Exam II Study Guide Flashcards
beneificial to both organisms
mutualism
one organism benefits while the other is unharmed
commensalism
free living and parasitic existence during its life cycle
facultative parasite
completely dependent upon their host for existence
obligate parasite
cause infections
endoparasites
cause infestation (fleas)
ectoparasites
host in which the sexual, adult, stage of the life cycle occurs
definitive host
host in which the asexual (larval) stage of the life cycle occurs
intermediate host
animals other than man which harbor human parasites
serves as a source of infection
reservoir host
source of infection (could be reservoir)
mode of transmission (vector)
presence of susceptible host (whose resistance and habits are conducive to this becoming infected)
Requirements for transmission of a parasitic infection
Functions of ectoplasm
movement ingestion excretion respiration protection
Functions of endoplasm
nutrition
reproduction-mitosis
digestion
Sarcodina (amoeba) motility
pseudopods
fake feet;extension of cytoplasm
Mastigophora motility
flagella
“whip-bearing”
Ciliata motility
cilia
Sporozoa motility
non-motile in adult stage
motile in microgametes
Most important parasitic amoeba invasive-may contain ingested RBC lives in large intestine (colon) one nucleus with central karyosome even-staining peripheral chromatin
cyst- up to 4 nuclei, cigar shaped chromatoidal bars
Entamoeba histolytica
Resembles E. histolytica, but no cyst stage
Entamoeba gingivalis
Lives in large intestine
one nucleus with eccentric karyosome
uneven peripheral chromatin
contains ingested bacteria
cyst- up to 8 nuclei, irregular chromatoid bars with splintered ends
Entamoeba coli
Lives in colon
irregular eccentric karyosome - “lump of coal” - in both troph and cyst
cyst - up to 4 nuclei, NO chromatoidal bars
Endolimax nana
Non-pathogen
looks exactly like entamoeba histolytica, but Smaller
Entamoeba hartmanii
most easily recognized in the cyst form by the presence of large glycogen body that stains brown with Iodine
Iodamoeba butchlii
Slight pathogen
causing mild diarrhea
ONLY amoeba with two nuclei in troph stage
No cyst stage
Dientamoeba fragilis
leyden crystals - refractile, long spicules
produced by trauma to GI tract
granules of ruptured eosinophils
indicative of the presence of intestinal parasites
Charcot
Free living amoeba
can cause rapidly fatal form of meningitis
found in stagnant water(ponds)
best observed in CSF with hemacytometer
Naegleria fowlerii
Only parasitic class of Ciliata parasite of hogs ciliated trophozoite funnel shaped depression kidney bean shaped macronucleus pear shaped micronucleus
Cyst - large but more rounded, lacks external cilia
Balantidium coli
most important parasitic flagellete lives in duodenum troph is bilaterally symmetrical oval concave ventral sucking disc two nuclei, rod-like axostyle falling - leaf motility, flagella
cyst - up to 4 nuclei, oval
Giardia lamblia
monkey face, mild pathogen
Non pathogen
commensal flagellate
troph with a distinct curve to its body
single nucleus and cytosome
cyst - lemon-shaped, single nucleus and a cytosome
Chilomastix mesnili
Most common and largest species of Trichomonas
inhabits urogenital system
prominent undulating membrane
NO cyst stage
sexually transmitted, isolated from urine(female) more frequently than feces
Trichomonas vaginalis
keeps organism in rigid shape, provides support
axostyle
cell mouth
cytosome
aids in movement, outer edge of some flagella
undulating membrane
controls movement of flagella
blepharoplast
member of the class sporozoa cocidian lives in intestine of man and other animals
Isospora belli
crithidal form
leptomonad form
insect for host
L-D form associated with human infection single eccentric nucleus intracellular axosome vertebrate host
leishmanial form
associated with human infection long anterior flagella central nucleus undulating membrane vertebrate host
trypansomal form
Four morphological forms of blood flagellates
crithidial
leptomonad
leishmanial
trypansomal
Which form is also known as the Donovan (L-D) body?
leishmanial form
All Leishmania (as well as Trypansoma cruzi) occur in man as what intracellular inclusion in macrophages? What is their main host of invertebrate host?
L-D bodies
several species of sandflies (Phlebotomas)
What two species of Trypansoma causes sleeping sickness, are transmitted by the tsetse fly and can affect the CNS in chronic form?
T. gambiensie
T. rhodesiense
Is motile at only one point in its life cycle; microgametocytes(male sex cell) undergoes exflagellation, the sperm produced possess flagella for a brief period until fertilization occurs
Plasmodium
Pathology and symptoms of malaria
severe complications due to P. falciparum are due to vascular obstructions caused by “sticky” parasites in capillary beds; this form is known as Blackwater fever due to the severe hematuria that occurs.
symptoms - cyclic chills, fever, headache, muscular ache, nausea
What is confused with P. falciparum due to the ring forms of the trophozoite in the peripheral blood? Why is it necessary to distinguish the two?
Babesia microti
malarial drugs are toxic and are of no benefit in the treatment of infections caused by Babesia
-Transmitted by contact with infected cat feces
causes asymptomatic infection in pregnant woman which can result in congenital toxoplasmosis, leading to death or retardation of fetus
-Can grow in lab, in lab mice, but is diagnosed by serolgical techniques; significant rise in titre must be demonstrated; Sabin-Feldman dye test
Toxoplasma gondii
causative agent of a leading cause of death among AIDS patients; intersitial plasma cell pneumonia
likely to infect patients who are immunocompromised (Hodgkins disease, treatment of leukemia or cancer pt, pt on drug therapy or due to infection with HIV)
Pneumocystis carinii
intestinal sporozoan
can cause mild GI disturbances
easily identified by performing acid fast stain on dried smears of concentrated fecal specimens; oocysts of this organism are acid fast
Cryptosporidium
Espundia
mucocutaneous leishmaniasis
sandfly vector
Leishmania braziliensis
-aka and vector matching-
Oriental/Tropical sore
Baghdad/Dehli boil
cutaneous Leishmaniasis
sandfly vector
Leishmania tropica
Chaga’s
trypanosomiasis
visceral Leishmaniasis
kissing/reduviid bug vector
Trypanosoma cruzi
L-D bodies in tissue;visceral organs
West African/Gambian sleeping sickness
tsetse fly vector
Trypanosoma gambiense
East African/Rhodesian sleeping sickness
tsetse fly vector
Trypanosoma rhodesiense
Kala-azar
sand fly vector
Leishmania donovani
most common species of malaria;
enlarged RBC-prefers to infect retics
irregular in shape with ameboid extensions
Shuffner’s dots or granules
Plasmodium vivax
-morphology matching-
RBC appears enlarged
oval shape cells
irregular or fibriated edge on RBC
Plasmodium ovale
resembles rosette or daisy
band shape trophozoites
multiple meroizoites
Plasmodium malariae
applique forms
multiple ring forms(such as split-ring)
cresent shaped
Mauer’s dots or granules
Plasmodium falciparum
Name the three species with no cyst stage
Entamoeba gingicalis
Dientamoeba fragilis
Trichomonas sp.
