parasites and fungi - dr hussein

_______ is used in fungal nail and hair microscopic prep to dissolve tissue debris

KOH

ergosterol is in the cell membrane of ______

a. fungi

b. humans

a.

what is the MOA of itraconazole?

inhibits ergosterol synthesis

fungi is a _____ species, meaning it exists as mold/hyphae or yeast, depending on environmental conditions

dimorphic

what is typically the parasitic form of fungi?

a. yeast

b. mold

a.

what is typically the environmental form of fungi?

a. yeast

b. mold

b.

mold reproduces _______ via spores

a. asexually

b. sexually

c. either

c.

yeast reproduces _______ by budding

a. asexually

b. sexually

c. either

a.

yeast form of fungi occurs in ______ at 37ºC

a. body or lab

b. environment

a.

hyphal/mold form of fungi occurs in _______ at 25ºC

a. body or lab

b. environment

b.

how can you remember when fungi is going to be mold vs yeast?

mold in the cold, yeast in the heat

sporotrichosis is caused by the ________ form of sporothrix schenckii

yeast form

the cell wall of fungi is made of _________

chitin

protoplasm is interrupted by cross walls

a. septate hyphae

b. aseptate hyphae

a.

protoplasm is continuous and multinucleated

a. septate hyphae

b. aseptate hyphae

b.

what are the primary barriers to fungal infection?

primary barriers: intact skin and mucosal surfaces

so if skin is broken, it facilitates fungal infection

______ are sexual reproductive structures of fungi

a. spores

b. conidia

a.

_____ are asexual reproductive structures of fungi

a. spores

b. conidia

b.

onchomycosis is an infection of toenails that requires ________ treatment

systemic

agent: Lamisil

___________ cause mycetomas, inoculated through the skin due to soil molds

madurella mycetomatis

sporothrix schenckii is caused by _______

rose bush scratch

what is the treatment for sporothrix schenckii?

itraconazole — ergosterol synthesis blocker

_______ infection can occur following antibiotic treatment

candida albicans

what is an example of normal flora competing with fungi?

candida albicans proliferating after use of antibiotics or changes in nutrition — eliminates bacteria

list the flagellates we talked about

giardia lamblia (intestinalis)

trypanosoma cruzi

trypanosoma brucei

leishmania

trichomonas vaginalis

giardia lamblia (intestinalis) causes _______

steatorrhea

cyst

T/F giardia lamblia (intestinalis) lacks mitochondria

TRUE

what flagellate causes Romaña sign?

trypanosoma cruzi

trypanosoma cruzi is transmitted by ________

kissing, reduviid bug

trypanosoma cruzi is also known as _______

American trypanosomiasis

acute Chagas’ disease

what is the mode of transmission of trypanosoma brucei?

tsetse fly

_________ causes sleeping sickness

trypanosoma brucei

leishmania causes _______ at site of bite

boils

skin infection

what is another name for visceral leishmania?

Kala-azar

what is the vector for leishmania?

sandfly

________ is an STD, flagellate with NO cyst stage

trichomonas vaginalis

entamoeba histolytica is _______ ingested and causes _______

RBC ingested

causes amebic dysentery

what is the mode of transmission of entamoeba histolytica?

what secondary infection can happen?

mode of transmission: ingesting the cyst with contaminated veggies or water

secondary infection: shigella dysenteriae

entamoeba coli is _________

a. pathogenic

b. nonpathogenic

b.

do NOT contain RBCs

__________ is a brain eating ameba

naegleria fowleri

naegleria fowleri causes ________

primary amebic meningoencephalitis

list the symptoms of stage 1 primary amebic meningoencephalitis caused by naegleria fowleri

severe headache

fever

nausea

list the symptoms of stage 2 primary amebic meningoencephalitis caused by naegleria fowleri

vomiting

stiff neck

seizures

AMS

hallucinations

coma

___________ can cause eye infection (keratitis) associated with contact lenses

acanthamoeba

schistosoma haematobium egg has a _______

a. terminal spine

b. tiny (inconspicuous) lateral spine

c. large lateral spine

a.

schistosoma japonicum egg has a _______

a. terminal spine

b. tiny (inconspicuous) lateral spine

c. large lateral spine

b.

schistosoma mansoni egg has a _______

a. terminal spine

b. tiny (inconspicuous) lateral spine

c. large lateral spine

c.

T/F schistosomiasis requires snails (host) to complete its life cycle

TRUE

_________ is also known as Pharaoh’s curse

schistosoma haematobium

eggs are found in the urine for which blood fluke?

a. schistosoma haematobium

b. schistosoma japonicum

c. schistosoma mansoni

a.

eggs are found in the feces for which blood fluke?

a. schistosoma haematobium

b. schistosoma japonicum

c. schistosoma mansoni

b.

c.

schistosomiasis produce _______ larvae, which hatches from egg, survives in water, and infects snail

miracidium

schistosomiasis produce ________ larvae, which are free swimming, leaves snail, and penetrates human skin, infective stage

cercaria

where does plasmodium reproduce asexually in humans?

