VBS 2032: EXAM 3

In what ways do the complement pathways and humoral immunity interact?

- Both use Opsonization - Humoral immunity antibodies can lead to complement system activation - This is the classic pathway.

Draw the structure of IgG. What part recognizes the epitope? What part interacts with phagocytic cells? What are the parts called?

- Fab region contains both light chain and heavy chain the distal end contains the variable region. - Variable is what binds to unique epitopes. - The Fc portion binds to phagocytic cells

What kind(s) of antigens can stimulate T-independent B cell activation? Why might these antigens be inferior in producing a host protective response?

- Long polysaccharides *They have many subunits and binds to many B cell receptors - Polysaccharides don't produce host protective response because if T cell are not involved they can only make 1 antibody --> IgM antibodies *IgM antibodies do not get the same kind of immunolgical memories. (do not stick around long) - T cell independent B cell activation does not work as well in young children.

How does the lateral flow antibody test work? What factors could lead to a false negative?

- Strip that has a sample pad/ blood separator, conjugate release, test line, control line, nitrocellulose membrane, and absorption pad. Steps: 1. Sample loading: add drop of blood or serum in sample well 2. Buffer loading: add dilution phosphate saline buffer to sample well 3. Sample incubation: Capillary action moves sample across lateral flow test 4. Antibody-antigen recognition: Antibodies with specificity for COVID-19 bind to gold COVID-19 antigen, conjugates in conjugate pad 5. COVID-19 antibody detection: Sample enters testing well and COVID-19 antibody-antigen complex binds to immobilized anti-human IgG/IgM antibodies. 6. Control antibody detection: Rabbit antibody-gold conjugate binds to immobilized anti-rabbit IgG antibodies 7. Interpreting Results: Positive: 1 strip (line) each in C well and T well Negative: 1 strip (line) in C well False negative: sample degration or contamination can affect the results

How do TH cells participate in B cell activation? Why might a second signal act as a safety mechanism to protect the host?

- T-helper cells recognizes peptide fragments presented on MHC II molecules of B-cells and produce cytokines in response - 2nd signal needed for B cells to differentiate into plasma cells and B-memory cells *2nd signal acts as a safety mechanism to make sure the right cell is being degraded.

What cells participate in the process of antibody production? Where are they located?

- The bone marrow has stem cells to produce antibodies and other blood cells EX: T and B cells *Plasma cells and memory B cells produce antibodies in different situations. - Common lymphoid progenitor

- Why can't immunocompromised individuals receive an attenuated vaccine? - Can pregnant women receive an attenuated vaccine?

- Their immune systems are not strong enough to fight off a live or whole virus - No, their babies haven't developed a strong enough immune system to kill live viruses yet

1. How can Clostridium sp. persist in the environment? What growth requirements does it have? 2. What type of vaccine would be most effective against tetanus or botulism: toxoid or whole killed? Why?

1. - Clostridium has endospores that germinate and produce toxin at the site of infection - Toxin spreads along the nerves and can cause death - Endospores are extremely stable, and germinate under anaerobic conditions 2. Toxoid vaccine, because the toxin is responsible for severe disease

Compare and contrast active versus passive immunity.

Active: person's OWN body produce antibodies in response to presence of pathogen - life/many years 1. catching the disease a 1st time 2. vaccinations (of weak/dead pathogen) Passive: antibodies are GIVEN rather than produced by person's own body - immediate protection that only lasts up to a few months 1. from mother in pregnancy and breast-feeding 2. injections (containing antibodies from another person)

Define: - Acute Infection - Chronic Infection - Colonization - Endotoxin - Exotoxin - Immunocompromised - Infection - Infectious Disease - Latent Infection - Microbiome - Normal Microbiota - Opportunistic Pathogen - Primary Pathogen - Virulence Factors

Acute Infection: An infection characterized by symptoms that develop fairly quickly and last a relative short time Chronic Infection: An infection that generally develops slowly and lasts for months or years Colonization: Establishment and growth of a microorganism on a surface Endotoxin: The lipopolysaccharide (LPS) component of the outer membrane of Gram (-) bacteria - Lipid A is responsible for the toxic properties of LPS Exotoxin: A toxic protein produced by a microorganism - Often simply referred to as a toxin Immunocompromised: Having a weakness or decfect in the innate or adaptive defenses Infection: Colonization by a pathogen on or within the body Infectious Disease: An infection that prevents the body from functioning normally Latent Infection: Infection in which the infectious agent is present but not causing symptoms Microbiome: The total genetic information of a community of microorgansims in a given environmennt - Also the community itself Normal Microbiota: The group of microorganisms that routinely colonize the body of a healthy individual Opportunistic Pathogen: A microbe that causes disease only when introduced into an unusual location or into an immunocompromised host Primary Pathogen: A microbe able to cause disease in an otherwise healthy individual Virulence Factors: Traits of a microbe that promote pathogenicity

Conjugate vaccines like HiB work better than simple capsular polysaccharide vaccines because: A. T-dependent B cell activation takes place B. T-independent B cell activation takes place C. TC activation occurs D. complement system is involved

A. T-dependent B cell activation takes place *HiB vaccine involve T-dependent B cell activation takes place. This leads to prolonged activation of B-cell that produce antibodies or secrete antibodies for longer time

Define: - Antigen - Adaptive immune system - Antibodies - Enzyme-linked immunosorbent assay (ELISA) - Primary antibodies - Secondary antibodies - Specificity - Conjugated

Antigen: something your body perceives as foreign EX: bacteria, viruses or fungi Adaptive immune system: When you are exposed to an antigen, your body responds first with components of the innate immune system and begins to make antibodies and flags them for destruction by other cells of the immune system. Antibodies: proteins that recognize and bind to specific antigens - Contains 2 light and 2 heavy chains each with a constant and variable region Enzyme-linked immunosorbent assay (ELISA): uses antibodies to detect the presence of a disease agent (for example, viruses, bacteria, or parasites) in your blood or other body fluid. *Can use antibodies to detect the presence of antibodies Primary antibodies: In an immunoassay, the antibodies used to recognize antigens like disease agents Secondary antibodies: recognize primary antibodies and can be used in many different tests. An enzyme is conjugated or covalently linked to the heavy chain. Specificity: binding to a specific antigen of interest Conjugated:

Define: - Arbovirus - Blood-Brain Barrier - Central Nervous System - Cerebrospinal Fluid - Encephalitis - Meninges - Meningitis - Peripheral Nervous System - Transmissible Spongiform Encephalopathy

Arbovirus: Arthropod-borne RNA virus, carried by vectors such as mosquitoes Blood-Brain Barrier: Cells that work together to restrict exchange between the bloodstream and the brain Central Nervous System (CNS): Brain and Spinal cord Cerebrospinal Fluid (CSF): Fluid produced in the brain that flows within and around the CNS Encephalitis: Inflammation of the brain Meninges: Membranes covering the brain and spinal cord Meningitis: Inflammation of the meninges Peripheral Nervous System (PNS): Division of the nervous system that carries information to and from the CNS Transmissible Spongiform Encephalopathy (TSE): Chronic degenerative brain disease caused by prions - Characterized by spongy appearance of brain tissue

_________is the disease and ________ is the virus that causes the disease. A. SARS-CoV-2, COVID-19 B. COVID-19, SARS-CoV-2

B. COVID-19, SARS-CoV-2

The three pathogens that cause meningitis, H. influenza, N. Menigitidis, S. pneumoniae, have which of the following characteristics in common? A. Gram reaction B. Capsule formation C. Motility D. Intracellular growth E. Complement degradation

B. Capsule formation

The most common granulocyte in the blood is: A. lymphocyte B. neutrophil C. leukocyte D. RBC

B. neutrophil *This multi-lobed cell is also called a polymorphonuclear leukocyte (PMN)

Apoptosis is: A. infection by a virus B. programmed cell death C. cell lysis by a virus D. cancer cell development

B. programmed cell death

Microbial succession describes the process in which A. microbes succeed in fermenting a particular product B. the balance of microbes present changes over time C. microbial byproducts accumulate D. genes are exchanged via horizontal transmission

B. the balance of microbes present changes over time *This is what happens in most microbial communities as microbial byproducts accumulate and change the environment.

