SACHI BELLE SY CABACCANG, 2BSMT3 SHORT WRITING ASSIGNMENT 4

1. Why do we call Entamoeba hartmanni as the small race Entamoeba histolytica?

It is important to note that Entamoeba hartmanni is often smaller in size compared to Entamoeba
histolytica. This size difference is one of the ways in which these two species can be distinguished under a
microscope.

2. Is it necessary to treat patients with commensal protozoans?

No, because commensal protozoans are non-pathogenic and are harmless.

3. Should we report the presence of the non-pathogenic amoeba in the official fecalysis report?
No, because a non-pathogenic amoeba will not cause any symptoms or health problems.

4. What is the function of the ventral disk of Giarda lamblia trophozoites?

he ventral disk of Giardia lamblia trophozoites plays a crucial role in the parasite's ability to adhere to the
intestinal epithelium and cause disease.

5. How do you characterize the shape of the cytostome or mouth part of Chilomastix mesnili?
The shape of the cytostome in Chilomastix mesnili is characterized by a crescent or horseshoe shape. The
cytostome is located near the anterior (front) end of the parasite's body and is surrounded by a ring of microtubules,
which are part of the cytoskeleton. The crescent-shaped opening of the cytostome leads to a tubular structure
called the cytostomal tube, which extends into the body of the parasite.

6. Among the luminal flagellates, which species do not have a cyst stage?
Di entamoeba Fragilis. This organism was initially thought to be an amoeba, as its name suggests. Recent
research indicates that it is a flagellate lacking a flagellum. D fragilis does not form cysts; its trophozoites (the
majority of which have two nuclei) are usually 9 to 12 m long.

7. Describe the movement of Trichomonas vaginalis trophozoite.

The movement of Trichomonas vaginalis trophozoites is described as rapid and jerky, with the parasite
rapidly changing direction as it moves. The flagella beat in a coordinated fashion, propelling the parasite forward in
a twisting and turning motion. This movement allows Trichomonas vaginalis to navigate through the vaginal
environment and locate suitable areas to attach and feed.
In addition to flagellar movement, Trichomonas vaginalis can also undergo a rolling or tumbling motion,
which is thought to be mediated by the movement of the axostyle, a rigid structure located within the parasite's
body. This rolling motion allows the parasite to change direction quickly and evade obstacles in its path.

8. Give the drug choice for Trichomonas infection.

• Metronidazole or Tinidazole
− Mechanism of action Bioactivated to form reduced cyto-toxic products having nitro groups which
damage DNA.
− Clinical action DOC for trichomoniasis, given to both the partners.

9. Determine the infective stage of the following hemoflagellates:

• Trypanosoma cruzi – multiplying amastigote forms in the heart muscle. Trypomastigote forms can be found
in blood.
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• Trypanosoma Brucie gambiense – tsetse fly takes a blood meal (injects metacyclic trypomastigotes)
• Trypanosoma Brucie rhodiense – tsetse fly bites human trypomastigotes from salivary gland deposited
(anterior station transmission)
• Leishmania donovani – promastigote forms present in the midgut (majority) or foregut (small proportion) of
female sandfly
• Leishmania tropica – synonymous to Leishmania donovani, Promastigote forms present in the midgut
(majority) or foregut (small proportion) of female sandfly
• Leishmania Mexicana – the infective stage is the promastigote, which is found in the midgut of female
sandflies. Transmission occurs when an infected sandfly bites a human, injecting the promastigotes into the
skin.
• Leishmania infantum – the infective stage is the promastigote, which is found in the midgut of female
sandflies. Transmission occurs when an infected sandfly bites a human, injecting the promastigotes into the
skin.
• Leishmania Viannia brazilliensis – the infective stage is the promastigote, which is found in the midgut of
female sandflies. Transmission occurs when an infected sandfly bites a human, injecting the promastigotes
into the skin.
• Leishmania Leishmania major – the infective stage is the promastigote, which is found in the midgut of
female sandflies. Transmission occurs when an infected sandfly bites a human, injecting the promastigotes
into the skin.

10. In the sleeping sickness phase of Trypanosoma brucie rhodesiense, what is the specimen of choice for diagnosis?
• multiple blood samples (due to periodic release of trypomastigotes in blood)
• chancre fluid
• CSF
• lymph node aspirate
• bone marrow aspirate.

