Entamoeba histolytica (amoebiasis) Organism: Entamoeba histolytica ► Organism: Entamoeba histolytica ► At Risk : Anyone worldwide ► Humans Infected: 50 million cases of invasive disease/year ► Disease Outcome : 100,000 deaths/year ► Available Drugs : Dose limiting side effects.
Entamoeba histolytica (amoebiasis) Morphologic forms: 1- Active trophozoit form *Cytoplasm:(2/3endoplasm and 1/3 ectoplasm) * Nucleus: circle with karyosome * Replication stage 2-4 nucleus
Entamoeba histolytica (amoebiasis) Active trophozoit form
Entamoeba histolytica (amoebiasis) 2-Precystic form : *Intermediate stage *Low motility *Untrue morphologic stage of parasites *shape: oval or circle
Entamoeba histolytica (amoebiasis) Precystic form
Entamoeba histolytica (amoebiasis) 3-Cystic form: *Stable and non motile *Small and large cysts *Primary cyst with -1- nucleus *In replication stage 2-4 nucleus *Karyosome,, chromatoide body and glycogen in nucleus
Entamoeba histolytica (amoebiasis) Cystic form
Entamoeba histolytica (amoebiasis) Replication stage of cyst
Entamoeba histolytica cystic forms
Entamoeba histolytica (amoebiasis) Stability * Trophozoit form: unstable * Cystic form: stable in 20ºC for 3 days and In 45 ºC for 30 min * Cystic form also stable against low concentration of CL and HCL
Entamoeba histolytica (amoebiasis) Transmission *It is transmitted by cystic form* ☻ Direct transmission With contaminated hands ☻ Indirect transmision With contaminated food, water and arthropods.
Life cycle of Entamoeba histolytica
Entamoeba histolytica (amoebiasis) Pathogenesis ► Cases acute dysentery proteolytic ► Chronic stage : occur intestinal ulcer,inflammation and necrosis with proteolytic enzyme ► Heavy infection : occur intestine scleroses,hypertrophy and perforation ► Metastases : to liver and brain…
Entamoeba histolytica (amoebiasis) Intestinal ameobiasis ●Incubation period is 8 days or several month ● Acute stage: diarrhea with epithelium but without blood, and abdominal pine, loss of weight, flatulence and constipation. ● Sever infection : 10-20/day, diarrhea with blood, abdominal pine (colon)dehydration and fever.
Entamoeba histolytica (amoebiasis) Extra intestinal amoebiais ► Spread of intestinal amoeba from blood to liver, spleen,brain and lung. ► Direct extra intestinal amoebiasis (without intestinal infection)
Entamoeba histolytica (amoebiasis) Hepatit Amoebiasis ►Causes liver abscess ►Single abscess, different size, at the right lob of the liver.
Entamoeba histolytica (amoebiasis) Hepatic Amoebiasis ►Symptoms: liver pine, fever right hypochondrium pain,rarely diarrhea ►Transmit to pleura, peritone and pericardial area…..dead.
Entamoeba histolytica (amoebiasis) Pulmonary Amoebiasis ► 1- Direct primary infection (blood circulation) ► 2- secondary infection: after liver amoebiasis at the right pulmonary.. Cases are with: single or several abscess
Entamoeba histolytica (amoebiasis) Cerebral Amoebiasis ► Occur from complication of liver and pulmonary amoebiasis.. ► Cases are with single or several abscess
Entamoeba histolytica (amoebiasis Spleen and Cutaneous Amoebiasis ► Spleen abscess always seem with liver amoebiasis. ► Cutaneous amoebiasis seem in perianal site.
Entamoeba histolytica (amoebiasis Diagnosis ► Detection of trophozoit and cystic form of parasites in fresh stool. ► After 30min trophozoit form will destroy. ► Extra intestinal amoebiasis: detection of parasite cysts by lugol stain of infected tissue.
