Hemoflagellates Flashcards
what are the two genera that are considered medically important because they’re the only ones that can parasitize humans?
Trypanosoma & Leishmania
Previously, these two hemoflagellates are under Phylum Sarcomastigophora but now they are under Phylum what?
Phylum Euglenozoa
The primitive structure in hemoflagellates is represented by the genus what?
this genus is parasitic in insects
Leptomonas
actually, this is the other term for promastigote (or leptomonal form). kaya other morphological forms are just modified versions of promastigotes (Markell & Voge)
what morphological form in the genus Leptomonas has a centrally-located nucleus, and an anterior flagellum rising from a kinetoplast near the anterior end and is w/o an undulating membrane?
Promastigote
In the genus trypanosoma, what morphological form has a kinetoplast located posterior to the nucleus, and the flagellum passes anteriorly, forming the outer edge of the undulating membrane?
Trypomastigote
What do you call the morphological form that is found intracellularly in cardiac muscles that is characterized by:
1. loss of undulating membrane
2. loss of flagellum
3. its oval shape
Amastigotes
What are the only structures that you can observe in an amastigote?
- nucleus
- kinetoplast
- sometimes intracytoplasmic portion of flagellum
these are present in Leishmania which are always intracellular parasites, principally in cells of the reticuloendothelial system
In culture, Leishmania assumes what morphological form?
promastigote form
In trypanosomes, what morphological form is found in culture?
trypomastigotes
exhibit forms similar to those that occur naturally in insect host
- to clarify, metacyclic trypomastigotes siya ive searched nd metacyclic is produced in an intermediate host, and infective for the definitive host
- on d other hand, procyclic trypomastigotes i think (from pro, meaning forward) this is before the metacyclogenesis which’ll be d process of epimastigote transformation to metacyclic trypomastigote
Amastigotes are also called what?
- Leishman-Donovan bodies
- Leishmanial form
- Leishman-Donovan bodies kasi mostly caused by L. donovani and these are bodies found intracellularly (gogol)
- Leishmanial form bcoz ito form found in human and other vertebrate hosts (Mishra et al., 2012)
Promastigotes can be otherwise known as?
Leptomonas
found in sandly vector
where can you find the kinetoplast in the oval-shaped morphological form of hemoflagellates?
anterior to nucleus
to make things easy, lahat ng kinetoplast located anterior to the nucleus in all forms except for trypomastigote na posterior d nucleus na
What do you call the morphological life form of hemoflagellates that has a kinetoplast located anterior the nucleus and a single flagellum but without an undulating membrane?
promastigote
what morphological life form has an undulating membrane that is half of its body length? what about if the undulating membrane runs the length of the entire body?
epimastigote; trypomastigote
An epimastigote is also known as what?
Crithidia or Crithidial form
what are the different shapes that a trypomastigote may assume?
C-, S-, or U-shaped
what do you call the granules present in trypomastigotes?
volutin granules
American trypanosomiasis is also called as what? Also, it is caused by what parasite?
Chaga’s disease; Trypanosoma cruzi
African trypanosomiasis is caused by what parasites?
Trypanosoma brucei complex
T. b. gambiense & T. b. rhodesiense
In both forms of African trypanosomiasis, the parasites occur as ____ in the bloodstream lymphatics, and cerebrospinal fluid
what morphological life form?
trypomastigotes
African trypanosomiasis parasites have been reported to occur as what form in the choroid plexus (& possibly other organs)?
Amastigotes
present in experimental animals, sa tao no evidence pa so the life forms present in T. brucei complex still remain as trypo and epi
In Chagas’ disease, ____ are found in the bloodstream, and ____ occur intracellularly in cardiac muscle and other tissues.
trypomastigotes; amastigotes
what do you call the bugs that are vectors of Trypanosoma cruzi?
