miscellaneous protozoa Flashcards
what are the 4 groups of Miscellaneous protozoa
- ciliates
- hairlike cytoplasmic extensions called cilia (used for movement)
- human pathogen: Balantidium coli (intestinal spp.) - sporozoa
- live in intestine or tissues (intestinal or tissue infection)
- subclass: Coccidia
- reproduce in two ways: outside the body (asexual) and inside the body (sexual).
[Asexual reproduction (outside the body) – They multiply without needing a partner. This happens in the environment, like in contaminated food, water, or soil.
Sexual reproduction (inside the body) – Once inside a human or animal, they reproduce by combining genetic material, creating new parasite cells that continue the infection.]
- blastocystea
- intially considered a yeast but now a sporozoa
-example: Blastocystis hominis - pneumocystis jiroveci
- former name: Pneumocystis carinii
- as fungi
- cause lung infections, esp in ppl with weak immune system
examples of Intestinal species and Tissue species in simple
Intestinal species:
○ Isospora belli
○ Sarcocystis spp.
○ Cryptosporidium parvum
Tissue species
○ Toxoplasma gondii
2 New Genera under Miscellaneous Protozoa
Cyclospora cayetanensis
- stomach infections
Microsporidia
- known to produce intestinal disease in humans
- recent discoveries so no exact classifications yet
coccidia
Group of protozoan parasites in which asexual replication occurs outside a human host
When inside the human host, they replicate through sexual
Balantidium coli (Balantidiasis) lab diagnosis
Stool Examination (Wet Prep & Permanent Stains):
Detects trophozoites and cysts in stool.
Multiple samples required = accurate detection.
Sigmoidoscopy Material:
Patients with sigmoido-rectal infections to detect parasites in the intestine.
Isospora belli (Isosporiasis) lab diagnosis
Stool & Duodenal Content Examination:
Specimen of choice to detect oocysts in different stages (immature, partially mature, fully mature).
Intestinal Biopsy:
Detect intracellular forms of the parasite in case of low infection levels. [In such cases, doctors may take a small sample of the intestine (biopsy) to check for parasites inside the intestinal cells.]
Direct Wet Preparations & Concentration Methods:
Used when oocyst numbers are low
Iodine staining can enhance visibility.
Enterotest (String Test):
Helps collect parasites from the small intestine when stool samples fail to detect them.
Biopsy materialmore direct than stool = higher possibility to detect
Sheather’s Sugar Flotation:
Helps separate oocysts from stool for better detection.
Staining Techniques:
- Modified Acid-Fast Stain → Confirms oocysts in stool.
- Auramine-Rhodamine Stain → Used for preliminary detection.
Sarcocystis spp. (Sarcocystosis) lab diagnosis
Stool Examination (Wet Prep):
Detects mature oocysts in stool in wet prep. (mature ooocyst is the diagnostic stage)
Sporocysts may be seen singly or in pairs cemented together.
Routine Histologic Methods:
Muscle Biopsy
Used in cases of muscle infections to detect sarcocysts (cyst stage) in muscle tissues.
Cryptosporidium parvum (Cryptosporidiosis) lab diagnosis
Stool Examination (Oocyst Detection):
Iodine Stain
Modified Acid-Fast Stain
Formalin-Fixed Smears Stained with Giemsa
Serologic Tests (Antigen & Antibody Detection):
Enzyme-Linked Immunosorbent Assay (ELISA)
Indirect Immunofluorescence Assay (IFA)
Modified Zinc Sulfate Flotation & Sheather’s Sugar Flotation (Stool Concentration Techniques):
Separates oocysts from stool for better visualization.
Esp when the sample is under the phase contrast microscopy
Intestinal Biopsy:
Detects merozoites and gametocytes in intestinal tissue (not seen in stool samples).
Blastocystis hominis (Blastocystis Infection) lab diagnosis
Stool Examination:
- Iodine Wet Preparation → Detects peripheral cytoplasm (1 or more nuclei = light yellow) and central vacuole (does not stain, appears clear and transparent)
- Permanent Stain Preparation → Nuclei stain dark, while the vacuole may or may not stain (able to not stain at all to very apparent)
Saline (like water) Preparations Not Recommended:
Can lyse the organism, leading to false-negative results.
