MEDICAL PARASITOLOGY: PROTOZOANS – AMEBA, FLAGELLATES, CILIATES AND APICOMPLEXANS Flashcards
o Kingdom Protista
o Unicellular organisms that possess 2 nucleus/nuclei, cytoplasm, limiting membrane, and organelles
o Eukaryotic
o Cytoplasm has 2 region
o Do not possess a cell wall
o Possess locomotory structures
o Manner of reproduction:
- Sexual
- Asexual
- both
Protozoan
What are the 2 regions of cytoplasm of protozoans?
- Endoplasm
- Ectoplasm
- Inner region
- for nutrition, food synthesis and storage (metabolism)
Endoplasm
- Outer region
- for protection, ingestion, and organelles for locomotion
Ectoplasm
What are the locomotory structures?
- Pseudopodia (Falsely locomotion)
- cilia
- flagella
What protozoans that does not have locomotor structures?
Apicomplexa (malaria)
What protozoans that does have complicated life cycle because they undergo both sexual and asexual manner of reproduction?
Apicomplexa (malaria)
What are the manner of reproduction?
- Sexual
- Asexual
- both
locomotion for SUBPHYLUM SARCODINA: Ameba
pseudopodia
SUBPHYLUM SARCODINA: Ameba Inhabit in the large intestine except
Entamoeba gingivalis
all SUBPHYLUM SARCODINA: Ameba undergo encystation except
Entamoeba gingivalis
This process where trophozoites would transform to become cyst
Encystation
The Mode of reproduction of SUBPHYLUM SARCODINA: Ameba
Asexual
- found in oral cavity/mouth
- no cyst stage
- Infective stage: trophozoite stage
o Entamoeba gingivalis
It is in the edge of the nucleus of entamoeba
peripheral chromatin
It is used to differentiate the members of entamoeba
Peripheral chromatin
the Infective stage of SUBPHYLUM SARCODINA: Ameba is the cyst except
Entamoeba gingivalis
All are commensals/nonpathogenic except
Entamoeba hystolytica
Vegetative stage, Motile and Feeding stage of intestinal ameba
Trophozoite
Non-motile and Resistant stage of intestinal ameba
Cyst
Stool consistency of the intestinal ameba trophozoite
watery/diarrheic stool
Stool consistency of the intestinal ameba cyst
formed stool
Stain/s that can be added in wet mount to identify the intestinal ameba trophozoite
- Quensel’s Stain
- Buffered Methylene Blue
Stain/s that can be added in wet mount to identify the intestinal ameba cyst
- Lugol’s Iodine
- D’ Antoni
the only pathogenic member ameba
Entamoeba histolytica
Final host of E. coli and E. histolytica
man
Mode of transmission of E. coli and E. histolytica
Ingestion of cyst
habitat of E. coli and E. histolytica
Large Intestine
usual size of E. coli trophozoite
20-25 um
usual size of E. histolytica trophozoite
15-20 um
movement of E. coli trophozoite
Non-progressive; sluggish
movement of E. histolytica trophozoite
Progressive; Unidirectional movement
describe the pseudopodia of E. histolytica trophozoite
Finger-like; hyaline
describe the pseudopodia of E. coli trophozoite
Blunt; granular
no. of nucleus of E.coli trophozoite and E. histolytica trophozoite
1
describe the peripheral chromatin of E. coli trophozoite
Coarse, Rough, Uneven (CRU)
describe the peripheral chromatin of E. histolytica trophozoite
Fine, Smooth, Even (FES)
Karyosome is composed of
RNA
describe the karyosome of E. histolytica trophozoite
Centrally located; small
describe the karyosome of E. coli trophozoite
Eccentric; Large
Diagnostic/distinguising characteristics of E. coli trophozoite
- Ingested debris, bacteria, yeast
- Dirty looking
Diagnostic/distinguising characteristics of E. histolytica trophozoite
- Clean looking
- Ingested RBC
Usual size of E. histolytica cyst
12-15 um
Usual size of E. coli cyst
15-25 um
No. of nuclei of E. histolytica cyst
Up to 4 nuclei;
- quadrinucleate (mature form)
No. of nuclei of E. coli cyst
Up to 8 nuclei
describe the karyosome of E. coli cyst
Eccentric
describe the karyosome of E. histolytica cyst
Centrally located
It is the energy source Made up of RNA (crystalline RNA)
Chromotoidal bar
describe the Chromotoidal bar of E. histolytica cyst
Cigar/sausage shape
describe the Chromotoidal bar of E. coli cyst
Splintered/broom stick appearance
What are the other inclusion of E. coli cyst and E. histolytica cyst
Glycogen vacuoles
2 amoebas that commonly encountered in stool specimens
- Entamoeba histolytica
- Entamoeba coli
Non-pathogenic ameba that are morphologically similar to Entamoeba histolytica (same in the appearance and size)
- Entamoeba dispar
- Entamoeba moshkovskii – also known as Laredo strain
- Entamoeba bangladeshi
E. histolytica and the other 3 non-pathogenic ameba that are morphologically similar can be differentiated through
- molecular methods
- zymodeme analysis
- isoenzyme analysis
90% of Entamoeba histolytica infections are ______
asymptomatic
10% of Entamoeba histolytica infections are ______
Symptomatic
What disease if the stool is:
- watery, mucoid
- Presence of trophozoites
- Fishy odor
- Few Bacilli (few bacteria)
Amebic dysentery: Bloody diarrhea
