Microbiology - Mycology & Parasites Flashcards Preview

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Flashcards in Microbiology - Mycology & Parasites Deck (84):
1

Systemic mycoses

- can cause pneumonia and can desseminate
- dimorphic fungi
- cold (20 C) = mold; heat (37C) = yeast
- Only exception is coccidioidmycosis, which is spherule (not yeast)
- can mimic TB (granuloma formation) except there is no person to person contact

2

Treatment for systemic mycoses

Fluconazole or Itraconazole for LOCAL infecton

3

Systemic mycoses (Name them) - Hint 4

Histoplasmosis
Blastomycosis
Coccidiomycosis
Paracoccidiomyocosis

4

Histoplasmosis

- found in MIssissippi and Ohio River Valleys
- Causes pneumonia
Macrophage filled with Histoplasma (smaller than RBC)
- Found in bird or bat droppings

5

Blastomycosis

- found in states east of MS River or Central America
- Causes inflammatory lung disease and can disseminate to skin and bone
- Forms granulomatous nodules
- Broad-base budding (same size as RBC)

6

Coccidiomycosis

- found in Southwestern US, California
- Causes pneumonia and meningitis
- Can desseminate to bone and skin
- Case rate increases after earthquakes (spores in dust are thrown up in aire and becomes spherules in lungs)
- Spherules flled with endospores (much larger than RBC)

7

Paracoccidiomycosis

Latin America
Budding yeat with "captain's wheel" formation (much larger than RBC)

8

Tinea versicolor

- caused by Malassezia furfur
- degradation of lipids that causes acids that damages melanocytes and cause hypopigmented and/or hyperpigmented patches
- Occurs in hot, humid weather

9

Treatment for tinea versicolor

Topical miconazole, selenium sulfide (Selsun

10

"Spaghetti and meatball" appearance on KOH prep

Tinea versicolor

11

Other tinae

Tinea pedis (foot)
Tinea cruris (groin)
Tinea corporis (ringworm on body)
Tinea capitis (head, scalp)
Tinea unguium (Onychomycosis, on fingernails)

12

Appearance of tinea

Pruritic lesions with central clearning resembling ring, caused by dermatophytes (Microsporum, Trichophyton, Epidermophyton)

- See mold hyphae on KOH

13

Candida albicans

- opportunistic fungal infections
- systemic or superficial infection
- oral or esophageal thrush in immunocompromised pts (AIDS, diabetes, steroids, neonates)
- vulvovaginitis (diabetic patents)
- endocarditis in IV drug users

14

Treatment of Candida albicans

- Topical azole for vulvovaginitis
- fluconazole or caspofungin for oral/esophageal thrush
- Fluconazole, amphotericine B or caspofungin for systemic disease

15

Aspergillus fumigatus

Invasive aspergillosis, especially in immunocompromised and those with chronic granulomatous disease

- Aspergillomas found in lung cavities, especially after TB infection
- Acute Angles in Aspergillus

16

Aspergillus fumiagtus infection with asthma or CF

Allergic bronchopulmonary aspergilosis (APBA)

17

Discuss Aspergillus and Hepatocellular carcinoma

- some Aspergillus species produce ANAFLATOXINS associated with HCC

18

Cryptococcus neoformans

Opportunistic fungal infection
Cryptococcal meningitis, Cryptococcosis
Heavily encapsulated yeast. Not dimorphic.
- Acquired through inhalation with hematogenous dissemination to meninges
- "Soap bubble" lesions in brain

19

Diagnosis for Cryptoccocus neoformans

- "Soap bubble" lesions in (HIV patienty?)
- Culture on Sabouraud's agar
- Stains with India ink
- Latex agglutination test detects polysaccharide capsular antigen (is more specific)

20

Mucor and Rhizopus spp.

Mucormycosis
- Disease mostly in ketoacidotic diabetic and leukemic patients
- Fungi proliferate when there is excess ketone and glucose, penetrate cribiform plate, and enter brain
- Rhinocerebral, frontal lobe abcesse

21

Sx: Occurs in ketoacidotic diabetic and leukemic patients
Headache, facial pain, black necrotic eschar on face, may have cranial nerve involvement

Mucor and Rhizopus spp.

22

Pneumocystis jirovecci

Causes PCP, a diffuse interstitial pneumonia
- Inhaled. Most infections are assymptomatic
- Immunosuppression (e.g. AIDS) predisposes to disease.

