Parasitology - Classification And Amoeba Flashcards
Types of Amoeba
Intestinal
Free living
Examples of intestinal Amoeba
E. Histolytica
E. Coli
Examples of Free living Amoeba
Naegleria fowleri
Acanthamoeba
Example of Ciliated Parasites
Bolantidium Coli
Example of Flagellated Parasites
Intestine - Giardia lamblia
Genital - Trichomonas vaginalis
Blood and tissue - Leishmania, Trypanosoma
Examples of Sporozoan parasites
Malaria, Babesia
Toxoplasma, Coccidian parasites
Stages of Entamoeba histolytica
3 stages
Trophozoite
Pre-cyst
Cyst - Infective stage
Host in case of Entamoeba histolytica
Humans
Infective form in case of Entamoeba histolytica
Quadrinucleated cyst
Infective dose of Entamoeba histolytica
Small infectivity dose - less than 100 cysts
Entamoeba histolytica cysts can survive in
Chlorination of water
Mode of transmission of Entamoeba histolytica
Feco oral (MC)
Rarely homosexual
Which organisms needs Small infectivity dose
CHHOTA SMALL
C - Cryptosporidium
H - E. Histolytica
H - eHec
S - Shigella
Giardia lamblia
Virulence factor in case of Entamoeba histolytica
Gal/Gal NAC lectin antigen
Enzymes involved in Entamoeba histolytica
Metallo- collagenase
Neuraminidase
Life cycle of Entamoeba histolytica
Ingestion of mature cyst (Feco oral) - Excystation in Small intestine - Formation of 8 trophozoites - Encystation in large intestine - Cyst formation - Cysts nd trophozoites passed in feces - In environment cyst survives - again ingestion
Organs affected in Entamoeba histolytica
Intestine - Travellers diarrhea
Ulcer seen in intestine due to Entamoeba histolytica infection
Flask shaped ulcer - Inside flask - Trophozoites + which engulfed the RBCs (Erythrophagocytosis)
Clinical features of Entamoeba histolytica infection
Asymptomatic intraluminal amoebiasis (M/C)
Amoebic colitis - bloody diarrhea
Complications of Entamoeba infection
Appendicitis
Perforation
Peritonitis
Most common extraintestinal organ involved in Entamoeba infection
Liver - Right lobe (Post superior surface of liver) - leading to Amoebic liver abscess
Gross finding in case of Amoebic liver abscess
Anchory sauce appearance
Microscopic examination finding in Amoebic liver abscess
Trophozoites in pus
Ameboma/Amoebic granuloma involves which region
Chronic condition
Rectosigmoid region
Trogocytosis means
Attachment of Gal/Gal NAC Lectin - killing/Nibbling of cell
Sample taken for diagnosis of Entamoeba
2 stool samples (consecutive days) - intermittent shedding
Finding of stool samples in Entamoeba infection
Trophozoites in stool - Active disease
Only cyst in stool - Carrier state
Trophozoites appearance in Entamoeba histolytica infection
Has pointed pseudopedia
Nucleus - 1 (central karysome) - Cart wheel nucleus
Shows Erythrophagocytosis
Cyst seen in Entamoeba histolytica infection
Quadrinucleated cyst (1-4 nuclei)
Chromatid body/bar
Composition and stain used to see Chromatid body/bar
Composition - Ribonucleoprotein
Stain - iron hematoxylin
Cyst in E. Coli
Cyst - nuclei 1-8,
Thin Filamentous chromatoidal bar
Trophozoites seen in E coli
Blunt pseudopodia
Nucleus - 1 (Eccentric karyosome)
No RBC engulfed
Culture media used for diagnosis of Entamoeba infection
Polyxenic medium
Axenic culture medium
Polyxenic medium used for diagnosis of Entamoeba
Supplemented with bacteria (low parasite load)
Nelson culture
Balamuth medium
Bocck and Dr Bohlar medium
Axenic medium used for diagnosis of Entamoeba
Pure, no bacterial supplementation
Diamond medium
Miscellaneous stool M/E finding in Entamoeba infection
Charco Leydeu crystal -
Composition - Galactin 10 from Eosinophils
Treatment of Entamoeba infection
Metronidazole X 10 days
Followed by luminal amoebicide Paramomycin (for asymptomatic carrier)
Different type of Entamoeba species are differentiated on basis of
PCR
Enzyme studies (Zymodene Studies)
Free living Amoeba includes
Naegleria
Acanthamoeba
Balamuthia
Human acquires Naegleria fowleri infection while
Swimming
Naegleria fowleri entry site and causes which disease
Enters via cribriform plate - reaches brain - cause PAM(Primary Amoebic Meningoencephalitis)
Trophozoites of Naegleria fowleri shows
Flagella
Trophozoites in Acanthamoeba shows
Spinous Acanthopodia
Disease caused by Acanthamoeba
Granulomatous Amoebic Meningoencephalitis (GAM)
Most common Risk factor in case of Naegleria fowleri and Acanthamoeba
N. Fowleri - Swimming
Acanthamoeba - Immunodeficiency
Infective forms of Naegleria fowleri and Acanthamoeba
N. Fowleri - Trophozoite Acanthamoeba - Trophozoite (spikes) and Cyst (wrinkled outer wall)
Clinical course of Naegleria fowleri and Acanthamoeba infection
N. Fowleri - Acute (Fatal <5 days)
Acanthamoeba - chronic
Spread of Naegleria fowleri and Acanthamoeba
N. Fowleri - Neural
Acanthamoeba - Blood
Diagnosis of N. Fowleri
CSF - Trophozoite
Increased polymorphs
Diagnosis of Acanthamoeba
On Brain Biopsy - Trophozoites and Cysts
Culture used for Naegleria fowleri and Acanthamoeba
Non nutrient agar (NNA) with lawn culture of E coli
Culture used for Naegleria fowleri
Non nutrient agar (NNA) with lawn culture of E coli
Gold standard method of diagnosis for N. Fowleri and Acanthamoeba
NAAT
Treatment of N. Fowleri infection
Amphotericin B
Treatment of Acanthamoeba
Pentamidine + Azole + Sulfonamide + Flucytosine
Balamuthia Mandullaris causes
Granulomatous Amoebic encephalitis (GAE)
Infective form of Balamuthia Mandullaris
Trophozoites - fish shaped
Cyst - smooth
Balamuthia Mandullaris can infect which type of patients
Can occur in both immunocompromised and Immunocompetent individuals
Acanthamoeba can also cause which eye related complication
Contact lens keratitis
Which is only Ciliated Parasite of humans
Balantidium coli
Which is the largest protozoa invading human intestine
Balantidium coli
Infective form for Balantidium coli
Cyst
Nucleus in case of Balantidium coli
Both trophozoites and cyst have binucleated - macro and micronucleus
Motility shown by Balantidium coli
Rotating motility
Reservoir in case of Balantidium coli
Pig
Treatment of Balantidium coli infection
Doxycycline