Identify the disease if the stool is:
- watery, mucoid
- Presence of trophozoites
- Fishy odor
- Many Bacilli (many bacteria)
- and caused by Shigella
bacillary dysentery
disease manifestation of E. histolytica
- Amebic dysentery: Bloody diarrhea
- Formation of flask shaped ulcers
- Colitis (fulminant colitis)
- Amebomas
manifestation of disease in E. histolytica mistaken for carcinomas (mass like lesions with abdominal pain)
Amebomas
The most common site of Extraintestinal amebiasis
Liver
Extraintestinal amebiasis can infect and destroy the liver causing
Amebic Liver Abscess (ALA)
Other organs affected by Extraintestinal amebiasis: (result to abscess formation)
- Brain
- Lungs
What are the Virulence factors of E. histolytica
- GalNac Lectin
- Amebapore
- Cysteine Proteinases
Virulence factor of E. histolytica that causes attachment to the target cells
GalNac Lectin
Virulence factor of E. histolytica that causes formation of holes/pores
Amebapore
Virulence factor of E. histolytica that causes spread of the parasite; tissue destruction
Cysteine Proteinases
Stool examination used to diagnose the movement of E. histolytica
DFS (Direct Fecal Smear)
Concentration Techniques used to recovers cystic stages of E. histolytica
Formalin Ether Concentration Technique (FECT)
Stool examination used for Confirmation of Intestinal Protozoans
Permanent Stained Smear
stool adhesive used in Permanent Stained Smear
Polyvinyl alcohol
Fixative used in Permanent Stained Smear
Schaudinn’s
classic stain used for better nuclear detail in Permanent Stained Smear
Iron hematoxylin
Stains that are used in Permanent Stained Smear
- Iron hematoxylin
- Trichrome stain
Culture media used for lab diagnosis of E. histolytica
- Boeck’s
- Rice Egg Saline
- Diamond
- Balamuth’s Egg Yolk Infusion
- Robinson’s and Inoki
Recommended culture media for lab diagnosis of E. histolytica
Robinson’s and Inoki
▪ More sensitive than microscopy
▪ Not routinely used
Anchovy sauce like
Liver Aspirates
Treatment forMetronidazole E. histolytica
- Metronidazole
- Iodoquinol
- Diloxanide Furoate
treatment used for invasive amebiasis
Metronidazole
treatment used for asymptomatic cyst carriers
Diloxanide Furoate
small race of E. histolytica
Entamoeba hartmanni cyst
- Similar to Entamoeba histolytica but smaller in
size
Movement of Entamoeba hartmanni trophozoite
sluggish; non-progressive
- Nucleus: 1
- Central karyosome with evenly distributed peripheral chromatin
- Movement: progressive; unidirectional
o Can be acquired by a person who has direct contact with pigs and monkeys, working in a pig farm
Entamoeba polecki trophozoite
- Nucleus: 1
- Karyosome: Central with evenly distributed peripheral chromatin
- Chromotoidal bars –angular or pointed ends
- Presence of glycogen mass
Entamoeba polecki cyst
morphologically similar to E. polecki
E. chattoni
- Nucleus: 1
o Large eccentric karyosome is surrounded by achromatic granules
o No peripheral chromatin - Large glycogen vacuole
Iodamoeba butschlii cyst
Describe the karyosome of Iodamoeba butschlii cyst
“Basket of Flowers appearance”
- Nucleus: 1
o Central karyosome surrounded by refractile, achromatic granules
o No peripheral chromatin - The cytoplasm is coarsely granular, vacuolated
- amoeba of pigs
Iodamoeba butschlii trophozoite
Movement of Iodamoeba butschlii trophozoite
sluggish and non-progressive
- Oval
- Nucleus: 2-4
- Blot-like karyosome
- Eccentric; prominent; cross eyed cyst
- No peripheral
Endolimax nana cyst
- Nucleus: 1
- Blot-like karyosome; no peripheral chromatin (crosseyes cyst)
- very small ameba/protozoan
Endolimax nana trophozoite
Movement of Endolimax nana trophozoite
sluggish
- Nucleus: 1
- Centrally located karyosome
- Pseudopod: varying appearance
- May ingest bacteria, debris and WBC
- Non-pathogenic: may be seen in patients with pyorrhea alveolaris
Entamoeba gingivalis trophozoite
Parasite that has no cyst stage
Entamoeba gingivalis
Gums infection caused Entamoeba gingivalis
pyorrhea alveolaris
Parasite found in the environment inhabiting lakes,
pools, tap water, air conditioning units and heating units
Opportunistic Amebae/Free-living pathogenic ameba/Facultative parasite
Facultative parasite usually invade ____ if ever they become parasitic
CNS
3 commonly Opportunistic amebae
- Naegleria fowleri,
- Acanthamoeba spp.,
- Balamuthia spp.
Certain bacteria that has symbiotic relationship with Opportunistic Amebae
Legionella
bacteria that is found in air-conditioning units
Legionella
Most pathogenic and Most virulent Ameboflagellate
Naegleria fowleri
What is the mode of transmission of Naegleria fowleri
entry to Olfactory epithelium, respiratory tract, skin and sinuses during swimming in contaminated pools, water, ponds, or lakes.
Infective stage of Naegleria fowleri
Trophozoite
Naegleria fowleri Trophozoite is biphasic. What are the two forms of Naegleria fowleri Trophozoite?