This type of vaccine is produced from an inactivated toxin: A. subunit B. toxoid C. attenuated D. whole killed E. DNA

B. toxoid

Define: - Bioinformatics - National Institute for Biotechnology Information (NCBI)

Bioinformatics: refers to the field of science in which biology, computer science, and information technology merge to form a single discipline. * "computational biology" National Institute for Biotechnology Information (NCBI): a portal to an enormous amount of biological data, including nucleic acid and protein sequences 2 databases of sequence information: 1. GenBank is a comprehensive database. - It contains all the nucleic acid and protein sequences that have ever been uploaded to it. 2. RefSeq is a curated database. - It attempts to contain just one sequence for a given nucleic acid or protein from a single species.

- What types of molecules does the blood brain barrier (BBB) allow to pass into the brain? - What is blocked? - How does this protect the brain, but also leave it potentially vulnerable?

Blood-brain barrier: capillaries allow nutrients to pass - Allow: Oxygen and CO2, Glucose, nutrients - Blocked: cells, antibodies, and some antibiotics - It protects the brain from microbes, but there is a potential that there still may be some

The specificity of a PCR reaction is determined by: A. the nucleotides B. the temperature of the reaction C. the sequence of the DNA primers D. reverse transcriptase

C. the sequence of the DNA primers *These determine which DNA sequences will be amplified. Different pairs of primers are used to test for the presence of each pathogen. Different pairs of primers can be designed that amplify distinct regions of the same genome.

Coliforms are: A. Gram-positive stapylococci that can ferment mannitol B. Gram-positive rods that can ferment lactose C. Gram-negative rods that do not ferment lactose D. Gram-negative rods that can ferment lactose

D. Gram-negative rods that can ferment lactose *Another important point is that coliforms produce gas during lactose fermentation at 35-37oC.

A fly transmitted fecal coliforms to an uncovered dish at a picnic. This is an example of what type of transmission: A. Direct B. Airborne C. Biological vector D. Mechanical vector

D. Mechanical vector (Fly just carries the pathogen)

Bacterial meningitis could develop from: A. otitis media B. pneumonia C. sinusitis D. all of the above E. None of the above are correct

D. all of the above

RhoGam would be given when A. an Rh+ mother is pregnant with an Rh- child B. an Rh+ mother is pregnant with an Rh+ child C. an Rh- mother is pregnant with an Rh- child D. an Rh- mother is pregnant with an Rh+ child

D. an Rh- mother is pregnant with an Rh+ child * RhoGam may also be given shortly after birth. The objective is to block the baby's Rh antigen so that the mother's immune system does not "see" it. Doing this protects a potential second Rh- baby from maternal IgG antibodies that could cross the placenta.

A new virus infects and destroys CD8 (Tc) cells. What consequences might this have for infected patients? A. low antibody levels B. low macrophage activation C. low complement activation D. higher cancer risk

D. higher cancer risk MHCI: CD8/T-cytotoxic cells (Tc) recognize antigens bound to MHC-I proteins Tc cells Function: - Kill cancer cells

- Which class(es) of antibody participate in each function of antibodies. - Which type has a dimeric structure? Which type has a pentameric structure?

Classes of antibodies: IgM: - The largest antibody (first produced during primary response) - Principal antibody produced by T-independent antigen - Can bind 10 epitopes, to activate complement (complement system activation) *pentameric structure IgG: - Most abundant in blood and tissues - Longest lived - Facilitates phagocytosis and activates complement. - Is an opsonin *dimeric structure IgA: - Most abundant antibody - Present in secretions - Protects mucous membranes. IgD: not common, unknown functions IgE: - Fc binds to basophil and eosionphils - Involved in allergic reactions, releases histamine. - Release toxic granules and help kill larger microbes. *dimeric structure

Define: - Concept Maps - Lysozyme

Concept Maps: Map that can identify connections between terms and concepts. Lysozyme: an important component of the innate immune response EX: tears, breast milk, saliva and mucous in humans, egg whites contain an abundance of lysozyme

A new type of therapy was recently approved by the FDA for treatment of acute lymphoblastic leukemia (ALL). For this treatment, the patient's _________ are removed and genetically engineered to produce cancer-targeting ________. A. dendritic cells, PRR B. macrophage, TLR C. B cell, BCR D. NK cell, TCR (T-cell receptor) E. TC cell, TCR (T-cell receptor)

E. TC cell, TCR (T-cell receptor)

Emerging infectious diseases are always novel. - True or False

False

Where are lymphoid cells produced?

From stem cells in the bone marrow and then circulated in the blood to the lymphoid tissue

List and describe the various functions of antibodies.

Functions of antibodies: Neutralization: Viruses and toxins are prevented from binding to their targets because they are bound to antibodies instead Cross-linking: Phagocytosis is more efficient *Due to antibodies being bivalent, this allows several antibodies to bind to numerous bacteria Antibody-dependent cellular cytotoxicity: - Natural killer cells release toxic products. - Infected "self" cell (killing own cell infected with viruses to stop replication) Opsonization: - Phagocytes have Fc receptors; similar to C3 opsonization. - Antibodies coat bacteria to make engulfing easier Complement system activation: - This is the classical pathway (as antibodies bind to antigen, C3 convertase is created) - (opsonization by C3b→ inflammatory response → lysis of foreign cells) Immobilization and prevention of adherence: - Interferes with motility and attachment of invaders

Define: - Microbial intoxication - Microbial Infection - Incubation period - Prodromal period - Period of illness - Convalescent period - Sympotomatic - Asympotomatic - Vertical disease transmission - Horizontal disease transmission - Direct disease transmission - Indirect disease transmission - Biological vector - Mechanical vector - Portal of exit - Portal of entry - Epidemiology - Endemic - Incidence - Herd immunity - R0 - R

