94. Microbiology p206-217
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- Sexually transmitted diseases
- What are the three clinical stages of syphilis
- 1st degree, 2nd degree, and thrid degree
- Lymphogranuloma venereum is caused by what organism?
- Chlamydia trachomatis
- A painless chancre is a sign of what disease?
- 1st degree syphilis
- What organism causes chlamydia?
- Chlamydia trachomatis
- What are the clinical features of Gonorrhea?
- Urethritis, cervicitis, PID, prostatitis, epididymitis, arthritis
- What serotypes of Chlamydia trachomatis cause chlamydia?
- D-K
- What are the features of AIDS?
- Opportunistic infections, Kaposi's sarcoma, lymphoma
- The clinical feature of Trichomoniasis is what?
- Vaginitis
- Chancroid is caused by what organism?
- Haemophilus ducreyi
- Gummas, tables dorsalis, general paresis, aortitis, Argyll Robertson pupil are clinical features of what STD?
- 3rd degree syphilis
- HSV-2 causes what disease with what features?
- Genital herpes with painful penile,vulvar, or cervical ulcers
- Ulcers, lymphadenopathy, and rectal strictures are signs of what disease?
- Lymphogranuloma venereum
- Which organisms cause Condylomata acuminata?
- HPV 6 and 11
- Hepatitis B causes what clinical feature?
- Jaundice
- What are the clinical features of 2nd degree syphilis?
- Fever, lymphadenopathy, skin rashes, condylomata lata
- Chancroid has what clinical feature?
- Painful genital ulcers
- What serotypes of Chlamydia trachomatis cause Lymphogranuloma venereum?
- L1-L3
- Trichomonas vaginalis causes what disease?
- Trichomoniasis
- Urethritis, cervicitis, conjunctivities, Reiter's syndrome, and PID are features of what diesease?
- Chlamydia
- Koilocytes are characteristic of what diease?
- Condylomata acuminata
- What organism causes 1st, 2nd, and 3rd degree syphilis?
- Treponema pallidum
- Pelvic inflammatory disease
- What are the top bugs that cause PID?
- Chlamydia trachomatis (subacute, often undiagnosed), Neisseria gonorrheae (acute, high fever)
- What is a risk factor for ectopic pregnancy, infertility, chronic pelvic pain, and adhesions?
- Salpingitis
- What is the most common STD in the US?
- Chlamydia trachomatis (3-4 million cases per year)
- What type of abscesses can occur in PID?
- Tubo-ovarian abscesses
- What does the chandelier sign test for?
- Cervical motion tenderness
- What are some of the manifestations of PID?
- Purulent cervical discharge, salpingitis, endometriosis, and hydrosalpinx
- What STDs other than C. trachomatis and N, gonorrhea cause PID?
- Gardnerella (clue cells) and Trichomonas (motile on wet prep)
- Nosocomial infections
- p. 207
- What are 2 of the most common causes of nosocomial infections?
- E. Coli (UTI) and S. aureus (wound infection)
- When in a renal dialysis unit which pathogen should you be concerned about?
- HBV (blood products)
- What is the most likely pathogen when a water source (water aerosols) is involved?
- Legionella
- What pathogen is often found on respiratory therapy equiptment?
- Pseudomonas aeruginosa (AIRuginosa when AIR or burns are involved?
- What are the two pathogens most commonly associated with urinary catheterization?
- E. coli and Proteus mirabilis
- Being in a newborn nursery is a risk factor for what pathogens?
- CMV and RSV
- Which pathogen would most associated with hyperalimentation (total parenteral nutrition)
- Candida albicans
- Infections dangerous in pregnancy
- What are the organisms that can cross the blood-placenta barrier and be dangerous in pregnancy?
- ToRCHcS=Toxoplasma, Rubella, CMV, HSV/HIV, Syphilis
- Bug hints (if all else fails)
- Name the associated bug
- Branching rods in oral infection
- Actinomyces israelii
- Surgical wound
- S. aureus
- Pus, empyema, abscess
- S. aureus
- Pediatric Infection
- Haemophilus influenzae (including epiglottis)
- Sepsis/meningitis in newborn
- Group B strep
- Dog or cat bite
- Pasteurella multocida
- Pneumonia in cystic fibrosis, burn infection
- Pseudomonas aeruginosa
- Currant jelly sputum
- Klebsiella
- Traumatic open wound
- Clostridium perfringens
- Antibody structure and function
- p. 208
- Which part of the light and heavy chain recognizes the antigen?
