Block V, Week Vi

Front 1

what is the "hygiene hypothesis?"

Back 1

the idea that at a young age we are exposed to nonpathogenic organisms and make antibidies to them. These antibodies can crossreact with pathogenic organisms encountered later in life. When a child grows up in a clean, hygenic house it is hypothesized that they are more prone to infection.

Front 2

regarding AIDS:
1. what is the "top" viral opportunistic infection?
2. what is the "top" bacterial opportunistic infection?

Back 2

1. Cytomegalovirus (CMV) retinitis
2. MAC (mycobacterium avium-intracellular complex)

Front 3

regarding AIDS:
1. what is the "top" protozoal oppportunistic infection?
2. what is the "top" fungal opportunistic infection?

Back 3

1. Toxoplasmosis of the brain
2. PcP - Pneumocystis jirovecii pneumonia

Front 4

which bacterial opportunistic infection is very similar to TB but only causes symptoms in the immunocompromised host?

Back 4

MAC (Mycobacterium avium-intracellular complex)

Front 5

what are 6 characteristics of fungi?

Back 5

1. eukaryotic
2. non-photosynthetic
3. chitin cell walls
4. Spores (asexual or sexual)
5. can be single celled (yeast)
6. can be filamentous (molds, hyphae, mycelium)

Front 6

what are the 4 classes of fungi?

Back 6

1. Ascomycetes
2. Basidiomycetes
3. Zygomycetes
4. Deuteromycetes
(ABZD)

Front 7

what are the sexual spores of Zygomycetes called and are they internal or external spores?

Back 7

Zygospores (external)

Front 8

what are the asexual spores of Zygomycetes called and are they internal or external spores?

Back 8

Sporangiospores (internal)

Front 9

what are the sexual spores of Ascomycetes called and are they internal or external spores?

Back 9

Ascospores (internal)

Front 10

what are the asexual spores of Ascomycetes called and are they internal or external spores?

Back 10

Conidiospores (external)
"ascus" - "little sac"

Front 11

what are the sexual spores of Basidiomycetes called and are they internal or external spores?

Back 11

Basidiospores (external)
"basidio" = stick

Front 12

what are the asexual spores of Basidiomycetes called and are they internal or external spores?

Back 12

Conidiospores (external)

Front 13

What are the asexual spores of Deuteromycetes called and are they internal or external spores?

Back 13

Conidiospores (external)

Front 14

In summary:which classes of fungi have asexual spores that are CONIDIOSPORES and are EXTERNAL?

Back 14

Ascomycetes
Basidiomycetes
Deuteromycetes
(all but Zygomycetes)

Front 15

How would a fungal disease...
1. cause allergies?
2. manifest in the skin?
3. manifest in the respiratory system?

Back 15

1. airborne spores
2. athelete's foot, ringworm
3. similar to and often confused w/ TB

Front 16

How does a KOH mount help us identify fungi?

Back 16

the acid disintegrates the tissue, leaving only the fungal hyphae to see.(this is due to acid resistance by their chitin walls)

Front 17

what is the name of the stain that causes fungi to fluoresce green or blue-green?

Back 17

Calcofluor white

Front 18

India Ink (nigrosin) is useful to identify which fungi in which fluid?

Back 18

THE CAPSULE OF Cryptococcus neoformans in CSF

Front 19

India ink is essentially what kind of stain? (what does it "pick out")

Back 19

India ink is a negative stain for fungal capsules.

Front 20

What does PAS (Periodic Acid Schiff) stain?

Back 20

PAS stains carbohydrates in the chitin cell wall

Front 21

What color do fungi stain in a Gomori-Silver stain?

Back 21

black or deep brown

Front 22

What are the 6 antifungal antibiotics available?

Back 22

1. Amphotericin B (and derivatives)
2. 5-fluorocytosine
3. Azoles
4. KI
5. Topicals
6. Griseofulvin

Front 23

What is the MOA of amphotericin B?

Back 23

destroys membrane function by binding sterols

Front 24

What is the drawback of amphotericin B?
(be specific)

Back 24

nephrotoxicity
(kidneys have lots of sterols)

Front 25

what are the two derivatives of amphotericin B?

Back 25

1. ABLC (Amphotericin B Lipid Complex)
2. ABCD (Amphotericin C Colloidal Dispersion)

Front 26

What are the advantages of using amphotericin B derivatives (ABLC, ABCD) instead of amphotericin B?