- Ameba (Limax form)
- Flagellate form
What form of Naegleria fowleri can be found in clinical specimen, biopsies or tissue specimen?
Limax form
Disease Manifestation and Pathology of Naegleria fowleri
Primary Amoebic Meningoencephalitis (PAM)
Virulence factor of Naegleria fowleri used to attached to the tissues and also release enzymes that can destroy the brain
Amebostomes
Diagnosis of Naegleria fowleri
- CSF examination
- Culture
- Molecular techniques (PCR, Immunofluorescence (IF)
What is the result of CSF examination if there is a presence of N. fowleri?
- elevated WBC
- no presence or very few bacteria
Treatment for patient with N. fowleri
Amphotericin B with Clotrimazole
Opportunistic ameba Larger or bigger than Naegleria fowleri.
Acanthamoeba spp.
mode of transmission of Acanthamoeba spp
entry through nose or break in the skin
infective stage of Acanthamoeba spp
Cyst and Trophozoite
It is a spinny projection found in the pseudopodia of the acanthamoeba
Acanthapodia
no. of nucleus of Acanthamoeba spp.
1
Describe the double cell wall of Acanthamoeba spp.in cyst stage
o Outer: wrinkled
o Inner: polygonal/ polyhedral
Chronic type of disease and the progression is slow caused by Acanthamoeba spp.
- Immunocompromised patients are affected
Granulomatous Amoebic Encephalitis (GAE)
Risk factor of Amebic keratitis
used of the contaminated contact lens solution
Usually seen in AIDS patients
- caused by Acanthamoeba spp.
Cutaneous lesions; Sinusitis
Diagnosis for N. fowleri
o Brain biopsy
o Corneal scrapings (Calcofluor white)
o Skin biopsy
o CSF exam
o Staining of Cyst with Periodic Acid Schiff (PAS)
o Indirect Immunofluorescence
Treatment
Fluorocystine
Ketoconazole
Amphotericin B
Mode of transmission of Balamuthia mandrillaris
entry thru nose, skin
The disease caused by Balamuthia mandrillaris
Granulomatous Amoebic Encephalitis (GAE)
irregular; finger-like, broad pseudopodia opportunistic ameba
Balamuthia mandrillaris trophozoite
It is the stage the Balamuthia mandrillaris which has outer irregular wall and inner round wall
Balamuthia mandrillaris cyst
Diagnosis for Balamuthia mandrillaris
- Brain biopsy
- IF
Class Zoomastigophora
- Intestinal and urogenital flagellates
- Hemoflagellates
All inhabit the large intestine except
Giardia lamblia, Trichomonas vaginalis, Trichomonas tenax
All undergo encystation except
Trichomonas species
Infective stage of INTESTINAL AND UROGENITAL FLAGELLATES
cyst except Trichomonas
All are commensals in INTESTINAL AND UROGENITAL FLAGELLATES except
Giardia lamblia, Trichomonas vaginalis, Dientamoeba fragilis
Mode of reproduction of INTESTINAL AND UROGENITAL FLAGELLATES
asexual reproduction through binary fission
- Also known as G. duodenalis and G. intestinalis
- it affects humans and animals
- pathogenic intestinal flagellate
Giardia lamblia
Important reservoir of Giardia lamblia
Beavers
diagnostic stage of Giardia lamblia
Cyst, Trophozoite
Infective stage of Giardia lamblia
Cyst
MOT of Giardia lamblia
ingestion of cyst
Parasite that has Pear, pyriform, Bilaterally symmetrical shaped and an appearance of Old Man’s Face with Glasses/“Someone is looking at you”, Curved spoon (side view)
Giardia lamblia Trophozoite
no. of nuclei of Giardia lamblia Trophozoite
2
no. of flagella of Giardia lamblia Trophozoite
8 or 4 pairs of flagella
Giardia lamblia Trophozoite used or employed this for attachment and act as Virulence factor
Ventral sucking disk
describe the Parabasal body/ Median body of the Giardia lamblia Trophozoite
(2) hammer shaped/ claw hammer
What is the motility of Giardia lamblia Trophozoite?
“Falling Leaf” motility
- Oval
- Football shape with 4 nuclei, parabasal bodies, axoneme
o A group of axoneme would eventually become an axostyle
Giardia lamblia cyst
What are the disease caused by Giardia lamblia
Giardiasis
* Beaver fever
* Traveler’s Diarrhea
* Gay Bowel Syndrome
Symptom of Giardiasis
Explosive Watery Diarrhea
What are the chronic disease caused by Giardia lamblia?
- Steatorrhea
- Weight loss
- Malaise
- Foul smelling stools: “Rotten eggs” odor because of malabsorption
Lab diagnosis for Giardia lamblia
- Stool exam
- Duodenal aspirates
- Entero-test; (Beale’s String Test)
- Serology
- Molecular methods
- Biopsy
This procedure will ask the patient to swallow the capsule with string and then the loose end of the string taped on the face of the patient and wait 4 hours. After 4 hours, string will be pulled out
- If the string become color green that means it reach in the duodenum
Entero-test; (Beale’s String Test)
treatment for Giardia lamblia
Metronidazole
Parasite that is Non pathogen/Commensal flagellate residing the colon
Chilomastix mesnili
appearance of Chilomastix mesnili trophozoite
Asymmetric; pear shaped
No. of flagella of Chilomastix mesnili trophozoite
4
What is the Motility of Chilomastix mesnili trophozoite
Boring/Corkscrew
It is the mouth of the Chilomastix mesnili trophozoite
Cytostome
What is the appearance of Cytostomal fibril of Chilomastix mesnili?