Entamoeba histolytica (amoebiasis Direct microscopy : Detection of trophozoit and cystic form of parasites in fresh stool. trophozoit
Entamoeba histolytica (amoebiasis Treatment ► Metronidazole 750mg + diloxanide furoate 500mg X days.. ► Metronidazole + Iodoquinol 650mg X days ► Metronidazole +tetracycline 250mg X days
Entamoeba histolytica (amoebiasis OR ► Chloroquine 500mg X 1.. 7days (iiver amoebiasis) 0R ► Paromycine 250mg//kg X 3.. 7days
Gastrointestinal system protozoon Entamoeba coli
non- pathogenic ► Entamoeba coli is a non- pathogenic species of Entamoeba that frequently exists as a commensal parasite in the human gastrointestinal tract especially in the colon. species Entamoebacommensal parasite gastrointestinal tract
Entamoeba coli ► Clinically, E. coli (not to be confused with the bacterium Escherichia coli) is important in medicine because it can be confused during microscopic examination of stained stool specimens with the pathogenic Entamoeba histolytica bacteriumEscherichia colipathogenic Entamoeba histolytica
Entamoeba coli ► The presence of E.coli does’nt need treatment treatment as it is considered harmless. ► However it should be noted that when a person becomes infected with this benign entamoeba, other pathogenic organisms may have been introduced as well, and these other pathogens might cause infection or illness.pathogenic
Entamoeba coli ► The identification of intestinal amoebae depends on the size and shape of trophozoites and cysts and on number of nuclei and aspect of karyosome and chromatin.
Entamoeba coli ► Entamoeba coli trophozoites measure µm and have a vescicolous nucleus with a large eccentric karyosome and an irregulary distributed peripheral chromatin. The cytoplasm is vacuolated containing bacteria and yeast.
Entamoeba coli ► ► E.coli cysts are spherical and measure µm (usually 15-20). ► Mature cysts have 8 nuclei with a large karyosome (central or eccentric) and an irregular (sometimes regular) chromatin. ► The nuclei can be numerated with careful focusing.
Entamoeba coli ► While this differentiation is typically done by visual examination of the parasitic cysts via light microscopy, new methods using molecular biology techniques have been developed also.light microscopymolecular biology
Entamoeba coli ► E.coli cysts
Life cycle of E.coli
Entamoeba coli ► Cysts and trophosoits of E.coli are larger then E.histolytica. ► E.coli is the only species in the genus encountered in humans with more then four nuclei in the cyst stage.
Entamoeba coli ► Cysts and trophosoits of E.coli are larger then E.histolytica. ► E.coli is found in the mouth between the gingival pockets.
Gastrointestinal system protozoon Giardia lamblia (Giardia intestinalis) Gastrointestinal system protozoon Giardia lamblia (Giardia intestinalis)
Giardia lamblia ► It is an intestinal flagellate flagellate ► Lives in duodenum and jejunum and jejunum ► Cause “Giardiasis”
Giardia lamblia ► ► Human pathogen: G. lamblia or G. intestinalis or G. duodenalis, ► ► Two life stages: trophozoite and cyst. HISTORY HISTORY ► ► First observed 1681 by Anthony van Leeuwenhoek
Giardia lamblia ► ► First observed 1681 by Anthony van Leeuwenhoek ► ► Described ~200 years later by Vilem Lambl ► ► First cultured in 1960’s ► ► Confirmed pathogen 1970’s ► ► One of most common intestinal parasites ► ► Causes Giardiasis (beaver fever) ► ► Geographic region with poor water sanitation
Giardia lamblia ► ► Species details –Single-celled protist –5 species of Giardia ► ► G. intestinalis/lamblia G. muris in rodents, birds, reptiles G. agilis in amphibians G. ardae in great blue heron G. psittaci in budgerigar
Giardia lamblia ► Morphology Cyst ► Infective stage in the environment, ► Persist in cold water up to several months ► Egg-shaped, 8-14µm by 7-10µm ► Organelle duplication w/out cytokinesis results *in four nuclei (Nu) *four median bodies (MB) *four axonemes (Ax)
Giardia lamblia ► Morphology Trophozoite ► Cannot survive in the environment ► Motile 4 pairs of flagella ► Pear shaped, bilaterally symmetrical ► Relatively flattened, 10-12µm long ► 5-7µm wide with a large sucking disk on the anterior ventral side ► Two nuclei
Giardia lamblia - Life cycle - 2 trophozoites released per cyst Multiply by binary fission every 12 h Sucking disc used for attachment Cyst forms in transit to colon
Giardia lamblia Clinical Symptoms and Pathogenesis ► ► Ingested cysts excyst in response to stomach acidity. ► ► Attach (via their sucking disk) to microvilli of epithelium in small intestine, causing epithelial damage and interfering with gut transport processes.
