Protozoans: Amoebas And Flagellates

Naegleria fowleri is a free-living amoeba that causes primary amoebic meningoencephalitis, a rare but serious infection of the brain. This amoeba is commonly found in warm freshwater environments such as lakes, hot springs, and poorly maintained swimming pools. Infection occurs when contaminated water enters the nose and allows the amoeba to travel to the brain. The infection is usually fatal, with symptoms including severe headache, fever, nausea, vomiting, and stiff neck. Prompt medical attention is crucial for any suspected cases of Naegleria fowleri infection.

Trichomonas vaginalis is not transmitted through ingestion of contaminated food and water. It is a sexually transmitted parasite that primarily infects the urogenital tract. Therefore, it is not included in the list of parasites transmitted through contaminated food and water.

A pear-shaped flagellate with a visible parabasal body and a "falling leaf" motility in a direct saline mount of diarrheal stool specimen is most probably Giardia lamblia. Giardia lamblia is a parasite that causes giardiasis, a common intestinal infection. It is characterized by its pear-shaped appearance, the presence of a parabasal body (a unique structure found in Giardia), and its distinct "falling leaf" motility pattern. Chilomastix mesnili, Trichomonas hominis, and Trichomonas vaginalis do not exhibit these specific characteristics, making Giardia lamblia the most likely answer.

The warm, liquid stool specimen received in the lab and the observation of ameboid forms that average 20 microns in diameter, with a nucleus showing evenly distributed peripheral chromatin and a central karyosome, along with directional motility and ingestion of a red blood cell, are all characteristic features of Entamoeba histolytica. This is a protozoan parasite that causes amoebic dysentery and can invade the intestinal wall, leading to tissue destruction and systemic infection. Therefore, the correct answer is Entamoeba histolytica.

Granulomatous Amoebic Encephalitis (GAE) is caused by Acanthamoeba spp. This is a type of amoeba that can infect the central nervous system and cause severe inflammation and tissue damage. Acanthamoeba spp. are commonly found in soil, water, and other environments, and can enter the body through the respiratory system or through open wounds. Once inside the body, they can travel to the brain and cause the symptoms of GAE, which include headache, fever, stiff neck, and neurological abnormalities. Treatment for GAE is challenging, and the disease often has a poor prognosis.

Protozoan parasites are classified into different groups based on their ability for locomotion. Locomotion refers to the movement of an organism from one place to another. This ability is an important characteristic used to categorize protozoan parasites into different groups. The other options, such as multiplication, infection, and adaptation, are not the primary basis for the classification of these parasites.

Chilomastix mesnili is the correct answer because it matches all of the given characteristics. It has a lemon shape and mimics Giardia lamblia cyst, but with a clear space at the end. It has an internal structure that resembles a "shepherd's crook" or safety pin, and it contains a single nucleus, cytosome, and a retracted flagella. The other options do not match all of these characteristics.

In cysts of Iodamoeba butschlii, a glycogen mass is typically found. This is a characteristic feature of this organism's cysts.

Trichomonas vaginalis is a sexually transmitted protozoan parasite that matches the given description. It is flagellated and has a pear-shaped body with a short undulating membrane and four flagella. This parasite is commonly found in the urogenital tract and can cause trichomoniasis, a sexually transmitted infection.

The correct answer is Entamoeba coli cyst. The question asks for the complete identification of the name and stage of the parasite, and the answer provided fulfills this requirement. Entamoeba coli is a species of amoeba that can be found in the human intestine. The cyst stage is the dormant form of the parasite, which allows it to survive outside the host and be transmitted to new hosts.

Identifying the species of an immature amoebic cyst can be challenging because the cysts of different species may look similar at this stage. However, Dientamoeba fragilis is not known to form cysts, so it would not be found in infections caused by this parasite. This makes it easier to exclude Dientamoeba fragilis as the correct answer in this case.

Naegleria fowleri is the correct answer. Naegleria fowleri is a parasite that undergoes a specific life cycle.

Amoebas and flagellates are both single-celled organisms that can be found in aquatic environments. They both have a nucleus, which contains their genetic material. However, they differ in their modes of locomotion. Amoebas move using pseudopodia ("false feet"), which are temporary extensions of their cytoplasm, while flagellates move using flagella, which are whip-like appendages.

The most important feature in differentiating cysts of Entamoeba histolytica from Entamoeba dispar is that the cysts cannot be morphologically differentiated. This means that there are no visible differences in the number of nuclei, size of cyst, or shape of karyosome between the two species. Therefore, other methods such as molecular techniques are needed to accurately differentiate between the two species.