Back 26

less nephrotoxicity

Front 27

Which fungus is ABCD as effective as amphotericin B against?

Back 27

Aspergillus

Front 28

1. what is the MOA of 5-fluorocystine?
2. what are the advantages and drawbacks?

Back 28

1. Inhibits DNA synthesis
2. less toxic,
only effective against a limited range of fungi.

Front 29

Name 2 commonly used Azoles

Back 29

fluconazole
ketoconazole

Front 30

MOA of Azoles?

Back 30

inhibits ergosterel synthesis
(ergosterel is specifically made in the fungal membrane)

Front 31

What is the only organism KI is effective against?

Back 31

Sporotrichosis

Front 32

1. Topicals are good against?
2. example of a topical?

Back 32

1. dermatophytoses
2. tolnaftate

Front 33

What is the name of the oral drug used for severe systemic dermatophytoses?

Back 33

Griseofulvin

Front 34

MOA of Griseofulvin?

Back 34

interferes with microtubule function

Front 35

1. which organism causes Pneumocystis pneumonia (PcP)?
2. what is significant about this organism?

Back 35

1. Pneumocystis jirovecii
2. It only causes pneumonia in immunocompromised persons.

Front 36

what is a typical microscopic observation seen when diagnosing PcP?

Back 36

dark black cysts in lung
(seen with Grocott silver stain)

Front 37

what is the recommended treatment for PcP?

Back 37

cotrimoxazole or pentamidine

Front 38

which antifungal can be administered prophylactically to prevent PcP?

Back 38

cotrimoxazole

Front 39

Along with PcP, what is one of the most frequent fungal diseases?

Back 39

Candidiasis
(Candida albicans ~60%)

Front 40

Structural characteristics of Candidiasis?

Back 40

dimorphic:
pseudomycelial form
"germ tube" formation at 37 deg.C

Front 41

what is the normal habitat/reservoir for Candida?

Back 41

mouth
large intestine
vagina

Front 42

what three lab tests are used to diagnose Candidiasis?

Back 42

1. germ tube test
2. cornmeal test
3. sugar assimilation

Front 43

what is the name of the Candidiasis infection in the...
1. mouth
2. Skin
3. Vagina
4. corners of mouth

Back 43

1. Thrush
2. Cutaneous Candidiasis (dermatocandidiasis)
3. Vaginitis
4. perleche

Front 44

What is the treatment for:
1. Thrush
2. Cutaneous candidiasis
3. Systemic candidiasis

Back 44

1. restore normal flora (lactobacilli in yogurt)
2. topical Tx: clotrimazole or nystatin
3. Amphotericin B

Front 45

why is Candida albicans considered an opportunistic fungi?

Back 45

in the immunocompromised person it can cause systemic Candidiasis

Front 46

Cryptococcosis usually begins with _1__ and can spead to the __2__ or __3__ to cause __4__ or __5__.

Back 46

1. lung infection
2. blood
3. lymph
4. meningitis
5. skin lesions

Front 47

what is the treatment regimen for cryptococcosis?
- what for lung inf. and meningitis
- what for skin lesions

Back 47

- Amphotericin B (lung infection and meningitis)
- fluconazole (skin lesion)

Front 48

when cryptococcosis is seen in the clinic what kind of suspicion should be raised?

Back 48

AIDS
80-90% of cases worldwide
>50% of cases in U.S.

Front 49

where is Cryptococcosis more common than PcP as an opportunistic pathogen?

Back 49

Africa and Southeast Asia

Front 50

what is the habitat/reservoir of Cryptococcosis neoformans?

Back 50

pigeon or other bird droppings
eucalyptus trees

Front 51

describe the physical characteristics of Cryptococcus neoformans

Back 51

dimorphic
filamentous mycelium at room temp.

at 37 deg. C yeast produces a VERY LARGE CAPSULE (this capsule is easily seen with India ink negative stain)

Front 52

1. What is the method of transmission for Cryptococcosis?
2. What contributes to its virulence?

Back 52

1. inhalation of spores
2. antiphagocytic capsule

Front 53

How is Cryptococcosis diagnosed in the lab?

Back 53

1. in meningitis cases: direct examination of CSF
2. in pneumonia cases: direct examination of sputum and tissue
3. brown colonies on birdseed (niger) agar

Front 54

Which class of fungi (1) and specific genera (2) cause phycomycosis (mucormycosis)?

