Question | Answer |
6 stages of plasmodium | ring, developing troph, immature schizont, mature schizont, microgametocyte, macrogametocyte |
Balantidium coli | large, ciliated protozoan; infective-cyst; diagnostic-troph/cyst; bean-shaped macronucleus; cilia- on surface of troph; between walls on cyst |
Balantidium coli reservoir | pig |
Balantidim coli lifecycle | ingestion of contaminated food/water; excyst in sm. intestine; trophs to lg intestine to replicate by binary fission; encyst in lumen of lg. intestine to infective mature cyst passed in feces |
Balantidiasis | worldwide infection of Balantidium coli; asymptomatic - diahrrhea, dysentery, abdominal pain, weight loss |
Isospora belli | coccidial parasite - AIDS patients; oocyst -infectious/diagnostic; oval transparent, 4 sm. sporozoites surrounded by thick cell wall |
specimen for Isospora belli and lab prep/stains | fresh feces or duodenal contents from enterotest; direct wet prep; iodine prep; modified acid-fast stain |
Isospora belli lifecycle | ingestion of infective mature(sporulated) oocyst in contaminated food/water or oral-anal sexual contact; oocyst excysts in sm. intestine to sporozoites; asexual(schizogony) in cells of intestinal mucosa oocysts excreted on stool |
Isosporiasis | asymptomatic/symptomatic infection of Isospora belli; mild gastroenteritis to severe dysentery |
Charcot-Leyhen crystals | in Isospora belli -breakdown of eosinophils |
Cryptosporidium parvum | life-threatening in AIDS patients; oocyst -infectious; seen using iodine/modified acid-fast stain; asexual/sexual reproduction; infection from ingestion of contaminated food/water or person-person specimen-stool |
Blastocystic hominis | pathogenicity is questionable; vacuolated form -lg. central vacuole filled w/ fluid(90% of cell); 10% contains 2-4 nuclei saline lyse organism- use iodine prep |
Toxoplasma gondii | tissue protozoan oocyst -infectious 2 troph forms - tachyzoites/bradyzoites crosses placenta |
Toxoplasma gondii lifecycle | cat-definitive host; mice/rats-intermediate hosts; humans-accidential host; ingestion of infected cat feces (litter box); in human-tachyzoites from ingested cyst, tissue damage/initial infection -->to tissue/organs cysts filled w/ bradyzoites formed |
Pneumocystis carinii | affects lung tissue of AIDS patients; lifecycle is unknown; troph is mostly seen - ameboid w/ 1 nucleus; histology procedure- Gomori's silver stain - immunofluorecence |
Babesia microti | resembles plasmodium spp.; invade RBCs; only in ring form; rings-have sm. chromatin dot and scant amt. of cytoplasm |
Babesia microti infectious stage,vector,host | Sporozoites - infectious; vector-Ixodes scapularis tick; host-white footed mouse/rodent; accidental host-human |
Ascaris lumbricoides | "Roundworm of man"; creamy-white color,pink tint |
Ascaris lumbricoides lifecycle | ingestion of infective eggs; larvae from eggs in lg. intestine to blood stream; liver-lung migration; larvae coughed up, swallowed back to intestine; mature to adult worm in sm. intestine; exit via mouth, nose, anus |
Necator americanus | New World Hookworm; cutting plates |
Ancylosotma duodenale | Old World Hookworm; cutting teeth |
Strongyloides stercoralis | Threadworm; direct, indirect, autoinfection |