parasites exam 6

What is the Phylum Ciliophora known for?

A large and diverse group of protozoa characterized by the presence of cilia in at least one stage of their life cycle.

What is the primary mode of motility for ciliates?

Ciliates move by means of cilia.

How do most ciliates acquire food?

Most ciliates are phagotrophic and ingest food through a cytosome.

What are the two types of nuclei present in ciliates?

Ciliates generally have a macronucleus and a micronucleus.

What are the two forms of reproduction in ciliates?

Asexual reproduction through binary fission and sexual reproduction through conjugation.

What is a trophozoite?

The growing and active stage of a ciliate.

What is a cyst in the context of ciliates?

A dormant stage that is usually infective.

Name an important ciliate that affects pigs and humans.

Balantidium coli.

What is the life cycle transmission route for Balantidium coli?

Transmission occurs via the fecal/oral route through ingestion of cysts.

What symptoms are associated with Balantidium coli infection?

Diarrhea, abdominal pain, and in rare cases, dysentery.

What is Ichthyophthirius multifiliis commonly known as?

Ich or white spot disease.

What is the primary host for Ichthyophthirius multifiliis?

Freshwater fish.

What are the symptoms of Ichthyophthirius multifiliis infection?

Small, raised white lesions on skin, fins, and gill tissue.

What is the primary pathogenic effect of Naegleria fowleri?

It causes primary amebic meningoencephalitis (PAM).

How does Naegleria fowleri infect the host?

Trophozoites migrate up olfactory nerves to the brain.

What is the life cycle of Entamoeba histolytica?

Involves cysts and trophozoites passed in feces, with mature cysts ingested leading to excystation.

What is the diagnostic method for Entamoeba histolytica?

Demonstrating trophozoites or cysts in feces through examination of multiple samples.

What is the significance of the cyst stage in amoebas?

Most amoebas have a resistant cyst stage that aids in transmission.

What distinguishes Entamoeba coli from Entamoeba histolytica?

Entamoeba coli has mature cysts with 8 nuclei, while E. histolytica has 4 nuclei.

What are opportunistic parasites?

Parasites that are normally free-living but become parasitic under certain conditions, often due to immunosuppression.

What is the role of good hygienic practices in preventing Balantidium coli infections?

Good hygiene helps prevent fecal/oral transmission of cysts.

What is the typical size of mature cysts of Entamoeba histolytica?

10 to 20 micrometers.

What are the common methods for diagnosing amebiasis?

Finding cysts or trophozoites in feces and using ELISA or PCR for definitive diagnosis.

What is the effect of Ichthyophthirius multifiliis on the fish industry?

It has a significant negative impact due to high mortality rates in affected fish.

What is the characteristic appearance of trophozoites of Ichthyophthirius multifiliis?

They have a C-shaped macronucleus used for identification.

What is the primary habitat for Naegleria fowleri?

Warm freshwater lakes, rivers, or heated swimming pools.

What is the primary method of transmission for Entamoeba histolytica?

Transmission occurs through ingestion of cysts from contaminated food or water.

What is the diagnostic form of Fowleri infection found in CSF?

Trophozoite

Which organism is associated with keratitis and granulomatous amebic encephalitis (GAE)?

Acanthamoeba species

What type of infection is more common in individuals with a compromised immune system?

Disseminated infection

How can Acanthamoeba enter humans through the eye?

Causing severe keratitis

What is the life cycle of Acanthamoeba species?

Cysts → Trophozoite → Mitosis

What is Balamuthia mandrilaris originally isolated from?

The brain of a baboon

What is the primary method of transmission for Blastocystis hominis?

Fecal-oral transmission

What is the pathogenicity status of Blastocystis hominis?

Not fully determined

What is the most common flagellate parasite in the US?

Giardia duodenalis

What disease does Giardia duodenalis cause?

Giardiasis (beaver fever)

What are the two forms in which Giardia exits the body?

Trophozoite and cysts

What is the morphology of Giardia trophozoites?

Pear or tear drop shaped with two nuclei and multiple flagella

What is the infective stage of Giardia duodenalis?

Cysts

What is the primary clinical sign of Giardia duodenalis infection?

Acute fatty diarrhea

What diagnostic method is used to identify Giardia trophozoites?

Fecal smear

What is the treatment for Giardia duodenalis infection?

Metronidazole (Flagyl)

What is the life cycle of Giardia duodenalis?

Fecal-oral transmission → Ingestion of cysts → Release of trophozoites in the duodenum

What are the assemblages of Giardia duodenalis that infect humans?

Assemblages A and B

What is the structure that helps Trichomonads attach to epithelial cells?

Axostyle

What is a common characteristic of Trichomonads?

They usually lack a cyst stage

What is the method of division in Trichomonads?

Longitudinal binary fission

What is the significance of hydrogenosomes in Trichomonads?

They produce ATP and metabolize pyruvate

What is the primary transmission method for Trichomonas vaginalis?

Direct contact (STD in humans)

What is the role of personal hygiene in preventing Giardia infections?

It helps protect water sources and reduces transmission

What is the characteristic of Giardia cysts?

