Other Protozoans : Coccidians

Apicomplexa

Phylum

Coccidians

Spore forming , microscopic, single celled, obligate intracellular protozoans

Coccidiosis

Coccidians Infects GI - Tract causing ?

Asymptomatic

Immunocompetent individuals

Opportunistic

immunocompromised host

Gametogony

Development of micro and macrogametocytes

Sporogony

• Sexual Cycle

• Results in the production of oocysts

Schizogony / Merogony

• Asexual Cycle

• Results in production of merozoites

Cystoisopora belli

• Day care centers

• Mental instructions

Humans

Only known host of Cystoisopora belli

Ingestion of Mature / Sporulated cyst

Transmission of Cystoisopora belli

2 - Sporocysts

4 - sporozoites

Total Sporozoites = 8

Sporulated oocyst Of Cystoisopora belli contains a total of how many sporozoites?

Distal Duodenum and Proximal ileum

Habitat of Cystoisopora belli

1. Sporulated oocyst —> ingested by humans

2. Stomach —> oocyst lyses —> releases sporozoites

3. Intestinal cells infected by sporozoites

4. Sporozoites —> schizogony —> merozoites

5. Merozoites —> infect other intestinal cells (undergo several cycles of schizogony)

6. Merozoites —> Micro and microgametocytes

Explain the life cycle of Cystoisopora belli

Cystoisoporiasis

• Generally asymptomatic

• GI tract infections ( diarrhea, anorexia, fever, vomiting, body malaise, weight loss)

Fat

severe infections of Cystoisoporiasis:

• Prolonged diarreha, __________ malabsorption, dissemination to other organs

1. Visualization of oocyst in fecal specimen

   • DFS

   • Concentration techniques

   • Acid fast Stinung

   • Phenol-auramine Staining

   • Iodine Staining

2. Entero - test (String Capsule Test)

3. Duodenal Aspirate

Give Diagnosis for Cystoisoporiasis

Eosinophilia and Charcot - Leyden Crystals

Appears as translucent, oval structures measuring 20-33 um x 10-19 um

____________ may be seen in stools.

Trimethoprim sulfamethoxazole

Treatment for Cystoisoporiasis

Cyclospora cayetanensis

Raspberries , lettuce , and basil pesto salad

Cyanobacterium-like body (CLB)

Cyclospora cayetanensis is originally called ?

Ingestion of Mature / Sporulated oocyst

Transmission of Cyclospora cayetanensis

2 - Sporocysts

2- Sporozoites

Total : 4

Sporulated oocyst of Cyclospora cayetanensis contains a total of how many sporozoites?

Jejunum

Habitat of Cyclospora cayetanensis

1. Unsporulated oocyst undergpes complete sporulation in a warm environment (7-12 days)

2. Sporulated oocyst is ingested by human, reaches jejunum and releases sporozoites

3. Sporozoites infect intestinal cells and undergo 2 cycles of schizogony

   • 1st gen : Schizonts contain (8-12 merozoites)

   • 2nd gen : Schizonts contain 4 merozoites

4. Merozoites differentiates to form micro and macrogamete

Life cycle of Cyclospora cayetanensis

Cyclosporiasis

• Generally self-limiting

• Alternating bouts of diarrhea and constipation

D-xylose

What type of malabsorption is under Cyclospora cayetanensis?

1. Visualization of oocyst in fecal smear

   • DFS

   • Concentration techniques

   • Acid fast Staining

2. PCR

3. Fluorescence microscopy

Diagnosis for Cyclospora cayetanensis

Fluorescent microscopy

Most important diagnosis in Cyclospora cayetanensis

• Self-limiting : treatment is not necessary

• Trimethoprim sulfamethoxazole

Treatment for Cyclospora cayetanesis

Cryptosporidium spp.

• Has a universal distribution

• C. parvum causes infections akong vets, visitors in diary farms and zoos

Person to person

Mode of transmission for Cryptosporidium spo.

• C. parcum

• C. hominis

2 species under Cryptosporidium

Ingestion of thick - walled oocyst

Mode of infection for Cryptosporidum spp.

• No sporocysts

• 4 sporozoites

Thick - walled oocyst of Cryotosporidum spp. contains how many sporocyst and sporozoites?

In Cryptosporidium , Sporozoites become ___________________ and attach to the brush border.

1. Macro and microgametocyte fertilization (small intestine) —> sporulated oocyst

2. a. Thin walled oocyst burst inside small intestines —> release sporozoites

   b. Thick walled oocyst —> passed out in feces

3. Ingested —> oocyst releases 4 sporozoites —> infect intestinal cells

4. Merozoites mature —> macro and microgametocytes

Life cycle of cryptosporidium spp.

Cryptosporidiosis

• Sx: prolonged watery diarrhea , can result to Blunted intestinal villi

• Aids patient

General malabsorption

Type of malabsorption (Crytosporidium spp.)

1. Acute gangrenous cholecystitis

2. Pneumonia, Bronchiolitis

3. Conjuctivitis

4. Widespread dissemination

Extra-intestinal manifestations of Cryptosporidium spp.

