Chapter 5: Hemoflagellates Flashcards
What are the FOUR morphologic forms of hemoflagellates?
- Amastigote
- Promastigote
- Epimastigote
- Trypomastigote
This morphologic form contains a nucleus, a basal body structure (called a blepharoplast), and a small parabasal body.
Characteristics:
- Roundish to oval, measures 5 by 3 µm in size.
- The dotlike blepharoplast gives rise to and is attached to an axoneme.
- Kinetoplast is an umbrella term often used to refer to the blepharoplast and small parabasal body.
Amastigotes
This morphologic form has a large single nucleus located in or near the center of the long slender body.
Characteristics:
- Long and slender, measures 9 to 15 µm in length.
- The kinetoplast is located in the anterior end of the organism.
- A single free flagellum extends anteriorly from the axoneme.
Promastigotes
This morphologic form has a body that is slightly wider than that of the promastigote.
Characteristics:
- Long and slightly wider than promastigote form, measures approximately 9 to 15 µm in length.
- The large single nucleus is located at the posterior end of the organism.
- The kinetoplast is located anterior to the nucleus.
- An undulating membrane, measuring half the body length, forms into a free flagellum at the anterior end of the epimastigote.
Epimastigotes
This morphologic form is represented in its straight form for comparison purposes because it denotes the individual structures.
Characteristics:
- Long and slender, it measures 12-35 µm long by 2-4 µm wide.
- C, S, or U shapes often seen in stained blood films.
- Posteriorly located kinetoplast from which emerges a full body length undulating membrane.
- The single large nucleus is located anterior to the kinetoplast.
- An anterior free flagellum may or may not be present.
Trypomastigotes
Quick Quiz 5-1
This is the only hemoflagellate morphologic form
that does not have an external flagellum.
A. Trypomastigote
B. Amastigote
C. Promastigote
D. Epimastigote
B. Amastigote
Quick Quiz 5-2
Hemoflagellates are typically found in stool samples.
A. True
B. False
B. False.
It should be found in the blood, lymph node and ulcer aspirations, tissue biopsies, bone marrow, and cerebrospinal fluid (CSF).
These two morphologic forms are routinely found in human specimens.
Amastigote & Trypomastigote
It is a general term used to describe diseases caused by the hemoflagellate genus Leishmania.
Leishmaniasis
Quick Quiz 5-3
The symptoms of hemoflagellate infections range from minor, such as irritation at the infection site, to serious (comatose state and death).
A. True
B. False
A. True
A common name for an infection with Leishmania tropica; it is a cutaneous form of leishmaniasis presenting with pus-containing ulcers.
Baghdad boils
A common name for a cutaneous form of infection caused by Leishmania mexicana.
Bay sore
A form of cutaneous leishmaniasis cased by L. mexicana; it is commonly found in Belize, Guatemala, and the Yucatan peninsula in areas where chicle sap is harvested for making chewing gum.
Chiclero ulcer
A common name for the visceral leishmaniasis caused by Leishmania donovani.
Dum-dum fever
Another name for an infection resulting from Leishmania braziliensis, the principle cause of mucocutaneous disease in Central and South America, particularly in Brazil.
Espundia
Another name for an infection with Leishmania guyanensis, the principle cause of mucocutaneous
leishmaniasis in the Guianas, parts of Brazil, and Venezuela; also known as pian bois.
Forest yaws
Another name for the most severe form of visceral leishmaniasis caused by members of Leishmania donovani complex.
Kala-azar
A common reference for the cutaneous leishmaniasis caused by the infecting agents comprising the Leishmania tropic complex.
Oriental sore
Another name for infection with L. guyanensis; also known as forest yaws.
Pian bois
A reference to mucocutaneous leishmaniasis in the Peruvian Andes.
Uta
What are the commonly associated disease and condition names of Leishmania braziliensis complex?
- Mucocutaneous leishmaniasis
- Chiclero ulcer
- Espundia
- Forest yaws
- Pian bois
- Uta
This parasite complex of organisms is found in Mexico, Argentina, Panama, Colombia, the Peruvian Andes, Guiana, Brazil, Bolivia, Paraguay, Ecuador, and Venezuela.
Characteristics:
- These organisms are the causative agents and may also be referred to as New World.
Leishmania braziliensis complex
In laboratory diagnosis, what is the specimen choice for identifying the amastigotes of L. braziliensis complex?
- Biopsy of the infected ulcer
- Microscopic examination of the Giemsa-stained preparations
In laboratory diagnosis, what is the specimen sample may be collected for promastigotes of L. brazilensis complex?
Enzyme analysis & Molecular techniques
Note:
Promastigotes may be present when the sample is collected immediately after introduction into the patient.
In laboratory diagnosis, restriction analysis of kinetoplast DNA in L. braziliensis complex is a technique referred to as schizodeme analysis, nuclear DNA hybridization, and isoenzyme patterns, known as?
Zymodeme analysis
What is the most effective treatment for L. braziliensis complex?
Pentosam
Some alternative treatments:
- Amphotericin B
- Fluconazole
- Ketoconazole
- Itraconazole
Quick Quiz 5-5
The organism causing chiclero ulcer is most likely found in:
A. Texas
B. South American rainforest region
C. Nova Scotia
D. Egypt
B. South American rainforest region
Quick Quiz 5-6
Which of the following is not an acceptable treatment for mucocutaneous leishmaniasis caused by L. braziliensis?
A. Amoxicillin
B. Pentosam
C. Ambisome
D. Fungizone
A. Amoxicillin
What are the commonly associated disease and condition names of Leishmania donovani complex?
- Visceral leishmaniasis
- Kala-azar
- Dum dum fever
This parasite has a complex of organisms found in India, Pakistan, Thailand, Africa, the Peoples Republic of China, the Mediterranean, Europe, Africa, the Near East, parts of the former Soviet Union, the Middle East, Yemen, Oman, Iraq, Kuwait, Saudi Arabia, United Arab Emirates, Bahrain, and Central and South America.
Characteristics:
- These organisms are the causative agents and may also be referred to as Old or New World.
Leishmania donovani complex