Pathogens

Front 1

What are the mechanisms that Staphylococcus aureus uses to avoid destruction of the immune system.

Back 1

-Coated with Protein A
-Coagulase
-Capsule/slime Layer

Front 2

What are the enzymes Staphylococcus aureus has that contribute to its pathogenicity?

Back 2

Hyaluronidase, Staphylokinase, Lipase and Beta-lactamase (provides resistance to penicillin)

Front 3

What Toxins does Staphylococcus aureus produce?

Back 3

Cytolytic toxins, exfoliative toxin, Toxic Shock syndrome toxin and Enterotoxins.

Front 4

What Is protein A?

Back 4

Coats staphylococcus aureus cells. It binds to antiboides and prevents phagocytosis so they cannot be broken down.

Front 5

What is coagulase?

Back 5

An enzyme produced by S. aureus that can solubalize certain proteins in the blood and forms blood clots around the bacteria to "hide" them

Front 6

What is Hyaluronidase

Back 6

An enzyme (produced by S. aureus as well as C. dificile)
--in C. dificile it breaks hyaluronic acid which is part of connective tissue of intestine, causes it to slough off.
--in S. aureus: breaks down hyalurionic acid which is part of the junction between cells, and allows them to gain access by moving in between cells.

Front 7

What protection does a bacteria have if it has a capsule/slime layer?

Back 7

--in S. aureus: prevents recognition by leukocytes

Front 8

What is Staphylokinase?

Back 8

In S. aureus, it allows the cell to chew its way out of blood clots that it had been "hiding" in after it reproduced in the safety of the clot.

Front 9

What are lipases?

Back 9

In S. aureus--breaks down lipids, that is why it can live on the skin so easily.

Front 10

What are cytolytic toxins?

Back 10

in s. aureus, they lyse or breakdown cytoplasmc membranes of the leukocytes

Front 11

What is the exfoliative toxin?

Back 11

in s. aureus, it digest the bridges between epidermal cells, leads to skin cells separating and sloughing off the body

Front 12

What are enterotoxins?

Back 12

In. s. aureus. They contain 5 which stimulate muscle contractions of the intestinal muscles and cause nausea and vomiting. It is associated with the s. aureus infection that causes food poisoning. They are very heat stable.

Front 13

Describe beta hemolysis

Back 13

In streptococcus pyogens. When it is cultured on blood agar, it creates a clear zone around the colony,which is called this.

Front 14

What is protein M?

Back 14

Secreted by streptococcus pyogens. It interferes with lysis by the immune system.

Front 15

Describe hyaluronic acid capsules.

Back 15

In S. pygoens: it hides it from the immune cells, because hyaluronic acid is normally found in b/w human cells, so the immune system bypasses it as a human cell

Front 16

What is Streptokinase?

Back 16

Enzyme produced by S. pyogens. It chews through existing blood clots (such as those formed to protect the rest of the body from toxins, like on a wound)

Front 17

What are Pyrogenic toxins?

Back 17

S. pyogens. Stimulate cells to release cytokines that cuase fevers, rash and can initiate shock.

Front 18

What is Streptolysin?

Back 18

These lyse red and white blood cells--interfere with oxygen carrying, and prevent clotting.

Front 19

Describe Polysaccharide capsules.

Back 19

Found in Streptococcus pneumoniae. It is a sugar based capsel that protects the bacteria from digestion/destruction after it has been phagocytosed.

Front 20

Describe Phosphorylocholine.

Back 20

In S. pneumoniae. It binds to receptors on cells in lungs ands timulates endocytosis, which it then gains access to cell lining of lung tissue (where it can hide because of capsule), and then can easily pass into the blood

Front 21

Describe Secretatory IgA protease

Back 21

Found in S. ppneumonia. IgA is an antibody that will want to stick all over the pathogen. The IgA will then bind to the mucous--and act as a bridge between mucous and pathogen to carry it out of the lungs. IgA protease cuts IgA in half.

Front 22

Describe Pneumolysin

Back 22

protein secreted by S. pneumoniae that binds to cholesterol in the cell epithelial membrane of the lungs--causes cells to lyse and break open.

Front 23

What are the diseases caused by Streptococcus pyogens?

Back 23

Pharyngitis, which can lead to Scarlet fever or Rheumatic Fever.

Cutaneous: Pyoderma, Impetigo and Necrotizing Faciitis.

Front 24

Describe Pharyngitis and how it can develop into other dramatic infections.

Back 24

It is strep throat (red throat with white lesions)
Scarlet fever--is caused by toxins of pharyngitis infection--rash on chest, strawberry red tongue and skin sloughs off
Rheumatic Fever--caused by the immune response to pharyngitis infection, and responds in a dramatic way, causes inflammation of the the heart valves due to antibody reaction.

Front 25

What are the three forms of Tuberculosis?

Back 25

Primary form: respiratory--forms tubercle in the lung
Secondary: tubercle ruptures and releases many more bacteria into the system and re-infect
Disseminated form: infection has moved into the blood stream and can affect many organs/tissues.

Front 26

Describe the primary form of TB.

Back 26

1. inhale respiratory droplet from someone else--macrophage cells try to remove bacteria but cannot digest it and it and the bacteria then lives in the macrophage.
2. It eventually kills the macrophage cell releasing repoduced cells
3. These recruit new macrophage cells--which also get infected
4. Immune response occurs--inflammation that surrounds macrophage cells= tubercle, as tubercle grows a layer of collagen surrounds it and cells begin to die= caseous necrosis (core of tubercle)

Front 27

What are coliforms?

