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216 Cards in this Set

  • Front
  • Back
Are infectious disease preventable?
Yes, through vaccination.
Where are most infectious diseases a problem?
They are a major cause of disability and death around the world but majorly in developing countries. Infectious Disease is the cause of 6/10 deaths.
Why is infectious disease a problem in developing countries?
Poverty, poor nutrition, lack of access to health care, lack of clean water, lack of sanitary sewers, overcrowding, etc.
Define Infection
Invasion or colonization of the body by a pathogen.
Define Disease:
Any change from a state of health.
Can you have an infection without yet having a disease?
Yes.
Define Acute Disease
Develops rapidly and lasts a short period of time. For example the common cold.
Define Chronic disease
Develops slowly and it is continual or recurrent. For example, Hepatitis C.
Define Latent Disease
Pathogen can remain inactive for long periods of time. For example, Herpes.
Define Communicable Disease:
Any Disease that spreads from one host to another host either directly or indirectly. For example, Flu.
Define Contagious Disease
Disease that is easily spread from host to host. For example, chicken pox.
Define Non-Communicable Disease
Disease that cannot be spread host to host. For example, heart disease.
Define Epidemiology
The study of where and when disease occurs.
Define Incidence:
The number of new cases of a disease in a given area/population during a given period of time.
Define Prevalence
Total number of cases of a disease in a given area/population during a given time period.
Existing + New = total
Define Endemic Disease:
Occurs at a relatively stable frequency in a given population/area.
Define Epidemic Disease:
Disease that occurs at a greater than normal rate in a given population/area.
Define Pandemic Disease:
Epidemic that occurs simultaneously on more than one continent.
Define Sporadic Disease:
Only a few cases occur.
Define Etiology
The study of which microbe is the cause. Koch's postulates are used to determine etiology.
Name Koch's postulates:
1. Suspected Pathogen must be present in every case of the disease.
2. Pathogen must be isolated and grown in a pure culture.
3. Pure culture must cause the identical disease when inoculated into a healthy host.
4. Re-isolate pathogen from experimental host and compare it to the pure culture, must be identical.
What is a sign?
Objective manifestation of disease. Can be measured and observed by others. Examples: rash, fever, vomiting, swelling, etc.
What are symptoms?
Subjective manifestation of disease. Cannot be measured, observation of patient. Examples: Dizzy, fatigue, nausea, headache.
Define Pathogenicity:
Ability of a microbe to cause disease.
Define Virulence:
Degree of pathogenicity.
what do virulence factors do? and what are examples of them?
Virulence factors increase the virulence of a pathogen. Examples: Extracellular Enzymes, Toxins(enterotoxin, exotoxin, endotoxin), Anti-Phagocytic Factors
Who produces Extracellular enzymes? And where are they excreted?
Extracellular enzymes are produced by some bacteria. They are excreted into the environment.
What is the role of coagulase?
Clot formation
What is the role of kinase?
Clot Busters
Role of hyaluronidase:
invade into deeper tissue
Role of Leukocidin:
Decreases phagocytosis.
What are toxins? Name two types.
Chemicals produced by some bacteria that harm tissues or trigger host immune responses. For example, a toxoid vaccine disables toxin in a tetanus shot. Three two types of toxins are Exotoxins and Endotoxins.
What are extoxins? Who produces them and where are they excreted?
Exotoxins are some gram (+) bacteria and some gram (-) bacteria. They are produced by some bacteria and excreted into the environment.
Where is the gene to produce toxins located?
It is located on a plasmid.
What does a Cytotoxin do?
Kills host cells and affects host cell function.
What does a Diphtheria cytotoxin do?
Decrease protein synthesis in human cells.
What does a Neurotoxin do?
Interferes with nerve function. Examples are Tetanus Toxin, and Botulism Toxin both cause paralysis.
What does Enterotoxin do?
Kills cells lining the G.I. tract.
What are Endotoxins?
LPS in Gram (-) outer membrane. LPS can cause fever, trigger inflammation, hemorrhage, clots, shock, death.
