environmental assay data sheet

Blastocystis hominus PCR test

Test code: X0049 - Ultrasensitive qualitative detection of Blastocystis hominis by real time PCR

Blastocystis hominis is a single-celled parasite that is often found in the intestines of humans and many animals. It is classified as a stramenopile, a group that also includes algae, diatoms, and water molds. Stramenopiles are a diverse group of organisms characterized by a flagellate stage in their life cycle, featuring stiff tubular hairs on one flagellum. When B. hominis is detected in stool, it appears as a round-to-oval cell (usually 8–10 µm, range 5–40 µm) with a large central vacuole (body) surrounded by a thin rim of cytoplasm containing up to 6 nuclei.

Blastocystis is one of the most common intestinal parasites worldwide. The prevalence rate is ~5–23% in industrialized countries and can reach 50–100% in developing regions. The infection rate is even higher in people who live or travel to areas with poor sanitation, work with animals, or attend childcare facilities. This parasite is transmitted via the fecal-oral route, often through contaminated food or water, contact with infected human or animal feces, or poor hygiene.

It's not clear whether Blastocystis causes disease because most people who carry the organism are asymptomatic. When symptoms occur, they may include watery diarrhea, abdominal pain, excessive gas, nausea, loss of appetite, anal itching, fatigue, weight loss, and occasionally skin rashes or hives.

Microscopic examination of fresh stool or antigen detection can be used to diagnose the infection. However polymerase chain reaction is increasingly being used to replace these traditional methodologies due to the high sensitivity and specificity of this method (Roberts et al., 2011; Šloufová et al., 2022)

Utilities:

• Check for Blastocystis hominis in water sources
• Selection of appropriate remediation regimens
• Check for post-remediation absence of this agent
• Help confirm the presence of this agent in animals
• Early prevention of the spread of this agent among animals
• Help minimize human exposure to this agent

References:

Roberts T, Barratt J, Harkness J, Ellis J, Stark D. Comparison of microscopy, culture, and conventional polymerase chain reaction for detection of blastocystis sp. in clinical stool samples. Am J Trop Med Hyg. 2011 Feb;84(2):308-12.

Specimen requirements: 0.2 ml feces or fecal swab, or environmental surface swab (cotton or synthetic tip) or swipe pad (approx 2" x 2"), or 2 ml of soil, or contaminated water, or water filter media

Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Qualitative real time polymerase chain reaction

Normal range: Nondetected