www.thehorrorzine.com/Morbid/necrotizing_fasciitis.html

Chemical weapons:
* Toxins: - Affect functionality of host tissue
* two kinds: endotoxins and exotoxins

Toxins of Pathogens: (Fig. 14.9 b, Table 14.8)

Exotoxins:

Molecule type: proteins
secreted from __live cells_______________
Gram reaction of producers______both + and -_________
Effect felt ____specific cells/ tissues_____________
Specific __immune response (antitoxins)___________________ produced by immune system in response to toxins

·         Heat denatured toxin can be made into a toxoid….

toxoid production possible to make ___as a vaccine___________

Exotoxin types:

Cytotoxins: directly kills cells (by affecting cell membrane and making it burst and cause large lesions)
Ex.  Anthrax








Enterotoxins:  affect digestive tract (usually intestines)

-          Fluid loss from blood into intestines and/or peristalsis

o   Diarrhea, cramping, nausea

o    Ex. Cholera organism fig 21.21

o   Example: staph. Aureus, E. coli O157:H7, Samonella

Neurotoxins:  affect nervous system (fig 19.14)

1.       botulism (__flaccid______ paralysis)

2.       tetanus (___rigid_______ paralysis)

Mechanism of action of botulism toxin    (Fig. 19.14)
toxin binds to ___nerve ending_________________
prevents ______release of neurotransmitter (acetylcholine)____________________
no muscle ____contraction_______________ occurs
__FLACCID________ paralysis
                (often misdiagnosis as a stroke)
Infant botulism:
FDA Medicinal uses of “Botox”:

***most potent toxin known to men*** Migranes…. (in temple area)

***uncontrollable muscle contractions

***excessive sweating

Can wear off in a month or 2 months….

 ---what does the bacteria gain from this toxin? Hypothesis…. Spores, anerobic, waste by product of another reaction?

Mechanism of action of tetanus toxin  (Fig. 19.16, 19.17)
toxin binds to ____nerve ending________________
prevents __inhibitory neuron neurotransmitter release______
no muscle _____relaxation_________ occurs
___rigid___________ paralysis

Endotoxins:  (Lipid A)  Figure 14.9b, Table 14.7

Molecule type: Lipid
Found in cell within __Lipid A of LPS layer of cell wall________
Gram reaction of producers: Gr – cells ONLY
released from cell: only when the cell dies
effect: systemic
            *endotoxin shock: fever, inflammation, Blood pressure drop, shock, blood congulation, etc
- lipids- do NOT trigger specific immune response = no antitoxins made in body
                Do NOT: trigger specific immune responses
                So NOT usable to make ____vaccines________________

Intro to Defense section:

·         Level one: on the surfaces

o   Non-specific, non-solicited response (example. repelled by surface defense, always there, example the fact that your skin is salty)  

·         Level 2: beneath the surface

o   Non-specific, semi solicited (example: white blood cells: always there but will respond to the need to localized invasions, inflammatory response)

·         Level 3: Systemic response

o   Specific, solicited (targeted to very specific pathogens, never kicks in until it get on and through skin)

What defenses contribute to each leavel of protection?

Pictures…

Level 1 skin defenses Fig 15. Table 15.1

Weapon	Type  (Chemical or Physical)	Specifically causes (molecular basis)	End result (symptoms or benefit)
ligand	P-molecule
Fimbrae	P-hairlike
Capsule/glycocalyx	P-slimy
Invasins	C-Enzyme
Coagulase	C-Enzyme
Kinase	C-Enzyme
Hyaluronidase	C-Enzyme
Collagenase	C-Enzyme
Leucocidin	C-Enzyme
M protein	C-Enzyme
Hemolysin	C-Enzyme
Digestive enzymes	C-Enzyme
Neurotoxin	C-Exotoxin/protein
Enterotoxin	C-Exotoxin/protein
Cytotoxin	C-Exotoxin/protein
Endotoxin	C-lipid