1. Visualization of oocyst in fecal specimen

   • Cannot be detected by DFS

   • Sheather’s sugar flotation

   • Formalin ether concentration

   • Kinyoun’s AF

2. Intestinal Biopsy

3. Bronchioalveolar lavage

4. Enzyme immunoassays, DNA Probes

Diagnosis of Cryptosporidium spp.

Kinyuoun’s Acid Fast

Quickest and cheapest diagnosis for Cryptosporidium spp.

red-pink doughnut

Cryptosporidium spo. Appears as ________ circular organisms in blue background in Kinyoun’s modified acid fast staining

Nitazoxanide

Treatment for Cryptosoridiosis

Toxoplasma gondii

• Endemic worldwide

• Infects humans, domestic and wild animals

• Diseases is onyl manifested in caes if immune deficiency

Cat family

Definitive host of Toxoplasma gondii

Rats, birds, pigs, sheeps

Intermediate host of toxoplasma gondii

Humans

Accidental host of Toxoplasma gondii

Toxoplasma gondii

Similar in appearance as Csytoisopora but smaller

Tachyzoites and Bradyzoites

Extraintestinal stages of Toxoplasma gondii

Tachyzoites

• Motile and rapidly dividing form

• Single central nucleus

• Crescent-shaped

Bradyzoites

• Slowly dividing form

• Nucleus oriented posteriorly

• Thousands enclosed in a cyst

2 - sporocysts

4 - sporozoites

Number of Sporocysts and sporozoites of Toxoplasma gondii

Micro + macrogametocytes —> Zygote —> unsporulated oocyst —> Sporulated oocyst—> ingested by intermediate host —> tachyzoites —> muscles and neurons —> encyst ad Bradyzoites —> consumed by cats —> Gametocytes

life cycle of Toxoplasma gondii

Sporulated oocyst

Infective stage of Toxoplasma gondii when consuming contaminated food or water

Encysted bradyzoites

Infective stage of Toxoplasma gondii when Eating raw/ undercooked meat

Tachyzoites

Infective stage of Toxoplasma gondii un blood transfusion

Tachyzoites

Infective stage of Toxoplasma gondii when there us Transplacental infection

Tachyzoites & Bradyzoites

Infective stage of Toxoplasma gondii when there is Organ transplantation

1. Tachyzoites enter blood circulation

2. Encyst in neural and muscle tissue —> encysted bradyzoites

3. Immune system of the host goes down

4. Bradyzoites excyst to become motile Tachyzoites

5. Widespread dissemination

Life cycle of Toxoplasma gondii (Human infection)

Toxoplasmosis

disease of toxoplasma gondii

Skeletal muscle, myocardium, brain, and eyes

Tissue cyst in humans (Toxoplasma gondii)

Farigue, lymphadenitis, fever, chills

Acute infection (Toxoplasma gondii)

Encephalomyelitis, myocarditis, hepatitis, retinochorditis

Chronic infection (Toxoplasma gondii)

Congenital Toxoplasmosis

• Mother to child transmission (first trimester)

• Severe and fata

• Hydrocephalus

• Intracranial calcification

• chorioretinitis

TRIAD of Congenital tocoplamosis

1. tissue biopsy

2. Blood smear showing Tachyzoites

3. PCR, ELISA

4. Serologic testing using Serum or CSF

   • IgM, IgG antibody detection

   • Sabin Feldman dye test (S&S)

Toxoplasma gondii diagnosis

Sabin Feldman Dye Test

• Most sensitive and specific test for toxoplsma gondii

• Require laboratory grown toxoplasma gondii

• Mixed with patient’s serum

Pyrimethamine plus Sulfadiazine

With folinic acid or Leucovorin

Treatment for Toxoplasma gondii

Methylene blue

Positive result = no stained organism

Sabin Feldman Dye test is stained with ____?

Positive result = ?

Sarcocystis spp.

• Initially reffered as Miescher’s tubules

• Over 130 recognized species

Carnivores (Humans, dogs, wolves, foxes, Raccoons?

Definitive host of Sarcocystis spp.

• S. hominis (beef)

• S. suihominis (pork)

Humans serve as definitive host for 2 spp. of Sarcocystis

Herbivores ( Bovine, rabbits)

Intermediate host of Sarcocystis spp

Sporulated oocyst, sporocyst

Diagnostic & Infective stage of Sarcocystis spp.

3

(Sarcocystis spp.)

In the blood vessels, sporozoites undergo how many generations of schizogony?

Sarcocystosis

Sx: Prolonged watery diarrhea (2weeks)

1. Intestinal form

2. Muscular / invasive form

2 types of Sarcocystosis

Intestinal form

• From ingestion of sarcocyst with bradyzoites

• Mild and lasting under 48 hours

Sx : Diarrhea, n/v , abdominal pain

Muscular / Invasive form

From ingestion of oocyst or Sporocyst

• Rare, may involve a wide variety of tissues

• Sx: Myalgia, rashes, lymphadenopathy

1. Visualization of oocyst in fecal specimen

   • Direct Fecal Smear

   • Fecal flotation technique

2. Biopsy of muscle stained with H&E

Diagnosis of Sarcocystosis

S. hominis

Microscopic in muscle of cattle

S. suihominis

Macroscopic in muscle of pig

Albendazole

Treatment of Sarcocystosis