Mycology/Parasitology Flashcards
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
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
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)
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
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
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
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)
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
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
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+
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
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
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
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
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
Cryptosporidium
protozoa - cysts in water
- -> watery diarrhea (me), or severe diarrhea (AIDS)
- see Cysts on ACID-FAST STAIN
- Rx: Nitazoxanide in immunocompetent/me
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
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)
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
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)
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)
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)
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
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
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
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
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
Ascaris Lumbricoides (nematode - intestine)
- GIANT ROUNDWORM
- Fecal-oral, eggs in feces
- -> intestinal infestation
- Rx: Bendazole or pyrantel pamoate
“ASCARY as fuck”
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
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)
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)
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)
Loa Loa
nematode
- Deer fly, horse fly, mango fly –> Swelling in skin, worm in conjunctiva
- Rx: Diethylcarbamazine
THE ONE IN YOUR FUCKING EYEBALL
Wuchereria bancrofti
nematode - tissue
- Female mosquito –> blocks lymphatic vessels: ELEPHANTIASIS
- Latency: 9mo-1yr
- Rx: Diethylcarbamazine
“Wuch, such a big BANK”
Toxocara canis
nematode - tissue
- Food contaminated w eggs –> Visceral larva migrans (travel from gut to organs)
- Rx: Albendazole or mebendazole
“TOXic CANned food”
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!!
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
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”
Schistosoma Haematobium
flukes
- Snails are host, CERCARIAE (free swimming larvae) penetrate skin
- chronic infxn –> Squamous cell ca. of bladder
- Rx: Praziquantal
Schistosoma Mansoni
flukes
- snails are host, CERCARIAE (free swimming larvae) penetrate skin
- -> Liver and spleen granulomas, fibrosis, inflammation –> PORTAL HTN
- Rx: Praziquantal
Clonorchis sinensis
- From undercooked fish
- -> biliary tract inflammation –> Pigmented gallstones
- Assoc w cholangiocarcinoma
- Rx: Praziquantal
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!!”
Brain cysts, seizures
Taenia solium (cysticercosis)
Liver cysts
Echinococcus granulosus
Vit B12 deficeincy
Diphyllobothrium latum
Biliary tract ds, cholangiocarcinoma
Clonorchis sinensis
Hemoptysis
Paragonimus Westermani
Portal HTN
Schistosoma mansoni
Hematuria, bladder ca.
Schistosoma haematobium
Microcytic anemia
Ancylostoma duodenale, Necator americanus
Perianal pruritus
Enterobius vermicularis
Diarrhea w peripheral Eosinophilia
Strongyloides Ancylostoma Ascaris Toxicara Trichura Trichinella (not giardia or entamoeba)
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
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*
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