RBCs

what is the mode of transmission of plasmodium?

female Anopheles mosquito

-sexual reproduction

plasmodium ________ is the most deadly malaria

falciparum

if p. falciparum is non-resistant, what is used to treat it?

chloroquine

characteristics of p. falciparum

gametocyte

banana/crescent-shaped

p. falciparum can cause ________

CNS infection and black water fever

what kind of plasmodiums are persistent and stay in hypnozoite stage in liver for 5 years?

p. vivax

p. ovale

what is the mode of transmission of babesia microti?

where does it live?

same area as: ____ ?

MoT: hard bodied tick

lives in RBC

same area as lyme

what effect does toxoplasma gondii have in the first trimester?

spontaneous abortion

birth defects

what is the major source of toxoplasma gondii human infection?

opportunistic infection in ______ pts?

major source: cat feces

opportunistic: AIDS pts

T/F protozoa are eukaryotes with a cell wall

FALSE

lack a cell wall

how do you diagnose pinworm (enterobius vermicularis)?

scotch tape technique

how do you self-reinfect pinworm (enterobius vermicularis)?

what is a major symptom?

touch your butt, eggs from perianal area get on your fingers, then you touch your mouth

sx: pruritus (itching)

what causes elephantiasis (filariasis)?

mode of transmission?

cause: wuchereria bancrofti

MoT: mosquito

if you ingest third stage larva with the fresh-water copepod crustacean: cyclops (aka water flea), what parasite can you get?

dracunculus medinensis (Guinea worm)

with dracunculus medinensis, worm protrudes _______

at contact with water

how do you get ascaris lumbricoides?

ingesting embryonated eggs contaminating leafy vegetables

T/F there is a lung stage with ascaris lumbricoides

TRUE

which can autoinfect (complete lifecycle within same host)?

a. hookworms

b. strongyloides

b.

which release eggs into stool?

a. hookworms

b. strongyloides

a.

what is the infective stage of onchocerca volvulus?

mode of transmission?

infective stage: 3rd stage larva

MoT: blackfly bite

what can cause river blindness? west africa

onchocerca volvulus

trichinella spiralis is a ______

mode of transmission?

nematode

MoT: undercooked pork

trichinella spiralis cause cysts in ______

brain

striated muscle

cardiac muscle

identify each as pig, cow, or fish tapeworm

taenia saginata

diphyllobothrium latum

taenia solium

taenia saginata: cow

diphyllobothrium latum: fish

taenia solium: pig

what is diagnostic of taenia solium?

proglottids in feces

what are the modes of transmission of taenia solium?

ingesting cysticercus in pork, undercooked

ingesting vegetables contaminated with eggs

where are proglottids found with taenia saginata?

underwear

feces

taenia saginata can grow up to _______

20 meters

mode of transmission for taenia saginata?

diphyllobothrium latum?

taenia saginata: cysticercus in undercooked beef

diphyllobothrium latum: undercooked fish/sushi

list the criteria of biological warfare (BWF)

unusual agent, virus or bacteria, for the geographical area

unusual multiple resistance to antibiotics

vector does NOT exist in the area

people in areas with filtered air NOT affected

features of bacillus anthracis (anthrax)

exotoxins: EF & LF

capsule

spore forming: infectious form

T/F brucellosis and tularemia require high doses

FALSE

low doses

brucellosis is a bacterial species that is transmitted by __________

erythritol aerosol

unpasteurized milk/dairy

brucellosis is mammalian associated

list what mammal each is associated with:

b. abortus

b. melitensis

b. suis

b. abortus: cattle

b. melitensis: goats/sheep

b. suis: pigs

what is the vector for tularemia?

characterized by _____?

vector: tick, rabbit

characteristics: splenomegaly, lymphadenopathy, skin/mucous membrane ulceration, pneumonia

Q fever (coxiella burnetti) is a _______ infection that can come from _____

macrophage infection

milk products

list symptoms of acute Q fever (coxiella burnetti)

granuloma

hepatomegaly

splenomegaly

list symptoms of chronic disease: Q fever (coxiella burnetti)

endocarditis: damaged heart valve

_________ causes bubonic and pneumonic plague

yersinia pestis

which has no person to person spread?

a. bubonic

b. pneumonic

a.

how is yersinia pestis transmitted?

rat flea

-infected flea bites human

_________ causes rice water diarrhea and dehydration

vibrio cholerae (cholera)

vibrio cholerae activates ___________

adenylate cyclase

smallpox is a _____ virus

a. DNA

b. RNA

a.

how is smallpox spread?

aerosol

T/F smallpox is considered eradicated —> we don’t vaccinate for it —> majority of US population has NO IMMUNITY to it

TRUE