Block D 2 Flashcards
protozoan cell biology and disease
what is entamoeba histolytica
a pathogenic protist
how is entamoeba histolytica transmitted
through contaminated water and food
what disease does entamoeba histolytica cause
amoebiasis
what does entamoeba histolytica produce
cysts
infective form resistant to gastric acids in the stomach
what does excystation lead to (entamoeba histolytica)
8 trophozosites/cysy in the small intestine
symptoms of amoebiasis
can be asymptomatic
or lead to diarrhea and/or dysentry (inflammatory diarrhea)
if left untreated what can amoebiasis cause
can invade the liver and occasionally the brain (10%)
treatment of amoebiasis
azoles
in particular metronidazole
(paramomycin or iodoquinol for luminal amoebiasis)
diagnosis of amoebiasis
cysts in the stool
symptoms of non invasive infection of entamoeba histolytica
intestinal disease
diarrhea
ulcers in colon
symptoms of invasive infection of entamoeba histolytica
extraintestinal disease
abscess in liver, lung, and brain
what is balantidium coli
ciliated, intestinal human and swine parasite
how are infections caused in balantidium coli
cysts
how is balantidium coli transmitted in humans
through faecally contaminated water
what are symptoms of balantidium coli and what does it resemble
can be asymptomatic
or lead to diarrhea and/or dysentry (inflammatory diarrhea)
amoebiasis
how is balantidium coli diagnosed
in stool and colon tissue
treatment of balantidium coli
tetracycline
metronidazole
iodoquinol
what is giardia intestinalis
flagellated anaerobic parasite
what does giardia intestinalis have
mitosomes (mitochondial remnant organelles)
what does giardia intestinalis produce
highly resistant cysts
what disease can giardia intestinalis cause
giardiasis (a common waterborne disease)
symptoms of giardiasis
-explosive foul smelling diarrhea
-intestinal cramps
-nausea
-weight loss
-malaise
diagnosis of giardiasis
cysts and trophozoites in faeces
treatment of giardiasis
metronidazole nd tinidazole
what is trichomonas vaginalis
flagellated anaerobic parasite
how is trichomonas vaginalis transmitted
transmitted person to person by sexual intercourse
can survive on moist surfaces and so can also be transmitted via toilet seats, sauna benches, and towels
symptoms of trichomonas vaginalis in males
mostly asymptomatic
symptoms of trichomonas vaginalis in females
vaginal purulent discharge
itching
burning
how is trichomonas vaginalis diagnosed
by microscopy and cell culture from patient secretions
how is trichomonas vaginalis treated
metronidazole
what is cryptosporidium parvum
protist that lives as a parasite in warm blooded animals
what does cryptosporidium parvum cause
diarrhea
what does cryptosporidium produce
thick walled cells (oocysts) that are shed in faeces of infected animals
how are oocysts transmitted in cryptosporidium parvum
through faecally contaminated water (swimming pools)
what are oocysts highly resistant to (cryptosporidium parvum)
chlorine and UV radiation
what are the most effective methods for removal of oocysts (cryptosporidium parvum)
sedimentation and filtration methods
where does the parasite develop in cryptosporidium parvum
just under host epithelial cell membrane in an intracellular but extracytoplasmic position
at what stages are the oocysts formed when expelled from the host (cryptosporidium parvum)
fully formed
what is said about the infection from oocysts (cryptosporidium parvum)
no need for sporulation and therefore cysts and immediately infective (auto-infection)
how is cryptosporidium parvum diagnosed
in stool sample with direct fluorescence antibody assay (DFA)
how is cryptosporidium parvum treated
infection of self limitied
nitazoxanide can be used (interferes with anaerobic energy metabolism)
what is toxoplasma gondii
apicomplexan protist that lives in warm blooded animals
what is the lifecycle of toxoplasma gondii similar to
cryptosporidium parvum with same intermediate stages
what does toxoplasma gondii produce
oocysts that are shed in the faeces of infected animals
how are the oocysts transmitted (toxoplasma gondii)
cats
undercooked meats
symptoms of toxoplasmosis
mainly asymptomatic
what can toxoplasmosis damage
eyes, brain, and other organs in immune compromised individuals
what can toxoplasmosis cause
birth defects
treatment of toxoplasmosis
sulphasdiazine and pyrimethamine
what is naegleria fowleri
a free living amoeba found in soil and water
how is naegleria fowleri usually transmitted
swimming in warm, soil, contaminated water sources (hot springs or lakes)