“Shepherd’s Crook” appearance”
What is the appearance of posterior part of Chilomastix mesnili?
spiral groove/twisted jaw appearance
What is the appearance of the Chilomastix mesnili cyst?
Nipple/ Lemon Shaped
The Nipple/ Lemon Shaped of the Chilomastix mesnili cyst is also called as?
Hyaline knob
- It is Pathogenic (Diarrhea)
- Formerly under the ameba
- NO visible flagella
Dientamoeba fragilis
No. of nuclei in cystic stage of Dientamoeba fragilis
2
The appearance of 2 nuclei in Dientamoeba fragilis trophozoite
Rosette like (fragmented chromatin 3-5 granules/nucleus)
Mode of transmission of Dientamoeba fragilis
via helminth eggs; Oral-fecal
o Those people who had Ascaris or Enterobius infections, possible they can also be infected Dientamoeba
How to diagnose Dientamoeba fragilis Trophozoite
permanent stained smear
Treatment for Dientamoeba fragilis
Iodoquinol
Diseases caused by Dientamoeba fragilis
Intermittent diarrhea, abdominal pain; eosinophilia; pruritus in the anal area
Closest relative of Dientamoeba
Trichomonas
- Oval trophozoite; 1 nucleus
- 3 anterior flagella & 1 posterior flagella
- Jerky motility
Enteromonas hominis trophozoite
No. of nuclei in Enteromonas hominis cyst
2/4 nuclei
- 1 anterior and 1 posterior flagella
- Cleft like cytostome
- Jerky motility
Retortamonas intestinalis trophozoite
Apperance of Cytostomal fibril of Retortamonas intestinalis
“Bird’s beak”
SUBPHYLUM MASTIGOPHORA: Flagellates that has No cyst stage; possess 4-5 flagella (trophozoite stage)
Trichomonas spp.
the most pathogenic trichomonas spp.
T. vaginalis
What is the habitat of Trichomonas vaginalis?
Urogenital Area
Mode of transmission of Trichomonas vaginalis
Intimate contact, Infant deliver, contaminated underwear, and towels
a wave-like structure on the lateral part of the trophozoite and is used for motility
- 1/2 of the body
Undulating Membrane
o dot-like structure throughout the body.
o iron-rich (iron-loving)
o can only be found in T. vaginalis
Siderophil granules:
leading non-viral STD worldwide caused by T. vaginalis
: Trichomoniasi
Disease manifestation of T. vaginalis infection in females
Vaginal pruritus, Strawberry cervix, Frothy discharge
Disease manifestation of T. vaginalis infection in males
asymptomatic, occasionally Non-gonococcal urethritis, prostatitis
Virulence factors of T. vaginalis
adhesins, cell detaching factor
inflammation of cervix with reddish dots (petechial spots)
Strawberry cervix
Formerly known as T. hominis
Commensal (non-pathogenic) but may be misdiagnosed as T. vaginalis especially in children if there is fecal contamination of urine
Pentatrichomonas hominis
Habitat of Pentatrichomonas hominis
Colon
Mode of transmission of Pentatrichomonas hominis
ingestion of trophozoite
describe the nucleus of the Pentatrichomonas hominis
Rounded (no peripheral chromatin)
Undulating Membrane of Pentatrichomonas hominis
Full body length
Smallest among the 3 Trichomonas species
Trichomonas tenax
Habitat of Trichomonas tenax
Mouth (tartar or teeth)
Mode of transmissionof Trichomonas tenax
direct contact (kissing, sharing of utensils)
describe the nucleus of Trichomonas tenax
ovoidal
Undulating Membrane of Trichomonas tenax
2/3 of the body
Disease manifestation of Trichomonas tenax
periodontal diseases
respiratory infections
Lab diagnosis for Trichomonas spp.
- Wet mounts if vaginal and urethral discharge, stool exam, mouth scrapings
- stained smears (giemsa or Pap’s)
- Culture (gold standard)
- Antigen detection (rapid detection for T. vaginalis)
- Serology
- Molecular methods
- Flagellates that are found in the blood and other fluids (CSF) and in tissues
- Vector borne parasites
Hemoflagellates
Medical important genera of hemoflagellates
o Trypanosoma
o Leishmania
four morphological forms of hemoflagellates (based on the location of kinetoplast and flagella)
- Amastigote (Donovan Leishman)
- Promastigote (Leptomonas)
- Epimastigote(Crithidia)
- Trypomastigote
Energizing structure of hemoflagellate made up of DNA.
Kinetoplast
Only the epimastigote and trypomastigote are seen in the life cycle of_____
Trypanosoma brucei infections
Only the promastigote and amastigote are seen in _____
Leishmania infections
Diagnostic stages (found in humans) in hemoflagellates
amastigote and trypomastigote
Infective stage of Trypanosoma cruzi
metacyclic trypomastigote
Infective stage of Trypanosoma brucei
metacyclic trypomastigote
Infective stage of Leishmania
promastigote
Stage of hemoflagellate that has:
- No flagella
- Intracellular
- Found on the host cell
Amastigote
Stage of hemoflagellate that has:
- Anterior flagella
- Kinetoplast: anterior to the nucleus
- Nucleus: found in the center of the slender stage
Promastigote
Stage of hemoflagellate that has:
- Anterior flagella
- Undulating membrane: 1/2 of the body
- Kinetoplast: anterior to the nucleus
- Nucleus: posterior part of the parasite.