Back 27

Example, E. coli. Aerotolerant or facultative anaerobe, fermetns lactose to form gas w/in 48 hours at 35 degrees C in lactose broth.
(Definition: Enteric Gram - bacteria that ferment lactose to gas and are found in the intestinal tracts of animals and humans.)

Front 28

What is a virulence plasmid?

Back 28

codes for fimbriae (which can stick to things)--an adhesion protein. FOund in E. coli

Front 29

What is the Shiga like toxin?

Back 29

In E. coli. It resembles toxins that look like the shiga bacteria
--they disrupt 60s units of eukaryotic ribosomes,
--disrupt cell metabolism,
--disrupt cell membranes and stick to others (meaning it sticks to good E. coli we want in our intestine) and it can spread through immune cells.

Front 30

Describe the course of infection of Salmonella.

Back 30

--Passes through the stomach and attach to the cells lining the small intestine then:
1. The bacteria inserts proteins into the host cells, inducing the normally nonphagocytic cells to endocytize the bacteria
2. The salmonellae then reproduce withing the endocytic vesicles
3. eventually killing the host cell
4. ANd inducing the signs and symptoms of salmonellosis. Cells of some strains can subsequently enter the blood, causing bactermia.
5. Localized infection throughout the body, including in the linking of the heart, the bones and the joints.

Front 31

What are papillomas?

Back 31

growths of skin and mucous membranes caused by the papilloma virus.

Front 32

What is the p53 mammalian tumor repressor gene?

Back 32

It senses DNA damage in animal cells and initiates cell death. The papilloma virus that causes cervical cancer produces a protein that shuts off p53 and cells reproduce rapidly causing cancer.

Front 33

Describe the three stages of infection of Trypanosoma brucei.

Back 33

1. Bite becomes lesion
2. Parasite in blood= fever, lymph node swelling
3. Central nervous system= coma or death.

Front 34

Describe the Corynebacterium diptheriae toxin.

Back 34

-- THe bacterium contains a lysogenic bacteriophage that codes for diphteria toxin, which is directly responsible for the signs and symptoms of diphtheria. Cells lacking the phage are not pathogenic.
--It has three parts, Mimics growth factor so binds to growth factor receptors which signals endocytosis. One part gets cleaved off and enters the cell. The toxin in the cell destroys the elongation factor that is involved in protein translation. The action of the toxin is enzymatic so a single molecule of toxin destroys every molecule of elongation factor in the cell.

Front 35

Compare antigenic shift to antigenic drift.

Back 35

Antigenic shift: Major antigenic change that occurs on average every 10 years and results from the reassortment of genomes from different influenzavirus strains within host cells. (Occurs in Orthomyzoviruses)
--Antigenic drift: Phenomenon that occurs every 2-3 years when a single strain of the influenza mutates within a local population.

Front 36

Describe the life cycle of the papillomavirus.

Back 36

--lives and reproduces in keratinocytes (special layer of the epidermis)
--enters through abrasion, goes through endocytosis
--inside keratinocytes, the cell divides and divides rapidly

Front 37

Describe the life stages of Giardia intestinalis.

Back 37

Parasitic trophozoite, and a free living cyst

Front 38

What is a diplomonad?

Back 38

a cell with two identical and functional nuclei.

Front 39

What is the life cycle of a plasmodium?

Back 39

THree Stages of life:
1. Outside the RBC--from mosquito (puts it into the blood)--then it travels to the liver
2. In RBC it reproduces, lyses 48-72 hours later. Or will develop into mating types
3. Reproductive cycle: takes place inside the mosquito.

Front 40

What are the diseases caused by Streptococcus pneumonia?

Back 40

Pneumoccal pneumonia, Sinusitis, Otitis media and Pneumococcal meningitis.

Front 41

What are the two forms of leprosy?

Back 41

aka Hanson's Disease
--Tuberculoid Leprosy: if the body has a strong immune response to exposure you can lose feeling because of damages to the nerves, and dead skin falls off
--Lepromatous Leprosy: Not strong enough immune system leads to a loss of extremities.

Front 42

Describe Typhoid Fever.

Back 42

+Humans are the sole host to Salmonella typhi. Infection occurs via the ingestion of food or water contaminated with sewage containing bacteria from carriers, who are often asymptomatic. An infective does is only about 1000-10000 cells.
--The bacteria pass through the intestinal cells into the bloodstream, there they are phagocytized but not killed by phagocytic cells, which carry the bactreia to the liver, spleen, bone marrow and gall bladder

Front 43

What are metachromatic granules?

Back 43

Starch storage mechanism inside Coryneobacterium cells--they can be used to identify bacteria because they stain differently.

Front 44

Describe lipid A.

Back 44

Found in Gram negative bacteria. This causes Gram - to be more virulent. WHen bacteria is killed there is a release of lipid A in the body and it is toxic leading to fever, inflammation, shock, Disseminated intravascular coagultion (blood clots)

Front 45

Describe the pathogenicity of Enterobacteriaceae.

Back 45

--highly antigenic--meaning they have many mechanisms to be pathogenic
--Lipopolysaccharide membrane in which all the following cause immune response, a common antigen, O Polysaccharaide, Lipid A
--K and H antigens (capsule and flagella proteins)--the bacteria can change between K and H causing different body to reproduce antigens.