What do Anti-Phagocytic Factors do?
Decrease Phagocytosis. Have glycocalyx/slime layer/capsule. Some capsules, even if phagocytosis occurs, prevent fusion with lysosomes. example, Streptococcus pyogenes.
Define Symbiosis:
Two different organisms living together.
What are the three types of symbiosis?
Mutualism, Commensalism, Parasitism.
Define Mutualism:
Microbe and host benefit.
For example, G.I. tract, reproductive tract.
Define Commensalism:
One organism benefits, other organism is not harmed and does not benefit (neutral). Examples: S. aureus, S. epidermidis on skin.
Define Parasitism:
Microbe benefits and the host is harmed. For example, Giardia lamblia.
Define Reservoirs of Infectious Disease
Sites where pathogens are maintained as a source of infection.
What are the three types of Reservoirs?
Animal Reservoir, Human carriers, Non-living Reservoirs
Where is the disease in an animal reservoir?
In the animal itself, the tissue, and the waste.
What are human carriers?
Have no signs or symptoms but have pathogen and can transmit it.
What are examples of Non-living Reservoirs?
Water
Food
Soil
What are portals of entry used for?
The pathogen uses portals of entry to enter humans.
What are the portals of entry?
Skin
Mucous Membranes
Placenta
Parental Route
When does skin become a portal of entry?
When the skin is broken, because unbroken skin is an excellent barrier to pathogens. Make sure you wash cuts/abrasions to help prevent pathogens from entering.
What portal of entry is the most frequently used?
Respiratory Tract
What does the portal of entry Mucous Membranes include?
Respiratory tract, reproductive tract, conjunctiva, G.I. Tract, Urinary tract, etc. Mucous membrane lines all body cavities that are open to the exterior.
What happens during the parenteral route, portal of entry?
Pathogen is deposited directly into the tissue.
What are portals of exit?
Pathogens must be able to exit in order to infect others. Most pathogens exit the way that they entered. There are also secretions such as: Urine, Feces, saliva, breast milk, semen, respiratory droplets, etc.
Is it best for a pathogen to hang on once it enters a human?
Yes.
What do pathogens use to "hang on"?
Glycocalyx, slime layer, capsule.
Fimbrae
Helminths use suckers, hooks.
Virus' attach to receptors on host cells.
What is biofilm?
A web of bacteria and polysaccharides.
What are the five stages of Infectious Disease?
1. Incubative Period
2. Prodromal Period
3. Illness
4. Decline
5. Convalescence
Incubation Period
Infected until first signs and symptoms. Length of time in incubation depends on the virulence of microbe. It also depends on: Initial number of pathogens, overall health of patient, site of infection, and how quickly the pathogen divides.
Prodromal Period
Not all infection diseases have a prodromal period, there is a short time of generalized mild signs and symptoms.
Illness
When you have the most severe signs and symptoms.
Decline
The body begins to return to normal state, signs and symptoms decrease, immune system kicked in or medical treatment did.
Convalescence
Recovered from infectious disease, no signs and symptoms, repair any damage but some damage may be permanent.
Is an infectious disease infectious during every stage.
Yes, until full convalescence.
Define: Modes of transmission of Infectious Disease
The way a pathogen moves from a reservoir or portal of exit to a portal of entry in a new host.
What are the 3 modes of transmission?
Contact Transmission
Vehicle Transmission
Vector Transmission
What are the three types of contact transmission?
Direct Contact Transmission
Indirect Contact Transmission
Droplet Transmission
What happens during direct contact transmission?
Person to person body contact between the hosts. for example: touch, kiss, handshake, etc.
Many are STDS.
What happens during indirect contact transmission?
person to person via a fomite...for example: toy, toothbrush, kleenex, etc.
What is a fomite?
Inanimate object.
What happens during Droplet Transmission?
It's transmitted via respiratory droplets.
What is vehicle transmission?
Pathogen is spread via a vehicle.
What is a vehicle?