Cyclospora cayetanensis (Cyclosporiasis) lab diagnosis
Stool Examination:
Non-Traditional Concentration Methods → Does not use formalin to prevent destruction of oocysts.
Sporulation Observation:
Oocysts sporulate best at room temperature.
Addition of 5% Potassium Dichromate → Helps sporocysts become visible.
Flotation Methods:
Phase Contrast Microscopy & Bright-Field Microscopy → Best for isolating oocysts.
Modified Acid-Fast Stain:
Helps confirm the presence of oocysts.
Autofluorescence Test:
Oocysts autofluoresce under UV light, making detection easier.
Microsporidia (Microsporidiosis) lab diagnosis
Serologic Tests:
Detects some species-specific antibodies in blood.
Cell Culture:
Some species will grow in culture
Staining:
detest all or part of the spore microscopically
Thin Smear with Trichrome & Acid-Fast Stain:
show desired spores
Giemsa-Stained Biopsy Material & Fecal Concentrates:
- readily shows the spores
Transmission Electron Microscopy (TEM)
for speciation of the microsporidia
Toxoplasma gondii (Toxoplasmosis) lab diagnosis
Serologic Tests (Antibody Detection):
- Double-Sandwich ELISA
→ Detects IgM antibodies in congenital infections.
- Indirect Hemagglutination (IHA) & ELISA
→ Detects IgG antibodies for past infections.
Indirect Fluorescent Antibody (IFA) Test:
→ Detects both IgM & IgG levels.
Microscopic Examination:
Detects tachyzoites and bradyzoite cysts in human tissue samples.
Animal Inoculation:
Rarely used, involves injecting suspected infected tissue into lab animals to confirm infection.
Pneumocystis jiroveci (Pneumocystis Pneumonia - PCP) lab diagnosis
Respiratory Sample Collection:
Sputum
Bronchoalveolar Lavage (BAL)
Tracheal Aspirates
Bronchial Brushings
Lung Tissue Samples
Staining Techniques:
Giemsa & Iron Hematoxylin Stains
Histologic Procedures:
Gomori’s Methenamine Silver Stain
Monoclonal Fluorescent Stain:
this test only happens when there is only small no. of organisms present in Isospora belli
enterotest
(there is low infection)
Balantidium coli life cycle
Infection:
Humans ingest infective cysts in contaminated food or water.
- infective form - cyst
Excystation:
In the small intestine, cysts excyst, and trophozoites emerge.
Trophozoite Activity:
Trophozoites reside in the
- cecal region,
- terminal ileum,
- mucosa/submucosa of the large intestine
Multiplication:
Trophozoites divide by binary fission, producing two young trophozoites.
Encystation:
In the lumen of the intestine, trophozoites encyst, mature, and are excreted in feces.
Cyst Survival: Cysts can survive for weeks in the environment, unlike delicate trophozoites.
Comparison: Life cycle is similar to Entamoeba histolytica but differs in that B. coli does not undergo nuclear multiplication in the cyst phase.
Isospora belli life cycle
Infection:
Humans ingest mature (sporulated) oocysts from contaminated food or water.
- infective and diagnostic stage - mature or sporulated oocysts
Excystation:
Oocysts excyst in the small intestine, releasing sporozoites.
Asexual Reproduction:
Sporozoites undergo schizogony in intestinal mucosal cells, producing merozoites.
Sexual Reproduction:
Gametogony occurs in the same intestinal cells, forming macrogametocytes and microgametocytes.
Gametocyte Fusion:
Gametocytes fuse to form oocysts, which are excreted in feces.
Immature Oocysts:
Immature oocysts may be excreted but cannot infect until they mature outside the host.
Sarcocystis Species life cycle
Infection through Meat:
Humans ingest uncooked pig or cattle meat containing sarcocysts.
Definitive Host:
Humans are the definitive host for sexual reproduction (gametogony).
Intermediate Host: Humans can also serve as an intermediate host where sarcocysts develop in striated muscle.
Ingestion of Oocysts:
Humans can ingest oocysts from other animals not having an intermediate host, which also leads to infection.