11. Describe the disease called Dum Dum fever or black fever disease.
Chronic, usually fatal disease occurring in tropical areas of Asia and the Western Hemisphere,
characterized by irregular fever, enlargement of the spleen, anemia, and emaciation.

12. Describe how the following diagnostic tests are performed: xenodiagnoses and Dr, Montenegro skin test.
• Xenodiagnoses - a medical test that involves the use of live vectors, such as insects, to detect the
presence of a pathogen in a patient's blood or tissues. In this technique, the patient is bitten by an insect
that is known to be a vector for the pathogen of interest. The insect is then allowed to feed on the patient's
blood and is subsequently dissected or tested to determine if it has acquired the pathogen.
• Dr. Montenegro Skin Test – a diagnostic test used to detect previous exposure to the parasite that causes
leishmaniasis, a parasitic disease transmitted by the bite of infected sand flies. The Dr. Montenegro skin
test involves the injection of a small amount of a leishmanial antigen into the skin of the patient, typically on
the forearm. The antigen is a purified protein extract from the parasite that is capable of eliciting an immune
response in individuals who have been previously exposed to the parasite. After 48-72 hours, the site of
injection is examined for the presence of a localized, raised red bump or swelling known as a papule. The
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size of the papule is measured, and a positive reaction is indicated by a papule diameter greater than or
equal to 5 mm.

13. What is NNN medium? Give its composition.

NNN medium, also known as Novy-MacNeal-Nicolle medium, is a type of culture medium that is commonly
used for the cultivation of Leishmania parasites, which are responsible for causing the disease leishmaniasis. The
composition of NNN medium varies depending on the specific formulation and the laboratory that prepares it.

Composition

Ingredients Gms / 100 ml

Part- A
Lab Lamco powder /Meat extract: O.3
Peptone: 0.5
Sodium chloride: O.8
Agar: 1.5.
Ph: 7.3 ± 0.2
Part B
Sodium chloride: O. 8
Potassium chloride: 0.02
Calcium chloride: 0.02
Anhydrous potassium dihydrogen phosphate: 0.03
Dextrose (Glucose): 0.25
Final pH (at 25°C): 7.0 ± 0.2

14. Aside from the vacuolated form of Blastocystis hominis, list and describe the appearance of the other three forms.
Other forms of Blastocystis hominis are granular, amoeboid and cystic form.
Granular Form – common in older cultures; it resembles the vacuolar form however; it does not contain granules in
the central body and the cytoplasm. It shows a lesser degree of pleomorphism compared to the vacuolar form. It
has three identified types which are the metabolic, reproductory and lipid granules.
1. Metabolic granules – found in the cytoplasm; it carries out various metabolic pathways of the organism
2. Reproductory granules – only seen within the central body
3. Lipid granules – seen in both the cytoplasm and central body; it serves as the storage body
Amoeboid Form – irregular in shape and possesses one or two pseudopodia however, it is considered non-motile.
Cytoplasm contains either single large vacuole or multiple smaller vacuoles which feed on bacteria to acquire
nutrition for encystment. Identified in symptomatic patients with diarrhea but it is also suggested that amoeboid
forms have the possibility of being pathogenic according to some recent reports.
Cystic Form – most recently described form of Blastocystis hominis; remain viable for up to 1 month even on
exposure to air. Distinct feature is the presence of thick multi-layered cyst wall. Spherical to ovoid in shape and
smaller than vacuolar and granular forms. Condensed cytoplasm with varying numbers of mitochondria and small
vacuoles. Transmissible infective form which enters a host and develop into vacuolar form.
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15. How do you describe a zoonotic infection? What are its implications in the transmission of the parasite.
A zoonotic infection is a type of disease or infection that can be transmitted from animals to humans. In
zoonotic infections, the parasite or pathogen that causes the disease is able to jump the species barrier, usually
through close contact with infected animals, their body fluids, or contaminated surfaces.
Zoonotic infections can have significant implications for the transmission of the parasite or pathogen that
causes the disease. This is because animals often act as reservoirs for the parasite, which means they can carry
and transmit the parasite to other animals or humans even if they do not show any symptoms of the disease
themselves.