Back 54

Fungi - Zygomycetes
Genera - Rhizopus, Mucor

Front 55

1. Which organism causes Aspergillosis?
2. Describe the organism structure
3. Which other fungal organism has a similar structure?

Back 55

1. Aspergillus fumigatis
2. structure - filamentous "bread mold"
3. Penicillin

Front 56

1. What is a potential complication of Aspergillosis?
2. How often does this occur in Aspergillosis cases?

Back 56

1. spread to heart and CNS
2. 25% of cases

Front 57

what would you prescribe to treat Phycomycosis, Aspergillosis and Penicillinosis?

Back 57

Amphotericin B

Front 58

a systemic rash that is an allergic reaction (to circulating antigen that originated from a primary dermatophyte infection) is known as?

Back 58

dermatophytid (ID) reaction

Front 59

In diagnosing a dermatophytosis, which causative organism will show up on a PAS stain?

Back 59

Pityriasis versicolor

Front 60

Which species of fungi fluoresces under a Wood's light?

Back 60

Microsporum

Front 61

fill in the following for the Microsporum species:
1. Infection site
2. # of Macroconidia
3. wall type of macroconidia
4. # of Microconidia

Back 61

1. skin, hair
2. lots
3. thick, rough
4. lots

Front 62

fill in the following for the Trichophyton species:
1. Infection site
2. # of Macroconidia
3. wall type of macroconidia
4. # of Microconidia

Back 62

1. skin, hair, nails
2. few
3. thin, smooth
4. few

Front 63

fill in the following for the Epidermophyton species:
1. Infection site
2. # of Macroconidia
3. wall type of macroconidia
4. # of Microcondia

Back 63

1. skin, nails
2. in 2's and 3's
3. thick, smooth
4. none

Front 64

What are the three classes of dermatophytes?

Back 64

1. Microsporum
2. Trichophyton
3. Epidermophyton

Front 65

Describe the hallmark symptoms of Sporotrichosis

Back 65

"Gardener's disease"
1. begins as a primary lesion, usually on hands or feet
2. chain of lesions move along the lymphatics up the arm

Front 66

what is the etiologic agent of Sporotrichosis?

Back 66

Sporothrix shenckii

Front 67

Describe the morphology of Sporothrix shenckii

Back 67

Dimorphic
filamentous hyphal form at room temp. ("floret" conidiospores)
"cigar" form yeast, often in "cigar packets"

Front 68

Chromomycosis is often confused with what subcutaneous mycosis because they present similarly?

Back 68

Bacterial mycetoma

Front 69

what is the clinical presentation of both chromomycosis and bacterial mycetoma?

Back 69

large, distended swelling of the infected area

Front 70

What are the casuative agents of Chromomycosis (2) and what type of fungi are they?

Back 70

1. Cladosporium
2. Phialophora
Both are "dematiaceous" (dark colored) fungi

Front 71

What is the main diagnostic feature of chromomycosis?

Back 71

can see brown to black hyphae without using any tissue stain

Front 72

which organism is responsible for bacterial mycetoma (namely Madura foot and Lumpy jaw)

Back 72

Actinomyces israelii

Front 73

what are the diagnostic features of (A. israelii caused) bacterial mycetoma?

Back 73

1. "sulfur granules" (bacterial colonies)are present in the exudate and visible to the human eye
2. dark filaments seen microscopically

Front 74

which two stains are commonly used in diagnosis of (A. israelii caused) bacterial mycetoma?

Back 74

1. Brown & Benn stain
2. Gomori methamanine silver stain

Front 75

how can you tell the difference between a bacterial mycetoma caused by Actinomyces israelii or Nocardia asteroides?

Back 75

A. isrealii - anaerobic
N. asteroides - aerobic
(both are Gram + branching rods)

Front 76

what are the 2 fungal caused subcutaneous mycoses?

Back 76

1. Sporotrichosis
2. Chromocycosis

Front 77

what are the 3 fungal caused systemic mycoses?

Back 77

1. Histoplasmosis
2. Blastomycosis
3. Coccidiomycosis

Front 78

what are the general morphological characteristics of organisms causing systemic mycosis?

Back 78

dimorphic
filamentous at room temp.
yeast form at 37 deg. C

Front 79

what is the general method of transmission of systemic mycosis infections?

Back 79

aerosol/respiratory
*no known human to human transmission*

Front 80

which fungus causes Histoplasmosis?