Sexual and Asexual Reproduction:
Both reproduction types occur in humans, depending on whether they are the definitive or intermediate host.
Cryptosporidium parvum life cycle
Infection:
Humans ingest mature oocysts from contaminated food or water.
Excystation:
Sporozoites emerge in the upper gastrointestinal tract and invade epithelial cells of the gut.
Reproduction:
Both asexual (schizogony) and sexual reproduction (gametogony) occur within epithelial cells.
Autoinfection:
The thin-shelled oocyst causes autoinfection by rupturing inside the host and reinfecting epithelial cells.
Excretion of Oocysts:
The thick-shelled oocyst is excreted in feces, which can infect a new host.
Two Forms of Oocysts:
- Thin-shelled oocysts: Cause autoinfection.
- Thick-shelled oocysts: Excreted, remain intact, and infect new hosts.
Blastocystis hominis life cycle
Reproduction:
Reproduces by sporulation or binary fission.
Sexual and Asexual Reproduction:
Exhibits both types of reproduction, with pseudopod extension and retraction for movement and feeding.
Cyclospora cayetanensis life cycle
Infection:
Humans ingest oocysts from contaminated food or water.
Excystation:
In the small intestine, sporozoites are released and invade epithelial cells.
Asexual Reproduction:
Sporozoites undergo schizogony, producing merozoites.
Sexual Reproduction:
Macrogametocytes and microgametocytes form oocysts.
Oocyst Excretion:
Oocysts are excreted in feces.
Oocyst Maturation:
Immature oocysts mature outside the body in one or more weeks, becoming capable of infecting a new host.
Microsporidia life cycle
Transmission:
Can be direct or involve an intermediate host.
Infection:
Humans are infected when spores inject sporoplasm into host cells.
Reproduction:
New spores form within infected host cells and are released, leading to new infections.
Spores in Environment:
Spores are excreted in feces or urine and can infect other hosts (e.g., carnivorous animals).
Toxoplasma gondii life cycle
Definitive Host:
Cats (or other felines).
Intermediate Host:
Rodents (mice or rats).
Infection in Cats:
Cats ingest infected rodents, releasing bradyzoites that convert to tachyzoites.
Reproduction in Cats:
Sexual reproduction occurs in the gut of the cat, producing immature oocysts, which are shed in feces
Oocyst Maturation:
Oocysts mature outside the host within 1–5 days.
Infection in Rodents:
Rodents ingest mature oocysts, leading to tachyzoite formation in the intestinal epithelium, which migrate to the brain or muscle, where they form cysts filled with bradyzoites.
Cycle Continuation:
Cats ingest infected rodents, and the cycle repeats.
Pneumocystis jiroveci life cycle
Life Cycle Status: The life cycle of Pneumocystis jiroveci is still considered unknown, but some presumptions can be made about its progression once inside the host.
Steps in the Life Cycle:
Trophozoite Residence:
Once inside the host, P. jiroveci resides in the alveolar spaces of the lung tissue.
Mature Cysts:
Mature cysts rupture, releasing trophozoites that actively grow, multiply, and feed within the host.
Trophozoite to Precyst/Cyst Conversion:
Trophozoites eventually convert into precysts and cysts, which may be found in organs such as the spleen, lymph nodes, and bone marrow.
clinical symptoms of Balantidium coli
Asymptomatic Carrier State:
Some individuals are asymptomatic carriers of B. coli, similar to carriers of Entamoeba histolytica.
Balantidiasis:
Symptoms can range from mild colitis and diarrhea to severe balantidiasis.
- Full-blown Balantidiasis:
Resembles amebic dysentery.
Abscesses and ulcers may form in the mucosa and submucosa of the large intestine.
Secondary bacterial infections may occur.
- Acute Infection:
Symptoms include up to 15 liquid stools per day, containing pus, mucus, and blood.
- Chronic Infection:
May result in a tender colon, anemia, cachexia, and alternating diarrhea and constipation.
Extraintestinal Infections:
B. coli may invade areas other than the intestine, such as:
Liver
Lungs
Pleura
Mesenteric nodes
Urogenital tract
These invasions are rare.