Microbial intoxication: a disease that results from ingestion of a toxin that was produced by a pathogen in vitro (outside the body). - TOXIN IS INGESTED! EX: Staph aureus, food poisoning! Microbial Infection: the bacterium multiplies in the body EX: staph aureus; skin infection! Incubation period (Phase 1 of infectious disease): the period between exposure to an infection and the appearance of the first symptoms - interval between initial infection and first signs and symptoms Prodromal period (Phase 2 of infectious disease): vague, general symptoms - short period after incubation; early, mild symptoms Period of illness (Phase 3 of infectious disease): most serve signs and symptoms *Sympotomatic Convalescent period (Phase 4 of infectious disease): as person begins to respond to the infection, symptoms decline *Non-diseased and disability of death Sympotomatic: shows signs or symptoms of a disease Asympotomatic: showing no symptoms of disease Vertical disease transmission: from parent to child - offspring EX; HIV Horizontal disease transmission: from one member of a species to another - Person to person EX: cold Direct disease transmission: (<1 meter) Transmission of blood or body fluids through touching - Sneeze or cough (droplet) - Handshake - Sexual contact Indirect disease transmission: Transmission of blood or body fluids through contact with an intermediate contaminated object (razor, extractor, or environmental surface) - Airborne - Fomites - Food/water - Vectors Biological Vector: part of the pathogen's life cycle occurs in the vector *Nonhuman animals - Mosquitoes carry the malaria parasite! Mechanical vectors: just carries - houseflies, cockroaches Portal of Exit: any body opening on an infected person that allows pathogens to leave EX: mouth, rectum Portal of Entry: a way for the pathogen to enter the body EX: nose, wound Epidemiology: study of distribution and causes of disease in populations Edemic: constantly present in a population EX: the common cold is endemic in MN, but Malaria is not in MN Incidence: Number of new cases in a give time (year) in a given population (usually expressed per 100,00 people) EX: From the MDH: there were 375 cases/100,00 people in MN in 2014 Herd Immunity: protection of an entire population based upon a critical concentration of immune hosts that prevents the spread of an infectious agent R0: Basic reproductive number - How many cases an infected person will cause in a susceptible population R: Effective reproductive number - How many cases an infected person will cause in a population with some immunity

Define: - antigen - T-independent B cell activation - T-depdendent B cell activation - Agglutination - hemagglutination

antigen: a molecule that can elicit an immune response and antibody formation T-independent B cell activation: which results in IgM antibodies T-depdendent B cell activation: which produces IgM, IgG and other antibody classes (isotypes) Agglutination: reactions occur when antigens are clumped together by antibodies hemagglutination: The reaction when red blood cells are involved in agglutination reactions

Define: - coliform - fecal coliform - enrichment technique

coliform: Gram- negative, rod-shaped bacterium that can ferment lactose with the production of acid and gas when incubated at 35-37oC fecal coliform: presence of coliforms suggests that food is contaminated with fecal matter and may contain pathogens that are transmitted through the fecal-oral route EX: E.coli enrichment technique: a small amount of homogenate is first cultured in a semi-selective liquid media that permits growth of the desired organism

Why isn't Lyme disease contagious? Can you think of another example of non-contagious disease?

*Lyme disease is not contagious; tick has to be vector - Malaria is not contagious Contagious: disease spread person to person EX: colds, flu

How is each phase of a clinical vaccine trial different? Why are preclinical trials necessary?

*Often 15 years Phases: 1. Exploratory: (2-4 years) - scientist sequence the DNA or RNA genome of the pathogen - Try to identify forms of pathogen that are weakened or attenuated - Will look for pathogens that could stimulate a protective immune response 2. Pre-clinical: (1-2 years) - Testing various types of vaccines in cell culture and then in animal models - Helps researchers measure the type of immune response is generated (antibodies, cytotoxic t cells *If appropriate immune response is generated, the animal may be challenged with the pathogen to measure whether the vaccine offers protection - Many candidate vaccines never progress beyond this stage *If a candidate vaccine can produce a safe and effective protective response in animal models, it may be approved for use in phase 1 clinical trails. 3. Phase I: - Involve 20-80 volunteers - Researchers assess the safety the vaccine and measuring what type of immune response is generated *Promising candidates move to Phase 2 4. Phase II: -Involves several 100s of volunteers - Safety is carefully monitored and researchers may test various vaccine delivery methods and timing for boosters - Different doses of vaccines will be tested for safety and immunogenicity *Trials are randomized and controlled using a placebo group 5. Phase III: - Involve tens of thousands of people - Safety is monitored - Vaccine efficacy is tested *Does the candidate vaccine prevent disease? *Does it prevent infection with the pathogen? *Does it lead to production of antibodies or other immune responses? - Vaccines can stall in this phase because sometimes epidemics naturally fade away or virus can mutate so the vaccine is not effective against the circulating strain 6. Phase IV: - Conducted to continue monitoring safety 7. Review/ Approval: - Once safety and efficacy had been established, a vaccine can be licensed for use 8. Manufacturing/QC (Production): - Only a few companies in the world have the capacity to manufacture 100s - 1000s - 1,000,000s of vaccine doses

1. What are some ways that our normal microbiota protect us from disease? 2. What factors influence host immunity? 3. What are virulence factors? What are some examples and how do they increase the pathogenicity of the microorganism?

1. - Competing with invaders for space and nutrients - Producing compounds (bacteriocins) which kill other bacteria - Lowering the pH so that other bacteria can't grow 2. - Age - Nutritional Status - Amount of sleep - Smoking Dysbiosis: microbial imbalance 3. Virulence factors→ how much they can cause disease EX: • Toxins EX: Enterohemorrhagic E coli produce shiga toxin • Adhesins EX: HIV bind to a receptor on human CD4 cells • Bacterial Fimbriae (Pili) EX: Fimbrated E. coli strains can colonize the urinary bladder • Extracellular enzymes EX: Necrotizing enzymes of Streptococcus pyogenes • Capsule or slime layer EX: Klebsiella pneumoniae or Streptococcus pneumoniae • Flagella EX: Salmonella spp. • Conversion to intracellular pathogens EX: Mycobacterium tuberculosum • Avoidance of immune system

1. How does Mycobacterium tuberculosis evade the immune system? 2. How do some bacteria evade the complement system?

1. - Has an Acid-Fast cell wall that resists digestion. Bacteria multiply within human macrophage cell * once inside macrophage, it's not broken down 2. - Antigenic Variation - Capsule or Slime Layer - Facultative intracellular pathogen - Leukocidins destroy white blood cells. - IgA proteases destroy some antibodies. - Elastase inactivates complement proteins - Long polysaccharide chains in LPS prevent MAC insertion into membrane.

1. What is a common virulence factor for bacteria that cause meningitis? 2. How does the immune system response create the severe symptoms of bacterial meningitis? 3. Do most people who are exposed to Listeria monocytogenes develop Listeriosis? Who is most at risk and what are the consequences? What are some foods to avoid?

