Kingdom Protista Parasites

Question 1

Naegleria fowleri

Answer 1

• Motility: Pseudopod
• Mode of Transmission: trophozoite in soil or water enters nose
• Infective Stage: biflagilated trophozoite
• Hosts: Human
• Disease/Miscellaneous Info: Amebic meningoencephalitis (brain eating amoeba)

Question 2

Acanthamoeba spp.

Answer 2

• Motility: Pseudopod
• Mode of Transmission: contact with amoeba in contaminated soil or water
• Infective Stage: trophozoite or cyst
• Hosts: human
• Diseases/Miscellaneous Info: Keratitis (eye), Amebic encephalitis (Portal of entry- eye, skin, respiratory)

Question 3

Trichomonas vaginalis

Answer 3

• Motility: flagella
• Mode of Transmission: Sexual Intercourse
• Infective Stage: trophozoite (no cyst form)
• Hosts: human
• Diseases/Miscellaneous Info: Trichomoniasis (STD)

Question 4

Trypanosoma brucei

Answer 4

-Motility: flagella
-Mode of Transmission: bite from tsetse fly; Transplacental
-Infective Stage: trypomastigote
-Hosts: Definitive: human
Intermediate: tsetse fly
-Disease/Miscellaneous Info: African Sleeping Sickness (CNS infection–> coma)

Question 5

Trypanosoma cruzi

Answer 5

-Motility: flagella
-Mode of Transmission: bite from kissing bug; Transplacental
-Infective Stage: trypomastigote
-Hosts: Definitive: Human
Intermediate: kissing bug
-Disease/Miscellaneous Info: Chagas Disease (Cardiomyopathy)

Question 6

Leishmania donovani

Answer 6

-Motility: flagella
-Mode of Transmission: Bite from sand fly
-Infective Stage: promastigote
-Hosts: Definitive: human
Intermediate: sand fly
-Disease/Miscellaneous Info:
>Visceral Leishmaniasis (Kala azar)
>Cutaneous Leishmaniasis (oriental sore)

Question 7

Toxoplasma gondii

Answer 7

-Motility: none
-Mode of Transmission: Ingestion of oocyst; Transplacental
-Infective Stage: oocyst
-Hosts: Definitive: feline
Intermediate: rodent, bird and human
-Disease/Miscellaneous Info: Toxoplasmosis (about 22% of US population infected)

Question 8

Plasmodium species

Answer 8

-Motility: none
-Mode of Transmission: Bite from female Anopheles mosquito
-Infective Stage: Sporozoite
-Hosts: Definitive: female Anopheles mosquito
Intermediate: Human
-Disease/Miscellaneous: Malaria (>200 million new cases each year)

Question 9

Different parts of plasmodium

Answer 9

• Sporozoite
• ookinete
• Ring stage trophozoite
• oocysts

Question 10

Location of Asexual and Sexual Reproduction of Plasmodium

Answer 10

Asexual cycle occurs in the human

Sexual cycle occurs in mosquito

Question 11

Plasmodium lifecycle

Answer 11

1. Mosquito takes blood meal and injects sporozoite from saliva
2. Sporozoites make way to the liver–> begins to feed and grow–> produce merozoites
3. liver cells rupture releasing merozoites and enter blood stream; merozoites infect red blood cells and reproduce and burst out of infected cells; the resulting merozoites can infect other RBCs yielding cycle of infection and eruption
4. Some of the infecting merozoites develop into sexual forms called gametocytes which are either male or female–> mosquitos take these in when taking a blood meal and goes to their gut and initiates next stage of plasmodium life cycle
5. In the mosquitos gut, The gametocytes escape the RBC and develope into male and female sex cells called gametes which fuse to produce the first cell of the next generation the zygote which then matures into a motile cell ookinete and migrates to the wall of the mosquitos gut where it develops into an Oocyst. Cell division occurs in the Oocyst to produce many new cells in the form of sporozoites. The Oocysts ruptures releasing the sporozoites which migrates to the salivary glands. From the salivary glands the sporozoites can affect next human host and repeat the plasmodium lifecycle

Question 12

Entamoeba histolytica

Answer 12

• Motility: pseudopod
• Transmission: fecal-oral ingestion of cyst
• Infective stage: cyst
• Hosts: Human
• Disease: amebiasis