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Flashcards in Mycology/Parasitology Deck (55):
1

Histoplasmosis
-Dimorphic fungi (cold - mold, heat-yeast)

-Dimorphic
-Mississippi, Ohio river valley (bat/bird droppings, chicken coops)
-Path: Macrophage filled w oval yeast form of Histoplasma
--> Pneumonia, HILAR lymphadenopathy
-as it targets histiocytes and the RES, may see Hepatosplenomegaly.
-pts w underlying lung ds: may develop "TB-like" sxs: weight loss, cavitations in lung, painful oral ulcers, hepatosplenomegaly.
-Disseminated only in Immunocompromised.

Histo Hides in macrophages

2

Dimorphic fungi

-Cold 25C: mold/hyphae. Heat/tissue: Yeast (except Cocci* spherules filled w endospores)
--> Pneumonia and can disseminate
-Sysetmic mycoses can mimic TB (granuloma formation) but no person-person transmisstion
-Rx local infxn: Fluconazole, itraconazole
-Rx systemic infxn: Amphotericin B
-Histo, Blasto, Cocci, Paracocci, Sporo

3

Blastomycosis

-East of Mississippi river and Central america, Great Lakes region
-soil --> inflammatory lung ds/pneumonia --> skin and bone
-Forms granulomatous nodules*
-Biopsy: large round yeast w single broad-based bud
-Broad Based Budding (Blasto Buds Broadly)
(can all occur in immunocompetent host)

4

Coccidiomycosis

-Dimorphic* (spherules in tissue vs yeast)
-SW US (dust)
-->pneumonia, meningitis* --> Skin and bone
-case rate incr after earthquakes (San Joaquin Valley - "Valley fever")
-Path: Spherules filled w endoscpores (is a spherule in tissue (37 degree), not a yeast)
-but would see mold still at 25C

5

Paracoccidioidmycosis

-Dimorphic*
-Latin America
-->chronic mucocutaneous or cutaneous ulcers --> LN --> lungs
-Cold/25C: multiple Blastoconidia
-Biopsy/heat: Budding yeast w "captains wheel" formation/budding blastoconidia

Paracoccidio parasails w the Captains Wheel all the way to Latin America

6

Malassezia Furfur

--> Tinea Versicolor
-Degradation of lipids --> acids --> damage melanocytes (HYPO or HYPERpigmented patches - noticeable w tanning*)
-Hot and humid weather
-KOH prep: "spaghetti and meatball" = mold and yeast simultaneously

7

Common dermatophytes

Microsporum
Trichophyton
Epidermophyton
-KOH prep: MOLD (not dimorphic)
--> Tinea pedis (athlete's foot)
--> Tinea cruris (Jock itch)
--> Tinea corporis (ringworm, on the body)
--> Tinea capitis (head, scalp)
--> tinea unguium (onychomycosis on fingernails)

8

Candida Albicans
*Opportunistic

-Systemic or superficial YEAST infxn
-Cold: pseudohyphage, budding yeast. Warm: GERM TUBE, true hyphae
-Immunocompetent: vulvovaginitis, diaper rash
-Immunocompromised: Oral/esophageal thrush, endocarditis in IV drug users --> disseminated, chronic mucocuntaenous candidiasis
-common contaminant of sputum cultures (bc it lives in your GI/mouth/skin/vagina)
-Rx: topical azole for vagina
-Rx local: Fluconazole or Caspofungin
-Rx systemic: Amphotericin B, Fluconazole, Caspofungin

9

Aspergillus
*Opportunistic

-monomorphic, only exists in mold form
-1) Invasive, esp in immunocompromised and those w CGD (i.e. Neutropenic pts/Leukemic). Lung* (hemoptysis, lung granulomas)
-2) Allergic bronchopulmonary aspergillosis (ABPA): asthma, CF
-3) Colonizing --> Aspergillomas
-Some produce aflataxons --> HCC
-Path: Septate hyphae w (A)cute (A)ngles. Replicate: Conidiophore