1. - If bacteria enter the bloodstream - Lack of vaccine - Inflammatory response 2. - The inflammatory response Vasodilation: - leads to fluid buildup and nerve damage - Neutrophils enter the CSF, damage tissue - Clotting obstructs blood flow - Tissue swelling blocks CSF flow, causes fluid buildup 3. - No, in healthy people they experience mild flu-like symptoms or are asymptomatic - Pregnant women, elderly, and immunocompromised are most at risk - Foods to avoid: raw sprouts, soft cheeses, unpasteurized raw milk, smoked seafood, deli meats and hot dogs (cold not heated)

1. How can a primary infection lead to a secondary infection? 2. When do opportunistic pathogens cause disease?

1. - In the case of the flu, the mucocilliatory escalator is damaged which results in secondary infection because bacteria can travel down to lungs Process: 1. flu virus attaches to muco-ciliary layer of upper respiratory tract from inhalation of the virus (primary infection) 2. muco-ciliary cells are damaged from bacteria that you already carry 3. allows these bacteria to travel to your lungs (secondary infection) *primary infection→ Flu virus *Secondary infection→ streptococcus pneumoniae 2. *Primary pathogen: something that causes disease in healthy people - influenza, measles, tetanus *opportunistic pathogen: disease in weak immune system people - Can cause disease in healthy people if introduced in wrong location like a cut. - Reduction in your own microbiota → overgrowth of opportunistic pathogen can cause disease. EX: * vaginal yeast infection after antibiotics * c. diff colitis after antibiotics

1. What role does the lymphatic system play in the adaptive immune system? 2. How do TC cells recognize cancerous "self" cells? 3. How could gut microbes influence the development of autoimmunity in a disease like MS?

1. - The lymph system absorbs proteins and tissue fluid lost at capillaries; this fluid, which has antigens in it, flows to the secondary lymphoid organs to start the process of T and B cell activation 2. - Most cells have MCHI proteins - Cancer cells display abnormal proteins on their MHCI receptors 3. - Thymus (primary lymphoid organ), where immature T cells mature after leaving bone marrow - T cells with receptors that recognize self-epitopes are destroyed via apoptosis so we don't have autoimmune disease (i.e. MS, type I diabetes).

1. Compare and contrast basic features of the peripheral and central nervous system (CNS). 2. Describe how the body protects the CNS.

1. Central Nervous System: brain, meninges, and spinal cord. - Together with the peripheral nervous system, it has a fundamental role in the control of behavior. PNS: Motor and sensory neurons that convey messages between the CNS and the rest of the body 2. - The brain and spinal cord are enclosed in bony structures - Also protected by 3 layers of membranes called the meninges

1. Which cells recognize antigen presented on MHCI proteins? MHCII proteins? 2. What types of cells have MHCII proteins? What types have MCHI proteins?

1. MHCI: CD8/T-cytotoxic cells (Tc) recognize antigens bound to MHC-I proteins MHCII: CD4/T-helper cells (TH) recognize antigens bound to MHC-II proteins 2. MCH I: - Antigens found inside the cell bind to _______ protein - Tc cells recognize ______ antigens MCH II: - Antigens found outside the cell bind to _______ protein - TH cells recognize _____ antigens *Dendritic cells have both MCH I and MCH II proteins - Recognize antigens via PRRs

1. How could a protozoal parasite enter the brain? How might climate change affect disease risk in MN? 2. How does the brain become infected with the rabies virus? How are humans at risk? What is the treatment protocol following an animal bite?

1. Naegleria fowleri is a protozoal parasite: - travels from the nose along olfactory nerve to the brain - Thrives in warmer waters 2. - Replicates in muscles at the site of bite - Virus travels along the nerves to CNS where it replicates in neurons of gray matter - Wash wound, anti-rabies antiserum, rabies vaccine

1. What types of vaccines are currently being developed for COVID-19? 2. Approximately how many COVID-19 vaccines are currently in preclinical trials? In Phase III?

1. Types being made: - DNA and RNA vaccines - Subunit vaccines: consists of a single or mixture of proteins - Inactivated viral particles - Chimeric viruses - Attenuated viruses 2. - More than 30 companies are in the exploratory and preclinical phases - None is phase III at the moment

1. What types of cardiovascular problems are associated with COVID-19? 2. Can COVID-19 result in injury to the nervous system? 3. What are hyposmia/anosmia, hypogeusia/Ageusia? How are these dysfunctions related to COVID-19?

1. - ACE2 is expressed in the heart - The intense release of multiple cytokines and chemokines can lead to vascular/myocardial inflammation and plaque instability - Direct viral infection of the myocardium is a possible explanation - The effects on the CV system might be long-lasting 2. YES Injury to the NS due to COVID-19: - GBS (Guillian-Barre Syndrome): acute, bilateral, areflexia, and ascending flaccid paralysis - MFS (Miller-Fisher Syndrome): Ophthalmic variant of GBS - ADEM (Acute disseminated encephalomyelitis): CNS and PNS white matter destruction - High co-infection rates - 21% of patients positive for at least one other pathogen - Viral or bacterial 3. Hyposmia/Anosima: absent/reduced ability to smell (CN 1) Hypogeusia/Ageusia: absent/reduced ability to taste (CN 7 and 9) dysfunctions related to COVID-19: - Sensory changes independent of nasal congestion - Taste and smell abnormalities added to CDC and WHO list of COVID-19 symptoms

1. What types of virulence factors help a pathogen spread through the body, evade the host immune defenses or cause damage to the host? 2. If you only stay home during the symptomatic phase of illness, will you avoid infecting other people? 3. What is the difference between an asymptomatic carrier and a person with a latent infection?

1. - Attachment - Multiplication - Invasion or spread - Evasion of host defenses - Damage of host issues 2. No, oftentimes people are contagious before the symptoms appear 3. Asymptomatic people are still contagious, there body is just able to suppress the systems due to their specific immune response Latent infections are not contagious, virus is not actively replicating Latent infections: Pathogen is not eliminated from the body, but is not actively replicating - may become activated and cause disease - infection is NOT spread EX: herpes simplex virus 1 and 2 (mouth, lip, and genital blisters - Varicella zoster (chicken pox) - Mycobacterium tuberculosis (tuberculosis)

1. In what way(s) do B and T cells "see" antigens differently? In what way is this process the same? 2. What cell presents antigens to T cells, resulting in T cell activation?

1. - B cells have B cell receptors (look like antibodies) capable of seeing antigens, usually need T cell to activate and make antibodies, sometimes T-cell independent - T cells have T cell receptors and can only see antigen if antigen is presented to them (by dendritic cell) so then T cell can see it 2. - Usually dendritic cells, present antigen epitopes on either MHCI or MHCII - Dendritic cells located in tissues have cell extensions that can reach across mucous membranes to sample the surface

1. What important vaccine prevents bacterial meningitis in young children? What typically causes viral meningitis and where do the viruses come from? 2. What causes meningococcal meningitis? Have you been vaccinated? Could you become infected with serogroup B? 3. What is a common source of bacterial meningitis in the elderly (and less so in young children)?

1. - Hib vaccine - Most common cause of viral meningitis in young children is enteroviruses, which are non-enveloped and come from fecal-oral route 2. - It is caused by the bacterium Nicerium gonnohrea - Yes - Possibly because there is not a large amount of vaccines for that serogroup 3. The meningitis is Pneumococcal Meningitis which is caused by encapsulated Streptococcus pneumoniae strains

1. What are some examples of when Koch's postulates could not be satisfied? 2. How did Zimbler et al. determine that a mutated form of pla increased the virulence of Y. pestis? 3. What virulence factor allows the pathogen to live inside of fleas? How does this influence the transmission of the bacterium?

