Sphaerita spp.

Sphaerita spp.

“Big bugs have little bugs, on their backs to bit them’

Little bugs have lesser bugs, and so on ad infinitum”

Anonymous

Some protozoan parasites can themselves be parasitized.  A hyper-parasite! The genus Sphaerita is considered to be a lower fungus and some species are capable of invading the cytoplasm of some amoeboid parasites.  Another parasite of parasites is Nucleophaga species which invades the nucleus.  Sphaerita, (sometimes called Polyphaga spp.) appear as tightly packed clusters within the cytoplasm and measure approximately 0.5 µm to 1.0 µm.

The parasite show below is possibly an Entamoeba coli, however the nucleus is not visible as it is out of the plane of focus.  Sphaerita appears as the small dots within the cytoplasm.

 An amoeboid parasite itself parasitized by the fungal parasite Sphaerita spp.  The Sphaerita appear as the neatly arranged circular dots withing the cytoplasm.

 Iron hematoxylin stain (X1000) Nikon

 An amoeboid parasite itself parasitized by the fungal parasite Sphaerita spp.  Doesn't appear to be digested material or inclusions. This parasite appears to have a rather dark blotchy karyosome reminiscent of Iodamoeba  bütchlii.  Unfortunately I failed to record measurements when I took these photos.  E.coli, Iodamoeba  bütchlii and E.nana were all present in this particular specimen.

Iron hematoxylin stain (X1000) Nikon

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Entamoeba coli:

Parasite

Enatamoeba coli is an amoeba which inhabits the human gut. It is considered to be an non-pathogenic commensal organism which along with thousands of other types of organisms makes up the normal gut flora. In the laboratory care must be taken in distinguishing the non-pathogenic Entamoeba coli from the pathogenic Entamoeba histolytica. Entamoeba can exhibit two forms, the trophozoite (troph) shown here and a cyst form which can exhibit up to 8 nuclei.

Treatment is not necessary but presence of this organism in a stool sample may indicate that a person has been exposed to a contaminated source bearing faecal matter and further investigation may be warranted.

The photomicrograph above is of an Entamoeba coli trophozoite in a concentrated faecal specimen stained by the Iron Haematoxylin method. A coarse cytoplasm is seen and the cell has a nucleus with dense unevenly distributed nuclear chromatin at it’s periphery and a central nucleolus. x1000.

Cryptosporidium parvum:

Protozoan Parasite


Cryptosporidium is a coccidian protozoan parasite who’s oocysts can infect humans usually by the oral-fecal route. Contaminated water is often the source of infection. In recent reports improperly washed produce was implicated as the source of infection. In immunocompetent patients, cryptosporidiosis is an acute, self-limiting diarrhoeal illness lasting about 1 to 2 weeks. Symptoms may include frequent watery diarrhoea, nausea, vomiting, abdominal cramps with low grade fever. No safe and effective therapy for cryptosporidial enteritis has been successfully developed. Since cryptosporidiosis is a self-limiting illness in immunocompetent individuals, general, supportive care is the only treatment for the illness. In immunocompromised patients (AIDS, transplants, cancer patients, the illness may be much more serious. No effective treatment is available other than to prevent dehydration and let the illness run it’s course.

The above micro photograph is of a Cryptosporidium oocyst from a concentrated stool sample stained by Carbol Fuschin, then decolourized by acid-alcohol. The oocysts are “acid fast” and resist decolorization whereas other material loses the resulting red colour. The remaining material in the slide is fecal debris and normal intestinal bacterial. x1000.

Strongyloides stercoralis:

Parasite: Nematode


Strongyloides stercoralis is a human parasitic roundworm (Nematode) about 2.5 mm in length. The adult parasitic stage lives in tunnels in the mucosa of the small intestine. The genus Strongyloides contains 53 species and S. stercoralis is the type species. The infectious larvae penetrate the skin when there is contact with the soil. Some of them enter the superficial veins and ride the blood vessels to the lungs, where they enter the alveoli. They are then coughed up and swallowed into the gut, where they parasitize the intestinal mucosa. S. stercoralis has a very low prevalence in societies where faecal contamination of soil is rare.

Ivermectin is the drug of first choice for treatment. Thiabendazole was used previously, but owing to its high prevalence of side effects and lower efficay, it has been superceeded by ivermectin and as second line, albendazole.

The above photomicrograph is of the Strongyloides larvae in a wet preparation of concentrated fecal material. x800.