- Body is wider than promastigote
Epimastigote
- Anterior flagella
- Undulating membrane: full body length
- Kinetoplast: posterior to the nucleus
- Has U-, C-, or S-shaped appearance
- Contain granules (known as volutins granules)
Trypomastigote
Habitat of Trypanosoma cruzi
reticuloendothelial system, cardiac muscle, CNS
Vector of Trypanosoma cruzi
reduviid bug/Kissing Bug (Triatoma)
mode of transmission of Trypanosoma cruzi
Feces of vector entering the bite wound; blood transfusion, organ transplants; transplacental
disease commonly found in south africacaused by Trypanosoma cruzi
American Trypanosomiasis or Chagas disease
signs of infection include the development of Chagoma, Romaña’s sign, and others are fever and lymphadenopathy
Acute phase of chagas disease
painful reddish nodule at the site of the bite of reduviid bug
Chagoma
periorbital swelling after the bite of reduviid bug
Romaña’s sign
after 10-20 years of trypanosoma infection.
o Enlargement of the vital organs (heart, esophagus, colon).
o Common cause of death involves heart diseases
Chronic phase of chagas disease
Lab Diagnosis for Chagas disease
- Giemsa staining of CSF, Blood, Lymph
- Xenodiagnosis
- Culture
- Serology
Treatment for chagas disease
- Nifurtimox
- Benznidazole
use of kissing bug. Patient is allowed to be bitten by
the bug. If the parasite develops in the bug after a few weeks, the patient is positive
Xenodiagnosis
Common culture method for diagnosis of Chagas disease
Novy MacNeal Nicolle
Common serology method for diagnosis of Chagas disease
Machado Guerreiro (complement fixation technique)
Stages used to diagnose Trypanosoma cruzi in chagas disease
- Trypomastigote
- Amastigote (tissues) commonly encountered
in chronic phase.
Stages used to diagnose Trypanosoma cruzi in chagas disease
- Trypomastigote
- Amastigote (tissues) commonly encountered
in chronic phase.
agent of African Sleeping Sickness
Trypanosoma brucei
vector of Trypanosoma brucei
Tse-tse fly (Glossina spp.)
Example of Glossina spp.
- G. pallidipes
- G. morsitans
- G. palparis
habitat of Trypanosoma brucei
blood, lymph, CSF
Agent of Rhodesian/East African Sleeping
Sickness
Endemic in S. and E. Africa
Trypanosoma brucei rhodesiense
agent of Gambien/West African Sleeping Sickness
o Endemic in W. and C. Africa
Trypanosoma brucei gambiense
o Acute rapidly progressing
o CNS stage takes place early (<9mos)
o Minimal lymphadenopathy
o Anthropozoonotic: animals (most common) and humans are affected
o High parasitemia
Rhodesian/East African Sleeping Sickness
o Prominent lymphadenopathy
o Chronic progression
o Anthroponotic: humans are affected
o Low parasitemia
Gambien/West African Sleeping Sickness
Laboratory diagnosis of Trypanosoma brucei
- Trypanosomal chancre (early sign)
- Winterbottom’s sign
- Kerandel’s sign
- In-vitro autoagglutination in blood
- Elevated serum and CSF IgM
- Mott cells in CSF (morula cells)
painful ulceration caused by Trypanosoma brucei
Trypanosomal chancre
▪ cervical lymphadenopathy
▪ enlargement of lymph nodes
▪ swelling or bumps on the neck region
Winterbottom’s sign
Delayed sensation to pain result to Trypanosoma brucei infection
Kerandel’s sign
Diagnostic stage of Trypanosoma brucei
Trypomastigotes in bite lesion, blood, CSf, lymph node
aspirate
Diagnosis for Trypanosoma brucei
o Concentration of Buffy Coat; quantitative buffy coat (QBC)
o Serology – IHAT, ELISA, Rapid tests
o Molecular methods
o Animal inoculation and Culture
Treatment for Trypanosoma brucei infection
Pentamidine
Suramin
Melarsoprol
(MelaSun Po)
intracellular protozoan
Leishmania
Vector of Leishmania spp.
Sand fly
GENUS of Leishmania spp.
- Phlebotomus spp.
- Lutzomiya spp.
MOT of Leishmania spp.