- Variable part
- The interchain and intrachain bonds in the antibody are of what type?
- Disulfide bonds
- What is the term called when the antibody prevents bacterial adherence?
- Neutralization
- The amino terminal is part of which fragment of the antibody?
- Fab fragment
- The fab fragment of the antibody is composed of which chain(s)?
- Light and heavy chains
- Describe the Fc fraction of the B cell receptor.
- Constant, Carboxy terminal, Complement-binding (IgG + IgM only), Carbohydrate side chains
- What is the purpose of opsonization?
- The antibody promotes phagocytosis
- The hypervarible region is a compontent of which fragment of the antibody?
- Fab fragment
- Only the heavy chain contributes to which fraction of the antibody?
- Fc
- Why does an antibody activate complement?
- To enhance opsonization and lysis
- The constant part of the heavy chain of IgM and IgG does what?
- Fixes complement
- Immunogloblulin isotypes
- p. 209
- Which isotype has an unclear function?
- IgD
- What is the main anitbody in a second response to an antigen?
- IgG
- When is IgM produced?
- Primary response to an antigen
- Which isotype induces the release of mediators from mast cells and basophils when exposed to an antigen?
- IgE
- Where is IgD found?
- On the surface of many B cells and in serum
- Which isotype fixes complement, crosses the placenta, opsonizes bacteria, and neutralizes bacterial toxins and viruses ?
- IgG
- Which isotype that guards the mucous membranes from attachement of bacteria and viruses?
- IgA
- IgE stimulates which type of hypersensitivity reaction?
- Type I
- IgE mediates immunity to what?
- Worms
- Which isotype fixes complement but does not cross the placenta?
- IgM
- Which isotype has the lowest concentration in the serum?
- IgE
- Which isotype found in secretions?
- IgA
- Which isotype crosses the placenta?
- IgG
- Ig epitopes
- Which Ig epitope is common to a single class of Ig (5 classes, determined by the heavy chain)?
- Isotype (IgG, IgA, IgM, IgE, IgD) Isotype=iso (same). Common to same class.
- Which Ig epitope is determined by antigen-binding site?
- Idiotype (specific for a given antigen) Idiotype=idio (unique). Hypervariable region is unique.
- Which Ig epitope differs among members of the same species and can be on the light or heavy chain?
- Allotype (polymorphism)
- MHC I and II
- Antigen presenting cells have which type(s) of MHC protein?
- MHC I and MHC II
- Which class MHC proteins is the main determinants of organ rejection?
- MHC II
- How many class I genes does the MHC consist of?
- 3 (A, B, C)
- What class of MHC antigen loading occurs in acidified endosomes?
- MHC II
- All nucleated cells have which type of MHC protein(s)?
- MHC I
- Which class MHC protein has 1 polypeptide with beta 2 microglobin?
- MHC I
- Where does MHC I antigen loading occur in the cell?
- RER (viral antigens)
- What are the 3 MHC II genes?
- DP, DQ, DR
- Which class MHC protein has 2 polypeptides and and alpha and beta chain?
- MHC II
- Differentiation of B and T cells
- p. 210
- Which helper T cell is involved in antibody-mediated immunity?
- Th2 cell
- In an environment with a lot of IL-12, naïve helper T cells will mature to which helper T cell?
- Th1 cell
- Why do Th2 cells produce IL-4 and IL-5?
- To help B cells make antibody (B=2nd letter of alphabet)
- Gamma interferon is secreted by what cell to activate macrophages?
- Th1 cell
- Which growth factor induces the maturation from naïve helper T cell to Th2 cell?
- IL-4
- Th1 secretes what growth factor to activate CD8 cells?
- IL-2
- IL-4 and IL-5 are released from Th2 to activate what type of cell?
- B cell
- Why do Th1 cells produce IL-2 and gamma-interferon?
- To activate macrophages (increase killing efficiency of intracellular bacteria) and CD8 cells
- Which helper T cell is involved in cell-mediated immunity?Th1 cell
- Major function of B cells and T cells
- Choose either B (antibody-mediated immunity) or T cell (cell-mediated immunity)
- Allergy (hay fever)
- B cell
- Regulation of antibody response (help and suppression)
- T cell
- Autoimmunity
- B cell
- Allergy (poison oak)
- T cell
- Host defense against infection (opsonize bacteria, neutralize toxins and viruses)
- B cell
- Host defense against infection (especially Mycobacterium uberculosis, viruses, and fungi)
- T cell
- Graft and tumor rejection
- T cell
- Adjuvant definition
- What is the short definition of an adjuvant?