Reduviid bugs (Triatoma, Panstrongylus, Rhodnius)
Trypanosomes in reduviid bugs develop in what part of the bug?
hindgut
trypo to epi eong sa midgut
then carried in feces (seen in T. cruzi)
what do you call the infective stage of T. cruzi?
metacyclic trypomastigotes
A triatomine bug is also known as?
- Assassin bug (bites during night)
- Kissing bug (prefers to bite in mucosal areas or lips)
Unlike usual bugs wherein transmission is through saliva, T. cruzi is transmitted through what?
feces
Diagnostic stage of T. cruzi
C- or S-shaped trypomastigotes in blood films
MOT of T. cruzi
- Entry of metacyclic trypomastigotes in site of bite
- Blood transmission
- Vertical transmission
After the entry of metacyclic trypomastigotes in the body, what happens next? (cruzi life cycle)
just explain in own terms d life cycle (pls press 5 na agad hehe)
- penetration of cells (pwede ring ingested by phagocytes)
- transformation from metacyclic trypomastigote to amastigote
- amastigote multiplication through binary fission
- amastigote to trypomastigote transformation
- host cell will burst then trypomastigotes will enter bloodstream (& infect other cells ulet)
- triatomine bug will eat again then ingest trypomastigotes
- ingested trypomastigotes will transform into epimastigotes in midgut and multiply by binary fission
- after multiplication, epimastigotes will transform to metacyclic trypomastigotes in the hindgut
- then triatomine bug will bite again
transformation is fast but promastigote form is present in vector
Laboratory diagnosis for T. cruzi
- Blood (thick and thin smears)
- CSF, tissue sample, lymph examination
- Serology
- Lesion aspiration
- Concentration methods
- Electrocardiography
- Xenodiagnosis
- Culture
- PCR
What do you call the serological laboratory diagnosis test wherein it is a complement fixation test using the antigen of T. cruzi?
Machado-Guerreiro test
what do you call the laboratory diagnosis wherein blood is fed to the bug then if, after some time, epimastigotes are observed you are infected?
xenodiagnosis
what serological test has been described that detects T. cruzi antigens in the urine of px?
ELISA
enlarged lymph nodes may yield amastigotes in SEM
At the site of T.cruzi infection, the organisms proliferate, producing an erythematous indurated area known as a ____. This lesion occurs most frequently on the face but may appear elsewhere on the body
chagoma
Trypomastigotes or amastigotes may be aspirated from the chagoma in the early stages of the infection
what do you call the sign that is characterized as unilateral edema affecting both the upper and lower eyelid, usually with conjunctivitis, and sometimes spreads to involve the cheek and neck?
Romaña’s sign
Unilateral ocular and facial edema, involving the submaxillary lymph nodes, is also known as what syndrome?
present in american trypanosomiasis
oculoglandular syndrome
opthalmonganglionary complex
symptoms of generalized infection of T. cruzi may appear from ____ days to ____ weeks or more after the bite
4 days to 2 weeks
Lymphatic spread then carries the trypomastigotes of T. cruzi to regional lymph nodes where they transform into what upon ingestion by histiocytes or other cells?
Amastigotes
Can trypomastigotes of T. cruzi invade macrophages or other cells or are they reliant on phagocytes for their transformation to amastigotes (which is essential for their life cycle)?
Yes, trypomastigotes may actively invade macrophages or other cells
Evidence suggests that lectin-like carbohydrate interactions are involved in the binding of trypanosomes to the host cell. A protein on the surface of the trypomastigote has been shown to bind to N-acetylglucosamine on the host cell
During the acute stage of American trypanosomiasis, organisms will appear in the blood and persist at about how many days?
10 days
The high levels of CSF albumin probably correlate with the presence of amastigotes in meningeal and neuronal tissues, known to occur in what disease? (from T.cruzi)
acute chagasic meningoencephalitis
Invasion of the CNS in Chaga’s is marked by inflammation of what parts in the brain?
cortex and meninges
The antibody-mediated immunity w/ regard to American Trypanosomiasis is associated mainly with what class of immunoglobulins?