1. - Something is making people sick, but it cannot be isolated and grown in pure culture - When an organism must grow in biofilm and if more than one organism present it causes disease - Asymptomatic carriers cannot neatly characterize people via those who get sick vs. those who do not - Is there is no animal model then one cannot perform tests 2. Koch's postulates ! ! ! ! ! ! - There is a virulence gene in pla of the ancestral strain which has become mutated in the modern form 3. Yirsinia murine Toxin (ymt)

1. Exposure to a pathogen does not always result in disease. Why not? 2. What is the difference between symptoms and signs of a disease?

1. - There has to be the correct portal of entry. - There are physical and chemical barriers that prevent disease like lysozyme and mucus. - Normal microbiota are also present. - The right host receptor has to be present. - Innate and acquired immunity also prevents disease. 2. Signs: Something that you can measure (measurable objective result obtained by a test) EX: temperature, BP, fever, cough Symptoms: personal subjective feeling given by the patient (harder to measure) EX: headache, sore throat, muscle pain, fatigue, nausea

1. Whycan't some people receive vaccinations? 2. What is the difference between R0 and R? What factors influence these numbers? 3. How does the value of R0 influence vaccination strategies? 4. How long do you think we should practice social distancing during the COVID-19 pandemic? Why?

1. - They are immunocompromised or pregnant - Younger kids can't always get vaccinated 2. R0: Basic reproductive number - How many cases an infected person will cause in a susceptible population R: Effective reproductive number - How many cases an infected person will cause in a population with some immunity

1. What are typical sources for bacterial and aseptic meningitis? What one is more common? More serious? 2. What are some distinctive symptoms of meningitis? 3. Why are neonates susceptible to bacterial meningitis and how is this prevented?

1. Bacterial: - Most serious consequences - Specific bacteria affect different age groups - Source: respiratory tract, colon/vagina, food Aseptic (usually viral): - More common - Milder - Usually self-limiting - Often fecal-oral 2. -Severe headache -Neck and back stiffness -Fever -Photophobia -Nausea and vomiting 3. - Group B Strep is a bacterium found in lower GI or genital/urinary tract - It can be acquired in utero or from birth canal - Babies have underdeveloped immune systems - Not protected by their mother's IgG - Pregnant women who test positive are given antibiotics shortly before birth to prevent transmission to the baby

1. What is the difference between direct and indirect transmission? What are some examples of each? 2. What is the difference between a biological and a mechanical vector? 3. What is herd immunity and how does it protect unvaccinated members of the population?

1. Direct transmission: refers to transfer of a sickness/pathogen via one person/animal to another (handshake, sex, mucosal droplets inhaled) - Person, mosquito, animal bite - Typically less than a meter Indirect transmission: refers to transfer via a nonliving object - Airborne, fomites, food/water, vectors 2. Biological Vector: part of pathogen's life cycle occurs in the vector that is nonhuman - Mosquitoes! Carry! Malaria! Mechanical Vector: it is just a carrier - Houseflies, cockroaches 3. - Herd immunity occurs when the majority of a population/group is immune to a disease/sickness via immunization. - The principle demonstrates that as long as most people in the population are immune, they will not become sick and therefore will not spread the sickness to those who are not vaccinated/immune. - Therefore, this protects the few who are not vaccinated/immune from getting sick. - Very beneficial for those who cannot get vaccinated: pregnant, immunocompromised, young kiddos, old people

1. What kind of Foods does the FDA and USDA-FSIS inspect? 2. What is the definition of an "outbreak" and "outbreak strain"? How does the term "outbreak strain" differ from strain? 3. Generally speaking, how is an outbreak of foodborne illness investigated?

1. FDA: oversees about 80% of food supply, domestic and imported food products Includes: - Packaged food, fresh produce, and most fish and dairy USDA-FSIS: inspects all meat, poultry, and processed products 2. Outbreak: group of cases occurring during a brief time interval and affecting a specific population Outbreak Strain: are isolates of the same species that are both EPIDEMIOLOGICALLY related (ex: by time, place, and common source of infection) and GENETICALLY related (ex: have indistinguishable genotypes) Strain: a pure culture isolate; subgroup with a species 3. Host: • Who got sick? • When? • What did they eat? • Where? • Age? • Gender? • Symptoms? Microbe: • What organisms is isolated from patients? • Are isolates identical? • Can the same isolates be found in suspect food? • Do isolate match those in national database? (PulseNet) • Are isolates present in the food supply chain?

1. What is the function of the ACE 2 receptor? What would happen if a drug blocked the receptor? 2. What is Acute Respiratory Distress Syndrome (ARDS)? 3. What are some differences between lungs in young and older people? How do these differences contribute to increased disease and mortality in older people?

1. Function of ACE 2 Receptor: - Part of the renin-angiotensin-aldosterone system (RAAS) pathway. - It regulates Angiotensin II (ANG II) which increases blood pressure, damage to blood vessel linings, inflammation, and various types of tissue injury. - ACE2 converts ANG II to other molecules that counteract the effects of ANG II. Drug blocked the ACE 2 receptor: - Lung injury - Inflammation - Leaky vessels 2. Acute Respiratory Distress Syndrome (ARDS): Occurs when fluid builds up in the tiny elastic air sacs (alveoli) in your lungs - The fluid keeps your lungs from filling with enough air, which means less oxygen reaches your bloodstream. - This deprives your organs of the oxygen they need to function. 3. Young: - Average airspace size - Increased proliferation - High elasticity - Resident immune cells Older: - Average airspace size - Increased apoptosis - Senescence markers - Increased size - Decreased elasticity - Increased soluble and cellular inflammation *Age you age your immune system is not a strong and cannot fight of certain pathogens as quickly leading to more illness

1. What is the function of the cerebral spinal fluid (CSF) and how does it circulate? 2. Describe the ways that microbes can enter the CNS. 3. How are CNS infections detected? How would septic and aseptic meningitis look the same? Different?

1. Functions: - provides cushioning, buoyancy - carries nutrients, collects wastes Circulation: - produced in the choroid plexus - circulates in ventricles, subarachnoid space - absorbed into bloodstream *normally sterile) 2. - Travel along nerves (rabies, tetanus toxin) • High levels in the blood --> hematogenous spread (Streptococcus pneumoniae, Neisseria meningitidis) • Surgery, trauma • Spread from adjacent infected sites (sinusitis, otitis media, pimples 3. - CSF is analyzed for number of white and red blood cells *samples stained and cultured for bacteria - Lumbar puncture performed to obtain cerebral spinal fluid

1. What are the "O", "H" and "K" antigens? 2. What has the highest and lowest resolution in distinguishing between two strains: Antigenic typing, Whole genome sequencing (WGS), Pulsed field Gel Electrophoresis (PFGE)? 3. What hypotheses are we testing in our experiment with grocery store chicken? 4. What questions can we ask when we have whole genomic sequence from the isolates?

1. Somatic (O): cell wall antigens Surface (K): capsular antigens H: Flagellar antigens 2. Highest resolution: Whole Genome sequencing Middle resolution: Pulsed field Electrophoresis Lowest resolution: Antigenic typing 3. Do poultry raised without antibiotics contain less antibiotic-resistant E. coli? 4. - Same O and H antigens? - Same MLST (sequence type) - Identical or nearly identical genome sequence?

