Protozoa

Question 1

Giardia Lamblia

Answer 1

Flagellate

Contaminated water (Cyst)

Fecal oral route

Acute diarrhea

Binucleated

Four pairs of flagella

Treat: metronidazole

Question 2

Trichomonas Vaginalis

Answer 2

Flagellate

Sexually transmitted

Multiplies on mucosal membranes

Flagella are undulating

Causes vaginitis in females; urethritis, enlargement of prostate in males

Treatment: metronidazole

Question 3

Trypansoma Brucei

Answer 3

Hemoflagellate

Carried in Tsetse fly

Epimastigotes multiply in gut and salivary glands of fly, trypomastigotes multiple in blood stream of host outside of cells

3 stages: localized (inflamed lesion), acute (in blood stream), chronic (penetrates CNS)

Can cause Chagas’ disease

Question 4

Leishmaniasis

Answer 4

Hemoflagellate

Carried in sandfly

Promastigote multiplies in sandfly; amastigote multiplies intracellularly in host macrophages

Visceral disease causes hepatosplenomegaly
Cutaneous disease causes skin ulcers

Question 5

Chagas’ Disease

Answer 5

Caused by typanosoma cruzi

Can cause cardiomyopathy, invasion of CNS, megacolon, periorbital swelling (Romana’s sign)

Question 6

Entamoeba histolytica

Answer 6

Amoeba

Causes amoebic dysentery: bloody diarrhea, liver abscesses, RUQ pain

Fecal oral transmission (cyst in water)

Invade and ulcerate host intestinal wall

Question 7

Amoebic meningoencephalitis

Answer 7

Amoeba

Rapidly fatal meningoencephalitis

Enters through nose and follows olfactory nerves to brain

Question 8

Balantidium coli

Answer 8

Ciliate (only one that causes disease in humans)

Largest parasitic protozoan

Fecal oral transmission (ingestion of cyst)

Question 9

Babesia

Answer 9

Apicomplexa

Carried by Ixodes tick

Causes fever and hemolytic anemia

Question 10

Apicomplexa

Answer 10

Type of protozoa that invade cells as growing trophozoites, then schizonts divide, and lysis and release of protozoa

Have an apical complex to invade and infect

Question 11

Malaria life cycle in humans

Answer 11

After infected by mosquito (sporozoite form is infectious form)

1. Initial round of replication in liver by sporozoites
2. Sporozoites become trophozoites
3. Trophozoites become merozoites
4. Merozoites infect RBCs
5. Mereozoites form more trophozoites
6. Gametocytes produced are infectious for mosquitos

Question 12

Cryptosporidium

Answer 12

Apicomplexa

Fecal oral transmission

Causes diarrhea, especially chronic diarrhea in AIDS patients

Acid fast cysts in stool

Question 13

Toxoplasma

Answer 13

Apicomplexa

Maternal-fetal transmission; consuming cysts in meat; oocytes in cat poop

Can cause brain abscesses, necrosis of muscle, eye or brain