Leishmania is a genus of parasites that is transmitted through sandfly bites. It causes a disease called leishmaniasis, which can present with symptoms such as abdominal discomfort and distension, low grade fever, anorexia and weight loss, hepatomegaly and splenomegaly, severe anemia, and low white blood cell counts. Leishmaniasis can be fatal in 90% of cases. Therefore, the correct answer is Leishmania.

The correct answer is Giardia lamblia trophozoite. Giardia lamblia is a parasite that causes giardiasis, a gastrointestinal infection. The trophozoite stage is the active, motile form of the parasite that lives in the small intestine of the host. This stage is responsible for causing the symptoms of giardiasis, such as diarrhea, abdominal pain, and bloating.

The symptoms described, including diarrhea with flatulence and foul smelling stools, are consistent with a Giardia lamblia infection. Giardia lamblia is a parasite that commonly causes gastrointestinal symptoms such as diarrhea, abdominal cramps, and bloating. It is often transmitted through contaminated water sources, which could have been the case during the camping trip if the teenagers drank untreated water from the mountainous river. Naegleria fowleri is a brain-eating amoeba that causes a rare and severe infection, not gastrointestinal symptoms. Entamoeba coli and Entamoeba histolytica are both parasites that can cause intestinal infections, but their symptoms typically differ from those described in the question.

The correct answer is Entamoeba histolytica trophozoite. This is the name and stage of the parasite. Entamoeba histolytica is a protozoan parasite that causes amoebiasis, an intestinal infection. The trophozoite stage is the active, feeding stage of the parasite, where it feeds on host tissue and causes damage.

The disease most commonly associated with Acanthamoeba spp. is Acanthamoeba keratitis. This is a rare but serious eye infection caused by the Acanthamoeba amoeba, which can affect the cornea of the eye. It typically occurs in contact lens wearers who do not follow proper hygiene practices or use contaminated water for cleaning lenses. In addition to Acanthamoeba keratitis, Acanthamoeba infections can also lead to other health issues, including infections in the central nervous system.

The most dependable procedure for accurate, specific diagnosis of an intestinal amoebic infection is the iodine saline wet mount. This technique involves adding iodine to a saline solution containing the fecal specimen, which helps to stain and visualize the amoebic cysts or trophozoites. This method is highly specific for identifying amoebic infections and is more reliable compared to other procedures such as the direct saline wet mount, formalin ether sedimentation technique, or permanently stained smear.

Trichomoniasis infection causes all of the symptoms mentioned in the options. Therefore, none of the above options are correct.

The correct answer is "Chilomastix mesnili cyst." Chilomastix mesnili is a parasitic protozoan that infects the human intestine. It exists in two forms, trophozoite and cyst. The cyst stage is the infective stage of the parasite and is responsible for transmission to a new host. The correct answer correctly identifies the name of the parasite (Chilomastix mesnili) and the stage (cyst) in which it exists.

Organisms under subphylum Sarcodina use pseudopods for locomotion. Pseudopods are temporary extensions of the cell membrane that help in movement. These organisms are known as amoebas and they extend their pseudopods in the direction they want to move, allowing them to crawl or swim through their environment. The use of pseudopods is a characteristic feature of Sarcodina, enabling these organisms to move and capture their prey efficiently.

The correct answer is Entamoeba histolytica cyst. Entamoeba histolytica is a parasite that causes amoebic dysentery and other intestinal infections in humans. The cyst stage is the infective form of the parasite that is able to survive outside the host and can be transmitted through contaminated food or water. Identifying the correct name and stage of the parasite is crucial for accurate diagnosis and treatment of the infection.

The life cycle stage that many protozoans spend part of their lives and are mostly involved in feeding and reproduction is the trophozoite stage. During this stage, protozoans actively feed, grow, and reproduce, carrying out essential life processes. This is in contrast to the cyst stage, which is a dormant and protective stage that some protozoans enter to survive harsh environmental conditions.

The correct answer is "Iodamoeba butschlii cyst." Iodamoeba butschlii is a species of amoeba that can infect the human gastrointestinal tract. It exists in two forms, the trophozoite and the cyst. The cyst stage is the dormant, resistant form of the parasite that allows it to survive outside the host and be transmitted to new hosts. The correct spelling of the parasite's name is important for accurate identification.

The correct answer is "Trichomonas species trophozoite, Trichomonas sp. trophozoite, Trichomonas spp. trophozoite, Trichomonas sp trophozoite, Trichomonas spp trophozoite, Trichomonas specie trophozoite". This is because the question asks for the identification of the name and stage of the parasite, and all of the given options correctly identify the parasite as Trichomonas species and the stage as trophozoite.