MICP FINALS

• Protozoa


  Single cell-like organism
• Protozoa


  • Spherical to oval or elongated
  • Classifies based on locomotion (movement)
• Subdivisions of Phyla of Protozoa

  • PHYLUM SARCODINA (Ameoba) – moves by pseudopodia (false feet)
  • SPOROZOA – do not move
  • MASTIGOPHORA – move by flagella
  • CILIPHORA – move by means of cilia
• Facultative Parasites


  Free living
• Naegleria Fowleri normally resides in soil or water
• Naegleria Fowleri gains access to CNS or to the eyes
• Reproduction of Protozoa


  Binary Fission (Sarcodina, Mastigophora)
• Modes of Transmission (MOT) of Protozoa


  • Person to person
  • Ingestions of contaminated food and water
  • Direct contact through vectors
• CYST


  The infective stage or the stage of parasite that enters the host, dormant non-motile form of protozoa
• TROPHOZOITE


  Pathogenic stage or the stage of parasite responsible for the disease production, motile, feeding, dividing stage of protozoa
• Protozoal infections most often diagnosed by microscopic examinations of body fluids, tissue specimens, feces
• Entamoeba Histolytica is an intestinal protozoan
• Life cycle of Entamoeba Histolytica

  1. Non motile cyst (1st stage)

  2. Motile trophozoite (2nd stage)
• Cyst of Entamoeba Histolytica


  Found in non-diarrheal stools
• Trophozoite of Entamoeba Histolytica


  Found in intestinal & extraintestinal lesions & in diarrheal stools
• Modes of Transmission (MOT) of Entamoeba Histolytica

  • Ingestion of cysts in contaminated food &water by fecal-oral route
• Entamoeba Histolytica secrete enzymes, cause local necrosis producing flask-shape ulcer associated with parasite
• Amebiasis


  Disease caused by Entamoeba Histolytica, characterized by bloody-mucus diarrhea
• Amoeboma - granulomatous lesion may form in cecum, can resemble malignant tumor of colon
• Amebic abscess of liver - right upper quadrant pain, fever, tender "anchovy sauce" appearance of abscess
• Laboratory Diagnosis of Entamoeba Histolytica

  Trophozoites in diarrheal stools or cysts in formed stools
• Treatment of Entamoeba Histolytica

  • Metronidazole or Tinidazole
  • For Asymptomatic cyst carrier- iodoquinol or paromomycin
• Prevention of Entamoeba Histolytica

  • Avoid fecal contamination of food & water
  • Proper handwashing
  • Avoid night soil (human feces) for fertilization of crops
  • Adequate cooking of vegetables
• Acanthamoeba & Naegleria are minor protozoans pathogens that cause meningoencephalitis
• Both Acanthamoeba & Naegleria are found in soil & fresh water lakes
• Laboratory Diagnosis of Acanthamoeba & Naegleria

  Finding organism in CSF (Cerebrospinal fluid)
• Acanthamoeba


  Causes keratitis, can survive in cold water, carried into eyes or skin during trauma, occurs in immunocompromised individual, & in patients wearing contact lens
• Treatment of Acanthamoeba


  • Pentamidine, Ketoconazole, Flucytosine
• Prevention of Acanthamoeba


  • Adequate boiling of water
  • Masks should be worn while cleaning, since dust carries cyst
• Naegleria


  Infection occurs in healthy individuals, children, can survive in thermal spring water, acquires intranasally when swimming in contaminated water
• Treatment of Naegleria


  Amphotericin B
• There is no means of prevention for Naegleria
• Balantidium Coli is the largest protozoan to infect humans
• Infection by Balantidium Coli

  1. Ingestion of cysts in food or contaminated with animal or human feces

  2. Excyst in small intestines & travel to colon, producing an ulcer similar to E. histolytica
• Extraintestinal lesions do not occur in Balantidium Coli infection
• Dysenteric type of diarrhea may occur in Balantidium Coli infection
• Laboratory Diagnosis of Balantidium Coli

  Stool examination finding of LARGE trophozoites or cysts with a characteristic V shaped nucleus in stool
• Prevention of Balantidium Coli


  • Avoid contamination of food & water by feces of domestic animals
• Giardia Lamblia is a protozoan in the phylum Sarcomastigophora
• Life cycle of Giardia Lamblia

  1. Cyst gives rise to 2 trophozoite

  2. Trophozoite is pear-shaped with 4 pairs of flagella