Giardia lamblia Clinical Symptoms and Pathogenesis ► ► Epithelial mucus is thinned, lymphocytes and other inflammatory cells infiltrate, physical blocking of absorption may occur, and enterobacteria may proliferate, causing more epithelial damage. ► ►D istention and flatulence can occur.
Giardia lamblia Clinical Symptoms and Pathogenesis ► ► Symptoms include profuse and watery to semisolid, greasy, bulky and foul- smelling diarrhea; abdominal cramps; nausea; vomiting; anorexia; low-grade fever and flu-like headache. General malaise, weakness, weight loss.
Giardia lamblia ► ► Symptoms more likely in children and immunosuppressed adults than in healthy adults. ► ► Infectous dose is low (about 10 cysts; possibly less). ► ► Incubation period from 7-11 days.
Giardia lamblia ► ► Duration of illness varies: few days to months. ► ► Infection may resolve spontaneously. often, subchronic stage develops with mild to moderate symptoms occurring periodically.
Giardia lamblia Epidemiology ► ► Many animals are major reservoirs: dogs, mice, horses, sheep…. ► ► Contamination is by “Fecal-oral route” ► ► Transmission by contaminated water and food is common ► ► Transmission is generally in day-care centers, with poor hygiene and sanitation.
Giardia lamblia Epidemiology ► ► Levels in sewage are estimated in the range of 3,000 to 30,000 per liter. ► ► Animal-to-human transmission occurs, but pathogenicity and virulence of non- human sources for humans is still uncertain. ► ► Strain differences documented both antigenically and genetically.
Giardia lamblia. “Diagnosis” ► ► Diagnosis is by microbiological examination of stool samples to check for the parasite. ► ► Because Giardia can be difficult to diagnose, the patient will ask to submit multiple stool specimens collected over a few days.
intestinalis trophozoite in a wet mount stained with iodine. G.lamblia trophozoite in a wet mount stained with iodine. G.lamblia cysts stained by metilen blue
Gi ardia lamblia :D iagnosis Gi ardia lamblia :D iagnosis ► ► Microscopic detection based on finding distinctive trophs. or cysts in stools, with our without dye staining or immunofluorescent (fluorescent antibody) staining. ► ► Newer clinical diagnostic detection by enzyme immunoassay (EIA; ELISA). ► ► Molecular detection by PCR is now being used for detection and characterization.
Giardia lamblia Visualization methods ► Laser scanning cytometry ► Immunofluorescent antibodies ( Giardia –specific) for enumeration ► Differential interference contrast (DIC) for confirmation4,6-diamidino 2 phenyl-indole dihydrochloride (DAPI) for viability ► Propidium iodide (PI) for non- viability
Giardia lamblia Electron microscopy pictures
Environmental Control of Giardia ► ► Water: physical and chemical treatment (coagulation-flocculation, sedimentation, filtration and disinfection) will reduce Giardia ► ► Relatively resistant to chemical desinfection but relatively sensitive to physical disinfection by UV radiation or heat. ► ► Pasteurization and thermal treatments is effective for foods
Giardia lamblia Protection from Giardiasis ► Washing hands thoroughly with soap and water. ► Not drinking untreated water or not use ice made from untreated water. ► Washing all food that is to be eaten raw by uncontaminated water..
Giardia lamblia Treatment Treatment ► Quinacrine HCl,Metronidazole (Flagyl) and Furazolidone (Furoxone). ► Oral Quinicrine HCl cures about 90% of infections. ► Probiotics could help the treatment treatment
Giardia lamblia ► Giardia can infect all people,young ► Giardia can infect all people,young children and pregnant women. ► Rapid loss of fluids from ► Rapid loss of fluids from diarrhea can be especially diarrhea can be especially life threatening. life threatening. ► Fluid replacementis an ► Fluid replacement is an important part of the treatment important part of the treatment