Micro: Fungal And Parasitic Infections Flashcards Preview

Respiratory II > Micro: Fungal And Parasitic Infections > Flashcards

Flashcards in Micro: Fungal And Parasitic Infections Deck (72)
Loading flashcards...
1
Q

What are the 3 kinds of Fungi ?

A

True Mold, True Yeast and Dimorphic

2
Q

Which form of dimorphic fungi are pathogenic and diagnostic ?

A

YEAST (yeast in the beast)

3
Q

List the 4 major dimorphic fungi

A

Blastomyces, Coccidiodes Histoplasma and sporothrix

“Can Have Both Shapes”

4
Q

List two True yeast fungi

A

Cryptococcus Neoformans and Candida

5
Q

List two True Mold pathogens

A

Aspergillus and Mucor.

6
Q

Where is Coccidiodes immitis found geographically ?

A

South West US, San Jaoquin Valley.

7
Q

Transmission of Coccidiodes immitis

A

Inhalation of mold (anthroconidia)

8
Q

Diagnostic form of Coccidiodes is referred to as a …

A

Spherule.

9
Q

In progressive pulmonary disease associated with Coccidiodes, pulmonary nodules can lead to what complication ?

A

Pneumothorax and Hemoptysis

(this is not diagnostic however, as most dimorphs can do this .

10
Q

What skin condition is associated with Coccidiodes ?

A

Erythema Nodosum (this is diagnostic for fungal infection. No other fungi make this )

Seen in 25% of cases

11
Q

What media do you grow coccidiodes on ?

A

Sabourad Dextrose.

12
Q

What preparation destroy bacterial and animal cells but preserves fungal cells ?

A

KOH prep ?

13
Q

What is the main treatment for uncomplicated coccidiodes

A

Fluconazole

14
Q

What would you give a pregnant woman who is infected with coccidiodes ?

A

Amphotericin B (Fluconazole and all Azoles are teratogenic)

15
Q

What is the treatment would you give an Immunocompromised patient ?

A

Amphotericin B followed by 1 yr of fluconazole.

16
Q

How would you describe the yeast of Blastomyces dermatitis ?

A

Broad based budding yeast ! (hyphae with nondescript conidia) ..

This is seen on microscopy (3 B’s )

17
Q

Where is Blastomyces found, geographically ?

A

Ohio and Mississippi River basins and the Great Lakes region

18
Q

What is the drug of choice for Blastomyces ?

A

Amphotericin B

Itraconozole may be used in immune competent adults

19
Q

Where is Histoplasma Capsulatum found geographically ?

A

Ohio, Missouri River Valleys

20
Q

Blastomyces is associated with what conditions (environmental) ?

A

Decaying matter such as leaves and rotting wood (beaver dams)

21
Q

Descibe a sever infection with blastomyces

A

ACUTE ONSET, lobar infiltrates, HIGH FEVER, cough.

May disseminate to : SKIN, CNS(AIDS patients)

22
Q

What is the DOC for treating a blastomyces infection ?

A

Amphotericin B

Itroconozole can be used in immune competent adults

23
Q

What cells does Histoplasma capsulatum infect ?

A

WBC’s.

They are INTRACELLULAR pathogens. (Yeast in the beast)

24
Q

Describe the Mold phase of Histoplasma

A

Hyphae with Microconidia ( is inhaled)

Tuberculate macroconidia

25
Q

Histoplasma is associated with what geographic location ?

A

Ohio, Missouri and Mississippi River Basins. (Much like Blastomyces)

26
Q

What animals/conditions are associated with greater risk for Histoplasma infection ?

A

BIRDS (Bird keepers, nest removal and places where birds and bats live like caves.)

27
Q

In the rare case of extreme infection with Histoplasma, what will be seen in the lungs on CXR ?

A

Patchy infiltrates (Lobar infiltrates are seen in Blastomyces infection)

28
Q

What is indicative of blastomyces infection while diagnosing with microscopy ?

A

Intracellular invasion of WBC’s

29
Q

How would you treat a severe/acute infection with Blastomyces ?

A

IV Amphotericin B followed by 12 wks of Itraconozole

30
Q

How would you treat a chronic infection with blastomyces ?

A

Amphotericin B followed by 2 years of Itraconazole

31
Q

Is Paracoccidiodes brasiliensis a yeast, mold or dimorphic ?

A

dimorphic !

32
Q

Where is Parracoccidiodes located geographically ?

A

Central and South America

33
Q

Describe the Chronic infection associated with Parracoccidiodes

A

Persistent Cough, Purulent sputum, Chest Pain and Fever.

Shows nodular, infiltrative, fibrotic and cavitary lesions.

34
Q

The multiple budding yeast pattern of Parracoccidiodes is reffered to as …

A

a “Pilots Wheel”

35
Q

Aspergillus is shown to have what angle in its septate hyphae ?

A

45 degrees

It is truly septated as well.

36
Q

What kind of conditions is Aspergillus associated with ?

A

Air

Soil

Decaying matter (like Blastomyces, however the later is a dimorphic while aspergillus is a true mold.)

Shower heads, water tanks and plants

37
Q

How is Aspergillus acquired ?

A

inhalation of conidia.

38
Q

What are the three Categories of Asperigillosus infections ?

