Microbiology Exam 3 Flashcards
Botulism
Etiology: Clostridium botulinum, Gram positive, bacillus, motile, endospores, obligate anaerobe
Reservoir: SOIL
Transmission: wound, food borne, infant
-Not an infection, technically and intoxication except for infant botulism where the vegetative cells cause the problem.
-Typical home canned vegetables
Signs and Symptoms: weakness, face drooping, fatigue, paralysis- muscle paralysis
Treatment and Prevention:
-antitoxins: antibodies for toxins
-antibiotics for vegetative cells
Cholera
Etiology: bacterial disease: Vibrio cholerae, flagella,
Reservoir: Humans
Transmission: indirect, fecal-oral
Signs and Symptoms: Very similar to travelers diarrhea, watery diarrhea. “rice water stools”, vomiting, rapid heart rate,
Treatment and Prevention: Replacing fluids/hydration-oral rehydration solution
Prevention- proper sanitation and vaccine
Hepatitis B
Etiology: Hepatitis B virus
Reservoir: Humans
Transmission: Sharing infected bodily fluids
Signs and Symptoms: Abdominal pain, dark urine, loss of appetite, jaundice, failure of liver
Treatment and Prevention: No treatment, hepatitis B vaccine
Herpes
Etiology: Virus Herpes simplex viruses HSV-1 and HSV-2
Reservoir: Humans
Transmission: HSV-1: contact with the saliva of carriers
-HSV-2: through sexual contact
Signs and Symptoms: Many may never develop symptoms, watery blisters, cold sore, lesions and sores on genitals
Treatment and Prevention: No treatment, antivirals lessen severity of flare ups
Lyme Disease
Etiology: Borrelia burgdorferi, spirochete, motile, anaerobic
Reservoir: white footed mouse, ticks
Transmission: through vectors, aka ticks
Signs and Symptoms: fever, chills, swollen lymph nodes, rashes, joint pAIN, SWELLING, facial palsy
Treatment and Prevention: antibiotics, insect repellant
Necrotizing fasciitis
Etiology: Streptococcus pyogene, gram positive, motile
Reservoir: Humans
Transmission: cut, wound, or insect bite, poor immunity
Signs and Symptoms: red, swelling, violet blisters, peeling, flakiness, pain, diarrhea, dehydration, toxic shock
Treatment and Prevention: surgery, antibiotics
Rabies
Etiology: Rabies virus
Reservoir: Raccoons, bats, skunks, foxes, coyotes
Transmission: Saliva of infected animal
Signs and Symptoms: fever, cerebral dysfunction, delirium, agitation, anxiety, confusion, abnormal behavior
Treatment and Prevention: Human rabies immune globulin and vaccines for bites
Syphilis
Etiology: Treponema pallidum, spirochete, gram negative, motile
Reservoir: Human
Transmission: sexual contact
Signs and Symptoms: can be infected for years without knowing, lymph nodes begin to swell, four stages:primary, secondary, latent, tertiary. rashes, headache, fatigue, neurological problems,
Treatment and Prevention: law of chastity, antibiotics
Typhoid Fever
Etiology: Salmonella typhi, gram negative, bacillus, motile, aerobic, flagella
Reservoir: Humans
Transmission: fecal-oral
Signs and Symptoms: constant high fever, spotty rash, stomach pain, flu symptoms
Treatment and Prevention: fluids, vaccination, antibiotics
Zika Virus
Etiology: Zika virus
Reservoir: mosquitos
Transmission: bite of mosquito, mother to fetus, sexual contact
Signs and Symptoms: fever, rash, red eyes, aches and pains
Treatment and Prevention: rest, fluids, tylenol, insect repellant, safe sex
First wall
skin, mucosal membranes, secretions: lactic acid, fatty acid
Second wall
non-specific internal defenses
Third layer
antigen specific immune responses
If you feel sick that means that the pathogen has made it to what wall?
the third
Examples of first wall
- tears
- lysozyme
- stomach acid
- normal flora
Examples of second wall
- Neutrophils, basophils, and macrophages; cell eating organisms
- natural killer cells
- inflammation
- fever
- interferons
- Always present and ready to go, non-specific
Interferons
interfere with viral replication
Examples of third wall
- Activated b-cells
- activated t-cells
- –cytotoxic t-cell
- –helper t-cell
- must be exposed to be activated
CD8 cells
cytotoxic t-cells
CD4 cells
helper t-cells
MHC class 1
found on ALL nucleated cells
MHC class 2
found on antigen-presenting cells (APC’s)
Chemotaxis
chemical detection of a phagocyte that leads them out of the blood vessel to the infection
-attachment proteins are produced, phagocytes start sticking, then they find a gap.
Diapedesis
white blood cells squeeze through blood vessel walls.
Obstenin
anything that enhances phagocytosis, compliment proteins. Coating antigen with antibody enhances phagocytosis with macrophages
Is the third wall adaptive or innate?
adaptive
Specificity
b-cells and t-cells are activated by ANTIGENS
Memory
activated cells have a better response to Ag that have entered the body 2 or more times.
