What is the Difference Between Amoeba and Leishmania

The main difference between Amoeba and Leishmania is that Amoeba causes amoebiasis while Leishmania causes leishmaniasis.  

Amoeba and Leishmania are two types of single-celled protozoa. They cause diseases in humans.

Key Areas Covered

1. What is Amoeba
     – Definition, Structure, Function
2. What is Leishmania
     – Definition, Structure, Function
3. Similarities – Amoeba and Leishmania
     – Outline of Common Features
4. Difference Between Amoeba and Leishmania
     – Comparison of Key Differences

Key Terms

Amoeba, Leishmania

What is Amoeba

Amoeba is a genus of unicellular eukaryotes living in freshwater ponds and wet soil. However, some of them are parasitic inside animal bodies. Ameboid cells have irregular shapes with a diameter of 0.1 mm. Their cytoplasm has two layers known as endoplasm, the inner layer, and ectoplasm, the outer layer. Other components of ameboid cells are the membrane-bound nucleus, food vacuoles, and contractile vacuoles. The locomotion of Amoeba occurs by forwarding its cytoplasm through the formation of a pseudopodium or a false foot. This movement is known as an amoeboid movement.

Figure 1: Amoeba

Furthermore, Amoeba ingests bacteria, algae, plant cells, and other microscopic organisms in a mechanism known as phagocytosis. Their digestion occurs inside a vacuole, and the elimination of waste occurs through exocytosis. Apart from that, Amoeba cause amebiasis in humans. The symptoms of the disease include nausea, diarrhea, weight loss, stomach tenderness, and occasional fever.

What is Leishmania

Leishmania is a parasitic protozoan responsible for the disease leishmaniasis. This disease occurs in the tropics, subtropics, and southern Europe. Moreover, the disease spread through the bites of phlebotomine sand flies. There are different forms of leishmaniasis. They include cutaneous leishmaniasis, which causes skin ulcers, and visceral leishmaniasis, which causes skin ulcers with fever, low red blood cell count, and enlarged spleen and liver. In addition, visceral leishmaniasis affects the spleen, liver, and bone marrow.

Figure 2: Leishmania donovani

Moreover, sandflies that spread leishmaniasis are smaller and around one-fourth of the mosquito. Apart from that, Leishmania donovani causes visceral leishmaniasis in India. However, Leishmania parasites contain a well-defined nucleus. Kinetoplasts and flagella include the cell organelles in Leishmania. In addition, the two structural variants of Leishmania are amastigote and promastigote. Amastigote is the mononuclear phagocytes in the circulatory system of humans, while promastigote is the extracellular motile form found in the alimentary tract of sandflies.

Similarities Between Amoeba and Leishmania

• Amoeba and Leishmania are two types of single-celled microorganisms.
• They are protozoans that cause diseases in humans.

Difference Between Amoeba and Leishmania

Definition

Amoeba refers to a single-celled animal that catches food and moves about by extending fingerlike projections of protoplasm, while Leishmania refers to a single-celled parasitic protozoan that spends part of its life cycle in the gut of a sandfly and part in the blood and other tissues of a vertebrate.

Taxonomy

Amoeba belongs to the family Amoebidae, while Leishmania belongs to the order Trypanosomatida.

Living

While Amoeba commonly lives in freshwater or are parasitic, Leishmania spreads through sandflies. 

Disease

Amoeba causes amebiasis, but Leishmania causes leishmaniasis.

Symptoms

Amoeba causes nausea, diarrhea, weight loss, stomach tenderness, and occasional fever, while Leishmania causes skin ulcers, low red blood cell count, fever, and enlarged spleen and liver.

Conclusion

In brief, Amoeba and Leishmania are two types of single-celled protozoans. Amoeba belongs to the family Amoebidae. It lives in freshwater and is parasitic on humans. Amoeba causes amebiasis, and the symptoms of the disease include nausea, diarrhea, weight loss, stomach tenderness, and occasional fever. On the other hand, Leishmania belongs to the order Trypanosomatida. However, it uses sandflies as the vector for the disease leishmaniasis. The symptoms of the disease include skin ulcers, low red blood cell count, fever, and enlarged spleen and liver. Therefore, the main difference between Amoeba and Leishmania is the type of disease they cause.

References:                     

1. “Amebiasis (amebic dysentery).” NEW YORK STATE. 
2. “CDC – Leishmaniasis.” Centers for Disease Control and Prevention. 

Image Courtesy:

1. “Amoeba (PSF)” By el:User:Kupirijo  – Own work (CC-BY SA 3.0) via Commons Wikimedia
2. “Leishmania donovani 01” By CDC/Dr. L.L. Moore, Jr. – Own Work (Public Domain) via Commons Wikimedia