Air, water, food, body fluids, etc.
What are the four types of vehicle transmission?
Airborne Transmission
Waterborne Transmission
Foodborne Transmission
Body-Fluid transmission
Airborne Transmission
Pathogen has to be able to survive outside host, and be resistant to drying. Is spread by respiratory droplets.
Waterborne Transmission
Drinking water, streams, lakes.
Fecal-Oral.
Feces has the pathogen; fecal contaminated water, ingest. bad news bears.
Foodborne Transmission:
Poorly processed food.
Food held at incorrect Temp.
food poorly cooked
Food poorly thawed.
Body Fluid Transmission:
Blood, urine, saliva, semen, vaginal secretions.
What are the two types of vector transmission?
Biological Vector, and Mechanical Vector.
Biological Vector
verctor = animal or arthropod.
Serves as a host for multiplication of pathogen.
Biological Vector:
Serves as a host for multiplication of pathogen.
Mechanical Vector:
Passively carry pathogen to a new host.
Define Nosocomial Infections:
Infection acquired from a healthcare facilities. Sometimes its the patients normal flora.
Where do you get nosocomial infections from?
Catheters, invasive medical procedures, ventilators, surgery.
What are the most common sites of Nosocomial Infections?
Urinary Tract Infection
Surgical Site
Lungs
Blood Stream
Common Nosocomial Infection Organisms:
Staphylococcus aureus
E. coli
Pseudomonas aeruginosa
Clostridium dificile
What is a healthcare facility a reservoir for?
Potential Pathogens
Why is the transmission rate in hospitals so high on the patients part? and on the staffs part?
Because the patients are weak, and immunocompromised!
The housekeeping in healthcare facilities is bad. Proper aseptic technique such has handwashing decreases the transmission of nosocomial infections by 50%.
What are way to decrease transmission of nosocomial infections?
Disposables, sharps disposal, protective clothing, isolate patients, educate patients, use antibiotics appropriately, surveillance!
How many Workers in the U.S. are at risk of occupational exposure to to blood-borne pathogens?
about 5.6 million
What percent of needle sticks are not reported?
50% are not reported of the 600,000-800,000 needle sticks/year.
What is the transmission rate for the Hepatitis B virus? and is there treatment for it?
6-30% transmission rate for a single needle stick.
There is a vaccine for this. Also, immunoglobulin treatment is available and is 90% effective.
What is the transmission rate for the Hepatitis C virus? Is there treatment?
The transmission rate is 1.8% for a single needle stick. There is no vaccine or immunoglobulin treatment. There is Interferon treatment (most people would rather die).
What is the transmission rate for the HIV virus? Is there treatment?
The transmission rate for a single needle stick is .3% there is no vaccine but there is HAART therapy.
Define Immunity:
The body's ability to resist infectious disease through non specific and specific defenses.
Define Non Specific Immunity:
AKA innate immunity. An inborn set of preexisting defenses against infectious disease. It is present at birth, is relatively non-specific, it provides immunity against a wide variety of pathogens. Provides instant protection against a pathogen.
What is involved in the first line of defense?
Skin and Mucous Membranes
When is skin a portal of entry?
When it is broken.
What is an excellent barrier against pathogens?
Unbroken skin.
What is the role of thick epidermis?
Thick layer that acts as a physical barrier.
What is the role of collagen and elastin fibers?
To give your skin strength and pliability.
What is the role of dendritic cells?
Cause Phagocytosis
What is the role of sweat?
Sweat is high in sold therefore it kills and inhibits most microbes.
What do antimicrobial peptides do? and who are they produced by?
AKA dermicidins.
They are produced by our sweat glands.
Kill gram (+) and gram (-) bacteria.
Action: Unknown
What is the role of Lyzozyme in sweat?
Destroys peptidoglycan.
What is the role of normal flora on the skin?
They are acquired in the first few months of life, and they compete out pathogens.
How do you get normal flora?
Birth, breathing, eating, handling...
When do pathogens become pathogenic?