Bite of vector; blood transfusion, contact, contamnation of bite wounds
Leishmania spp. that:
Target:
- Endothelial cells of skin capillaries; phagocytic monocytes
- Lesions on the skin are painless but highly disfiguring
Disease: Cutaneous Leishmaniasis, Old world Leishmaniasis, Aleppo Button, Delhi boil, Baghdad boil,
Jericho boil ( Si ALEPPO pumunta ng DELHI para bumili ng BAG kasama si JERICHO)
L. tropica
New World Cutaneous Leishmaniasis
- L. mexicana,
- L. braziliensis
Leishmania spp. that:
Target
Mucocutaneous junstionc (nasal septum, mouth, pharynx)
Disease:
Mucocutaneous Leishmaniasis (American, New world Leishmaniasis)
L. braziliensis
Leishmania spp. that:
Target:
Endothelial cells of Reticuloendothelial System
* Causes splenomegaly
Disease:
Visceral Leishmaniasis (Kala-azar, Dumdum fever, Black
fever)
The most severe/virulent
L. donovani
Diagnostic stage of Leishmania
Intracellular amastigotes
Amastigotes can be mistaken for _____ of Histoplasma capsulatum especially in cases of dumdum fever
yeast cells
Laboratory Diganosis of Leishmania
- Demonstration of lesions
- Biopsies (skin, tissue)
- Examination of BM spleen, lymph node
- Montenegro skin test (Leishmanin Skin test)
- Formol-Gel test
- Serology: IFAT
- Culture
- Molecular methods
detection of hypergammaglobulinemia in patients with
kala-azar
Formol-Gel test
Common culture medium for Laboratory Diganosis of Leishmania
Novy MacNeal Nicolle
Schneider’s drosophilia medium w/ 30% fetal bovine
serum
Treatment for Leishmania
Antimony compounds (Sodium stibogluconate, n-methyl-glucamine antimonite)
largest protozoan infecting man; medically important
ciliate
Balantidium coli
largest protozoan infecting man; medically important
ciliate
Balantidium coli
Final host of Balantidium coli
Man
Reservoir host of Balantidium coli
pigs
MOT of Balantidium coli
Ingestion of cysts
Habitat of Balantidium coli
Colon (cecum)
Infective stage of Balantidium coli
cyst
It is called Anterior Tapered
Balantidium coli trophozoite
Motility of B. coli trophozioite
“Thrown ball or rotary”
hair-like structures surrounding the whole parasite
Cilia
describe the Cytostome B. coli trophozioite
funnel-shaped mouth
anus; where waste products of B. coli are released
Cytopyge
nucleus that is kidney-shaped
Macronucleus
nucleus that is primarily used for reproduction
Micronucleus
It is for osmoregulation of B. coli
Contractile vacuoles
Describe the wall of B. coli trophozoite
Double-walled; refractive cyst wall enclosing the cilia
Manifestation of Balantidiasis/ Balantidial
dysentery
o Bloody diarrhea
o Flask shaped ulcers (wide and rounded ulcers)
o Extraintestinal may spread may occur (usually spread in the lungs, urogenital area, and mesenteries)
What is Virulence factor of B. coli?
Hyaluronidase
Lab Diagnosis for B. coli
Stool exam and Biopsy
Treatment for B. coli
Metronidazole
- Intracellular parasites
- Presence of the Apical complex:
PHYLUM APICOMPLEXA
used by Phylum apicomlexa for gaining entry of host cells
Apical complex
Reproduction of Phylum apicomlexa
Alternating asexual and sexual Generation (can happen in 1 or 2 hosts depending on the spp.)
most important parasitic disease in man
bad air
MALARIAL PARASITES
most important and most virulent;
#1 cause of malaria in the Philippines
Plasmodium falciparum
most widespread/ prevalent; except in Antarctica
Plasmodium vivax
least common malarial parasite
Plasmodium ovale
Malarial parasite that has long paroxysmal cycle and incubation period
Plasmodium malariae
zoonotic (malaria of monkeys)
o Endemic area: South-East Asia
o can be mistaken for P. malariae in microscopy (certain RBC stages)
Plasmodium knowlesi
diagnosis for malarial parasite
Molecular method (preferably)
It is Sexual reproduction that happens in the final host
sporogony
It is asexual reproduction that happens in the intermediate host
schizogony
Major malarial vector in the Philippines
Night biter
Female Anopheles minimus flavirostris
Habitat of malarial parasite in humans:
RBCs, liver cells (humans)
Infective stage of malarial parasite to mosquito
Gametocytes (Macrogametocytes, Microgametocytes)
Infective Stage of malarial parasite to Man (Transmission Stage)
Sporozoites
Mode of Transmission of malarial parasite
Mosquito bite; Blood transfusion; Congenital
Female anopheles mosquito bites humans and injects ____
sporozoites
Sporozoites must reach liver to become ____ and reproduce (around 40 minutes or less than an hour depending on the reference)
merozoites
Hypnozoites are seen in
P. vivax and P. ovale
It is caused by Hypnozoites
reactivation of hypnozoites
RELAPSE
Some merozoites enter the blood circulation to infect
RBCs
Merozoites of malaria in asexual cycle enter the blood circulation to invade RBCs to become:
ring forms
female gametocyte
Macrogametocyte
male gametocyte
Microgametocyte:
release sporozoites migrate to salivary glands of mosquito
ready to infect a susceptible human
Oocyst of malaria in sexual cycle
Most cases of malaria occur in
Africa
Symptoms and complications of malarial infection
o Paroxysms (chills, fever, sweating)
o Anemia
o Splenomegaly
