Intestinal` Protozoa
Giardia lamblia Giardia trophozoites (light microscope) ( SEM)
Giardia trophozoites (light microscope)
Giardia cyst (light microscope)
Giardia trophozoites (light microscope) Trichrome stain Unstained
Giardia lamblia : Life cycle
Giardia cyst (light microscope) Trichrome stain Unstained
Giardia trophozoites in tissue section
Giardia cyst and trophozoites IH stain
Giadriasis: Clinical Picture Asymptomatic infections ( majority) Symptomatic Infections: Typical picture: IP 1-2 wks followed by diarrhoea for about 6 wks, Atypical : Severe diarrhoea , malabsorption especially in children
Giardiasis: Laboratory diagnosis Stools examination :cysts or trophozoits Examination of duodenal contents : trophozoites
Giardiasis: Chemotherapy Drug of choice: Metronidazole
Intestinal Amoebae
Entamoeba coli
Iodamoeba butschlii trophozoite
Iodamoeba butschlii cyst
Endolimax nana cyst Endolimax nana cyst
Endolimax nana trophozoite Endolimax nana cyst
E. polecki cyst E. polecki trophozoite
Entamoeba coli (drawing) Entamoeba coli (Eosin)
Entamoeba coli ( cyst )
Entamoeba coli ( trophozoite)
Entamoeba hartmanni
Entamoeba hartmanni
Entamoeba histolytica
Entamoeba histolytica
E. histolytica E. histolytica
Entamoeba histolytica
Entamoeba histolytica
ENTAMOEBA HISTOLYTICA… 500 million people are infected. 100,000 deaths per year. Worldwide distribution. It is a waterborne infection. There are 6 species of Entamoeba: histolytica dispar hartmanni coli gingivalis polecki
E. histolytica vs E. dispar Entamoeba histolytica : amoebae that are pathogenic. E. dispar The non invasive form . The 2 amoebae can’t be distinguish by microscopic observation.
Entamoeba histolytica Mode of infection Water, food Flies can act as vector.. Can be sexually transmitted person -to -person contacts Not a zoonosis
Entamoeba histolytica Life cycle Trophozoite: vegetative stage, must encyst to survive in the environment. It is a fragile structure. Pre cyst: encysting trophozoites disgorging any undigested food. Cyst: infective stage. Resist to the harsh conditions of the environment.
Entamoeba histolytica The infective dose can be as little as 1 cyst. be as little as 1 cyst. The incubation period can be from few days to can be from few days to few weeks depending on the infective dose Cysts can survive for weeks at appropriate weeks at appropriate temperature and humidity.
Entamoeba histolytica PATHOLOGY Intsetinal amoebiasis : Remarkable and unique ability a to hydrolyse host host tissues with their active cysteine proteases present on the surface membrane of the trophozoite. Lesions are found in the caecum, appendix, or colon. They may heal. If perforation of the colon occurs, They may heal. If perforation of the colon occurs, My lead to a peritonitis that can lead to death. Amoeboma Granuloma obstructing the bowel
PATHOLOGY:Intsetinal amoebiasis :
PATHOLOGY:Intsetinal amoebiasis :
PATHOLOGY : Intsetinal amoebiasis Complications
Intsetinal amoebiasis : PATHOLOGY Intsetinal amoebiasis : Entamoeba histolytica
Intsetinal amoebiasis : PATHOLOGY Intsetinal amoebiasis : Entamoeba histolytica
Intsetinal amoebiasis : PATHOLOGY Intsetinal amoebiasis : E. Histolytica in mucosa. in mucosa. Numerous Numerous trophozoites can be seen with ingested seen with ingested erythrocytes.
PATHOLOGY: Extra-intsetinal amoebiasis :
Main Drugs for Treatment of Amoebiasis Intestinal : Asynpromatic (cysts only): diloxanide furoate (Furamide) Sympromatic(cysts and trophozoites): metronidazole Extra-intestinal: Metronidazole
Naegleria fowleri and Acanthamoeba Free-living Amoebae: Naegleria fowleri and Acanthamoeba
Acanthamoeba keratitis Patient upon presentation with Acanthamoeba keratitis. No severe pain was experienced by this patient, which made diagnosis difficult
Acanthamoeba keratitis The same patient who had just developed a classic ring infiltrate
Acanthamoeba keratitis The same patient1 year later with 20/30+ vision.
Acanthamoeba keratitis Acanthamoeba culture with a trophozoid in culture
Acanthamoeba in corneal scraping
Acanthamoeba trophozoite
Acanthamoeba brain
Acanthamoeba
Acanthamoeba ulcer
Naegleria brain
Cryptosporidium Parvum
Cryptosporidium Diagnosis
Cryptosporidium oocysts Cryptosporidium Diagnosis Cryptosporidium oocysts
Cryptosporidium Diagnosis Cryptosporidium , safranin Cryptosporidium , acid-fast stain
Cryptosporidium , acid-fast stain Cryptosporidium Diagnosis Cryptosporidium , acid-fast stain
Cryptosporidium Diagnosis
Cryptosporidium
Cryptosporidium Diagnosis Crypto-Gardia FAT
CryptosporidiosisTreatment Self-limited in immunocompetent patients In AIDS patients : paromomycin