When they have the opportunity, they are opportunists. Opportunities come up: immunosupressions, change in normal flora, change in the usual site of bactera.
What is sebum?
Sebum is an oily substance that decreases the pH of skin, which causes some microbes to be unable to grow. It also increases the skin's softness so it is less likely to tear or be damaged.
Where is Sebum produced?
In sebaceous glands.
What are some of the body cavities open to the exterior that are lined with mucous membranes?
Respiratory, G.I., urinary, reproductive, conjunctiva, etc.
Why is the respiratory tract the most frequent portal of entry?
The respiratory tract is thinner than skin, the cells are tightly bound together. Cells are continuously shed.
What does mucus do?
It traps pathogens.
What does cillia do?
It propels mucous and pathogens. For example coughing and sneezing to rid yourself of mucous with pathogens in it.
What does lyzozyme do?
Destroys peptidoglycan.
Mucus contains antibodies.
What is blood made of?
It's made of plasma and formed elements.
What is plasma?
The liquid portion of blood.
What are formed elements?
Blood cells or fragments of cells.
Where are blood cells produced?
In bone marrow.
What is the technical name for Red Blood Cells? and what does it carry?
Erythrocyes; carries oxygen and carbon dioxide.
What are platelets and what do they do?
They are cell fragments. They are responsible for clotting.
What is the technical name for white blood cells and what are they responsible for?
Leukocytes; immunity.
What are the 6 types of Leukocytes?
Basophils
Eosinophils
Neutrophils
Monocytes
Lymphocytes
Dendritic Cells
Basophils:
Inflammation/Allergy
Eosinophils:
Phagocytosis and Helminths
Neutrophils:
Phagocytosis
Monocytes:
AKA Macrophages
Phagocytosis
Lymphocytes
T & B cells.
Dendritic Cells:
Phagocytosis; they are scattered but concentrated in skin/mucus membranes.
What are the second lines of defense?
Phagocytosis
Extracellular Killing
Complement
Interferons
Inflammation
Fever
What is Phagocytosis?
Cellular eating.
What is a phagocyte?
phagocytic leukocyte (WBC)
What are the two most important phagocytes?
Neutrophils and Macrophages
What is the role of the phagocyte?
To clean up harmful pathogens/substances.
What are the steps in phagocytosis?
1. Chemotaxis: attract phagocytes to the site where they are needed.
2. Adherence: Phagocyte attaches to pathogen/substance/ foreign materials. Capsules decrease adherence. Antibody bound to material and complement bound to material increases adherence.
3. Ingestion: Use of pseudopodia to surround material and bring it into phagocyte.
4. Killing: Material is fused with lysosome and enzymes inside lysosome degrade/ break down material.
5. Elimination: remnants of material exit phagocyte via exocytosis.
What happens during Extracellular Killing?
Eosinophils attach to surface of helminths, weaken/kill helminth using an extracellular toxin. Natural Killer Cells secrete extracellular toxins. Ex: Viral infected cells, tumor cells, etc.
What is the Complement (C') ?
25 different proteins found in the blood. They assist or complement in destruction of pathogenic bacteria. They circulate the blood in inactive form. When one protein in C' is activated, all others are activated.
What are the two ways to activate C'?
Classical Pathway: Antibody bound to Antigen.

Alternative Pathway: Pathogen or Exotoxin.
What happens once C' is activated?
Cell Lysis
Call other immune cells to the area
Increase Phagocytosis
Increase inflammation
What are interferons?
Anti-viral proteins produced by some animal cells after they are infected with a virus.
What do interferons do?
They help neighboring cells, they interfere with viral replication, work against any virus. Signs and symptoms: malaise, muscle aches, chills, headache, fever. Used to treat things like: Hepatitis C, B, Herpes and HPV.
What are some triggers of inflammation?
Heat
Chemicals
U.V. Light
Abrasions, cuts
Trauma
What is the purpose of inflammation?
To localize a pathogen adn hopefully reduce the spread of the pathogen. It can help neutralize the toxin and aid in the repair of damaged tissues.