They are oval shaped and immediately infective

What is the common symptom of Giardia infection in animals?

Diarrhea

What is the recommended method for diagnosing Giardia cysts?

Fecal flotation test

What is tritrichomonas foetus?

An STD in cattle causing bovine genital trichomoniasis.

What disease does tritrichomonas blagburni cause in cats?

Chronic, waxing, and waning large bowel diarrhea.

What is histomonas meleagridis known for?

Causing blackhead disease in turkeys and other gallinaceous fowl.

What is the primary mode of transmission for histomonas meleagridis?

Ingesting Heterakis gallinarum eggs or cloacal drinking.

What are the symptoms of trichomoniasis in females?

Vaginitis, foul-smelling discharge, pain during intercourse, and painful urination.

What is the incubation period for trichomoniasis?

4 days to 4 weeks.

How is trichomoniasis diagnosed?

In pouch culture, direct smear, rapid antigen tests, or molecular diagnosis.

What is the treatment for trichomoniasis?

Metronidazole.

What is the significance of the trophozoite stage in trichomonas species?

It is the only stage present; no cysts are formed.

What are the common diagnostic tests for tritrichomonas foetus in bulls?

Preputial scraping, direct microscopic observation, culture, and PCR.

What are the economic impacts of histomoniasis in chickens?

Approximately $2 million per year in the US.

What is the characteristic appearance of histomonas meleagridis?

Pleomorphic, with no true cyst stage and various trophic stages.

What are the principal lesions caused by histomonas meleagridis?

Pinpoint ulcers in the cecum and liver.

What are the life cycle stages of kinetoplastids?

Trypomastigote, epimastigote, promastigote, and amastigote.

What is the role of the kinetoplast in kinetoplastids?

It contains unique mitochondrial DNA and is important for the parasite's structure.

What are the two sections of Trypanosoma classification?

Stercoraria (posterior development) and salivaria (anterior development).

What is antigenic variation in African trypanosomes?

The ability of the parasite to mix proteins to evade the immune system.

What is the main vector for Trypanosoma brucei?

The Tsetse fly.

What disease is caused by Trypanosoma brucei?

African sleeping sickness (HAT).

What are the two forms of African sleeping sickness caused by Trypanosoma brucei?

T. brucei gambiense (chronic) and T. brucei rhodesiense (acute).

What is the significance of the metacyclic trypomastigote?

It is the infective form that transfers infection between hosts.

What are the common symptoms of African sleeping sickness?

Fever, headaches, joint pains, and neurological symptoms in advanced stages.

What is the life cycle of Leishmania characterized by?

Development in insect vectors and mammalian hosts, with distinct stages.

What is the primary habitat for Trypanosoma species?

Blood, lymphatic system, and tissues of hosts.

How do kinetoplastids multiply?

By binary fission.

What is the role of insect vectors in the life cycle of trypanosomatids?

They transmit the parasites through blood feeding and provide a developmental stage.

What are the common symptoms of trichomoniasis in males?

Usually asymptomatic, but can include urethritis and prostate issues.

What is the significance of safe sex practices in preventing trichomoniasis?

They reduce the risk of transmission of the infection.

What is Trypanosoma brucei rhodesiense known for?

It represents under 5% of reported cases and causes an acute infection that develops rapidly and invades the central nervous system.

What is a key characteristic of Trypanosoma brucei gambiense?

It causes a chronic infection and is associated with Winterbottom's sign, which is swelling of lymph nodes.

What is the primary vector for Trypanosoma brucei?

Tsetse flies.

What are the symptoms of true sleeping sickness caused by T. brucei gambiense?

Behavioral and personality changes, apathy, confusion, fatigue, coordination loss, and somnolence.

What is the life cycle of Trypanosoma cruzi?

Kissing bugs take a blood meal, passing metacyclic trypomastigotes in feces, which enter the host through bite wounds or mucosal membranes.

What disease is caused by Trypanosoma cruzi?

Chagas' disease.

What are the two main phases of Chagas' disease?

Acute and chronic phases.

What is Romana's sign?

Periorbital swelling syndrome that occurs when feces from kissing bugs are rubbed into the eye.

What are the clinical forms of Leishmania infections?

Visceral, cutaneous, and mucocutaneous leishmaniasis.

What is the vector for Leishmania spp.?

Sand flies.

What is cutaneous leishmaniasis characterized by?

An erythematous asymptomatic papule that turns into a vesicle, pustule, and then an ulcer.

What is visceral leishmaniasis also known as?

Kala-azar or black fever.

What are the symptoms of visceral leishmaniasis?

Low-grade fever, malaise, generalized swelling of lymph nodes, enlarged liver and spleen, and joint problems.

How is Leishmania infantum transmitted?

From dogs to humans via sand flies.

What is the infective stage of Trypanosoma brucei?

Metacyclic trypomastigotes.

What are the life stages of Leishmania in the vertebrate host?

Amastigotes.

What is a significant ecological aspect of Trypanosoma cruzi?

It maintains wild, peridomestic, and domestic cycles involving wildlife, dogs, and humans.

What is the prevalence of Chagas' disease in the US?

Approximately 300,000 people are infected, many of whom are unaware.