Final Exam Review- Fungi and Parasites Flashcards Preview

Medical Microbiology > Final Exam Review- Fungi and Parasites > Flashcards

Flashcards in Final Exam Review- Fungi and Parasites Deck (43):

Candida albicans type and key concepts

Opportunistic infection. Found in indwelling catheters and parenteral nutrition. Mucocutaneous, esophageal (AIDS), vaginal, cutaneous.


Treatment for C. albicans

Fluconazole, amphotericin, echinocandins.


Cryptococcus neoformans

Opportunistic infection. Leading cause of fungal meningitis. Found in bird droppings. Causes halo shape when stained with India ink. Virulence factors include melanin and phenotypic switching (changes in capsule/cell wall).


Treatment for C. neoformans

Amphotericin, followed by fluconazole


Histoplasma capsulatum

Systemic dimorphic endemic fungus that hides in macrophages. Can be inhaled when spelunking or around bats. Causes necrotizing granulomas, diagnosed with a urine antigen test. Found in Ohio River Valley. Treat with amphotericin or itraconazole.


Treatment for histoplasma capsulatum?

Amphotericin or itraconazole


Blastomyces dermatitidis

Systemic dimorphic endemic fungus. Broad based budding. Also found in Ohio River Valley. Causes lung disease. Treat with amphotericin, itraconazole, fluconazole.


Coccidioides immitis

Systemic dimorphic endemic fungus. Crowds in southwestern US, spheroid is diagnostic, causes flu-like illness.


Paracoccidioides Brasiliensis

Mariner's wheel appearance. Male predominance, causes a cough and necrotizing granulomas. Treat with itraconazole.


Penicillium Marneffei

Opportunistic and dimorphic. In asia causes umbilicated skin lesions. Treat with amphotericin and 5FC.



Opportunistic infection, common in diabetes, treatment with iron chelators, causes black necrotic lesions. Has wide hyphae with right angle branching. Treat with posaconazole


Treatment for mucormycosis?

Posaconazole - stops angioinvasion and tissue death
and tissue debridement.



Opportunistic fungus with narrow hyphae that branch at acute angles. Has fruiting body. Causes Allergic BP aspergellosis (ABPA) and aspergillomas. Treat by reinstating the immune system, but if severe, try voriconazole.


How to treat aspergillosis?

Voriconazole or immune system reinstatement.



Caused by pneumocystic jiroveci, treat with TMP-SMZ. Common when CD4 <200.


Malassezia furfur

Dermatophyte that causes hypopigmentation (Pityriasis versicolor) and has a spaghetti and meatballs look with KOH stain.



Swollen foot with fungal granules


Sporothrix schenckii

Rose gardener's disease, lymphangitic spread. Treat with itraconazole.


Plasmodium falciparum

Apicompexa protozoan. Causes malaria. Fever, shivering, arthralgias, vomiting, end-organ failure, brain damage (infarct). Worst type. This form does not have a hypnozoite form, so primaquine is not useful. Multiply infected RBC's and heavy parasitemia. Transmitted by anopheles mosquitos.


Plasmodium Vivax

Has hypnozoite form. Can treat with primaquine, will relapse because schizonts will enter bloodstream. Enlarged erythrocytes. Every 48 hours


Plasmodium ovale

Trophozoite ring form is oval shaped. Causes malaria, also has hypnozoite form. Treat with primaquine. Every 48 hours


Plasmodium malariae

Affects aging RBCs, no hypnozoite form. Band like on peripheral blood smear. Every 72 hours.


Babesia microti

Apicomplexa protozoan that is transmitted by ixodes. Commonly affects people from cape cod and hamptons. Impossible to distinguish on PBC from plasmodia Causes wide range of clinical manifestations, mostly flu like, but really affects immunosuppressed and asplenics. Treat with atovaquone and azithromycin.


Entamoeba Histolytica

Fecal-oral transmission (analingus, contaminated water), causes amoebic dysentary (bloody diarrhea). Most asymptomatic though. Has two life forms: multiplying trophozoite and infective cyst. Treat with metronidazole and ionoquinol to kill cysts.