Balantidium coli epidemiology
Global Distribution:
Found worldwide but human infections are typically rare.
Transmission:
The infection is transmitted via ingestion of contaminated food and water, primarily through the oral-fecal route.
Person-to-person transmission is possible, often due to food handlers infected with B. coli.
Water contaminated with pig feces, as pigs are known to be a reservoir host, is a significant source of infection.
Balantidium coli treatment and prevention and control
TREATMENT
Prognosis Factors:
Severity of infection
patient’s response to treatment.
Medication of Choice:
Oxytetracycline (Terramycin)
Iodoquinol
Alternative Treatment:
Metronidazole (Flagyl)
Recovery Chances:
Asymptomatic and chronic patients have a higher chance of recovery.
PREVENTION AND CONTROL
Maintain good personal hygiene.
Ensure proper sanitary conditions.
Take precautions when handling pigs and their feces.
Balantidium coli notes of interest
Etymology: Balantidium means “little bag,” referring to its shape.
Pig Reservoir: It is estimated that 63% to 91% of pigs carry B. coli.
Balantidium suis: Pigs also carry another species, Balantidium suis, but it does not cause human infections.
Human Infection: Despite high exposure risk to pigs, the incidence of B. coli in those who regularly interact with pigs is low.
Isospora belli epidemiology
Isospora belli clinical symptoms
Asymptomatic:
In many cases, I. belli infections are self-limited, and the body can recover on its own without intervention.
Isosporiasis:
Symptoms can range from mild gastrointestinal discomfort to severe dysentery.
Mild Symptoms:
Abdominal pain
Anorexia
Weakness
Malaise
Severe Symptoms:
Weight loss
Chronic diarrhea
Eosinophilia (increased eosinophil count in blood)
Charcot-Leyden Crystals: These may form in response to eosinophilia and can be seen in stool samples.
Malabsorption Syndrome: Severe infections can lead to malabsorption of nutrients.
Fecal Characteristics:
- Foul-smelling, pale yellow, loose stools.
- Increased fecal fat levels.
Oocyst Shedding: Infected individuals may shed oocysts in their stool for up to 120 days.
Isospora belli epidemiology
Global Distribution:
I. belli is found worldwide but has traditionally been considered rare.
The rarity could be due to challenges in recognizing the organism, which may result in false-negative diagnoses.
Increase in Cases:
There was an increase in reported cases during and after World War II, particularly in:
Africa
Southeast Asia
Central America
Chile (South America)
AIDS Patients: The frequency of infections has notably increased in AIDS patients. Unprotected oral-anal sexual contact has been suggested as the primary transmission route in these cases. These infections are now considered opportunistic.
Isospora belli treatment and prevention and control
TREATMENT
For Asymptomatic or Mild Infections:
A bland diet and plenty of rest are usually sufficient for recovery.
For Severe Infections:
Chemotherapy is needed, including:
- Trimethoprim and Sulfamethoxazole
- Pyrimethamine and Sulfadiazine
For AIDS patients infected with I. belli, the treatment dosage may be lower but must be extended over a longer period.
PREVENTION AND CONTROL
Personal Hygiene
Sanitation Practices
Safe Sexual Practices
Sarcocystis Species clinical symptoms
Sarcocystis Infection:
Symptoms are generally rare, with documented cases primarily in immunocompromised individuals.
- Common Symptoms:
Fever
Severe diarrhea
Weight loss
Abdominal pain - Muscle Invasion Symptoms:
Muscle tenderness and other localized symptoms occur when Sarcocystis invades the striated muscle.
Sarcocystis Species epidemiology
Infections are relatively rare, even though Sarcocystis species are distributed worldwide.
Sarcocystis Species treatment and prevention and control
TREATMENT
- Humans as the Definitive Host:
Treatment for human infection is similar to Isospora belli infection.
- Chemotherapy:
Trimethoprim + Sulfamethoxazole
Pyrimethamine + Sulfadiazine
PREVENTION AND CONTROL
Humans as the Definitive Host:
Adequate Cooking: Ensure beef and pork are thoroughly cooked to avoid infection.
Humans as the Intermediate Host:
Proper Care: Careful handling and disposal of animal stool can prevent infection.