A

Allergic (3 Kinds)
Non-invasive Pulmonary Disease
Invasive Pulmonary Disease

39
Q

IgE Mediated Asthma to Aspergillus (1) will result in what clinical findings ?

A

Asthma, pulmonary infiltrates, eosinophilia, elevated serum IgE

40
Q

how can you diagnose an IgE mediated hypersensitivity to Aspergillus ?

A

Aspegillus antigen skin test

41
Q

Allergic Bronchopulmonary Aspergillosis (2) occurs when aspergillus growth is seen in the bronchial tree secretions. Describe the progression of hypersensitivities seen in this illness.

A

Type I: Fist to occur. Mediated by IgE –>
TypeIII: Mediated by IgG and IgM immune complexes –>
Type IV: Macrophage mediated destruction.

42
Q

Allergic Bronchopulmonary Aspergillosis is seen almost exclusively in patients with which two pulmonary disorders ?

A

Asthma
Cystic Fibrosis.

Rarely seen in absence of either of these.

43
Q

Famer’s Lung (3) , also knows as extrinsic allergic alveolitis is due to the inhalation of Thermophilic Actinomyces ( and aspergillus !). Where would find these pathogens ?

A

Moldy Hay or contaminated compost

44
Q

What kind of hypersensitivity is Farmer’s Lung ?

A

Type III most likely

45
Q

What is the prognosis for Farmers Lung ?

A

It will spontaneously resolve but WILL recur if exposure to toxin is present.

46
Q

What causes Winemakers lung ?

A

Botrytis cinerea

47
Q

What causes Coffee workers lung ?

A

Coffee bean dust

48
Q

What causes Poultry workers lung ?

A

Avian antigens

49
Q

What causes lab workers lung ?

A

rodent antigen

50
Q

In Non-Invasive Pulmonary Disease, what preceding illnesses lead to the formation of a ‘fungal ball’ of aspergillus ?

A

Disease the lead to cavitation of the lung such as:
TB
Cystic Fibrosis
Chronic Bronchitis

The cavities left by these diseases are ripe for infections with aspergillus.

51
Q

When is treatment indicated for Non-Invasive Aspergillosis ? What is the TOC for this infection ?

A

When there is massive hemoptysis

Surgical Removal

52
Q

What TOC for Allergic Aspergillosis ?

A

Removal of offending substance followed by Oral steroids and oral itraconozole.

53
Q

Invasive Pulmonary Disease (aspergillosis ) is seen in what subset of patients ?

A

Those who are IC : Neutropenic , Corticosteroid users, Transplant patients, Malignancy and AIDS

Rapidly fatal unless diagnosed ASAP (mortality rate of 70%)

54
Q

What is the TOC for Invasive Aspergillosis ?

A

Voriconozole (not Amphotericin B, which is often used in severe infections and preggers)

55
Q

How does Mucor present ?

A

Acute and rapidly progressing infection of the nasal, paranasal cavities and orbit of the eye.

56
Q

What populations are at risk for Mucor infection ?

A

Diabetics (DKA),Neutropenic, leukemia, lymphoma, solid transplants and burn patients

57
Q

What is seen grossly in Mucor infections ?

A

Black exudate around the eyes nose and mouth.

58
Q

What characteristics of Mucor fungi can differentiate it from Aspergillus on microscopy ?

A

Non-sepatated hyphae branching at 90 degrees (aspergillus is septate and branches at 45 deg)

59
Q

What is the treatment for a patient with Mucor ?

A

Reverse the underlying IC state
Systemic Amphotericin B
Debridement of fungal infections on the face etc.

60
Q

Stachybotrys chartarum is also known as …

A

Black mold
No real definable illness caused by this, produces a mycotoxin
Dr. Kell likes this though

61
Q

What population of patients will you see Pneumocystis Jiroveci in predominantly ?

A

AIDS PATIENTS !

Must prophylactically treat AIDS patients for this when CD4+ levels drop low enough (Bactrim) due to very high mortality among those affected due to respiratory failure

62
Q

What doe Pneumocystis jiroveci bind to in order to induce alveolar exudate ?

A

Receptors on Alveolar marcrophages

63
Q

When fluid from a patient with pneumocystis jiroveci is stained with Giemsa, what will you see on microscopy ?

A

“Dented Helmets”

64
Q

What is the treatment/Prophylaxis for pneumocyxtis jeroveci ?

A

TMP-SMX (Bactrim)

65
Q

Pargonimus westermani is also known as..

A

Giant Lung Fluke

66
Q

How does one contract P.westermani ?

A

Via ingesting raw seafood like crabs, crayfish etc

67
Q

What is important to ask in History when ruling in/out P. westermani infection ?

A

History of travel (not found in the US)

Asia, Africa, india or latin america

68
Q

What is the intermediate host of P. westermani ?

A

Snails !

69
Q

Lung fluke infection may cause Hemorrhagic Bronchopneumonia which presents as hemoptysis with ‘rust colored sputum’. How can you distinguish this from TB or S. pneumo infections ?

A

Look in the sputum, you will see gold brown percolated eggs !!!

70
Q

Where is another likely site of dissemination for P. westermani ?

A

the brain

may resemble meningoencephalitis.

71
Q

What is the treatment of choice for lung fluke ?

A

Praziquantal (DOC) or Triclabendazole.

72
Q

Tropical pulmonary eosinophilia is caused by which two organisms ?

A

Wuchereria bancrofti

Brugia malayi