- That which aids another
- Human vaccines contain aluminum hydroxide or what?
- Lipid adjuvants
- Adjuvants are ________ stimulators of the immune response but are not immunogenic by themselves.
- Nonspecific
- What are adjuvants given with to enhance response?
- Weak immunogen
- T-cell glycoproteins
- p. 211
- Cytotoxic T cells have which type of co-receptor?
- CD8
- CD4 cell secretes which 3 cytokines to activate B cells?
- IL-2, IL-4, IL-5
- What is the CD3 complex?
- A cluster of polypeptides associated with a T-cell receptor. It is important in signal transduction
- When a cell first gets infected with a virus which three cells respond?
- APC, B cell (through IgM BCR), and CD8 (through TCR and MHC I on infected cell)
- Name three antigen-presenting cells.
- Macrophage, dendritic cell, and B cell
- CD4 are on which type of T cells?
- Helper T cells
- CD4 cell secretes which growth factor to activate the CD8 cells?
- IL-2
- CD4 on helper T cells bind to what?
- MHC II on antigen-presenting cells. Product of CD and MHC=8
- CD8 on cytotoxic T cells bind to what?
- MHC I on virus-infected cells. Product of CD and MHC=8
- T cell activation
- What recognizes the foreign antigen that is presented by MHC II?
- TCR on the Th cell
- IL-2 from the helper T cell activates which cell to kill virus-infected cells?
- Cytotoxic T cell
- A foreign body is phagocytosed by what type of cell?
- APC
- The helper T cell is activated to produce which two cytokines in cell-mediated immunity?
- IL-2 and gamma-interferon
- What recognizes endogenously synthesized (viral or self) proteins that are presented by MHC I?
- TCR on cytotoxic T cell
- What is the costimulatory signal needed for a helper T cell to be activated by MHC II on an APC?
- B7 (protein on APC) and CD28 (receptor on helper T cell)
- Anergy
- p. 212
- The state when an immune cell matures but does not respond to antigens, this process is calledÂ…..
- Anergy
- Anergy in both T and B cells is caused byÂ…
- Their response to a self-antigen
- Where are B cells exposed to self-antigen
- bone marrow
- Which type of cell is more sensitive to anergic stimulus?
- T cells
- Important Cytokines
- P. 212
- What cytokine is an endogenous pyrogen?
- IL-1
- Which major cytokines are produced by Macrophages?
- IL-1, IL-6, and TNF-alpha
- What are the effects of the cytokines produced by macrophages?
- (1) causes the liver to make more complement, (2) fever, (3) mobilizes neutrophils from bone marrow, (4)helpts T-cells migrate to lymph nodes and mature, therefore, helps acute phase reaction
- IL-1 by itself causes what effects?
- Fever, stimulates the growth and differentiation of T and B cells, neutrophils, fibroblasts and epithelial cells
- What cytokine stimulates the growth of helper T and NK cells
- IL-2
- What cells secrete IL-2
- Helper T cells
- What cytokine has the same effect as GM-CSF
- IL-3
- What cytokines promote the growth and differentiation of B cells
- IL-4, IL-5, TNF-alpha
- What cytokine stimulates the synthesis of IgE and IgG?
- IL-4
- What cytokine stimulates eosinophil production?
- IL-5
- T-helper cells secrete which cytokines?
- IL-2, IL-4, IL-5, gamma interferon
- What cytokine stimulates the synthesis of IgA?
- IL-5
- What cytokine acts to attract neutrophils?
- IL-8 (major) and TNF-alpha (minor)
- What cytokine stimulates macrophages?
- gamma-interferon
- What is the difference between TNF-alpha and TNF-beta?
- TNF-alpha is secreted by macrophages, and TNF-beta is secreted by T lymphocytes. Their functions are similar.
- What do TNF-alpha and TNF-beta do?
- increase IL-2 output and B-cell proliferation, attracts neutrophils
- Cell Surface Proteins
- p. 212
- What markers identify T cells
- TCR and CD3
- what cells have receptors for MHC I
- NK cells
- What does MHC I do?
- presents self-antigens, in viral infections the molecules presented by MHC I will change, which is why NK cells respond to viral infections best.
- What cells have MHC I on their surface?
- all cells except RBCs
- what does MHC II do?
- Presents non-self antigens
- What cells have MHC II?
- macrophages, monocytes, dendritic cells (called professional antigen presenting cells)
- What markers are specific for B cells?
- CD20, CD19, IgM
- What marker disappears when B cells become anergic?
