PROTOZOA Flashcards
Causes a self-limiting diarrhea in immunocompetent individuals or life-threatening diarrhea in AIDS patients
Cryptosporidium parvum
-infection is associated with the consumption of water CONTAMINATED with INFECTED ANIMAL SPECIES
Dissemination to the liver can result in abscess formation with a characteristic anchovy paste aspirate
Entamoeba histolytica
-the organism can form an AMOEBOMA with the potential for penetration of the serosa and PERITONITIS
Common cause of amebic dysentery, infection leads to the formation of flask-shaped ulcers in the colonic mucosa
Entamoeba histolytica
-the finding of TROPHOZOITES WITH INGESTED RBCs in pathognomonic
The only common pathogenic protozoa of the small intestine
Giardia lamblia
-a HEART-SHAPED SYMMETRICAL trophozoite with 2 NUCLEI, 4 PAIRS OF FLAGELLA, and a LARGE SUCKING DISK for adherence to the mucosal surface
Causes flatulence and diarrhea with steatorrhea and the production of bulky greasy foul-smelling stool
Giardia lamblia
-infection is more common among DAY-CARE CHILDREN, CAMPERS consuming contaminated stream water, and homosexuals engaging in ORAL-ANAL CONTACT
Infection with different species results in dermal, mucocutaneous, and visceral forms of the disease
Leishmania spp.
-DERMAL LEISHMANIASIS is due to L. tropica, the MUCOCUTANEOUS FORM is due to L. brazilliensis, and the most severe form, VISCERAL LEISHMANIASIS, is due to L. donovani and can result in skin hyperpigmentation or KALA-AZAR
Transmitted by the sandfly, the amastigote stage survives and multiplies within macrophages
Leishmania spp.
-the only protozoan parasite capable of REPLICATION WITHIN THE PHAGOLYSOSOMES of reticuloendothelial cells
Free-living flagellated amoeba, acquired by swimming in freshwater ponds, causing a fulminant meningoencephalitis with death within a week
Naegleria fowleri
-another free-living amoebum, Acanthamoeba castellani, causes less severe disease, typically limited to CORNEAL UCLERATION and keratitis
Blackwater fever
Plasmodium falciparum
-seen in P. falciparum MALARIA, in which infected cells are ABNORMALLY ADHERENT and cause THROMBOSIS and ISCHEMIA with HEMOLYSIS, resulting in HEMOGLOBINURIA
Transmitted by the female Anopheles mosquito, with infection of RBCs and hepatocytes
Plasmodium spp.
-an obligate IC parasite, Plasmodium is typically seen as RING- or CRESCENT-SHAPED forms within RBCs on a Giemsa-stained peripheral blood smear
Some resistance to infection is provided to patients with sickle cell disease/trait, Glucose-6-phosphate dehydrogenase deficiency, and thalassemia
Plasmodium spp.
-symptoms of malaria include CYCLIC FEVER [every 48 hr=P. falciparum, every 72 hr=P. malariae], headache, anemia
Exposure of nonimmune mothers results in fetal transmission with the potential for stillbirth and intracerebral calcifications
Toxoplasma gondii
-infection may be acquired from cysts in RAW OR UNDERCOOKED MEAT or aerosolization of infected CAT FECES from LITTER BOXES
Usually asymptomatic in immunocompetent individuals, infection in an AIDS patient can result in fulminant, life-threatening encephalitis
Toxoplasma gondii
-visualized radiographically as a RING-ENHANCING MASS on CT scan; other ring-enhancing masses include cerebral abscess and Glioblastoma multiforme
A common cause of vaginitis, it often presents with vulvo-vaginal pruritis, with a profuse frothy discharge
Trichomonas vaginalis
-causes STRAWBERRY MUCOSA, spotty reddening and edema of the affected mucosa
Identified as pear-shaped, flagellated trophozoites with undulating movements on a wet-mount slide of vaginal or urethral discharge
Trichomonas vaginalis
-typically as STD, growth is associated with an abnormally ALKALINE pH OF THE VAGINA