Striated Muscle Involvement: No specific treatment is known if the infection resides in the striated muscle.
Cryptosporidium parvum clinical symptoms
Healthy Individuals:
- Self-limiting diarrhea lasting approximately 2 weeks.
- Additional symptoms may include:
Fever
Nausea
Vomiting
Weight loss
Abdominal pain
Immunocompromised Individuals:
- More severe symptoms, including:
Severe diarrhea
Malabsorption
Potential death
Migration of infection to other areas of the body, such as:
Stomach
Respiratory tract
C. parvum is a significant cause of morbidity and mortality, particularly in AIDS patients.
Cryptosporidium parvum epidemiology
found worldwide, with 20 known species, but only C. parvum infects humans.
Transmission:
Infection primarily occurs through:
Contaminated water or food with infected feces.
Person-to-person transmission.
At-Risk Groups:
Immunocompromised individuals (e.g., those with HIV/AIDS).
Children in tropical areas and daycare centers.
Individuals in animal centers or environments with animals.
Travelers to areas with poor sanitation.
Cryptosporidium parvum treatment and prevention and control
TREATMENT
Spiramycin has been helpful in clearing the infection in hosts, but it remains in the experimental stage.
PREVENTION AND CONTROL
- Water Treatment:
Proper treatment of water supplies to prevent contamination with infected feces.
- Hygiene Practices:
Use gloves and lab gowns when handling potentially infected materials.
Proper handwashing is essential to reduce transmission.
Disinfecting equipment that may be infected to prevent contamination.
Cryptosporidium parvum notes of interest
Initial Associations: Cryptosporidium species were first linked to poultry and cattle.
Neonatal Diarrhea in Animals:
C. parvum is now recognized as the cause of neonatal diarrhea in calves and lambs.
Blastocystis hominis clinical symptoms
Without Other Pathogens:
Symptoms include:
Diarrhea
Vomiting
Nausea
Fever
Abdominal pain
Cramping
With Other Pathogenic Organisms (e.g., E. histolytica, G. intestinalis):
- When B. hominis is present with other pathogens, it is thought to be the underlying cause of symptoms.
- Patients experience severe symptoms, similar to those described above.
Blastocystis hominis epidemiology
subtropical countries, such as:
Saudi Arabia
British Columbia
Transmission:
Infection occurs through ingestion of fecally contaminated food or water.
Blastocystis hominis treatment and prevention and control
TREATMENT
Iodoquinol or Metronidazole
PREVENTION AND CONTROL
Sanitation and Hygiene:
- Proper treatment of fecal material to prevent contamination.
- Handwashing is crucial to reduce transmission.
- Proper handling and cooking of food, as well as preventing fecal contamination of food or water.
Blastocystis hominis notes of interest
Historical Classification:
Initially thought to be algae, later identified as a harmless intestinal yeast, and since the 1970s, recognized as a protozoan parasite.
Genetic Studies:
In 1996, genetic analysis revealed that Blastocystis is not fungal or protozoan.
Its classification has since been revised, placing it in the Stramenopiles, a major line of eukaryotes.
Cyclospora cayetanensis clinical symptoms
Notable Difference:
Unlike Cryptosporidiosis, C. cayetanensis causes a longer duration of diarrhea in adults.
Cyclospora cayetanensis epidemiology
Cases have been reported in the US and Canada.
Children living in unsanitary conditions in Lima, Peru are also affected.
Travelers and expatriates in Nepal and parts of Asia are at higher risk of infection.
Cyclospora cayetanensis prevention and control
Properly treat water before use.
Only use treated water when handling and processing food to reduce contamination risk.
Microsporidiaclinical symptoms
Common Symptoms:
Enteritis (intestinal inflammation)
Keratoconjunctivitis (eye infection affecting the cornea and conjunctiva)
Myositis (muscle inflammation)
Rare Infections:
Peritonitis (inflammation of the peritoneum)
Hepatitis (liver inflammation)
Microsporidia epidemiology
Reported in AIDS patients from:
Haiti
Zambia
Uganda
UK
US
Netherlands
*Cases have also been noted in individuals with normal immune systems.