10

Cryptococcus neoformans
* opportunistic

--> MENINGITIS in AIDS pts
-Found in soil, PIGEON droppings
-Inhalation --> hematogenous spread to Meninges (may cause lung issue but usually asxs)
-Latex agglutination test: polysaccharide capsule antigen
-Path: Capsular halos. "Soap bubble" lesions in the brain
-Cryptococcal pneumonia dx: red on mucicarmine stain of lung tissue/bronchoalveolar lavage.
-Urease+

11

Mucor spp
Rhizopus spp
*opportunistic (in DKA, leukemic, burn)

--> Mucormycosis: DKA, Leukemic*, burn pts
-Fungi proliferate in blood vessel --> penetrate cribiform plate --> brain
-Sxs: HA, periorbital/facial pain, black necrotic eschar on face (may see CN involvement)
-Path: See broad NONSEPTATE hyphae w WIDE Angles

12

Pneumocystis jirovecii
*opportunistic

-"PCP": diffuse interstitial pneumonia-a yeast, inhaled
-Path: Disch shaped yeast forms on silver stain
-Prophylax in AIDS CD4 <200
-Rx: TMP-SMX, Pentamidine, Dapsone

13

Sporothrix schenckii

-Dimorphic
--> Sporotrichosis (Rose thrix/thorn! --> pustule/ulcer w nodules along lymphatics (ascending lymphangitis)
-Rx: Itraconazole or POTassium iodide ("Plant a ROSE in the POT")
-Path: round or cigar-shaped budding yeast; granuloma formation w giant cells, surrounded by plasma cells

14

Giardia lamblia
(protozoa - cysts in water)

-Campers w FATTY-Diarrhea - why it smells so bad!
-Dx: Trophozoites (smiley face ghost thing) or Cysts (oval) in the stool
-Rx: Metronidazole
-As few as 1 organism can cause an infxn

15

Entamoeba histolytica
(protozoa - cysts in water)

--> Amebiasis: Bloody diarrhea, Liver abscess w "anchovy paste"** exudate
-submucosal abscess ruptures in colon? see flask-shaped ulcer
-Get from cysts in water
-Dx: Trophozoites (rbc in cytoplasm**) or cysts (multi-nucleated) in stool
-Rx: Metronidazole; Iodiquinol for asxs
-as few as 1 organism can cause an infxn

16

Cryptosporidium
(protozoa - cysts in water)

--> watery diarrhea (me), or severe diarrhea (AIDS)
-see Cysts on ACID-FAST STAIN
-Rx: Nitazoxanide in immunocompetent/me

17

Toxoplasma gondii
(protozoa - CNS)

-From cysts in meat or Cat feces
--> Brain abscess in HIV (ring-enhancing on MRI)
--> Congenital (crosses placenta), triad = Chorioretinitis, hydrocephalus, intracranial calcifications
-Rx: Sulfadiazine + Pyrimethamine

18

Naegleria fowleri
(protozoa - CNS)

-from swimming in freshwater lakes ("Nalgene filled w freshwater")
-get to your brain by cribiform plate
--> (rapid, fatal) Meningoencephalitis
-Dx: Amoebas in CSF
-Rx: Amphotericin (most die)

19

Trypanosoma brucei
T. gambiense
T. rhodesiense
(protozoa-CNS)

-"African sleeping sickness" from painful TseTse fly bite
-->enlarged LN, recurring fever (due to antigenic variation), somnolence, coma
-Dx: by blood smear
-Rx: Suramin for blood borne, Melarsoprol for CNS penetration

20

Plasmodium
P. vivax/ovale
(protozoa - Heme infxn)

MALARIA - fever, HA, anemia, splenomegaly
-Anopheles mosquito
-fevers every 48 hr cycle
-Dormant form (hypnozoite) in liver ("VIVAx" for life = dormant form)
-Dx: blood smear, trophozoite ring form, RBC schizont w merozoites
-Rx: Chloroquine/Mefloquine, Primaquine** (test for G6PD first)

21

Plasmodium
P. falciparum
(protozoa - blood infxn)

