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Pathogens can enter through several diffrent area of the body known as,..?
portals of entry
What are some ways that micro's enter the skin?
hair follicles and sweat gland
What are some micro's that grow on the keratin of skin or infect the skin itself?
What can bore through intact skin?
hookworm larvae (necator americanus)
The route of micros's that go directly into the tissues beneath skin or mucous membrane is called?
- the parenteral route
- >examples are
- puntures, injections, bites, cuts, wounds, surgery, splitting due to swelling or drying of the skin
What is a necessary step in pathogenicity ?
Attachment to cell is through binding to micro's on surface of the that the pothogens specificllay. The pathogens surface molecules are called? Most are what kind of proten?
adhesins, or ligands... glycoproteins or lipoproteins
The surface molecule on the cell are called
What tract is the easiest and most frequent portal of entry?
How do mircoorganisms enter the gastointesinal tract?
> most are killed by acid in the stomach, the survivors cause disease
.ex.. polio, hepitias A, typhoid fever, cholera
food and water, contaminated fingers
Sexually contracted diseases such as hiv, genital warts, herpes, syphillis and gonorrhea go through what tract?
Perferred Portal: not all microbes cause diease the factor can depend on the portal of entry. Some microbes have more than one portal of entry (yersinia pestis).
- Salmonella typhi.. produces diease when ingested, but not skin.
- Steptococcus can cause pneumonia, but swallowed does not
potency of toxins expressed as (time of sickness before death)
LD50% lethal dose for 50% of the hosts
The dose required to produce viewable infection is the ?
ID 50% infectious dose on host (amount of time produces in body)
What can help resist the host defense by impairing phagocytosis?
- bacterial capsule
- >phagocytic cells cannot adhere to bacterium
- >antibodies to the capsule can be made, the encapsuled bacteria can be destroyedby phagocytosis
- ex: streptoccous and klebsiella pneumonia, hemophilus influenzae, bacillus anthracis, yersinia pestis
What is on streptoccous cell wall surface mediates attachment and helps resist phagocytosis?
What is on the cell wall of Mycobaterium turberculosis resists digestion by phagocytosis?
Can be acid fast fixed...
What is produced by bacteria that can aid in virulence?
What destroys neutrophils and leukocytes (WBC) which are active in phagocytosis?
What are hemolysis produced by streptococci?
Inactivated by oxygen is ?
Has inffinity for albumin?
>both kinds also lyse wbc
- streptolysins O
- streptolysins S
What are bacterial enzymes that cause lysis in erythrocytes (redblood cells)
Enzyme that is secreted by some bacteria such as steptococci (and some clostridia involved in gas gangrene).
>holds together certain cells of the body (connective tissue)
>may be involved in blackening of tissue
>helps microbes spread
- >hydrolyzes hyaluronic acid
Enyzmes that break don collagen which forms connective tissues of muscles.
>produced by species Clostridium involved in gas gangrene
In some cases attachment signals the host cell to allow the bacterium to enter the cell.
What is the host cell cytoskelton responsible for?
the cytoplasmic movements that bring the bacterium into the cell
Suface proteins that cause rearrangement of actin filaments in the cell are ?
> Salmonella tyhimerium adn enteropathogenic E.Coli produce this
When inside the cell some bacteria such as Shigella and Listeria can ?
use the actin to propel through the cell wall from one host to another
What are the enyzmes coagulates the fibrinogen in blood (coagulates).
clots may protect the bacteria for phagocytosis and walling off process of boils by staphylocci
Enyzme produced by bacteria breakdown fibrin and dissolve clots fromed by body to isolate infection..?
fibrinolysin(streptokinase) enyzmes that are injected to dissolve some types of blood clots in heart attack patients
necrotizing factor does?
kills body cells
hypothermic factors does>
decreases body temperature
detroys plasma membrane
breaks down protein, particulary in muscle tissue
scavenge iron from the host body fluids
When penetrating cell wall membrane or exiting one cell to another (reverse phagocytosis) is called
Poisinous substances produced by some microorganisms
Toxins that are produced inside the bacterium and released into the surrounding medium are?
Toxins that kill there host cell or affect their function are?
Toxins that intefere with nerve impulses.
Toxins that affects cells in the gastrointestinal tract are?
Antibodies produced by the body against exotoxins are?
Are inactivated toxins injected into the body to produce immunity are
What kind of phages are incorporated in the bacterial cell's chromosome?
Changes in the charateristics of the cell are called ?
A small circular DNA molecule for cytoplasm that replicates independently of the chromosome is called.. ? they carry bacteria from one bacteria to another
The state in which phage DNA is incorporated into the host cell with-out lysis is called... ?
The degree that bacteria overcomes the host is the...?
Lysogenic phages are incorporated in the bacterial cells chromosome is also known as ..
Shock is a life threatening loss of blood pressure, when it is caused by a gram negative organism it is called what?.. tumor necrosis factor involved in process
A fever is what kind of response?
Endotoxin response to the host are
chills, fever, weakness, generalized aches, shock, death even miscarriage
Endotoxins are made of...
lipopolysaccharides, lipid portion of the LPS outer membrane is Lipid A
Toxins that are part of the outer portion of the cell wall or gram negative bacteria are?