Molecular Koch's Postulates (Mice experiment)

1. Ancestral strain Y. pestis, + Pestodes F = limited infection 2. Ancestral strain Y. pestis, + Virulence gene pla = pneumonic plague 3. Ancetral strain Y. pestis + mutated virulence gene Plal259T = disseminated infection TEST POTENTIAL VIRULENCE GENES

1. How do antibodies promote phagocytosis? 2. Which antibody class functions as an opsonin?

1. Antibodies can coat bacteria and act as an opsonin, making it easier for phagocytes to attach and engulf the bacteria 2. IgG is an opsonin

1. What is an attenuated vaccine? 2. Give an example of a routinely used combination attenuated vaccine. 3. Describe the rVSV-ZEBOV vaccine against Ebola.

1. Attenuated vaccine: is a vaccine created by reducing the virulence of a pathogen but still keeping it viable or "live." 2. EX: measles vaccine, mumps vaccine, rubella vaccine, INFLUENZA vaccine, chicken pox vaccine, smallpox vaccine, yellow fever vaccine (all viral) - Typhoid vaccine (bacterial) - Attenuation takes an infectious agent and alters is so that it becomes harmless or less virulent. * these vaccines contrast to those produced by "killing" the virus (inactivated vaccine). 3. rVSV-ZEBOV (recombinant, replication-competent vaccine): consists of a vesicular stomatitis virus (VSV), which has been genetically engineered to express a glycoprotein from the Zaire ebolavirus so as to provoke a neutralizing immune response to the EBOLA virus

1. What agents typically causes encephalitis and how can it be prevented? 2. How is polio acquired? Do most people develop paralysis?

1. Encephalitis: Inflammation of the brain - Mosquitoes - Wear bugspray 2. - fecal oral route or respiratory route - No *Can be prevented with the inactivated Salk vaccine or live attenuated Sabin vaccine

1. What type of virus is SARS-CoV-2? (RNA/DNA, positive/negative sense) 2. How is SARS-CoV-2 transmitted? 3. What is the receptor for SARS-CoV-2 and where it is found in the body?

1. Enveloped positive-sense RNA virus 2. Initial transmission was thought to be exposure to contaminated animals at a wet market in Wuhan China. It is still not clear how it exactly happened. NOW: - Person to person is now the primary mode of transmission (direct transmission) - Respiratory droplets; coughs, sneezes, or talks can infect another person if it makes direct contact with the mucous membranes. - Droplets can not go beyond 6 feet. - Long-range airborne transmission has not clearly been documented. - SARS-CoV-2 has been detected in non-respiratory specimens, including stool, blood, ocular secretions, and semen, but the role of these sites in transmission is uncertain. - No proof of transmission through contact with non-mucous membrane sites (eg, abraded skin). 3. ACE 2 Receptor Found in: • Respiratory tract and Lungs • Heart • Kidneys • Gastrointestinal • Liver • Blood vessels

1. What is a fomite? 2. What types of microorganisms are transmitted directly? 3. What is the difference between a microbial intoxication and a microbial infection?

1. Formite: Inanimate object that transports microorganisms/pathogens EX: doorknob 2. Direct transmission: of a pathogen from one host to another typically involves immediate transfer of the infectious agent to an appropriate portal of entry. - This could occur via direct physical contact or projection of respiratory droplets onto mucous membranes. 3. Microbial intoxication: the toxin is ingested - Main question that determines this: how long did it take for you to get sick? Microbial infection: the toxin multiplies within the body

1. What are the functions of TC cells? 2. What type of pathogen would trigger a TC response? 3. Where does T cell activation take place? 4. Do T cells form memory cells?

1. Function of Tc Cells: *Kill cancer cells - Induce virally infected cells (or cells infected with intracellular microbes) → apoptosis 2. Pathogen triggering Tc response: - cancer cells, cells that are infected (particularly with viruses), or cells that are damaged in other ways. 3. Secondary lymphoid cells *lymph organs (lymph nodes, spleen, tonsils, gut (GALT)) 4. Yes, T cells form memory cells as well as B cells

1. What are the functions of activated TH cells? 2. What are the types of TH cells and how are they different?

1. Function of activated TH cells: - Always have CD4 receptors - Help immune system do a lot of things - Help B cells make plasma cells and memory B cells * secrete cytokines that cause changes in behavior for B-cells, B-cells differentiate into plasma cells - help Tc cells *have a role in proliferation of T-cytotoxic - help macrophages activate *bind to macrophage, release cytokines, macrophage is activated 2. Types of TH Cells TH 1: intracellular pathogens TH 2: mutilcellular pathogens - Asthma, allergies TH 17: Extracellular pathogens - Autoimmune

1. Why are boosters necessary for subunit vaccines? 2. Why are adjuvants sometimes necessary? 3. Why does the conjugate HiB vaccine work better than a capsule (polysaccharide) subunit vaccine?

1. Subunit vaccines only contain viral components, so boosters are needed to keep baseline level of immunity up in people *Subunit vaccines only contain essential antigens, will last a few weeks, boosters bring antibodies back up. 2. Adjuvants: a pharmacological or immunological agent that modifies the effect of other agents - Adjuvants may be added to a vaccine to boost the immune response to produce more antibodies and longer-lasting immunity, thus minimizing the dose of antigen needed. 3. - The conjugate HiB vaccine has polysaccharides linked to proteins, a modification that coverts the polysaccharide into T-dependent antigens. - Better than capsule (polysaccharide) vaccine because polysaccharide vaccine produces T-independent antigens (not effective in young children) while the HiB produces T-dependent antigens

1. How is an emerging infectious disease defined? 2. What factors influence the rise in emerging infectious diseases? 3. Are emerging infectious diseases always novel? 4. How can emerging infectious diseases become established?

1. Infections that have recently appeared within a population or those whose incidence or geographic range is rapidly increasing or threatens to increase in the near future. 2. Previously undetected or unknown infectious agents. 3. NO - Novel virus: An infection that has appeared in a population for the first time. (a virus that has not previously been recorded) - Emerging Infection: An infection that may have existed previously but is rapidly increasing in incidence or geographic range. - Emergence of antibiotic resistance, especially emergence to antibiotics used in human therapy. 4. WHO Priority Pathogens - priority 1: Critical - priority 2: High - priority 3: Medium

1. Watch the lab demo. What type of selective and differential liquid media was used in the enrichment technique with the chicken drumsticks? What does this media select for? 2. What temperature was used for incubation? Why?

1. MAC broth - Selects for gram-negative enterics *high temperaure (44C) selects for E. Coli 2. 44C - E coli can survive at 44C and at this temperature it can kill off unwanted bacteria and allows E coli to continue growing

1. During COVID-19, when do gastric symptoms usually appear? 2. How does COVID-19 affect the kidneys? 3. What is a cytokine storm and what cells initiate this during severe COVID-19?

1. Occurs prior to pulmonary symptoms - Spread of infection of the GI tract may result from viremia or from the mouth and upper respiratory tract, suggesting that the virus survives passage through the stomach 2. - COVID-19 might target the kidney cells - Too little oxygen can cause kidney to malfunction - Cytokine storms can destroy kidney tissue - COVID-19 causes blood clots that might clog the kidneys - May require dialysis *It is not known if functions resumes in full upon recovery and if there is any residual damage 3. Cytokine Storm: a potentially deadly overproduction of cytokines during an immune response to infection that can injury your own tissues - Pro-Inflammatory cytokines implicated in severe COVID-19 Cell initiated during server COVID-19: - Secreted in large part by macrophages, neutrophils, epithelial cells - High levels of IL-10 also seen in COVID-19 patients - complex role.