IgG
Treatment options for Chaga’s disease
- Nifurtimox
- Benznidazole
pwede rin Allopurinol
T. cruzi amastigotes require what element or nutrient for optimal growth and pathogenicity?
Iron
Depletion of host intracellular iron stores may protect against T. cruzi, whereas host responses that transfer iron to the intracellular sites may enhance pathogenicity
what are the cells that are preferentially parasitized by T. cruzi trypomastigotes?
- Cells of the reticuloendothelial system
- muscular tissue (cardiac, skeletal, smooth)
- neuroglia cells
____ consists of an intense inflammatory reaction, with invasion of histiocytes, adipose cells of the subcutaneous tissue and the adjacent muscle cells by the proliferating amastigotes, and of the area by neutrophilic leukocytes and lymphocytes
Chagoma
during the chronic phase of Chaga’s disease, what are the three common disorders associated w/ it?
eto eong mga paglaki ng organs i just can’t word it right
- cardiomegaly (arrythmias)
- megaesophagus (achalasia)
- megacolon (chronic constipations)
achalasia = The difficulty for food and liquid to pass through the food pipe into the stomach. This condition progresses gradually.
Treatment option for treatment of Chaga’s disease where this is the nitrofurfurlidine derivative and ihibits intracellular development of T. cruzi in tissue culture
Nifurtimox
Treatment options for treatment of Chaga’s disease where the mode of action is similar to that of metronidazole on T. vaginalis, namely inhibition of nucleic acid synthesis
an imidazole compound
Benznidazole
What parasite is transmitted via the reduviid’s saliva and not the feces?
this is nonpathogenic
Trypanosoma rangeli
metacyclic trypomastigotes via d salivary glands
Trypanosoma brucei gambiense causes the Gambian or ____ African form of the disease
east or west
West African
- rhodesiense = east
- rhodes = roads = daan
- east = right = tama
- therefore, rhodesiense = tamang daan
____, which causes Nagana disease in native game animals and a severe infection in many domestic animals but apparently does not infect humans.
Trypanosoma brucei brucei
Laboratory diagnosis of Trypanosoma brucei
- Blood examination
- CSF examination (double centri enhances detection)
- Chancre aspirate or enlarged lymph nodes
- PCR
- buffy coat examination (w/ Giemsa)
- Serum & CSF IgM levels
- Animal inoculation and culture
Immunoelectrophoresis or ultracentrifugation of the serum of T. brucei infected persons demonstrates a higher level of what immunoglobulin?
thought to be a result of the antigenic variability characteristic of these trypanosomes, confronting the immune system w/ constantly changing antigenic stimuli
IgM
IgM levels in serum are 4 times higher in infected ppl
What do you call the earliest sign of Gambian sleeping sickness that is characterized as a indurated and painful ulceration in the bite area?
Trypanosomal chancre
What do you call the sign that is described as the enlargement of the posterior cervical lymph nodes that happens during T. brucei gambiense’s febrile attacks?
Winterbottom’s sign
In terms of more chronicity, which of the two T. brucei is more acute/chronic?
- T. brucei gambiense = more chronic
- T. brucei rhodesiense = more acute
what is the infective stage (morphological form) of T. brucei to humans?
metacyclic trypomastigotes
trypanosomes of T. brucei evade host defense mechanisms by constantly changing what?
surface protein
or through antigenic variation
it turns off some gene coding for variant surface glycoprotein (VSG) and turning on another
MOT of T. brucei
- metacyclic trypomastigote entry through insect bite
- vertical transmission (uncommon)
vector of T. brucei gambiense
- T. b. gambiense = Glossina palparis & Glossina tachinoides
vector of T. brucei rhodesiense
- T. b. rhodesiense = Glossina pallidipes & Glossina morsitans
Absence of an elevated serum ____ level effectively rules out trypanosomiasis, whereas a detectable level in the cerebrospinal fluid is diagnostic for CNS trypanosomiasis.
what immunoglobulin in African trypanosomiasis?