Back 80

Histoplasma capsulatum

Front 81

regarding H. capsulatum:
1. at room temp. it resembles?
2. at 37 deg. C it resembles a yeast that divides how?

Back 81

1. "tuberculate" macroconidia (looks like thing on the end of a mace)
2. with a narrow neck between daughters

Front 82

what contributes to the virulence of Histoplasma capsulatum? (how does it infect the host cells)?

Back 82

it is an intracellular macrophage parasite

Front 83

what is the habitat/reservoirs of H. capsulatum?

Back 83

bird droppings
guano

Front 84

where is H. capsulatum geographically prevalent?

Back 84

in the Midwestern U.S.
(around Mississippi and Ohio rivers)

Front 85

Histoplasmosis often begins as __1___. It can then disseminate to which organs?

Back 85

1. pneumonia or TB mimic (flu-like symptoms)
2. organs with macrophages (blood, bone marrow, spleen, liver, lung)

Front 86

what is the recommended treatment for Histoplasmosis?

Back 86

Amphotericin B

Front 87

What is the organism that causes Blastomycosis?

Back 87

Blastomyces dermatitidis

Front 88

what is the dimorphic difference between blastomycosis and histoplasmosis?

Back 88

at 37 deg. C:

histo-narrow neck between daughters
blasto-thick neck between daughters (Blasto=BroadBasedBuds)

Front 89

how does blastomycosis present?

Back 89

1. pulmonary, "flu-like" symptoms
2. acute pneumonia or TB mimic
3. dissemination (cutaneous or any other organ - bones, urogenital, CNS etc)

Front 90

what is the organism that causes Coccidioidomycosis?

Back 90

Coccidioides immitis

Front 91

describe the morphology of C. immitis

Back 91

dimorphic
filamentous arthrospores (barrel-shaped spores in hyphae) at room temp.
spherules (large spheres filled with spores)seen at body temp.

Front 92

where is Coccidioidomycosis commonly seen and where is it prevalent?

Back 92

commonly seen (free-living) in SW US deserts
prevalent in San Jaoquin Valley, CA (hence "San Joaquin Valley Fever")

Front 93

what is the mode of transmission of coccidioidomycosis?

Back 93

VERY EASILY AEROSOLIZED, arthrospores are inhaled, cause spherules to grow in the lung.

Front 94

describe the clinical course of coccidiomycosis

Back 94

1. "San Joaquin Valley Fever" - pneumonia, flu-like symptoms
2. can disseminate to any organ, VERY DANGEROUS

Front 95

what is notable about coccidioidomycosis?

Back 95

it is the MOST RAPIDLY FATAL OF ALL SYSTEMIC FUNGAL INFECTIONS

Front 96

what is the diagnostic feature of coccidioidomycosis?

Back 96

spherules in sputum

Front 97

what is the preferred treatment for all the systemic mycoses?

Back 97

Amphotericin B

Front 98

define mycelium

Back 98

the mass of hyphae that make up the body of a fungus

Front 99

what is an arthrospore?

Back 99

a spore resulting from the fragmentation of a hypha

Front 100

define conidia

Back 100

asexual spores produced by fungi
(have Micro- and Macro-)

Front 101

What are the four forms of possible transplant rejection?

Back 101

1. Hyperacute
2. Acute
3. Chronic
4. Graft-vs-host

Front 102

which immunodeficiency disorder is caused by a failure of B cells to mature?

Back 102

Brutons agammaglobulinemia

Front 103

what is the heredity of Bruton's agammaglobulinema?

Back 103

X linked recessive
Boys get it

Front 104

what is the cause of Bruton's agammaglobulinema?

Back 104

mutation in tyrosine kinase - B cells never mature

Front 105

Hallmark of Bruton's agammaglobulinema?

Back 105

recurrent bacterial infections

Front 106

In Bruton's agammaglobulinema: Describe B cell levels in
1. serum
2. bone marrow
3. What about T cells?
4. What about plasma cells?

Back 106

1. Decreased
2. B cell precursors are present
3. T cells are uneffected
4. Plasma cells are nonexistant

Front 107

What is the treatment for Bruton's agammaglobulinema?