What are two elements of the third wall?
specificity and memory
Antigens
foreign substances (proteins, carbohydrates, etc)
epitopes
subcategory of an antigen, recognizes specific antigen
B-cells produce what?
antibodies, only effective against EXTRACELLULAR ANTIGENS = B-CELLS
Cytotoxic t-cells do what?
attack and destroy infected cells and cancer, only effective against INTRACELLULAR ANTIGENS = CYTOTOXIC T-CELLS
Humoral
antibody mediated immunity- extracellular
Cellular
cell mediated immunity- intracellular
Helper t-cells do what?
Help activate b-cells and cytotoxic (CD8) t-cells
What cells undergo screening?
All t-cells, don’t want to recognize self
Specific immunity process- activation of helper t-cells
- macrophages, dendritic cells and other APC’s carry out phagocytosis.
- they process and present the Ag on MHC class 2
- Helper t-cells then come in contact with the APC’s to become activated
- Helper t-cells can then “help” b-cells and cytotoxic t-cells become activated
What does it mean for a specific immune cell to be “naive”
the cells have not been activated yet
What is released by CD4 cells when a match is found?
cytokines
What is critical for MHC class 2?
phagocytosis, takes piece of antigen and displays it on exterior
Cytotoxic t-cell activation
-dendritic cells present Ag on MHC class 1 for CD8 cells
-helper t-cells required for activation: tells the cell “yes, you’ve got one”
-Once the cell is activated it goes on patrol to each cell
(hand grenade analogy)
normal cells present self protein on what class of of histo compatible complex?
MHC class 1
If a cell is infected with a virus, how the the cell tell the outside world?
By displaying a fragment of the virus on the MHC class 1 which a CD8 cell will come along and recognize then cause cell lysis
Protein Ag vs Carbohydrate Ag
carbohydrate antigens are not found on human cells. They are on bacterial capsules,
-Most of the time antibodies target PROTEINS rather than carbohydrates.
T- independent
carbohydrate, does not need help from helper t-cells, starts replicating and producing antibodies immediately
T-dependent
proteins, most common, b-cell binds to antigen, engulfs it, presents antigen on MHC class 2 and then helper t-cell comes and confirms that it is an antigen
Antibodies
y shaped proteins that bind
Neutralization
blocks adhesion of bacteria and viruses to mucosa
- blocks active site of toxin
- toxin like snake venom and tetanus toxin
Classes of Ab (antibodies, immunoglobulins)
IgD, IgM, IgG, IgA, IgE
IgD
Ag receptor, membrane receptor
IgM
pentameter, half life five days
IgG
highest numbers in blood, half life 23 days, crosses placenta
IgA
dimer, half life 6 days, secretions
IgE
half life three days, enhances inflammation, binds to mast cells and basophils
-excessive IgE equates to allergies
Immunizations
a vaccine is made from ANTIGENS to promote the immune response for down the road
Hypersensitivity
immune reaction that occurs in an exaggerated or inappropriate fashion
-allergies
Allergies
an exaggerated immune response to a harmless substance
-excessive inflammation
Hay fever
immune response to plant pollen, memory b-cells that have mad that class switch remember that
IgE binding
can bind to mast cells and basophils and act as an ag- receptor
Mast cells and basophils job
produce inflammation, results in a release of histamine and other chemicals
Histamine
trigger inflammation and allergy symptoms
Asthma
same process as allergies but the histamine and inflammatory chemicals is released in the lungs and cause the smooth muscle to contract.
Desensitization
method to cure allergies, exposing body to antigen via vaccine shot -b-cells will start making the correct class Ag and then the IgA antibody will bind to the antigen
Shock
low blood pressure, body-wide blood vessel dilation
Transplant rejection
Foreign proteins cause immune response, MHC class 1 itself is the antigen that causes the problems -cytotoxic t-cells attack these cells just like they would a tumor or virus infected cell
Autoimmunity
immune system reacting against normal body protein
-Helper b-cells
HIV vs AIDS
Human immuno virus causes the acquired immunodeficiency syndrome
HIV
infects helper t-cells and CD4, degradation of CD4 cells means that people die from common things
Blood typing
A, B, AB, O glycoproteins on outside of red blood cells
Rh-factor
if it has the Rh-protein then the blood type is positive, if it does not, its negative
How do leukocytes recognize pathogens?
Manos recognition
Simplified process of help t-cell activation
APC (macrophage) engulfs pathogen and presents it, CD4 binds to MHC class 2 presenting antigen. The helper says hey i’ve got one, the macrophage says sure enough and then releases cytokines to activate helper t-cells
Can b-cells release cytokines?
no, only macrophages (other APC’s) can release cytokines
Benefit of compliment and antibodies?
huge enhancement for phagocytosis
Complement elements
- enhancement
- increase inflammation
- killing
Hematopoiesis
cells in the bone marrow can turn into any of the leukocytes