23

Diagnosis of Pneuocystis jirovecci

- Diagnosed by lung biopsy or lavage
- Disc shaped yeat forms on methenamine silver stain of lung tissue
- Diffuse, bilateral CXR

24

Tx of pneumocystis jirovecci

TMP-SMX, pentamidine, dapsone
- Start prophylaxis when CD4 drops < 200 cells/mm

25

Sporothrix schenckii

Sporotrichosis
Dimorphic, cigar shaped budding yeast that lies on vegetation
- "Rose Gardner's disease" - when spores are traumatically introduced by skin (e.g. thorn)
- Causes local pustule or ulcer with nodules along draining lymphatics (ascending lymphaginitis)
- Little systemic illness

26

Treatment of sprothrix schenckii

Itracanazole or Potasium iodid

27

Opportunistic Fungal Infections

- Candida albicans
- Aspergillus fumagitus
- Cryptococcus neoformans
- Pneumocystis jirovecci
- Sporothrix schenckii
- Mucor and Rhizopus spp

28

GI infection protozoas

Giardia lamblia
Entamoeba histolytica
Cryptosporidium

29

Giardia lamblia

Giardiasis: bloating, flatulence, foul-smelling, fatty diarrhea (often seen in campers/hikers) -

30

Giardia lamblia transmission

Cysts in water

31

Diagnosis of Giardia lamblia

Trophozoites or cysts in stool

32

Treatment of Giardia Lamblia

Metronidazole

33

Entamoeba histolytica

Amebiasis: bloody diarrhea (dysentery), liver abscess ("anchovy paste" exudate
- RUQ pain
- Histology: flash-shaped ulcer is submucosal ulcer in colon ruptures

34

Transmission of Entamoeba histolytica

Cysts in water

35

Treatment of Entamoeba histolytica

Metronidazole
Iodoquinol for assymptomatic cyst passers

36

Diagnosis of Entamoeba histolytica

Serology and/or
Trophozoites (with RBCs in the cytoplasm)
Cysts (with multiple nuclei) in stool

37

Cryptosporidium

Severe diarrhea in AIDS
Mild disease (watery diarrhea in healthy individuals)

38

Transmission of cryptosporidium

Cysts in water

39

Diagnosis of Cryptosporidium

Cysts in acid-fast stain

40

Treatment of Cryptosporidium

Prevention ( by filtering city water supplies)
Nitazoxamide in immunocompotent host

41

Protoza-CNS infections

Toxoplasma gondaii
Naegleria fowleri
Trypanosomas brucei
T. gambiense
T. rhodesiense

42

Toxoplasma gondii

Brain abscess in HIV (seen in ring-ENHANCING lesions on CT/MRI)

43

Triad of Congenital Toxoplasmosis

Chorioretinitis
Hydrocephalys
Intracranial calcifications

44

Transmission of toxoplasma gondii

Cysts in meat or cat feces;
Crosses placenta (pregnant women should avoid cats)

45

Diagnosis of Toxoplasma Gondii

Serology
Biopsy
"Crescent shaped trophozoite within macrophages)

46

Treatment of Toxoplasma Gondii

Sulfadiazine + Pyremethamine

47

Naegleria fowleri

Rapidly fatal meningoencephalitis
- transmitted by swimming FRESHWATER lakes, enters via cribiform plate
- diagnosed by amoebas in spinal cord

Tx: amphotericin (for the few survivors)

48

Trypanosoma brucei

African sleeping sickness
- enlarged lymph nodes, recurring fever (due to antigenic variation)
- Somnolence, Coma
- transmitted by Tsetse fly, a painful bite
- diagnosed by blood smear

49

Treatment of Trypanosoma brucei (African sleeping sickness)

Suramin for blood borne disease
Melarsoprol for CNS penetration
Melatonin helps with sleep

50

Protozoa for Hematologic infections

Plasmodium
Babesia

51

Plasmodium
P. vivax/ovale
P. falciparum
P. malariae

Malaria: fever, headache, anemia, splenomegaly - seen in Africa, India

- transmitted by Mosquito (Anopheles)

52

P. vivax/ovale

malaria
- 48 hour cycle (tertian; includes fever on 1st day thus fevers are 48 hours apart)
- Dormant form (hypnozite) in liver - infects NEW RBCs

53

P. faciparum

sever; irregular fever patters
parasitized RBCS - infects ALL RBCs
- occlude capillaries in brain (cerebral malaria), kidneys, lungs

54

P. malariae

72 hours cycle

55

Malaria Diagnosed

Blood smear
Trophozoite ring form
RBC schizpont with merozoites

56

Treatment of malaria

Chlorquine - blocks Plasmodium heme polymerase
- Mefloquine
- Life threatening: quinidine (but test for G6PD deficiency
- Vivax/ovale - add primaquine if hypnozoite (test for G6PD deficiency)

57

Trypanosoma cruzi

Chagas disease:
- dilated cardiomyopathy
- mega colon, megaesophagus
- predominantly in South America
- transmitted by Reduviid bug ("kissing bug")
- diagnosed by blood smear
- treated with Nirfurtimox