What are the signs and symptoms of inflammation?
redness: blood accumulating in the area.
Pain: comes from local damage to tissue and nerves.
Swelling: Fluid accumulating
Heat: lots of blood means lots of body heat.
What are the steps of inflammation?
-Inflammation is triggered.
-Damaged cells in area release prostglandins, leukotrines, and histamine.
-Prostaglandins and leukotrines increase the permeability of blood vessels in the area; increase vasodilation; increase blood flow to area.
-Histamine helps in vasodilation
-Increase in blood flow brings clotting factor, immune cells=swelling.
-Blood clot forms if needed.
-Phagocytes arrive= phagocytosis if needed.
-Pus may form=plasma/dead cells/dead tissue, leukocytes and microbes.
-Tissue repair if it is needed. Regeneration/Fibrosis.
What are some examples of anti-inflammatory meds?
Anti-histamines
Anti-Prostaglandins (asprin, ibeuprofin, etc.)
What is a fever?
Its a body temperature greater than 100 degrees F. It is a systemic response and the hypothalamus in the brain sets the temperature.
What is the purpose of a fever?
To slow the rate, or growth/kill pathogen.
When can a fever be an issue?
When it is prolonged at a very high temperature.
What are the Signs of a fever?
Increase in heart rate; Increase in Respiratory rate; Increase in pulse; increase in metabolic rate/caloric demand.
What are the symptoms of a fever?
Malaise, body aches, dehydration, convulsions, hallucination, chills, coma, death.
What are some of the pyrogens that cause the hypothalamus to increase body temperature?
Bacterial Toxins
Bacteria
Viruses
Fungi
Helminths
Protozoa
Antigen/Antibody complexes.
What does a fever do?
Increases the effect of interferons
Inhibits/kills microbes
Increase in phagocytosis
Increase in Tissue repair
Increase in everything in specific immunity.
Define Specific Immunity:
the ability to recognize and defend against pathogens. AKA acquired Immunity.
When does Specific Immunity develop?
In response to a pathogen, it takes time. However, once established future response to the same pathogen is very quick.
How do you acquire specific immunity naturally and artificially?
Naturally= Infection
Artificially= Vaccination
What is our hope that non specific immunity does?
We hope that non specific immunity and its 1st and 2nd lines of defense eliminate the pathogen or at least limit the spread/reproduction of the pathogen until specific immunity can help.
What is an antigen?
A foreign substance that triggers a specific immune response.
-Bacteria, bacterial component, virus, parasite, etc.
-Your immune system can respond to millions of different antigens.
What is an epitiope?
A small part of an antigen that stimulates a specific immune response. A vaccine contains epitiopes.
What is an antibody?
AKA immunoglobulins (Ig)
It is a protein that binds to a specific antigen and tags the antigen for destruction by immune system.
What does the Lymphatic System include and what is it directly involved in?
Includes lymphatic vessels, lymph nodes, lymphatic organs/tissues. It is directly involved in specific immunity, it screens for antigens.
What are lymphatic vessels?
A one way system back to the heart. It returns leaked fluid (lymph) to circulatory system.
What are Lymph nodes?
They are cluster at portals of entries, there are hundreds located throughout the body. They receive lymph from lymphatic vessels. The cells that are in the lymph node screen lymph for antigens, if they find an antigen, specific immune response is triggered.
What are the Lymphoid organs and tissues?
Spleen filters blood and removes pathogens.
Tonsils, peyer's pathches, appendix, MALT (mucosa associated lymphatic tissue)...traps pathogens.
What is Humoral Immunity?
B cells (B lymphocytes) and antibodies. Deals with exogenous pathogens (outside your cells/loose pathogens)
Where do B cells arise from? and where are they produced/ where do they travel to?
Stem cells in bone marrow; produced in the bone marrow, travel to lymph nodes/ lymphoid organs/tissues.
Each B cell has about 100,000 what?
Copies of a very unique receptor on its surface.