16. What makes Balantidium coli invasive? Explain.

Balantidium coli is a parasitic protozoan that can cause disease in humans and other animals. It is the only
ciliate known to infect humans. Balantidium coli is invasive due to several factors:
1. Ability to penetrate the intestinal wall: Balantidium coli can invade the intestinal wall by using its cilia to burrow
through the mucous layer that lines the intestine. Once it reaches the intestinal wall, it can cause tissue damage
and inflammation.
2. Adhesive properties: Balantidium coli has a highly adhesive surface coat that allows it to attach to the intestinal
epithelium. This adhesive coat is thought to be composed of glycoproteins and other molecules that help the
parasite adhere to host cells.
3. Production of proteases: Balantidium coli is capable of producing proteases, which are enzymes that break
down proteins. These proteases may help the parasite to invade host tissues by breaking down extracellular
matrix proteins and other components of the host tissue.
4. Immunomodulatory effects: Balantidium coli can modulate the host immune response by inducing the
production of cytokines and other immune factors. This may allow the parasite to evade the host immune
response and establish a chronic infection.

Overall, the invasive properties of Balantidium coli allow it to penetrate the intestinal wall, cause tissue
damage and inflammation, and establish a chronic infection in some cases. In humans, Balantidium coli infections
are typically mild and self-limiting, but severe infections can occur in individuals with weakened immune systems or
other underlying health conditions.

17. Give the functions of the following structures seen in Balantidium coli: cytostome, cytopyge, micronucleus,
macronucleus and cilia.
• Cytosome – this is a structure that serves as the mouth of Balantidium coli, through which it takes in food
particles. It is a specialized region of the cell membrane that is surrounded by cilia and leads to a
cytopharynx, which is a tube-like structure that extends into the cytoplasm.
• Cytopyge – this structure serves as the anus of Balantidium coli, through which undigested food particles
and waste materials are expelled from the cell.
• Micronucleus – balantidium coli possesses two nuclei, one of which is the micronucleus. This structure
contains the genetic material of the cell and is involved in sexual reproduction and genetic exchange.
• Macronucleus – the macronucleus is the larger of the two nuclei and is involved in asexual reproduction
and the regulation of cell metabolism.
• Cilia – these are tiny hair-like structures that cover the surface of Balantidium coli and play a role in its
movement, feeding, and sensing of the environment. The coordinated movement of the cilia allows the cell
to move through its environment and capture food particles through the cytostome.
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18. Describe the characteristic ulceration caused by Balantidiasis vs. Entamoeba histolytica type of classical ulcer.
Balantidiasis is caused by the parasitic protozoan Balantidium coli, which primarily infects the large
intestine. The ulcers caused by Balantidiasis are typically shallow, irregularly shaped, and have a ragged,
undermined edge. The ulcers may be surrounded by a reddened or inflamed border. In severe cases, the ulcers
may extend through the entire thickness of the intestinal wall, leading to perforation and peritonitis.
On the other hand, Entamoeba histolytica is also a parasitic protozoan that primarily infects the large
intestine but can cause extra-intestinal infections as well. The ulcers caused by Entamoeba histolytica are typically
deeper and more well-defined than those caused by Balantidium coli. They are typically round or oval in shape, with
a smooth, punched-out appearance and a clean, sharp edge. The surrounding mucosa is typically inflamed and
edematous, and there may be areas of necrosis and hemorrhage surrounding the ulcer.
In summary, the ulcers caused by Balantidiasis are shallow, irregularly shaped, and have a ragged,
undermined edge, while the ulcers caused by Entamoeba histolytica are deeper, well-defined, and have a clean,
sharp edge. The surrounding mucosa is typically inflamed and edematous in both cases.

19. Discuss the impact of Balantidiasis among hog raisers.

Balantidiasis is a parasitic infection caused by Balantidium coli that affects humans and animals, including
pigs. Swine balantidiasis can have a significant economic impact on hog raisers, causing a decrease in weig ht gain,
reduced feed conversion efficiency, and a decrease in the quality of meat. Swine balantidiasis is more common in
younger pigs and can be transmitted through contaminated food and water. Preventing and controlling swine
balantidiasis is important to reduce the economic impact and public health risk associated with the disease, and can
be achieved through proper sanitation practices, regular monitoring and testing, and treatment of infected pigs.