Microbiology Unit 8

  1. Kingdom Protista
    • this is a parasite family
    • unicellar, eukaryotes
    • classified into 4 subphylas based on their means of locomotion: ameobas, ciliates, flagellates, and sporozoa
    • have 2 forms of life cycle: trophozoite and cyst
  2. Sarcodina
    • it is an amoeba class
    • moves by means of cytoplasmic protrusions called pseudopodia
    • parasite includes: Entamoeba histolytica
  3. Entamoeba hystolytica
    • causes amoebic dysentery AKA amoebiasis
    • produces bloody diarrhea
    • endemic in tropical and subtropical areas (Central and South America, Mexica, Phillipines, and Mexico)
    • this parasite feeds on RBC in the large intestine
    • Transmission: fecal-oral route and contaminated food or water
    • Dx: exam stool speciman for O&P (look for worm eggs)
    • Tx: Flagyl
  4. Mastigophora
    • is in the class flagellates
    • move by flagella
    • 2 groups: intestinal flagellates and hemoflagellates
  5. Giardia intestinals (lambia)
    • it is an intestinal flagellate causes giardiasis
    • most common in our area
    • AKA Beaver Fever
    • 2 forms: Troph (motile) and Cyst (non-motile)
    • Trophs: pear-shaped, has sucking disk to resist peristalsis, have a pair of nucleii that looks like eyes, several pairs of flagella
    • Cyst: is a resistant resting stage and has axostyles
    • Disease: frothy green diarrhea, flatulence, dehydration, cramping in upper GI tract
    • Transmission: contaminated water with deer, bear, and beaver feces; person to person; fecal-oral route
    • Dx: stool speciman under O&P for cyst eggs. If negative, perform a string test for troph. Blood test for antibody
    • Tx: Flagyl
  6. Trichomonas vaginalis
    • Disease: men - often asymptomatic, but the parasite lives on urethral surfaces, prostate or seminal vesicles; women - lives in the genital mucosa, can cause itching frothy discharge,vaginitis, and urinary problems
    • Transmission: can be a STD or live on fomites
    • Dx: wet prep of vaginal secretions so can be found in a pap smear-look for active motile trophs with undulating membrane
    • Tx: Flagyl
  7. Hemoflagellates
    • live in bloodstream or parasitic tissue
    • transmitted by biting insects
    • parasites: Leishmania
  8. Leshmania spp.
    • transmitted by the sandlfly insect---found in the desert
    • cutaneous "Baghdad boil"
    • infects WBC and causes fever and enemia
  9. Plasmodium spp
    • is a sporozoa -- no motility
    • Diseases: causes malaria , fever, chills, fatigue, periodic cyclic fevers, and can cause liver damage
    • Transmission: by anophele mosquito; the sporozoite is carred by mosquito in infected blood
    • Dx: see infected RBC in blood smears called ring form
    • Tx: Quinine drugs
  10. Toxoplasmic gondii
    • Disease: mild, self limiting disease and often asymptomatic. Only causes severe congenital defects if pregnant
    • Transmission: found in cat, cow, sheep feces; transmitted by contact with cat feces or eating undercooked infected beef or lamb
    • Dx: taxoplasmosis antibodies
    • Tx: no tx, mild sx
  11. Cryptosporidium spp
    • Disease: intestinal parasite infects intestinal lining--> causing diarrhea for 1-2 weeks, severe dehydration even death
    • Transmission: fecal-oral route, contaminated water with oocytes
    • Dx: FA smear with stool
    • Tx: no effective treatment
    • Prevention: filtration of water to remove cryptosporidium as chlorine does not kill the species
Card Set
Microbiology Unit 8