o Blackwater fever (P. falciparum) o Cerebral malaria (P. falciparum)
o DIC
o Proteinuria: Nephrotic syndrome
o Occurrence of relapse and recrudescence
Malarial pigment
the more pigment, the more severe the malaria is
hemozoin
infected RBCs become adherent to the blood vessels that causes other stages (schizonts) to not be observed under the microscope
Cytoadherence (P. falciparum)
Malignant tertian
Malaria/Subtertian
Malaria or estivoautumnal
malaria
Plasmodium falciparum
Paroxysmal cycle of Plasmodium falciparum
36-48 hours
RBC infected by Plasmodium falciparum
All forms
Size of Parasitized RBC in Plasmodium falciparum
Normal
Parasite that has: (ring form)
- Delicate small ring
- May have 2 chromatin dots
- Common multiple rings in an RBC
- Accole/applique forms – ring forms in the periphery
Plasmodium falciparum
Parasite that the Developing Trophozoite has:
Heavy ring forms;
not commonly seen
Plasmodium falciparum
Schizont of Plasmodium falciparum
8-36 merozoites ; rarely seen
describe the Microgametocyte of P. falciparum
Sausage shaped; diffuse chromatin (sabog)
describe the macrogametocyte of P. falciparum
rescent shaped; compact chromatin
describe the Stippling of P. falciparum
Maurer’s clefts (comma-like red dots)
Benign tertian malaria
Plasmodium vivax
Paroxysmal cycle of Plasmodium vivax
44-48 hrs
RBC infected by Plasmodium vivax
reticulocytes
Size of Parasitized RBC of Plasmodium vivax
Enlarged RBC (1.5-2 times)
RBC stages in Plasmodium vivax
All stages present
Describe the Ring Forms of Plasmodium vivax
Ring 1/3 diameter of RBC
Heavy chromatic dot
Signet ring appearance
Developing Trophozoite of Plasmodium vivax
Ameboid (bizarre looking, irregular shaped)
Developing Trophozoite of Plasmodium vivax
12-24 merozoites
Microgametocyte of Plasmodium vivax
Round; large pink to purple chromatin mass surrounded
by a pale halo
Macrogametocyte of Plasmodium vivax
Round; eccentric chromatin mass
Stippling of Plasmodium vivax
Schuffner’s (eosinophilic)
- More common
Ovale tertian malaria
Plasmodium ovale
Paroxysmal cycle of Plasmodium ovale
48 hours
RBC infected by Plasmodium ovale
Young (reticulocytes)
Size of RBC Parasitized Plasmodium ovale
Oval, some may be larger than normal; presence of fimbriated or serrated (pangil) edges in RBCs
Presence of RBC stages in Plasmodium ovale
All stages present
Describe the Ring Forms Plasmodium ovale
Larger rings; similar to P. vivax
Describe the Developing Trophozoite of Plasmodium ovale
Ring shaped; non ameboid; similar to P. vivax
Schizont of Plasmodium ovale
8 merozoites
Microgametocyte of Plasmodium ovale
Smaller than P. vivax
Macrogametocyte of Plasmodium ovale
Smaller than P. vivax
Stippling of Plasmodium ovale
James ; Schuffner’s (in some references)
Quartan malaria
Plasmodium malariae
Paroxysmal cycle of Plasmodium malariae
72 hours
RBC infected of Plasmodium malariae
Old (senescent)
Size of RBC Parasitized by Plasmodium malariae
Normal
Presence of RBC stages in Plasmodium malariae
Few rings, mostly trophozoites and schizonts
Ring Forms of Plasmodium malariae
Smaller rings (1/8 of cell)
Heavy chromatin dot
(Bird’s Eye appearance)
Developing Trophozoite in Plasmodium malariae
Band shaped trophozoite;
basket forms may be seen
Schizont of Plasmodium malariae
6-12 merozoites; rosette or fruit pie appearance
Microgametocyte of Plasmodium malariae
Smaller than P. vivax
*same pics with P. ovale
Macrogametocyte of Plasmodium malariae
Smaller than P. vivax
*same pics with P. ovale
Stippling of Plasmodium malariae
Ziemann’s
Spx for Lab diagnosis of malaria
o Capillary blood w/o AC (more preferred)
o Whole blood: EDTA (pero this is not preferred)
Best time/period for collecting the malarial specimen
collect blood at height of fever or every 6-8 hours
The GOLD STANDARD laboratory diagnosis for alarial infection
Microscopy
Smear prep. for malarial count
Thick smear:
Size of the thick smear
2 cm or 2.5 cm diameter
Dehemoglobinize using _____
Distilled water to lyse RBCs
Smear prep for malarial Species identification
Thin smear
Fixative of Thin smear
Methanol
Stain used for smear prep
Giemsa (pH 7.2)
pH must diluted (adjusted using PBS – Phosphate Buffered Saline)
Alternative stain for smear prep
Wright’s
Stain used for Quantitative Buffy coat (QBC)
acridine orange stain
anticoagulant used for Quantitative Buffy coat (QBC)
oxalate
Positive indicator for Quantitative Buffy coat (QBC)
(+) bright green and yellow under fluorescence microscope
Antigen detect in Rapid Diagnostic Tests (Immunochromatographic Methods)
- HRP-II
- Parasite LDH
- Aldolase
antigen that is Specific for P. falciparum
- histidine rich protein II
Antigen that is nonspecific P. falciparum
Parasite LDH
Test for for low parasitemia and mixed infections
Molecular: PCR
Culture media for Malarial infection
RPMI1640
Treatment for malarial infection
o Chloroquine: Main stay drug (has resistance as a disadvantage)
o Artemether Lumefantrine: for falciparum malaria
o Doxycycline: prophylaxis
Intracellular parasites that causes malaria-like infections
Babesia microti
Definitive host of Babesia microti
Ticks (Ixodes spp.)