Back 107

Prophylactic IV Immunoglobulin

Front 108

Describe symptoms seen in an IgA deficiency (4)
(remember most patients are asymptomatic)

Back 108

1. low levels of serum and secretory IgA
2. recurrent pulmonary infections, diarrhea
3. allergies
4. other autoimmune diseases

Front 109

What is the thing to watch out for in patients with an IgA deficiency?

Back 109

BE CAUTIOUS WITH TRANSFUSIONS
Many patients have serum Antibodies to IgA: this can cause a serious rxn. in tranfusion of blood with normal IgA antibodies in it.

Front 110

What are the serum B cell levels in CVID?

Back 110

normal
B cells just don't differentiate into plasma cells

Front 111

compare the pathology of lymphoid follicles seen in:
1. CVID
2. Bruton's agammaglobulinema

Back 111

1. hyperplastic lymphoid follicles
2. NO lymphoid follicles

Front 112

describe the pathophysiology of hyper-IgM syndrome

Back 112

- T cell disorder
- failure to isotype switch, therefore the only antibodies made are IgM
- results in immunodeficiency

Front 113

what is the hallmark presenting symptom of hyper-IgM syndrome?

Back 113

Recurrent pyogenic infections

Front 114

in hyper-IgM syndrome describe:
1. the serum B and T cell levels
2. Serum of the levels of different types of antibodies?

Back 114

1. B and T cells levels normal
2. Increased IgM
very little IgA, IgE, IgG

Front 115

what is the cause of DiGeorge syndrome (Thymic aplasia)

Back 115

Thymus and parathyroid glands fail to develop (because 2nd and 3rd pharyngeal pouches did not develop correctly)
Result: No T cells and hypocalcemia

Front 116

what do patients with DiGeorge syndrome (thymic aplasia) present with?

Back 116

recurrent fungal and viral infections (due to loss of T cell mediated immunity)

Front 117

describe severe combined immunodeficiency (SCID)

Back 117

NO T cells or B cells
therefore a defect in humoral and cell mediated response

Front 118

What is the treatment for an individual with SCID?

Back 118

Bone marrow transplant

Front 119

describe the pathology of Wiscott-Aldrich Syndrome

Back 119

X linked defect
- loss of cell mediated and humoral immunity
- still have a thymus

Front 120

in Wiscott-Aldrich Syndrome what are the levels of the following:
1. IgM
2. IgG
3. IgE
4. IgA

Back 120

1. low
2. normal
3. elevated
4. elevated

Front 121

presenting symptoms of a patient with Wiscott-Aldrich Syndrome?

Back 121

WIPE:
Wiscott-Aldrich
Infection
Purpura
Eczema
(also thrombocytopenia)

Front 122

what are the symptoms of a person who has a deficiency of C5,6,7,8,9 (complement mediators)?

Back 122

Recurrent Neisserial infections

Front 123

what are the symptoms of a person who has a deficiency of C1 inhibitor?

Back 123

Hereditary angioedema
(overactive complement)

Front 124

compliment defends against what kind of bacteria?

Back 124

Gram negative

Front 125

which antibodies activate the classic pathway of compliment?

Back 125

IgG
IgM
(GM makes CLASSIC cars)

Front 126

what activates the alternate pathway of compliment?

Back 126

molecules on the surfaces of microbes (esp. endotoxin)

Front 127

which type of transplant rejection am I?
* Occurs weeks after transplantation
*Cell mediated due to cytotoxic T cells reacting against foreign MHCs

Back 127

Acute Rejection

Front 128

Which type of transplant rejection am I?
* Antibody mediated vascular damage (fibrinoid necrosis)
*occurs months to years after transplant

Back 128

Chronic rejection

Front 129

which type of transplant rejection am I?
* antibody mediated due to already present anti-donor antibodies in the recipient.
*occurs within minutes of transplantation

Back 129

Hyperacute Rejection

Front 130

which type of transplant rejection am I?
* Grafted T cells reject host cells
* results in severe organ dysfunction

Back 130

Graft-versus-Host disease

Front 131

What are some symptoms of Graft-versus-Host disease? (4)

Back 131

jaundice
maculopapular rash
hepatosplenomegaly
diarrhea

Front 132

what are the 5 groups at risk of contracting AIDS?

Back 132

1. homosexuals
2. IV drug users
3. Blood recipients
4. hemophiliacs (recieve factor VII or IX)
5. heterosexuals making contact with high risk groups

Front 133

How can vertical transmission of HIV occur? (3)

Back 133

- transplacental
- via birth canal
- via breast milk