Lab 10 cryptosporidiosis

University of Sulaimani

School of ScienceDepartment of

Biology

University of Sulaimani

School of ScienceDepartment of

Biology

Practical Parasitology2nd stageLab 10:

Cryptosporidiosis

Enteric Apicomplexa:

Cryptosporidium parvum

Objectives: Students should be able to:Identify oocyst stage in a stool smear.Describe trophozoite, sporozoite, and oocyst

stages of C. parvum.List methodes of transmission and diagnosis.


Cryptosporidium parvum is another apicomplexan parasite

It is an enteric, anthroponotic and zoonotic parasite

One of the three most common diarrhea-causing pathogens in the world.

One of the most common causes of waterborne illness in the world.

Causes a self-limiting diarrhea in immunocompetent individuals.


G.D: CosmopolitanDefinitive Host: HumanReservoir Hosts: kittens, puppies, goats, calves, mice, …. Etc.Disease: Cryptosporidiosis.Habitat: Epithelial cells of the gastrointestinal tract, mainly

jejunumTransmission: Fecal-oral route.


TransmissionFood and water

contamination of drinking waterSwimming poolsuntreated groundwater or well wateran infected person or an asymptomatic carrier contaminates a food supply

Animal-person transmissionPerson-person (anthroponosis) transmissionoccurs at a high frequency in day-care centers.

Trophozoites are round or oval intracellular, but exocytoplasmic formshave a single prominant nucleusMeasure 2.0 to 2.5 µm in diameter. They are transitional stages from sporozoites and merozoites to meronts

Trophozoites

TEM

Sporozoites


Sporozoites are generally crescent or bow shaped, with the anterior end slightly pointed and the posterior end rounded.Measure 4.9 by 1.2 µm Each sporozoite contains a prominent nucleus in the posterior third of the body.

TEM

•Oocysts are double walled, rounded or ovoid and measure 5 to 6 µm in diameter.

•Contain bow-shaped 4 sporozoites, are sometimes visible inside the oocysts, indicating that sporulation has occurred.

sporozoite release from the C oocyst

Life cycle:Cryptosporidium parvum

rounded

SEM of type 1 meront

SEM of type 2 meront

Mouse small intestine infected with Cryptosporidium parvum. Small bodies seem to be on the surface of epithelial cells are various developmental stages of C. parvum enveloped by host cell membrane. H & E stain.

TEM of Immature oocyst of C. parvum.

TEM of Merozoites of C. parvum.

SEM of oocysts of C. parvum.

TEM: Meront stage of Cryptosporidium parvum under asexual division (endopolygeny).

TEM: Mature type I meront including eight merozoites.

SymptomsIn immunocompetent patients, include :•Frequent, watery diarrhea (1-2 week duration), yet self-limiting •Nausea, Vomiting , Abdominal cramps, and Low-grade fever

For immunocompromised persons, the illness is more severe:•Debilitating, cholera-like diarrhea (up to 20 liters/day), electrolyte imbalance, dehydration and sometimes death. •Severe abdominal cramps, Malaise, Low-grade fever, Anorexia and Weight loss.

Diagnosis Microscopy with an acid fast stained stool smear,

which will stain the oocysts bright red.Another form of microscopy is fluorescent

microscopy using monoclonal antibody to oocyst wall

acid-fast oocyst stain

Direct immunofluorescence antibody stain

DiagnosisEnzyme immunoassay (ELISA), for the detection

of cryptosporidial antigens in stool samples,.has greatest sensitivity and specificity

Molecular methods using PCR

Lane S: Molecular base pair standard (100-bp ladder). Black arrows show the size of standard bands.

Lane 1: C. parvum positive fecal specimen. The red arrow shows the diagnostic band for Cryptosporidium parvum zoonotic genotype (size: 435 bp).

Diagnosis


ReferencesChiodini PL, Moody AD, & Manser DW. (Atlas of

Medical Helminthology and Protozoology. 4th ed. Churchill Livingstone, Edinburg.

Smith HV, Cacciò SM, Cook N, Nichols RA, Tait A. (2007). Cryptosporidium and Giardia as foodborne zoonoses.Vet Parasitol. 149(1-2):29-40.

http://www.flickr.com/photos/dokidok/2369772294/sizes/m/in/photostream/

http://www.genomenewsnetwork.org/articles/2004/04/02/crypto.php

http://www2.mcdaniel.edu/Biology/eh01/waterpollution/3.diseasecarrying.html

http://jhyoung.myweb.uga.edu/Waterborne.htmlhttp://s02.middlebury.edu/BI330A/STUDENTS/hmiller/

index.htm

Referenceshttp://atlas.or.kr/atlas/alphabet_view.php?

my_codeName=Cryptosporidium%20parvumhttp://www.avianbiotech.com/diseases/

cryptosporidium.htmhttp://www.wadsworth.org/databank/crypto.htmhttp://dpd.cdc.gov/dpdx/HTML/ImageLibrary/A-

F/Cryptosporidiosis/body_Cryptosporidiosis_il3.htm

Next Lab

Blood-dwelling Apicomplexa:Plasmodium spp.

Health & Medicine

Lab 10 cryptosporidiosis