What does the receptor on the B cell do?
It allows the B cell to recognize and bind to one specific antigen (epitope).
What is the main function of B cells?
Antibody production.
Explain Colonal Selection of B Cells:
*Short answer question
-Before exposure to an antigen, you have just a couple of B cells with a receptor that can recognize and bind to that specific antigen.
-Antigen selects an existing B Cell.
-Some B cells are never selected because their antigen never arrives.
-Antigen Selects B cell, it binds to the receptor on the B cell.
-Antigen binding to the B cell receptor stimulates B cell to divide by mitosis and produce lots of identical B cell clones.
-Now there are hundreds of B cells that can recognize and bind that antigen.
- Swollen Lymph nodes= B Cell clonal selection.
What happens to B cell clones?
-Some of them become B memory cells.
-don't secrete antibodies.
-long-lived
-stay behind in case the same antigen is encountered again. If it is, B memory cells quickly divide to produce more B memory cells and plasma cells.
What are some ways to produce B memory cells against antigen?
By getting an infection or a vaccination.
What do B cells do when they become plasma cells?
secrete antibodies against the antigen, antibodies circulate in blood, lymph, body fluids, etc.
Antibodies will recognize and bind to the antigen.
What are Antibodies?
AKA immunoglobulins (Ig)
Proteins, Y-shaped.
2 antigen binding sites that are very specific, recognize and bind to only one antigen.
What happens when an antibody binds to its antigen?
-Prevents viral attachment to host cell.
-Neutralizes bacterial toxins
-Prevents bacterial attachment to cells/surfaces.
-Binding (agglutination) of pathogens togethers to restrict its movement.
-Increases phagocytosis by providing a "Neon eat me sign"
What are the five classes of antibodies?
IgM
IgA
IgD
IgG
IgE
IgM
1st antibody produced in response to the antigen.
-Short lived
-Early in the infection
-5-10% of circulating antibodies
IgA
Respiratory and G.I tracts, clostrium, breast milk,etc.
-tries to block attachment of pathogen to mucossal surface.
-10-15% of circulating antibodies
- Important in resistance to G.I. Infections in infants.
IgD
Acts as an antigen receptor on B cells.
0.2% of circulating antibodies.
IgG
Principle Antibody
-produced 24-48 hrs after antigen triggers a specific immune response.
-80% of circulating antibodies
-Main antibody in primary and secondary immune responses.
-Crosses Placenta and protects fetus
-Leaves circulation and enters tissue to recognizable and bind to its antigen.
-Ex: Booster shot in vaccine=increase of IgG against antigen.
IgE
Allergic Response
Lysis of Helminths

.1% of circulating antibodies.
Primary Response to antibody:
1st time your immune system recognizes and responds to that antigen.
-lag(time) before antibodies are produced.
-IgM, IgG
-Memory cells stay behind.
Secondary Response to antibody:
2nd and any additional times you encounter the same antigen.
-because of memory cells, response is very rapid.
-produce IgM and IgG quickly.
-Leave memory cells behind, usually IgG.
Call-Mediated Immunity:
T-Cells( T-lymphocytes)
If pathogen goes inside our cell, humoral immunity is not very helpful.
Cell mediated immunity is used to eliminated infected cells, abnormal cells and cancer cells.
What are T-Cells, where are they produced, etc.?
Formed from stem cells in bone marrow; travel to thymus, in the thymus T-Cells mature using thymic education(learned what is self and what is not) After t-Cells leave thymus, they use the blood/lymph to circulate; migrate to lymph nodes/tonsils/peyer's patches, etc.
-A T-Cell has about 100,000 copies of a unique receptor on its surface. T-Cell receptor has an antigen binding site on it that is very specific.
What are the two types of T-Cells?
Cytotoxic T-Cells
Helper T-Cells
Cytotoxic T-Cells:
-Have T-Cell receptor and CD-8 coreceptor on surface.
- Recognize and eliminate infected/abnormal/cancer cells.
-Kill.