1. What category of food is the most common source of foodborne illness? 2. What is the most common cause of foodborne illness? 3. What bacteria cause the most serious forms of foodborne illness?

1. Produce 2. - Norovirus • Salmonella • Clostridium perfringens • Campylobacter • Staphylococcus aureus 3. - Listeria - Clostridium botulinum - E. coli - Vibrio

1. What CNS infections can be treated with antisera? 2. What is a prion and how are prion particles thought to multiply in the brain? How can prion disease be prevented? 3. What is an example of a fungus that causes meningitis? Who is most at risk?

1. Rabies 2. - Prions infectious protein particles - They form PrP which is resistant to heat, formeldehyde, UV and ionizing radiation, proteases - Can be prevented by checking meats 3. - Cryptococcus sp. - Immunocompromised patients are most at risk

1. Which test is quicker: the Rapid Strep serological test or culture on blood plates? 2. Why do labs do both sets of tests when a patient is tested for Strep throat? 3. Could a patient have a negative Rapid Strep test but a positive culture test? What about the reverse?

1. Rapid Strep Serological test 2. Both are used mainly to make sure the diagnosis is correct. Rapid Strep Serological test is quick, but the culture provides more accurate diagnosis and takes 24-48 hours to get results 3. Yes because you could still have an infection from another type of bacteria or virus - The reverse: NO because if you test positive for the Rapid Strep Test, you will also be positive for the culture test

In an ELISA, an enzyme is conjugated to: A. the antigen B. the primary antibody C. the secondary antibody D. substrate

C. the secondary antibody *Secondary antibodies recognize primary antibodies and can be used in many different tests. An enzyme is conjugated or covalently linked to the heavy chain.

1. How does the prodromal period of disease differ from the symptomatic period? 2. What is a latent infection? Can someone with a latent infection transmit the infection?

1. Symtomatic stage has the severe symptoms whereas in prodromal you feel initial symptoms like being tired 2. When somebody carries the bacteria but is asymptomatic, asymptomatic people are still contagious. *Infection agent is present in body but person appears to be normal. They can still transmit the infection

1. What is GenomeTrakr? 2. How can whole-genome sequencing help stop epidemics from spreading?

1. Whole genome sequencing that drives the GenomeTrakr network that allows them to look into food borne outbreaks and track them back to their source exactly 2. Detects the source of the outbreak and stop food product to the food supply and prevent illnesses

1. Where did SARS-CoV-2 likely originate? 2. What animal carries a genetical similar virus? 3. When was the first infection detected in the US?

1. Wuhan China late 2019 2. Zoonotic virus identified to genetically resemble a strain from Horseshoe bats 3. 1/21/2020

1. How does the q-RT-PCR (Reverse transcriptase PCR) SARS-CoV-2 test work? What factors could lead to a false negative? 2. Explain how a patient could have a positive PCR test, but a negative IgG test (assuming the tests are valid). 3. Explain how a patient could have a negative PCR test, but a positive IgG test (assuming the tests are valid).

1. q-RT-PCR (Reverse transcriptase PCR) Process: 1. A swab is taken of the inside of a patient's nose or the back of their throat. - This sample is then sent to a lab to test 2. The RNA of the virus is extracted and purified. - An enzyme, reverse transcriptase, converts the RNA to DNA 3. The DNA is mixed with primers, sections of DNA designed to bind to characteristic parts of the virus DNA. - Repeatedly heating and cooling DNA with these primers and a DNA-building enzyme makes millions of copies of virus DNA 4. Fluorescent dye molecules bind to the virus DNA as it is copied - Binding makes them give off more light, which is used to confirm the presence of the virus in the sample False negative: - In some cases sample degradation or contamination can affect the results 2. 3.

During severe COVID-19, cytokine storm may be initiated by ________ and ________, which can result in damaging levels of inflammation. A. TH cells and microphages B. TH and Tc cells C. Macrophages and neutrophils D. RBCs and platelets

C. Macrophages and neutrophils

People infected with the Hepatitis B virus may develop joint pain, fatigue, fever, nausea, loss of appetite, and abdominal pain. Which of these is considered a sign of disease? A. joint pain B. fatigue C. fever D. nausea

C. fever

A disease with which of the following reservoirs would be the least difficult to eradicate (destroy completely; put an end to) using vaccination? A. domesticated animals B. wild animals C. humans only D. environment

C. humans only

After recovery from Chickenpox, most individuals are asymptomatic unless they develop Shingles late in life. During the asymptomatic period, the virus is: A. acute B. chronic C. latent D. eliminated from the body

C. latent Acute: infection that develops fairly quick and lasts a short time Chronic: infection that continuously produce of low levels of viral particles - Can last months or years Latent: viral infection in which the viral genome is present but not active, so that viral particles are not being produced.

- Describe the steps in an ELISA assay. (Make a drawing) - Why are the washes necessary? - What results would you get if you forgot to add the primary or secondary antibody?

ELISA assay Steps: 1. Load student samples (unknown antigens) in triplicate into wells of the microplate strips. - Incubate for 5 mins and rinse *lets the antigen bind to the wells 2. Add primary antibody to all wells. - Incubate for 5 mins and rinse *Primary antibody is very specific and binds to antigen of interest 3. Add enzyme-linked secondary antibody to all wells. - Incubate for 5 mins and rinse *Secondary binds to primary antibody *Purpose of secondary: amplify the reaction because it usually combines with multiple primary antibodies at once and more than one site on each primary antibody *The secondary antibody is used to conjugate the enzyme horseradish peroxide (BRP) 4. Add enzyme substrate to all wells. - Incubate for 5 minutes *The HRP catalyzes the conversion of the chroma genic substrate to a color we can measure - (When HRP cleaves the substrate, a color in formed. Within a certain range, the absorbance is proportional to the amount of antigen present, making this assay quantitative.) 5. Add stop solution - An acid that will denature the enzyme and stop its activity Washes are necessary: - To ensure the wash buffer is washing the unbound primary antibody out of the wells Results if forgetting to add the primary or secondary antibody: - Primary: there would be no attachment to the antigen -Secondary: cannot bind to the primary antibody since it is not present and enzyme will not conjugate or covalently link to the heavy chain.

Compare and contrast the terms "antigen" and "epitope". What types of molecules are best at stimulating antibody production?

Epitope: is the binding site of the antigen - Region of an antigen recognized by antibodies and antigen receptors on lymphocytes * Each antibody is specific for a unique _______. Antigen: are composed of epitopes - Molecule that reacts specifically with either an antibody or antigen receptor on a lymphocyte

- Compare and contrast IPV and OPV. When wild virus is circulating in an area, which polio vaccine is important? - What risk is associated with the oral polio vaccine?