- IgM is internalized in anergic cells
- What is a marker for Macrophages?
- CD14
- What is a marker for NK cells?
- receptors for MHC I, CD 16
- Acute Phase Response
- p. 213
- What cytokines are responsible for the Acute Phase Response?
- IL-1, IL-6, TNF-alpha
- How does the acute Phase Reaction cause a fever?
- IL-1 acts on the hypothalamus to increase body temp, fat is mobilized to increase energy, and muscle mass is used to create heat
- The Acute Phase Reaction involves the mobilization of which cells?
- B cells, T cells, Neutrophils
- Why is fever useful in an infection?
- Viruses and bacteria divide less in higher temperatures, it increases antigen production, and increases parts of the immunes response
- What does the liver do in the Acute Phase Reaction?
- Creates acute phase proteins (ex: C-reactive) which then activate complement and help in opsinization
- What does bone marrow do in the Acute Phase Reaction?
- Releases CSF which causes leukocytosis
- What do Dendritic cells do in the Acute Phase Reaction?
- the Professional antibody presenting cells migrate to the lymph nodes to initiate the adaptive response.
- Complement
- P. 214
- What kind of bacteria does complement act against?
- Gram negative
- Why does complement act preferentially against gram - bacteria?
- Complement initiators like to behind to carbohydrates, so gram- bacteria or noticed more than others.
- The classic pathway is initiated byÂ….?
- IgM or IgG (remember, GM makes Classic cars) antibody-antigen complexes
- The alternate pathway is initiated byÂ….?
- basically, everything else - endotoxins, microbial surfaces, IgA, etc.
- C1, C2, C3, C4 do what?
- Viral neutralization
- C3b does what?
- think B for Binding - anything that ends in b acts to opsinize bacteria
- What does C3a do?
- Think A for Inflame - anything that ends in a acts to increase the inflammatory response. C3a leads to anaphylaxis, along with C5a
- What is MC5b6,7,8,9?
- This is the name for the membrane attack complex that punches holes in membranes and actually kills the bacteria.
- What does a lack of C1 esterase cause and why?
- causes angioedema - which is basically overactive complement. This is because C1 is the initial step in the classic pathway, and if it cannot be limited, you over-react.
- What does a lack of C3 cause?
- sever and recurrent pyrogenic infections of the sinuses and UR tract, because C3 is the first common step in both pathways, and without it both pathways are crippled.
- Lack of C6, C7, and C8 cause what?
- Nisseria bacteremia. I have no idea why.
- Lack of decay accelerating factor (DAF) leads to what?
- Paroxysmal nocturnal hemaoglobinuria because the complement attacks the RBCs. DAF stops C3.
- What is the first step in the complement cascade that combines the two pathways?
- C3 activation
- What is the first step to bind to the cell membrane?
- C5a (after C5 is cleaved by C3 products)
- Interferon Mechanism
- P. 214
- What is the purpose of interferons?
- Interferons interfere is viral infection of cells and replication. They also activate NK cells to kill infected cells
- What do Alpha and beta interferon do?
- degrade viral mRNA, thereby inhibiting viral protein synthesis.
- what does gamma interferon do?
- upregulates MHC I and II in all cells
- Hypersensitivity
- P. 215
- What is another name for Type I hypersensitivity
- anaphylactic or atpoic
- What do type I, II, and III have in common?
- they all use antibodies
- What cells are involved in Type I?
- Mast cell and Basophils
- What Ig triggers Type one reactions?
- IgE
- What molecule acts as a mediator of this reaction?
- IgE causes the release of histamine. This is a very fast reaction. Think First is Fast.
- What are some examples of Type I reactions?
- Anaphylactic shock, asthma, hives, local wheal and flare reactions.
- What is another name for Type II Hypersensitivity?
- Cytotoxic (think Cy-2-toxic)
- What happens in this reaction?
- antibodies bind to a perceived "enemy" cell and use complement and phagocytosis to kill it.
- What antibodies are common in this reaction?
- IgM and IgG
- What are some examples of Type II reactions?
- Goodpasture's, autoimmune hemolytic anemia, graves disease, rheumatic fever, etc.
- What do Type II and Type III have in common
- They both use complement MAC (Membrane attack complexes) to do some of the work.
- What is different between Type II and Type III reactions
- Type III reactions involve neutrophils and the release of a large number of cytokines and inflammatory mediators. Type II also happens to specific cells or tissues, while type III is soluble.
- What is the mechanism of a Type III Hypersensitivity Reaction?