Helper T-Cells:
-Have T-Cell receptor and CD-4 coreceptor on surface.
-Helps in humoral immunity and cytotoxic T-Cells.
Major Histocompatability Complex:
AKA MHC
Proteins embedded in membrane of your cells. May genes are involved in the production of MHC; every person's MHC is unique.
What are the two types of MHC?
Class I MHC
Class II MHC
Where is Class II MHC found? What does it do?
-Found on the surface of B cells, macrophages, neutrophils, dendritic cells.
-Macrophages, neutrophils, dendric cells and B cells are antigen presenting cells (APC's)
-MHC II folds and forms a pocket/groove that an antigen (epitope) can bind to.
-APCs present Antigen to CD4 T-Cells.
Where is Class I MHC found? What does it do?
-Found on the surface of all nucleated cells.
APCs have MHC II and MHC I
- MHC-I folds and forms a pocket that an antigen (epitope) can bind to.
How does an Inactive Helper T-Cell become an Active Helper T-Cell?
*Short answer/detailed!
-Antigen enters via a portal of entry.
-At the portal of entry or in lymphatic system, the antigen is phagocytized by a phagocyte.
(If the phagocyte phagocytises the antigen at the portal of entry, it then enters the lymphatic system)
- Inside the phagocyte, the antigen is sent to the lysosome and inside the lysosome the antigen is broken down by enzymes into epitopes.
-Epitopes are displayed on the surface of the phagocyte along with MHC-II.
-The phagocyte with the epitope nad MHC-II displayed on its surfaces mixes and mingles with inactive T-Helper cells in lymph nodes/ lymphoid tissue.
-Phagocyte must locate the correct inactive T-helper Cell. Once the match is made:
-Phagocyte secretes cytokines (cytokines aka lymphokines are intercellular chemical isgnals)
-Cytokines activate this Helper T-Cell and stimulate that T-Cell to divide by mitosis and produce clones.
-Some of the T-Cell clones become active Th1 or Th2 cells.
-Active Th2 cells produce cytokines that stimulate antibody production by B cells (
Define Mycology:
The study of fungi.
Are fungi eukaryotes or prokaryotes?
Eukaryotes.
Are fungal species pathogenic.
About 30% are.
What are some disease that fungi can cause in plants?
Dutch Elm Disease, Rye Smut...
What disease do fungi cause in humans?
Athlete's foot, yeast infections, etc.
In microbiology what does fungi include?
Yeasts and Mold.
Compared to bacteria fungi are...
Larger, grow slower, and frow at a lower temperature.
What is the role of fungi?
Decomposers/Recyclers.
What does fungi produce?
Enzymes (ex beano), Medications (penicillins, ampicillin, etc.)
Describe Yeast:
Unicellular, non-filamentous. Microscopically oval shaped. Macroscopically moist, white, and creamy.
How does yeast reproduce?
Asexually by budding.
Describe mold:
Multi-Cellular and filamentous.
Another word for filaments...
Hyphae.
Define Mycelium:
A mass of intertwined hyphae.
How does mold reproduce?
Assexually via spores which can be inhaled by humans as a means of disease transmission.
Are human fungal pathogens opportunists?
Yes....they use opportunities such as Invasive medical surgery, medical therapy, pre-existing conditions, and life style factors.
What is available for fungal infections?
Drug therapy.
What are the three classes of drugs typically used to treat fungal infections:
Polyenes, azoles, and echinocandins.
What do polyenes do?
Drugs that work by attaching to the sterol component found in the fungal membrane, causing the cells to become porous and die. Two commonly used: nystatin( topical infections or taken orally) and amphotericin B (used to treat severe systemic fungal infections).
What do azoles do?
They stop fungal growth by preventing fungi from making an essential part of their cell wall. Three typical azoles are: Ketoconazole, fluconazole and itraconazole.
What are Echinocandins:
A class of antifunal drugs that work by disrupting the wall that surrounds fungal cells. Caspofungin and Micafungin are effective treatments for severe systemic fungal infection.