The main difference between Entamoeba histolytica and Giardia lamblia is that E. histolytica is a highly virulent and invasive organism that causes amoebiasis whereas G. lamblia causes giardiasis with severe acute diarrhea to chronic diarrhea.
E. histolytica and G. lamblia are two types of parasitic microorganisms causing diseases in humans. Moreover, the primary infection of both parasites is the upper and lower gastrointestinal tract.
Key Areas Covered
- What is Entamoeba Histolytica
- Definition, Features, Importance
- What is Giardia Lamblia
- Definition, Features, Importance
- Similarities Between Entamoeba Histolytica and Giardia Lamblia
- Outline of Common Features
- Difference Between Entamoeba Histolytica and Giardia Lamblia
- Comparison of Key Differences
Key Terms
Entamoeba Histolytica, Giardia Lamblia
What is Entamoeba Histolytica
Entamoeba histolytica is an anaerobic amoebozoan of the genus, Entamoeba. The main feature of E. histolytica is that it causes amoebiasis. Generally, E. histolytica frequently lives as a commensal within the large intestine with no overt clinical manifestations. However, trophozoites of amoeba can invade the colonic epithelium and produce ulcers and dysentery. This invasive disease can become progressively worse and lead to a more serious disease, metastasizing to other organs and causing extraintestinal amebiasis. In other words, E. histolytica is a facultative pathogen that exhibits a wide range of virulence.
Figure 1: E. histolytica
The non-invasive disease is often asymptomatic but can cause diarrhea or other gastrointestinal symptoms such as abdominal pain or cramps. This non-invasive infection can persist or progress to an invasive disease in which trophozoites penetrate the intestinal mucosa and kill the epithelial cells. The early lesion is a small area of necrosis, or ulcer, characterized by raised edges and virtually no inflammation between lesions.
What is Giardia Lamblia
Giardia lamblia is a flagellated parasitic microorganism of the genus Giardia. It colonizes the upper portions of the small intestine. It is also the most common protozoan that occurs in human stool. Normally, Giardia is non-invasive and often results in asymptomatic infections. In addition, symptomatic giardiasis is characterized by acute or chronic diarrhea and/or other gastrointestinal manifestations.
Figure 2: G. Lamblia
Moreover, the first signs of acute giardiasis include nausea, loss of appetite, and upper gastrointestinal uneasiness. These signs are often followed or accompanied by a sudden onset of explosive, watery, foul-smelling diarrhea. Stools associated with Giardia infection are generally described as loose, bulky, frothy, and/or greasy with the absence of blood or mucus, which may help distinguish giardiasis from other acute diarrheas.
Similarities Between Entamoeba Histolytica and Giardia Lamblia
- E. histolytica and G. lamblia are two parasites that infect the gastrointestinal tract of humans.
- Both protozoa cause severe disease.
- Their transmission occurs through the fecal-oral route.
- Moreover, they exhibit similar life cycles from the cyst stage to the trophozoite stage.
- The ingestion of contaminated foods and water by cysts can cause the disease.
- After the transmission to the proper host, the cyst transforms into a trophozoite that exhibits active metabolism.
- Trophozoites are usually motile.
- Some trophozoites undergo the formation of cysts in addition to undergoing replication.
- Furthermore, these cysts undergo a dormant period until ingestion by another host through the fecal-oral route.
Difference Between Entamoeba Histolytica and Giardia Lamblia
Definition
Entamoeba histolytica refers to an anaerobic parasitic amoebozoan, part of the genus Entamoeba, predominantly infecting humans and other primates, and causing amoebiasis, while Giardia lamblia refers to a flagellated parasitic microorganism of the genus Giardia that colonizes the small intestine, causing a diarrheal condition known as giardiasis.
Family
Entamoeba histolytica belongs to the Family Entamoebidae while Giardia lamblia belongs to the Family Hexamitidae.
Motivity
Moreover, Entamoeba histolytica contains pseudopodia for motivity while Giardia lamblia has flagella for motivity.
Diseases
Entamoeba histolytica causes amoebiasis while Giardia lamblia causes giardiasis.
Symptoms
The symptoms of amoebiasis include fulminating dysentery, bloody diarrhea, weight loss, fatigue, abdominal pain, and amoeboma, while the symptoms of giardiasis include severe acute diarrhea which may lead to chronic diarrhea and nutritional disorders.
Conclusion
In brief, Entamoeba histolytica, which belongs to the Family Entamoebidae, and Giardia lamblia, which belongs to the Family Hexamitidae, are two parasitic protozoa in the gastrointestinal tract. Entamoeba histolytica causes amoebiasis while Giardia lamblia causes giardiasis. Both diseases are severe. In addition, Entamoeba histolytica is motile with pseudopodia while Giardia lamblia is motile with flagella. However, the main difference between Entamoeba histolytica and Giardia lamblia is the diseases formed in humans.
References:
- Intestinal protozoa. Tulane University, 2022
Image Courtesy:
- “Entamoeba histolytica ” By Stefan Walkowski – Own Work (CC BY-SA 3.0) via Commons Wikimedia
- “Giardia lamblia SEM 8698 lores ” By CDC / Janice Haney Carr – Own Work (Public Domain) via Commons Wikimedia
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