IgM
What form of T. brucei has no known or suspected animal reservoirs?
T. b. gambiense
rhodesiense = may have animal reservoirs such as bushbuck, hartebeest, and domestic ox
Before, it was believed that the trypomastigotes of T. brucei complex were the only developmental stages in the host. Now, amastigotes are found early in infection in what organ?
choroid plexus
at least in experimental animals, amastigotes of T. brucei are found early in infection in the choroid plexus
What cell in the CNS appears to be the primary antigen-presenting cells regulating immune reactivity in the CNS parenchyma and is involved in the production of cytokines and prostaglandins?
Astrocytes
Neurologic signs in Gambian sleeping sickness may develop late. One sign, which is characterized as delayed sensation to pain may manifest. What do you call this sign?
Kerandel’s sign
pressure on the palms or ulnar nerve may be followed by severe pain a short time after pressure is removed
What do you call the sign in chronic Gambian sleeping sickness wherein it is described as the inability to straighten leg when hip is flexed at 90 degrees?
Kernig’s sign
In terms of parasitemia, which form of T. brucei presents itself with high parasitemia?
Trypanosoma brucei rhodesiense
What parasite causes the Rhodesian trypanosomiasis that leads to death before demonstration of nervous symptoms?
Trypanosoma brucei rhodesiense
Diagnostic stage of T. brucei
trypomastigotes in peripheral blood
in terms of lymphadenopathy manifestation, ano mas malala sa dalawang brucei?
Trypanosoma brucei gambiense
mas mataas lymphadenopathy ni gambiense kesa kay rhodesiense
best diagnostic method of T. b. rhodesiense
lymph node biopsy
The infection of ____ tends to be acute rather than chronic and untreated persons usually die within ____ months to a year after the onset of disease
T. brucei rhodesiense; 9 months deddo
what do you call the inflammation of the filtering units of your kidney that may also be seen during Rhodesian trypanosomiasis?
glomerulonephritis
hypocomplementemia too pwedeng makita (low complement levels)
what do you call the early stages of trypanosomiasis wherein it occurs when trypomastigotes enter the bloodstream and lymph system?
hemolymphatic sage
this is what u call the late stage of trypanosomiasis wherein there is already CNS involvement
Meningoencephalitic stage
life cycle of T. brucei
just explain in own words (pls press 5 na agad hehe)
- injection of metacyclic trypomastigotes through insect bites (Glossina spp.)
- metacyclic trypomastigotes will transform to bloodstream trypomastigotes then multiply by binary fission
- Glossina bugs will take a meal again then ingest bloodstream trypomastigotes then they will transform into procyclic trypomastigotes in the midgut of tsetse fly
- procyclic trypomastigotes leave midgut and transforms into epimastigotes then they will multiply in salivary gland then transform into metacyclic trypomastigotes
- then bite again si Glossina bug
What drug is used for treatment of all stages of African trypanosomiasis?
Melarsoprol
Except melarsoprol, what drugs are used for the treatment of African trypanosomiasis in its hemolymphatic stage?
- Pentamidine
- Suramin
In African trypanosomiasis, what drug interacts with kinetoplast DNA to kill trypanosomes but is unable to cross the blood-brain barrier?
Pentamidine
In Eastern Africa trypanosomiasis, what do you call the drug that is an enzyme inhibitor that is taken up by trypanosomes selectively during the hemolymphatic stage of the infection?
Suramin
less toxic ‘to
what do you call the drug that is effective against the hemolymphatic and meningoencephalitic stages of Gambian sleeping sickness and is not effective against its Rhodesian counterpart?
inhibitor of ornithine decarboxylase
Eflornithine
according to the CDC, this is combined with nifurtimox and is collectively known as NECT (nifurtimox eflornithine combination therapy) and is effectve s 2nd stage
what drug may u use in case melarsoprol fails? (African trypanosomiasis)
Nitrofurazone
Anong hemoflagellate ang makikitaan mo ng apat na morphological life forms?
pagod n ako
Trypanosoma cruzi
Anong hemoflagellate naman kapag epimastigote lang and trypomastigote ang observable morphological forms?