Microsporidia treatment
Albendazole: Recommended for the treatment of E. bieneusi infections.
Fumagillin (oral): Alternative treatment for E. bieneusi.
Albendazole plus Fumagillin eye drops: Used for treating Nosema infections
Toxoplasma gondii human infection
- Contact with Infected Cat Feces:
Ingestion of mature oocysts via hand-to-mouth transmission from sources like cat litter boxes or children’s sandboxes. - Ingestion of Contaminated Undercooked Meat:
Meat from cattle, pigs, or sheep infected after consuming oocysts in cat feces. Cysts in animal muscles can remain viable for years. - Transplacental Infection:
Asymptomatic mother unknowingly transmits infection to the fetus.
IgG (antibodies) cross the placenta, while IgM (specific immune response) does not.
Newborns may exhibit anti-T. gondii IgM for several months. - Contaminated Blood Transfusion:
Extremely rare method of transmission.
Toxoplasma gondii clinical symptoms
Asymptomatic Infection:
Disease only occurs when specific conditions are met, like virulent strain, host susceptibility (e.g., AIDS patients), or tissue destruction.
Toxoplasmosis Symptoms:
Acute: Fatigue, lymphadenitis, chills, fever, headache, and muscle aches.
Chronic: Maculopapular rash, encephalomyelitis, myocarditis, hepatitis, retinochoroiditis (rare cases of blindness).
Congenital Toxoplasmosis:
Severe and often fatal conditions.
Severity depends on maternal antibody protection and fetus’ age at infection.
Symptoms: Hydrocephaly, microcephaly, intracerebral calcification, chorioretinitis, convulsions, and psychomotor disturbance.
Outcomes: 5-15% mortality, 10-13% moderate to severe handicaps, 58-72% asymptomatic.
Cerebral Toxoplasmosis in AIDS Patients:
Headache, fever, altered mental status, focal neurologic deficits, brain lesions, and convulsions.
Primarily affects the central nervous system.
Diagnosis: Elevated spinal fluid IgG, tachyzoites in CSF, serum IgG remains unresponsive.
Cerebral Toxoplasmosis in Immunocompromised Patients:
Seen in organ transplant recipients or individuals with neoplastic diseases (e.g., Hodgkin’s lymphoma).
Affects those with suppressed immune systems.
Toxoplasma gondii epidemiology
Prevalence:
Infection occurs in 15-20% of the US population.
Transmission:
Hand-to-mouth from cat feces, undercooked meat consumption, or transplacental infection.
Survival of Oocysts:
Can survive up to 18 months in the environment, especially in winter.
Infant Transmission:
Approximately 4000 infants annually in the US are born with transplacental infections.
Toxoplasma gondii treatment and prevention and control
TREATMENT
First-line Treatments:
- Trisulfa pyrimidines and Pyrimethamine (Daraprim) for symptomatic cases (not recommended for pregnant women).
- Spiramycin: An alternative drug, especially for pregnant women.
- Corticosteroids & Folinic Acid (Leucovorin): To counteract side effects like bone marrow suppression in AIDS patients.
- Atovaquone: Effective for treating toxoplasmic encephalitis in AIDS patients.
PREVENTION AND CONTROL
- Avoid Contact with Cat Feces:
Wear protective gloves and disinfect litter boxes.
Place covers over children’s sandboxes when not in use.
- Handwashing: After handling cats or cleaning litter boxes.
- Avoid Contaminated Meat:
Do not taste raw meat.
Thoroughly cook all meat before consumption.
- Prevent Rodent Contact with Cats: To reduce infection risks.
- Feeding Cats: Only dry or cooked canned food to reduce risks of exposure to infected rodents.
Pneumocystis jiroveci clinical symptoms
Pneumocystosis (Atypical Interstitial Plasma Cell Pneumonia):
In Immunosuppressed Adults and Children:
- Nonproductive cough, fever, rapid respirations, and cyanosis (bluish tint due to lack of oxygen).
- One of the leading causes of death in AIDS patients.
- Often coexists with Kaposi’s sarcoma, a malignant skin disease.
In Infected Malnourished Infants:
- Symptoms include poor feeding, loss of energy, rapid respiration rate, and cyanosis.