Naeglaria fowleri/ balamuthia mandrillaris/ acanthamoeba

Infect in fresh water, no host-host transmission, usually kill host. Cause meningoencephalitis (innoculate nasopharynx and move to CNS).


Giardia lamblia

Fecal-oral transmission, causes putrid smelling diarrhea that lasts weeks, sulfur burps. Treat with metronidazole. Loss of brush border and inhibition of sucrase and maltase.


Trichomonas Vaginalis

Treat with metronidazole, causes green weeping cervical discharge, sexually transmitted.


Spore forming protozoa

Cause watery diarrhea, treat by restoring immune system.



Kinetoplastid protozoan. South America. Multiply in macrophages Transmitted via the sandfly, reservoir is dogs. Can be cutaneous (painless ulcer, think of the vet on vacation), mucocutaneous (spreads to mucous membranes of oropharynx), and visceral (hepatosplenomegaly, AKA DUM DUM FEVER). Treat with pentavalent antimony


Trypanosoma cruzi

Kinetoplastid protozoan. Causes Chagas disease and transmitted by the Reduviid bug. Causes Romana sign (edema of the eye where inoculated), chronic phase marked by megacolon, megaesophagus, cardiomegaly. Treated with Benznidazole and nifurtimox.


Trypanosoma brucei

Kinetoplastid protozoan (bar-like) transmitted by tse tse fly that causes sleeping sickness. Can be gambiense or rhodiense, but east african is worse. Initially causes winterbottom's sign (inflammation at inoculation site). Then causes personality changes, daytime somnolence, cns penetration. Antigenic variation and replication in bloodstream. Treat with suramin/melarsoprol for rhod. Pentamidine/melarsoprol for gamb.


Toxoplasma gondii

Kinetoplastid protozoan. Transmitted by cats, can cause congenital infection marked by retardation, choreoretinitis. Ring enhancing lesions in AIDS patients. Treatment with TMP-SMZ


Ascaris lumbricoides

Egg consumption leads to migration through wall up to lungs, causes Loeffler's Syndrome (allergic response to worms in alveoli), then swallowed to gut where they cause obstructions (esp in children) and malnutrition. Treat w/ albendazole and mebendazole


Necatur americanus/ancylostoma duodenale

Hookworms, have 2 pairs of cutting plates, penetrate intact skin, migrate through venous system up to lungs. Swallowed to gut. Important cause of childhood anemia (microcytic), also dog tapeworm (ancylostoma braziliense) causes creeping eruption. Albendazole/mebendazole


Strongyloides Stercoralis

Penetrates intact skin, causes superinfection with klebsiella and other gut flora by migrating around walls. Ivermectin, albendazole, mebendazole.


Enterobius vermicularis

Pinworm, causes perianal itching, use scotch tape to diagnose. Autoinnoculation, eggs hatch and move back in.


Trichuris trichura

Whipworm, causes tenesmus and rectal prolapse. Has polar plugs, also polyparasitism.


Wucheria bancrofti

Transmitted by mosquitos causes filariasis. Destruction of lymphoid organs and causes elephantiasis by backup. Even after treatment, elephantiasis persists.


Onchocerca volvulus

Causes river blindness when the worms migrate up to eye. Transmitted by blackfly treat with ivermectin.


Taenia solium

Pig tapeworm (cestode), has fewer proglottids but hooked scolex, more uterine branches than beef counterpart. Infects people who eat undercooked pork. Also, neurocysticercosis is cause of adult onset seizures in people who eat food contaminated with feces of people infected. Treat with praziquantel.


Diphyllobothrium latum

Fish cestode, causes macrocytic anemia, treat with praziquantel.


Echinococcus granulosis

Dog tapeworm transmitted in sheepherders causes hydatid cysts that burst and cause vomica. Treat with albendazole.



Flukes that pass through snails, gotten through freshwater by penetrating intact skin. Have lid like operculum. Cause egg induced granuloma formation --> hepatosplenomegaly, CNS involement, and hematuria. Treat with praziquantel.