Trypanosoma brucei complex
Anong hemoflagellate ang makikitaan mo ng amastigote and promastigote forms only?
Leishmania spp.
what sandfly spp is associated w/ old world leishmaniasis?
Phlebotomus
what sandfly spp is associated w/ new world leishmaniasis?
Lutzomyia
Three species of Leishmania were recognized, corresponding to the clinical entities of leishmaniasis including:
what r the three clinical manifestations of Leishmania
- Cutaneous leishmaniasis
- Mucocutaneous/mucosal leishmaniasis
- Visceral leishmaniasis
life cycle of leishmaniasis
exp in own words, need not accurate (pls press 5 na agad hehe)
- female sandfly takes a meal then injects promastigotes in the skin then promastigotes are phagocytized
- promastigotes transform into amastigotes in the phagocytes
- Amastigotes will then multiply in cells of various tissues and infect other cells
- sand fly takes another meal then ingests parasitized cells then amastigotes will transform into promastigotes and divide in the midgut
- after division, promastigotes will migrate to the proboscis then sandfly will bite again
what do you call the most common form of leishmaniasis characterized with skin lesions and ulcerations but can be self-healing over a period of months or years?
Cutaneous leishmaniasis
The old world cutaneous leishmaniasis is caused by?
- L. major
- L. aethiopica
- L. tropica
New world cutaneous leishmaniasis is caused by mga anong leishmania?
- L. mexicana complex
- L. braziliensis complex
Oriental sore, as seen in the old world cutaneous leishmaniasis is caused by?
L. tropica complex
includes:
- L. major = rural oriental sore (moist)
- L. aethiopica
- L. tropica = urban oriental sore (dry)
Leishmania what produces a chronic disease that, if not treated, lasts for a year or longer and is characterized by the production of single dry lesions in the face several months after infection?
Leishmania tropica
what leishmania produces an acute infection characterized by lesions that occur on the lower limbs, and are moist and tend to ulcerate very early; plus, there may be satellite lesions?
Leishmania major
Leishmania major produces an acute infection with a duration of how many months?
3-6 months
what is the known main causative agent of CL but has been one of the most neglected Leishmania species?
Leishmania aethiopica
New world cutaneous leishmaniasis is caused by the species of L. mexicana complex, of which ____ and ____ are the most important
what r the 2 leishmania from mexicana complex rspnsble for new world CL?
Leishmania mexicana & Leishmania pifanoi
The chiclero ulcer or Bay sore is caused by what leishmania?
Leishmania mexicana
what leishmania causes cutaneous and diffuse cutaneous leishmaniasis and is found in brazil? anong spp. vector nito?
Leishmania braziliensis & Lutzomyia
What do you call the clinical manifestation of leishmaniasis characterized by localized, non-ulcerating papule and develops diffuse satellite lesions and is otherwise known as Anergic or Lepromatous Leishmaniasis?
Diffuse Cutaneous Leishmaniasis
What do you call the subgenus that develops promastigotes in the hindgut?
normal leishmania kasi is sa midgut
subgenus Viannia
what do you call the enzyme that is able to distinguish the subgenus Viannia from other leishmanias?
aconitate hydrotase
incubation period of Leishmania tropica complex?
- L. major = 2 weeks
- L. aethiopica & tropica = months to years
first sign of infection in CL is what? this may itch inteensely and grow to 2cm or more in diameter
anong tawag doon sa kinakamot smth
small red papule
If cutaneous lesions are unable to heal, the px is said to be what?
anergic or hypersensitive
what do you call this patient that is incapable of mounting a response to infection which results from the deficiency in cell-mediated immunity and the characteristics of the parasite (L. aethiopica & pifanoi) itself?
