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Protozoa
- Kingdom Protista
- unicellular, eukaryotes
- 4 subphyla based on locomotion
- most have 2 forms in their life cycle
- trophozoite (vegetative) moving
- cyst (resistant) resting
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4 Subphyla based on locomotion:
- Sarcodina- amoeboid movement
- Ciliophora- move by cilia
- Mastigophora- move by flagella
- Sporozoa- non-motile
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Sarcodina
- Amoeboid movement
- move by cytoplasmic protrusions called pseudopodia
- 1. Entamoeba histolytica
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Entamoeba histolytica
- Sarcodina
- Lg. intestine
- Feeds on RBCs
- Produces ulcerative lesions, may spread to other organs
- amoebiasis (amoebic dysentary)
-bloody diarrheaFecal/oral, contaminated food/H20 - Dx: Ova & Parasites- stool
- Tx: Flagyl
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Mastigophora
- pear-shaped
- move by flagella, 2-8 depending on species
- 2 groups
- -intestinal flagellates
- -hemoflagellattes
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Intestinal flagellates
- live on intestinal or other mucosal surfaces
- 1. Giardia intestinalis
- 2. Trichomonas vaginalis
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Giardia intestinalis
- lamblia
- mastigophora, intestinal
- most common in US
- diarrhea, dehydration, flatulence
- troph-motile
- -pear-shaped
- -sucking disc
- -pair of nucleii-look like eyes
- -several pairs of flagella
- cyst-non motile
- -oval
- -4 nucleii
- -axostyles
- Reproduce in upper sm. intestine- doesn't invade tissue
- trans:
- -fecal/oral, contaminated water
- -person to person, daycare centers
- -deer, bear, beaver feces "Beaver fever"
- Dx: O&P, blood test for antibodies, string test
- Tx: Flagyl or Ciproflaxacin
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Trichomonas vaginalis
- "trich"
- men-urethral surfaces, prostate, seminal vesicles
- -asymptomatic
- women-genital mucosa
- -vaginitis
- -urinary probles
- -itchy foamy discharge
- trans:STD or fomites
- Dx: wet prep of vag. secretions, microscopic urine
- No cyst formtroph
- -1 nucleus
- -2-8 flagella
- -undulating membrane
- -aids in locomotion
- Tx: Flagyl partners too
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Hemoflagellates
- mastigophora
- live in bloodstream or parasitic tissue
- transmitted by biting insects1. Leishmania
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Leishmania
- hemoflagellate
- mastigophora
- sandfly bite
- infects WBCs, fever, anemia
- Cutaneous, "Baghdad Boil"
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Sporozoa
- Non-motile protozoa
- 1. Plsmodium
- 2. Toxoplasma gondii
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Plasmodium
- Malaria
- fever, chills, fatigue, liver damage
- P. vivax, P. ovale, P. malariae, P. falciparum (all cause malaria)
- Anopheles mosquito
- Tx: Quinine drugs, Chloroquin, Mefloquine, maralrone, doxycyline
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Toxoplasma gondii
- toxoplasmosis
- mild, self-limiting
(asymptomatic) - severe congenital defects in infantsbrain infection in AIDS
- Trans: cat, cow, sheep (birds and rodents carry), contact with cat feces or undercooked beek or lamb
- Dx: toxoplasma antibodies-blood test
- Tx: none, mild
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Cryptosporidium
- Opportunistic sporozoa
- Cryptosporidiosis
- -infects intestinal lining
- -normal -limited diarrhea 1-2 weeks
- AIDS and immunocompromised patients
- profuse diarrhea, severe, irreversible dehydration, death
- Trans: fecal/oral, contaminated water
- - Milwaukee, Door county wells- resists chlorine treatment
- Dx: FA smear-feces
- Tx: none
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Parasitic worms
- Helminths- Greek "to roll"
- large: adult forms can see with naked eye
- ova, larva are microscopic
- 2 groups
-roundworms (nemtodes) - -flatworms (cestodes-tapeworm, trematodes-flukes)
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Roundworms
- Nematodes
- sea, freshwater, soil
- polar to tropics
- they parasitize every type of animal and plant, causing economic damage and serious diseasebodies not segmented, but pointed at ends
- have complete digestive, excretory and nervous system
- separate sexes
- female is larger and produce eggs constantly 200,000/dayhookwoams have hooks or cutting devices for attachment to intestinal wall
- 1. Nectur americanus
- 2. Ascaris lumbricoides
- 3. Trichinella spiralis
- 4. Enterobius vermicularis
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Necatur americanus
- American hookworm
- roundworm
- Trans: larvae penetrate exposed skin, then to circulatory system
- Prevention: sanitation of human waste so parasite won't continue in soil, wear shoes
- Lifecycle: Foot>blood>lungs>cough/swallow>sm. intestines/lay eggs>eggs leave in fecal material
- Disease: severe anemia
- -a single worm can remove .1ml blood/day
- -usually involve mn worms-1000s
- Tx: Vermox
- Dx: eggs in O&P
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Ascaris lumbricoides
- roundworm (Nematodes)
- largest of roundworms
- Trans: ingest eggs>lungs>cough/swallow>digestive tract
- Disease: severe pneumonitis (cough, asthmatic breathing), diarrhea, vomiting, abd. pain
- Tx: Vermox
- Dx: Ascaris eggs in O&P
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Trichinella spiralis
- roundworm
- trichinosis
- Trans:undercooked pork or bear
- Lifecycle: eat>gastric juices free larva from cyst>duodenum>female worm burrow in lymph nodes/lay larvae>larv in lymph and blood>larva lodge in striated muscle tissue "encystment">cycle stops unless eaten
- Disease: muscles, diaphragm, thoracic, abd. walls, tongue, bicps, heart
- -severity depend on # of larvae
- -mild infection: GI discomfort, muscle pain, chills, weakness, increase eosinophils
- -severe infection: respiratory distress, heart involvement, death
- Dx: muscle biopsy
- -skin test
- -WBCs-look for eosinophils
- -destroys larvae after muscle penetration
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Enterobius vermicularis
- "pinworms"
- smallest parasitic roundworm
- most common helminth
- highest rate among children
- -direct or indirect transfer via clothing, bedding, toys, food
- Lifecycle: eat>intestinal tract/hatch/develop>after copulation>female to anal region>1000s of eggs>eggs out fecal matter
- Disease: anal scratching, itching, restlessness, insomnia
- -usually children
- Dx: scotch tape or pinworm paddle pressed against perianal skin
- -exam for ova (flattenend on one side)
- -sometimes adult on skin and feces
- -white forms
- -O&P not good
- Tx: Vermox, piperazine
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