MALARIA - fever, HA, anemia, splenomegaly
-Anopheles mosquito
-can be FATAL
-irregular fever patterns, parasitized rbcs occlude capillaries in brain (cerebral malaria), kidneys, lungs
-Rx: artemether/lumifantrine or atovaquone/proguanil, IV Quinidine* (if life-threatening - test for G6PD)

22

Plasmodium
P. malariae
(protozoa - blood infxn)

MALARIA - fever, HA, anemia, splenomegaly
-Anopheles mosquito
-72 hour cycle of fevers (quartan*)
-Rx: chloroquine/Mefloquine, IV Quinidine* (if life-threatening - test for G6PD)

23

Babesia
(Protozoa - blood infxn)

--> Babesiosis: Fever, hemolytic anemia
-New england Ixodes ticks
-Asplenic? more severe ds
-Dx: Blood smear: Ring form or "Maltest Cross". PCR
-Rx: Atovaquone + azithromycin

24

Trypanosoma Cruzei
(protozoa - visceral infxn)

-CHAGAS DS (South america - (C)ruzei for (C)hagas)
-Reduviid bug - "kissing bug" - painless bite
--> Acquired Achlasia/Hirschprungs. DILATED CARDIOMYOPATHY
-Dx: blood smear
-Dx: Nifurtimox

25

Leishmania donovani
(protozoa - visceral infxn)

-Sandfly bite --> Visceral Leishmaniasis
-Kala-azar (VISCERAL form): spiking fevers, hepatosplenomegaly, pancytopenia
-Cutaneous form: non healing ulcer
-Dx: Macrophages containing AMASTIGOTES
-Rx: Sodium stibogluconate

26

Trichomonas vaginalis
(protozoa - STI)

-Sexual contact (can't exist outside human bc can't form cysts)
--> Vaginitis: foul-smelling, green discharge, itching, burning
-Dx: Trophozoites on wet mount
-Rx: Metronidazole for pt and parter

27

Enterobius vermicularis
(nematode - intestine)

-PINWORM
-from food contaminated w eggs (fecal-oral)
--> anal itching (scotch tape test!)
-Rx: Bendazoles or pyrantel pamoate (worms are BENDy so give BENDazoles)

"Vermicularis" ~ "Hilarious" these worms ride the "ENTERO-BUS" like children ride the school bus

28

Ascaris Lumbricoides
(nematode - intestine)

-GIANT ROUNDWORM
-Fecal-oral, eggs in feces
--> intestinal infestation
-Rx: Bendazole or pyrantel pamoate

"ASCARY as fuck"

29

Strongyloides stercoralis
(nematode - intestine)

-Larvae in soil penetrate the skin (these worms are so STRONG they can penetrate your skin and go to your gut and then leave by your STERCOm/diarrhea)
--> intestines: vomiting, diarhea, anemia
-RX: Ivermectin, Albendazole

30

Ancylostoma duodenale
Necator americanus
(nematodes - intestine)

-HOOKWORMS
-Penetrate your skin and go to intestine, suck the blood from the walls
"These suckers are blood hungry! so hungry they'll pierce your skin and go straight for your DUODENUM, kind of like AMERICANS"
-Rx: Bendazole, pyrantel palmoate)

31

Dracunculus medinensis
(nematode - tissue)

-drinking water --> Skin inflammation/ulcers
-Rx: SLOW extraction of worm
"DRACULA has fangs and is stuck to your skin, must remove sloowwwwwwly)

32

Onchocerca volvulus
(nematodes - tissue)

-Female blackfly bite --> Hyperpigmented skin, RIVER BLINDNESS
("black flies, black skin nodules, Black sight")
-Allergic rxn to Mcirofilaria possible
-Rx: Ivermectin. (IVERmectin for rIVER blindness)

"The VOLVULUS will turn you around and around like whitewater rafting on a RIVER)

33

Loa Loa
(nematode)

-Deer fly, horse fly, mango fly --> Swelling in skin, worm in conjunctiva
-Rx: Diethylcarbamazine

THE ONE IN YOUR FUCKING EYEBALL

34

Wuchereria bancrofti
(nematode - tissue)