hindi raw ma-heal cutaneous lesions
anergic patient
anergic patients may have diffuse CL kasi wala silang panlaban
what do u call the patient that is capable of excellent antibody and cellular response but cannot completely eliminate the parasites so the central lesion heals but active peripheral ones continue to form?
hindi raw ma-heal cutaneous lesions
hypersensitive patient
hypersensitive patients may have diffuse CL coz they cannot completely erradicate the parasites
what do you call the type of response that may be seen in CL which is characterized by the inability to eliminate central cutaneous lesion so the peripheral ones continue to form?
leishmaniasis recidiva
Host recovery in cutaneous leishmaniasis depends on the development of what type of immunity?
under adaptive immunity
cell-mediated immunity
Laboratory diagnosis for Leishmaniasis
- Skin & Tissue biopsies for amastigote observation
- Lesion demonstration
- Culture in Novy-MacNeal-Nicolle (NNN) medium or Schneider’s medium
- Montenegro Skin Test (Leishmanin Skin Test)
- Formol Gel Test
- Serology
- Molecular Methods
In short, parasites in smears and culture of ulcer material (bone marrow in VL), skin test, serologic test, hamster inoculation
what culture media may be used for the diagnosis of leishmaniasis?
- NNN (Novy-MacNeal-Nicolle)
- Schneider’s medium
what do you call the test to determine if you have a previous exposure to leishmania and is done by injecting a suspension of parasites intradermally?
Montenegro Skin Test
positive result = there is enlargement
negative in diffuse CL and VL
What do you call the test wherein you use formalin and px serum together and test if formalin forms a gel-like substance? this is used to screen patients with kala-azar
Formol Gel Test
used to determine if there is hypergammaglobulinemia
Treatment options for leishmaniasis
- Antimony compounds
- Amphotericin B
- Pentamidine
- Nifurtimox
what are the two pentavalent antimony that are commercially available to treat leishmaniasis?
- sodium stibogluconate
- meglumine antimoniate
ML in old world is caused by what leishmania?
Leishmania tropica & Leishmania major
ML in new world is caused by what leishmania?
Leishmania braziliensis
The parasites in ML causes destruction in what parts of the body?
mucosal structures (nasal septum, palate, cartilages)
what do you call the rapid destruction of the nasal septum and deformation of the nose?
this is the primary ulcerative of ML
ulcers on the oral or nasal mucosa
espundia
this is what you call the redness and bulging swellings of the tip of the nose during ML
tapir nose
what do you call the ulceration of the pinna of your ear during ML?
Chiclero Ulcer
MOT of Leishmania spp.?
- bite of vector
- blood transfusion
the Leishmania spp. targets the cells of what body system?
reticuloendothelial system
VL is widely known by its Indian name ____.
kala-azar
As in cutaneous and ML, the causative organisms are parasites of the ____ system
reticuloendothelial
it is no longer considered that VL is caused by a single agent but by at least 3 species belonging to what leishmania?
Leishmania donovani complex
Infection caused by L. donovani is commonly referred to as what fever?
dum dum fever
out of the 3 species of the L. donovani complex, alin ang sa old at alin ang new?
- L. donovani = old
- L. infantum = old
- L. chagasi = new
tropica and amazonensis kasama rin s book and are old and new, respectively
what leishmania is the common causative agent of VL in Central and South America?
L. chagasi
L. amazonensis is from d Americas too but mas common causative agent si chagasi
Kala-azar means, literally, ____, having reference to a characteristic darkening of the skin, which has been most often noted in light-skinned Indians
black fever
A condition known as ____ is sometimes seen in patients who have been treated for VL and may occur in persons who deny any history of disease.
dermal leishmanoid
these are lesions that may be erythematous or depigmented macules distributed over the entire body or in patches
The most common symptom in VL in the nervous system was a sensation of ____; followed by deafness, foot drop, and multiple cranial nerve palsies.
burning feet
Aspiration from what is considered by some the diagnostic procedure of choice in VL?
Aspiration from sternal marrow
splenic puncture is risky but undoubtedly gud & liver puncture is not productive