IPV: - Whole killed virus - Series of boosters - Successfully lowered Polio morbidity dramatically - Immunity partially protective: wild virus can still replicate in vaccinated individuals OPV: - Live attenuated - Stimulates mucosal immunity (IgA) - Replicates in individuals upon vaccination --> can be transferred to unvaccinated - Eliminates virus from population - 1 in 2.4 million reversion Used when a wild virus is circulating the area (once it has been under control, then one can switch to inactivated polio vaccine) Risk of oral polio vaccine: - can be transferred to unvaccinated - vaccine-associated paralytic poliomyelitis (VAPP) which occurred in 1 in 2.4 million reversion

Define: - Lactobacillus bulgaricus - Streptococcus thermophilus

Lactobacillus bulgaricus: main bacterium used for the production of yogurt. It also plays a crucial role in the ripening of some cheeses, as well as in other processes involving naturally fermented products. Streptococcus thermophilus: Grows first by fermenting lactose and by cleaving milk proteins into amino acid *creates a low pH environment that favors the growth of L. bulgaricus and also provides amino acids

- What do leukocytes look like: lymphocyte, monocyte, neutrophil, basophil, eosinophil? - What is the difference between neutrophilia and neutropenia?

Neutrophilia: increased proportion of neutrophils in the blood - Common with acute bacterial infections Neutropenia: decreased proportion of neutrophils - May be seen with viral infections

Define: - PCR - Reverse Transcriptase - RT-PCR - Scalable

PCR: is a highest sensitive and specific technique that can be used in diagnostics. EX: Reactions contain DNA from the patient sample, a pair of primers that bind to the sequence of interest, dNTPS, buffer and the heat-stable DNA polymerase, Taq polymerase Reverse transcriptase: an enzyme originally isolated from a retrovirus RT-PCR: the reverse transcriptase must first copy the RNA into DNA and then the PCR reaction proceeds as before scalable: hundreds or thousands of reactions can be performed in a single day.

- In what ways are plasma cells and memory B cells different? - What cells bind IgE? How does this contribute to allergies and asthma?

Plasma cells: makes 5 classes of antibodies (IgM, IgA, IgD, IgG, IgE) Memory B-cells: live a long time, responsible for remembering antigens so immune system can react quickly in cases of further exposure *Plasma cells are able to secrete antigens immediately upon reinfection, while B cells can only do so after restimulation by specific antigens. IgE: - Bind to mast cells - Tells the immune system that there is an invader - Overacts and get inflammatory responses because histamine is released from mast cells. Contribution to allergies and asthma: - mast cells produce histamine when not supposed to sometimes and cause adverse responses - Happens when IgE is made at wrong time

How do primary lymphoid organs differ from secondary lymphoid organs?

Primary lymphoid organs: - Where lyphoid cells are produced - Primary immune organ is the bone marrow (where hematopoiesis occurs) Secondary lymphoid organs: - Where antibody production and activation of lymphoid cells takes place - Secondary lymphoid organs include: *tonsils *lymph nodes *spleen *gut-associated lymphoid tissue (GALT)

Describe the primary and secondary antibody response to an antigen. Which antibody is produced first?

Primary: develops in about a week with low level of antibodies - IgM spike after about 7 days (antibody that is produced first) - IgG spikes after 14 days Secondary: quicker and much more intense to clear away infections (more efficient response) - IgM spikes the same - IgG spikes dramatically and quickly

How does an RNA vaccine work? What advantages might this type of vaccine have?

RNA vaccine: - RNA is injected in the body - RNA encodes the information to produce the antigen (protein from a pathogen) that will stimulate the immune system - Inside the cells, the RNA is used to synthesize the antigen, which is exposed to the cell surface - Then, a subset of immune system cells recognizes the antigen and trigger an immune response Advantages: - Can be produced in lab from a DNA template using readily available materials - Less expensive and faster than conventional vaccine production - Perform better than DNA vaccines - Safer (as injection of RNA presents no risk of disrupting the cell's natural DNA sequence)

What is a toxoid vaccine? Give an example.

Toxoid vaccine: A vaccine made from a toxin (poison) that has been made harmless but that elicits an immune response against the toxin (based on toxin produced by certain bacteria). - Toxin invades the bloodstream and is largely responsible for the symptoms of the disease - The protein-based toxin is rendered harmless (toxoid) and used as the antigen in the vaccine to elicit immunity - They are SAFE, because they cannot cause the disease they prevent and there is no possibility of reversion to virulence - Do not spread to unimmunized individuals.

Lysozyme was discovered by Alexander Fleming. True or False

True * He discovered this when he found a drop of his own nasal secretions had antibacterial activity. This was before he discovered penicillin.

Define: - Neutrophils - Lymphocytes - Monocytes - Eosinophils - Basophils - Mast cells - Granulocytes - Agranulocytes - Differential white blood cell count

Types of White Blood Cells (5): 1. Neutrophils: phagocytizes bacteria - Granulocyte (granules in cytoplasm) - most frequent type of WBC - pale cytoplasm - 2-3 regularly shaped nuclei - Can be segmented or unsegmented 2. Lymphocytes: Group of WBC involved in adaptive immunity - Involve in immune response - Agranulocyte (no granules in cytoplasm) - Small - Large, round, dark nucleus - Cytoplasm appears as a rim around nucleus EX: B and T cells - B cell: programmed to make antibodies - T cell: lymphocyte that matures in the thymus 3. Monocytes: - Garbage trucks of the immune response - Agranulocyte (no granules in cytoplasm) - Huge (much bigger than lymphocytes) - Large, kidney-bean shaped dark nucleus - Cytoplasm appears foamy - They differentiate into either macrophages or dendritic cells when they migrate into tissues 4. Eosinophils: Kills parasitic worms - Granulocyte (granules in cytoplasm) - Cytoplasm appears pink or red - Nucleus is bilobed, evenly rounded lobes (more uniform than neutrophils) - Are involved in allergic reactions, causing some of the symptoms associated with allergies, but reducing others. 5. Basophils: Releases histamine and other inflammation-inducing chemicals - Least common WBC - Granulocyte (granules in cytoplasm) - Cytoplasm crowded by very dark granules - Cannot see bilobed nucleus because granules are so dense - Receptors on its surface bind IgE *Are involved in allergic reactions and inflammation Mast Cells: similar in appearance and function of basophils but found in the tissue - Receptors of Fc portion of IgE *Important in the inflammatory response and are responsible for allergic reactions Granulocytes: Neutrophils, eosinophils and basophils that contain cytoplasmic granules of proteins and other compounds used to kill bacteria. Agranulocytes: Lymphocytes and monocytes that lack granules Differential white blood cell count: determines if WBCs are present in normal proportions and is useful in diagnosing specific types of disease. - In sick patients, the percentages of certain types of WBCs will rise or fall depending on type of infectious agent or disease.

- What is variolation and how does it differ from smallpox vaccination? - Who discovered the smallpox vaccine?

Variolation: or inoculation was the method first used to immunize an individual against smallpox (Variola) with material from a patient or a recently variolated individual in the hope that a mild, but protective infection would result Smallpox vaccine: a vaccine that contains a live virus called vaccinia that is used to prevent smallpox, the vaccine does not contain the variola virus that causes smallpox, but exposes the immune system to proteins that look like the virus so that an immune response occurs. - Edward Jenner discovered the smallpox vaccine.