-Female mosquito --> blocks lymphatic vessels: ELEPHANTIASIS
-Latency: 9mo-1yr
-Rx: Diethylcarbamazine

"Wuch, such a big BANK"

35

Toxocara canis
(nematode - tissue)

-Food contaminated w eggs --> Visceral larva migrans (travel from gut to organs)
-Rx: Albendazole or mebendazole

"TOXic CANned food"

36

Taenia solium
(tapeworm)

-Larvae encysted in undercooked pork --> Intestinal infxn. Rx: Praziquantel
-Eggs in pork --> Cysticercosis(cysts everywhere)/Neurocysticercosis (cysts in brain). Rx: Praziquantel/Bendazoles

"SOLIUM ~ SODIUM" like salty bacon!!

37

Diphyllobothrium latum
(tapeworm)

-"D. LATUM" that worm that eats up all your VITAMIN B12
-From ingestion of larvae from fraw Freshwater FISH (it's a fish worm!)
-Rx: Praziquantal

38

Echinococcus granulosus
(tapeworm)

-Eggs from dog feces --> CYSTS IN LIVER.
-Can cause anaphylaxis if antigens released (surgeons pre-inject cyst w ethanol before removal)

-"GRANULEosus --> can relase ~histamine granules that would cause anaphlyaxis"

39

Schistosoma Haematobium
(flukes)

-Snails are host, CERCARIAE (free swimming larvae) penetrate skin
-chronic infxn --> Squamous cell ca. of bladder
-Rx: Praziquantal

40

Schistosoma Mansoni
(flukes)

-snails are host, CERCARIAE (free swimming larvae) penetrate skin
--> Liver and spleen granulomas, fibrosis, inflammation --> PORTAL HTN
-Rx: Praziquantal

41

Clonorchis sinensis

-From undercooked fish
--> biliary tract inflammation --> Pigmented gallstones
-Assoc w cholangiocarcinoma
-Rx: Praziquantal

42

Paragonimus westermani

Undercooked crab meat --> Lung inflammation and 2ndary bacterial infxn + Hemoptysis
-Rx: Praziquantal
"The refined westerman enjoys his CRAB cakes while he smokes his cigarrettes- what an idiot!! he's going to get lung damage!!"

43

Brain cysts, seizures

Taenia solium (cysticercosis)

44

Liver cysts

Echinococcus granulosus

45

Vit B12 deficeincy

Diphyllobothrium latum

46

Biliary tract ds, cholangiocarcinoma

Clonorchis sinensis

47

Hemoptysis

Paragonimus Westermani

48

Portal HTN

Schistosoma mansoni

49

Hematuria, bladder ca.

Schistosoma haematobium

50

Microcytic anemia

Ancylostoma duodenale, Necator americanus

51

Perianal pruritus

Enterobius vermicularis

52

Diarrhea w peripheral Eosinophilia

Strongyloides
Ancylostoma
Ascaris
Toxicara
Trichura
Trichinella
(not giardia or entamoeba)

53

Colonizing Aspergillus

= formation of Aspergillomas (fungus balls) in old lung cavities (e.g. those left by TB, emphysema, and sarcoidosis).
-May be asxs or produce cough/hemoptysis
-NOT invasive.
-On XRAY, aspergillomas will appear as radiopaque structures that shifts when pt changes position

54

Invasive aspergillus

=Aspergillosis (in immunocompromised - those that are neutropenic/CGD/leukemic), etc.
-Most commonly lung: hemoptysis, cough, pleuritic chest pain, fever
--> necrotizing pneumonia, granuloma formation
-predilection for blood vessels: hematogenous spread
-may cause tissue infarcts in skin, paranasal sinuses, kidneys, endocardium, brain.
-Rx: Amphotericin B
-NOT contagious*

55

Allergic Bronchopulmonary Aspergillosis (ABPA)

in pts w asthma
-pts present w wheezing and migratory pulmonary infiltrates
-Incr serum IgE and IgG against Aserpgillus
-Eosinophilia*
-can lead to proximal bronchiectasis
-Rx: Steroids