how does naegleria fowleri enter the body
through nose and directly burrows into brain
what occurs after naegleria fowleri enters the brain
extensive hemorrhage and brain damage (meningoencephalitis)
is naegleria fowleri fatal
yes, in most cases
how is naegleria fowleria diagnosed
cerebrospinal fluid
when is drug treatment effective with naegleria fowleri
if identified early
treatment of naegleria fowleri
azoles
amphotericin B
rifampicin
miltefosine
where is acanthamoeba found
fresh and salt water throughout the world
how can acanthameoba infection arise
contaminated contact lenses/cl case
broken skin>blood
infect mucosa
how many diseases can acanthameoba cause
3
what are the 3 diseases that can arise through acanthameoba
eye disease: acanthamoeba keratitis (AK)
cutaneous amoebiasis: skin disease
brain disease: granulomatous amoebic encephalitis (GAE)
how can acanthamoeba be diagnosed
microscopic examination of tissue samples
treatment of acanthamoeba
azoles
amphotericin B
rifampicin
miltefosine
(same as naegleria)
what is acanthamoeba kertitis (AK)
progressive sight-threatening corneal disease
what is the leading risk factor for AK
contact lens wear
what is the most common type of acanthamoeba infection
acanthamoeba keratitis (AK)
what is often required with cases of AK
corneal transplants
what is malaria caused by
apicomplexan parasite Plasmodium
what is used as vectors in the spread of malaria
anopheles mosquitoes
where is malaria generally found
tropical and subtropical regions
how many people are infected worldwide and how many die per year
~350 million
>1 million
what is required for a malaria diagnosis
identifying plasmodium infected erythrocytes in blood smears by microscopy
what drugs are used to prevent and treat infections
chloroquine and mefloquine (lariam)
pyrimethamine
doxycycline
clindamycin
what can malaria be controlled by
draining swamps
eliminating mosquitoes
P. malariea paroxysms onset
malaria quartana
72 h
P. vivax paroxysms onset
malaria tertiana
48 h
P. ovale paroxysms onset
malaria tertiana
48 h
P. falciparum paroxysms onset
malaria tropica
irregular ~48 h
what is leishmania
flagellated protozoan
how is leishmania transmitted
bite of sand fly
3 forms o fleishmaniasis
cutaneous
mucocutaneous
visceral
diagnosis of leishmania
microscopy of tissue specimen
PCR
serology
where does leishmania grow once in infected host
infects and grows in macrophages
what does leishmania mexicana cause
cutaneous
what does leishmania mexicana form
nodules and ulcers on skin
treatment of leishmania mexicana
pentavalent antimonial compounds
amphotericin B
miltefosine
what does leishmania braziliensis cause
mucocutaneous leishmaniasis
what does leishmaniasis braziliensis target
destroys mucosa and cartilage of mouth, nose, and throat
can mucocutaneous disease be fetal
if left untreated then yes
treatment of leishmania braziliensis
pentavalent antimonial compounds
amphotericin B
miltefosine
what does lishmania donovani cause
visceral lishmaniasis (VL)
where does the lishmania donovani parasite travel to
internal organs causing damage to liver, spleen, and bone marrow
can visceral disease be fetal
if left untreated, yes
is recovery possible for leishmania donovani (VL)
yes but occasional relapse possible
PKDL
treatment of leishmania donovani (VL)
pentavalent antimonial compounds
amphotericin B
miltefosine
how many subspecies are they of trypanosoma brucei
2
T. brucei gambiense
T. brucei rhodesiense
what does trypanosoma brucei cause
african sleeping sickness
how is trypanosoma brucei transmitted
bite of tsetse fly
where does trypanosoma brucei multiply
in the blood
what symptom occurs in stage I of trypanosoma brucei infection
intermittent fever
what system does stage II of african sleeping sickness affect
neuronal system
what does stage II of african sleeping sickness lead to
inflammation of brain tissue and necrosis
how is african sleeping sickness diagnosed
spinal puncture
microscopy of cerebro-spinal fluid
symptoms that occur during the meninoencephalitic stage of sleeping sickness
invasion of CNS
headaches
somnolence
abnormal behaviour
lethargy
loss of consciousness
coma
how is sleeping sickness treated
suramin
melarsoprol
pentamidine
eflornithine
what does trypanosoma cruzi cause
chagas disease
how is trypanosoma cruzi transmitted
bite and defaecation of kissing bug
triatomine bug
what does trypanosoma cruzi affect
heart, GI tract, CNS
in what countries does Chagas disease often occur
latin american countries
how is chagas disease diagnosed
microscopy or serology