- Symptoms may have a longer onset, lasting several weeks.
Chest X-ray Findings:
- Infiltrate observed on chest x-ray.
- Difficulty breathing, with low arterial oxygen tension (P02) and normal to low carbon dioxide tension (PCO2).
Primary Cause of Death:
Death typically results from impaired oxygen and carbon dioxide exchange in the lungs.
Pneumocystis jiroveci epidemiology
Geographical Distribution:
Found in the US, Asia, and Europe.
Transmission:
Spread via pulmonary droplets from person-to-person contact.
Can also pass through the placenta and infect the fetus, leading to stillbirth.
Pneumocystis jiroveci treatment and prevention and control
TREATMENT
First-Line Treatment:
Trimethoprim-sulfamethoxazole (Bactrim).
Alternative Treatments:
Pentamidine isethionate.
Cotrimoxazole.
PREVENTION AND CONTROL
Personal Protection:
- Protection from pulmonary droplets by using masks or other protective gear when necessary.
the largest protozoa known to humans
Balantidium coli
(balantidiasis)
TROPHOZOITES
- has ciliates = can move
- 2 nuclei
kidney-shaped nucleus (macronucleus: often appears as hyaline mass in unstained prep)
small spherical nucleus (micronucleus: not readily visible also in stain prep)
- small cytosome present
CYSTS
- has macro and mirco nucleaus: may not be observable
- has contractile vacuole
- double cyst wall (row of cilia btwn 2 cyst walls)
*matured cyst tends to lose their cilia
isospora belli morphology
OOCYST
- oval shaped, transparent
- smooth, colorless, 2 layered cell wall
sporoblast vs sporocyst
sblast: younger, no formed sporozoites [as oocyst matures, divide into 2 sporoblast]
scyst: mature, contain 4 sausage-shaped sporozoites
sarcocystis species morphology
- sarcocystis infection
MATURE OOCYST
- oval and transparent
- 2 sporocyst (each with 4 sausage-shaped sporozoites)
- clear, colorless, 2 layered cell wall
originally classified as a member of genus isospora
sarcocystis species
Cryptosporidium parvum morphology
- cyrptospordiosis
OOCYST
- roundish often confused w yeast w thick cell wall
- no sporocyst but contain 4 small sporozoites
- 1 to 6 granules
SCHIZONTS AN GAMETOCYTES
- schizonts contain 4 to 8 merozites, microhametocytes and macrogametocytes
Blastocystis hominis morphology
- Blastocystis hominis infection
VACUOLATED FORM
- vacuole: large, centrally located, fluid filled structure that consumes 90% of cell
- cytoplasm: has a ring around the peripheral
- nucleus: 2 to 4
Cyclospora cayetanensis morphology
- Cyclospora cayetanensis infection
OOCYST
- 7 to 10um
- when matures, form 2 sporocysts (each contain 2 sporozoites)
it is an intestinal coccidinal organism
Cyclospora cayetanensis
Microsporidia morphology
- Microsporidia infection, Microsporidial infection
SPORES
- extruding polar filaments (intiminate infection by injecting sporoplasm)
three out of five genera known to cause human disease have been reported in patient suffering from AIDS
Microsporidia
- Encephulitozoon and Pleistophora have also bee described as infecting AIDS patients (both cause severe tissue infections)
- noted for corneal infections, as well as Nosema
what is the most well known member of Microsporidia
Enterocytozoon bieneusi
Toxoplasma gondii morphology
OOCYST
- round to slightly oval
- 2 sporocyst (each containing 4 sporozoites)
TROPHOZOITES (has 2 forms)
- TACHYZOITES
actively multiplying
one end appears rounded
single centrally - nucleus
mitochondira and GB i present but not visible - BRADYZOITES
small physical appearance as tachy but smaller
gather in cluters inside a host
forms a cyst in host and muscle tissue
what is the infective form of T. gondii
oocyst
Pneumocystis jiroveci morphology
TROPHOZOITES
- common seen form
- simple ovoid and ameboid organism
CYST
- 4 to 8 intracystic bodies (arranged in rosette or scattered)