58

Leischemasia donovani

Visceral leischmaniasis
(kala-azar)- hyperpigmented skin pattches
Sx: Spiking fevers, Hepatosplenomegaly
Pancytopenia
- transmitted by sandfly
- diagnosed with macrophages containing amastigotes)
- treated with Sodium stibogluconate

59

Trichomonas vaginalis

Vaginitis: foul-smelling, GREENISH discharge; itching and burning
- transmitted by sex (can't exist outside of human)
- diagnosed by trophozoites (MOTILE) on wet mount
- treatmetn: metronidazole for patient and partner

** Not be confused with Gardnerella vaginella (bacterium)

60

Enterobious vemicularis (pinworm)

- nematodes (roundworm)
- get by ingesting food contaminated with eggs
- intestinal infection causing anal pruritis (diagnosed via Scotch tape tes)
- treated with benzadoles or pyrantel pamoate

61

Ascaris lumbricoides (giant roundworm)

- nematodes (roundworm)
- transmitted fecal-orally; eggs visible in feces in microscope
- intestinal infection
- - treated with benzadoles or pyrantel pamoate

62

Strongyloides stercolaris

- nematodes (roundworm)
- larvae in soil penetrate the skin
- intestinal infection causing VOMITING, DIARRHEA, ANEMIA
- treatment: ivermectin or albendazole

63

Acylostoma duodenale, Nectar americanicus
(Hook worms)

- nematodes (roundworms)
- larvae penetrate skin
- intestinal infection causing anemia by sucking blood from intestinal walls
- treatment: bendazoles or pyrantel pamoate

64

Dracunulus medinesis (Guinea worm)

- nematodes (roundworms)
- found in drinking water
- causes skin inflammation and ulceration
- treatment: slow extraction of worm

65

Onchocera volvuls

- nematodes (roundworm)
- transmitted by female blackfly bite
- causes hyperpigmented skin and river blindness
- possible allergic reaction to microfilaria
- treatment: ivermectin

66

Loa Loa

- nematodes
- roundworm
- transmitted by deerfly, horsefly, mangofly
- causes swelling in skin, worm in conjunctiva
- treatment: diethylcarmabazine

67

Wuchereria bancrofti

- nematodes
- block lymphatic vessels
- elephantiasis: takes 9 months - 1 year after bite to become symptomatic
- treatment: diethylcarbamazine

68

Toxocara canis

- nematodes
- transmitted by food containing eggs
- causes visceral larva migrans (moving larvae)
- treatment albendazole or mebendazole

69

Nematodes routes of infection

Ingested ("EAT") - Enterobius, Ascaris, Toxocara

Cutaneous ("SANd") - Strongyloides, Ancylostoma, Necator

70

Taenia solium

- tapeworm
- ingestion of larvae in undercooked pork
- ingestion of eggs
- can cause intestinal infection and cystercosis (infect skeletal muscle),
neurocysticosis
- treatment: praziquantel (and - bendazole for neurocysticercosis)

71

Diphyllobothrium latum

- tapework
- tapeworm (cestodes)
- ingesting of larvae from raw fish
- can cause Vitamin B12 deficiency (tapeworm competes for Vitamin B12) --> anemia
- treatment: praziquantel

72

Echinococcus granulosus

- tapeworm
- cestodes (tapeworm)
- ingestion from eggs from dog feces
- cysts in liver, causing anaphylaxis if antigens release (surgeons inject ethanol to kill cysts)
- treatment: - bendazoles

73

Shistosoma

- trematodes (flukes)
- transmitted by snailes; cercarie penetrate human skin
- cause liver and spleen granulomas and inflammation
- chronic infection with S. haematobium can lead to SCC of bladder
- treatment: praziquantel

74

Clonorchis sinensis

- trematodes (flukes)
- found in undercooked fish
- can cause biliary tract inflammation --> pigmented gallstones
- associated with cholangiocarcinoma
- treatment: praziquantel

75

Paragonimus westermani

- trematodes
- found in undercooked crab meat
- can cause lung inflammation and secondary bacterial infection, with hemoptysis
- treatment: praziquantel

76

Parasite : Brain cysts, seizures

Taenia solium (cysticercosis)

77

Parasite: liver cysts

Echinococcus granulosus

78

Parasite: Vitamin B 12 deficiency

D. latum

79

Parasite: Biliary tract disease, cholangiosarcoma

Clonorchis sinesis

80

Parasite: Hemoptysis

Paragonimus westermani

81

Parasite: Portal hypertension

Schistosoma mansoni

82

Parasite: Hematuria, bladder cancer

Schistosoma haematobium

83

Parasite: microcytic anemia

Ancylostoma, Necator

84

Paraisite: perianal pruritis

Enterobius