Intermediate hosts of Babesia microti
white footed mouse, deer, livestock, cattle
accidental hosts of Babesia microti
human
MOT of Babesia microti
bite of an infected tick (forest), blood transfusion; vertical transmission
Morphology of merozoites of Babesia microti
maltese cross or bunny ears
Ring forms of Babesia microti may be mistaken as _____
P. falciparum
Disease manifestation of Babesia microti
Babesiosis, Texas cattle fever, Nantucket fever, Redwater fever
S/S: flu-like, malaise, hepatomegaly, splenomegaly; usually selflimiting
B. microti severe infections in certain cases:
splenectomized individuals, immunecompromised,
coinfection with Lyme disease or (Borrelia)
Diagnosis of B. microti
o Microscopy
o Serology
o Molecular methods
Treatment of B. microti
Pyrimethamine and Sulfadiazine
Tissue Coccidians
Toxoplasma gondii
Definitive host of Toxoplasma gondii
Members of Felidae family
Intermediate host of Toxoplasma gondii
birds, rodents, pigs
Accidental or Dead End host of Toxoplasma gondii
Humans
Infective stages of Toxoplasma gondii
oocyst and tissue cysts
MOT of Toxoplasma gondii
o Ingestion of infected and undercooked meat
o Consumption of food or water contaminated with cat feces
o Blood transplant/organ transfusion
o Vertical transmission (torch testing)
Parasite stages in humans of Toxoplasma gondii
- Tachyzoites
- Bradyzoites
(elongated)rapidly multiply and infect cells of the intermediate hosts and non-intestinal epithelial cells of cats
Tachyzoites
multiply slowly
- Develop mostly in neural and muscular tissues
- May also develop in visceral organs
Bradyzoites
Disease manifestation of T. gondii
o Usually asymptomatic among immunocompetent
o Immunocompromised: encephalitis; retinochoroiditis, lymphadenopathy (AIDS), splenomegaly; brain focal lesions
o Congenital defect to the newborn
▪ Stillborn, abortion, encephalitis, hydrocephalus,
chorioretinitis, cerebral calcifications
Laboratory Diagnosis for T. gondii
- Sabin Feldman
- Frenkel test (skin test)
- ELISA, HAT, FAT
- TORCH testing
- Examination of tissue sections, CSF
- Molecular methods
Classic serologic test used for diagnosis of T. gondii
Sabin Feldman test
Spx used for Sabin Feldman test
Serum + live toxoplasma + methylene blue
Reagent for Sabin Feldman test
Methylene blue
Positive result of Sabin Feldman test
nonuptake of dye
AKA: C. parvum
Cryptosporidium hominis
size of Oocyst of C. hominis
4-6 um
infective once released
- contains 4 sporozoites
Oocyst
disease manifestation of C.hominis
Outbreaks or diarrhea; low infective dose
o Lalabas yung sporozoites because of its thin-walled oocyst
Treatment for C. hominis
Nitazoxanide; for AIDS – no effective Rx
Treatment for C. hominis
Nitazoxanide; for AIDS – no effective Rx
Intestinal Coccidians inhabit ____
small intestine (enterocytes –intestinal cells)
MOT of Intestinal Coccidians
ingestion of sporulated oocysts
AKA: Cyanobacterium like body
autofluorescence
Cyclospora cayetanensis
size Oocyst of Cyclospora cayetanensis
8-10 um
contains 2 sporocysts unsporulated/immature when released
Oocyst of Cyclospora cayetanensis
Disease manifestation of C. cayetanensis
Diarrhea implicated after consumption of contaminated fruits such as raspberries; basil, baby lettuce, snow peas
Treatment for C. cayetanensis
Trimethoprim-sulfamethoxazole (TMP-SXT)
Laboratory Diagnosis for Partially Acid Fast Intestinal Coccidians
- Stool examination
a. Concentration techniques: Sheather’s sugar Flotation, FECT
b. Staining method: Modified Kinyoun Method (most costefficient) - Other tests: molecular methods; serology; phase contrast microscopy
AKA: Isospora belli
Cytoisospora belli
describe the oocyst of Cytoisospora belli
ellipsoid/spindle shaped
o contains 2 sporocysts
o unsporulated/immature when release
Disease manifestation C. belli
Diarrhea; least common
Rx for C. belli
TMP-SXT
Sacrocystis in Beef
Sacrocystis hominis
Sarcocystis in pork
Sarcocystis suihominis
MOT of Sarcocystis
ingestion of uncooked meat containing mature sacrocysts
Diagnostic stage of Sarcocystis
Oocysts in stool; Sacrocyst in muscle
Manifestations of Sarcocystis
severe diarrhea, fever, weight loss, muscle pain
Lab test for sarcocystis
Zinc Sulfate Concentration for stool; biopsy (muscle)
NOW considered and fungus
Microsporidia
Microsporidia that Causes diarrhea among immunocompromised patients
Encephalitozoon and Enterocytozoon
Diagnosis for microsporida
detection of spores in stool, tissue biopsy (PAS, Silver stain, Giemsa); Modified trichrome; antigen detection, IF, PCR
- Formerly classified as a yeast
- Commensal of GI tract
- Zoonotic
Blastocytis hominis
no. of nucleus of Blastocytis hominis
(2-4) – found in periphery
MOT of Blastocytis hominis
Ingestion of thick-walled cysts
Forms of Blastocytis hominis
o Classic vacuolated form (central-body form)
o Granular forms
o Multivacuolar
o Avacuolar
o Ameboid form