- Soluble antibody-antigen complexes activate complement and attract inflammatory cells
- What are some examples of this?
- SLE, rheumatoid arthritis, etc
- What is serum sickness
- When you have a type III reaction to a foreign protein, such as an injected drug. It takes about 5-10 days, and you present with fever, utricara, arthralgia, and proteinuria
- What is Arthus Reaction?
- A local, subacute reaction to injected antibodies. Happens in the skin.
- Examples of the Arthus reaction?
- hypersensitivity pnemonitis and thermophilic actinomycetes
- What is the mechanism of a Type IV reaction?
- This is T-cell mediated and therefore delayed. Think that 4 is last.
- What are examples of this type of reaction?
- TB skin test, poison ivy, transplant rejection
- Immune Deficiencies
- P. 216
- Lack of B cells lead to what kind of disorders?
- Lack of Ig
- Give two examples of thisÂ…..
- Burton's Agammaglobulinemia, Selective Immunoglobin deficiency
- Burton's agammaglobulinemia is caused by what?
- X-linked defect that cause low levels in all Igs. Causes all kinds of bacterial infects. Think Boys and Bacteria for Burton's
- At what age do the infections start in Burton's?
- 6 months, because that is when the maternal IgG declines.
- What is the defect in Selective immunoglobulin deficiency?
- A lack of a certain class of Ig, probably caused by a defect in iostype switching.
- What Ig is most likely to be lacking?
- IgA, which results in sinus and lung bacterial infections
- What are three diseases that involve B and T cells?
- Wiscott-Aldrich syndrome, and Ataxia-telangiactasia
- What is SCID?
- Stem cell defect (can be anything, no one gene), leads to total lack of an immune system.
- How do the patients present?
- patients present early with viral, bacterial, fungal, and protazoal infections
- What is Wiskott-Aldritch Syndrome
- an X-linked defect that results in depressed cellular immunity and IgM formation
- How does it present?
- Triad of Eczema, thrombocytopenia, and pyrogenic infections. There is a specific inability to fight off encapsulated bacteria
- What are the Ig titers in a patient like this?
- IgA is elevated, IgE is normal, and IgM is depressed
- What is ataxia-telangiactasia?
- Defect in DNA repair that leads to neurologic problems (ataxia) and spider angiomas (telangiectasia) and IgA deficiency
- Name six phagocytotic disorders.
- Il-12 receptor deficiency, Hyper IgM syndrome, Job's syndrome, Chediak-Higashi disease, Chronic granulomatous disease, Leukocyte adhesion syndrome. (Use: In Heaven Jesus Can Comtemplate Love, use Job to remember the biblical link)
- What does Il-12 receptor deficiency cause?
- Myobacterial infections
- What does Hyper IgM syndrome cause?
- Because the cells can't class switch, you have only IgM, and nothing else, resulting is never pyrogenic infections at 6 months
- What will the titers look like in this disease?
- High IgM, low IgA, IgE, and IgG
- What causes Job's disease?
- T-cells fail to make interferon gamma and therefore neutrophils are not attracted to sites of infection
- What is the clinical picture in Job's disease?
- recurrent "cold" staph abscesses, eczema, and high levels of IgE
- What is Chronic Granulomatous Disease?
- a group of disorders that result in impaired neutrophils function
- How does CGD present?
- multiple opportunistic infections with bacteria
- What is the test for CGD?
- negative nitoblue tertraolium dye reduction test
- What is Chediak-Higashi disease?
- autosomal recessive disease of microtubule dysfunction, leading to impaired phagocytosis
- How does Chediak-Higashi disease present?
- Multiple pyrogenic Staph and strep infections
- What is Leukocyte Adhesions deficiency syndrome?
- deficiency of LFA-1 in phagocytotic cells, presents with pyrogenic infections
- Of the phagocytotic disorders, which two do not present with pyrogenic bacterial infections?
- Job's disease (no neutrophils action leads to "cold" abcesses) and IL-12 (mycobacterial infections)
- Passive vs. Active Immunity
- P. 217
- What is active immunity?
- slow onset, leads to long-lasting memory, happens after you are exposed to an antigen, basis for vaccines
- What is passive immunity?
- When you receive pre-formed antibodies, limited by the lifespan of the antibodies, rapid onset
- What diseases are treated by using passive immunity?
- Tetanus, Botulism, HBV, Rabies (To Be Healed Rapidly)
- What Igs are used for this treatment?
- high-affinity IgA and IgG
- What is another scenario in which Igs are transferred from host to patient?
- Maternal Igs are transferred to the infant.