Detection and quantification of Cryptosporidium in HCT-8 cells and human fecal specimens using real-time polymerase
Jonathan B Parr1, Jesus Emmanuel Sevilleja, Amidou Samie
1University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA.
Abstract:
Cryptosporidium is a significant cause of diarrheal illness worldwide, especially among children and immunocompromised patients. Currently used diagnostic techniques are time-consuming, require skilled technicians, and are not useful for quantification of oocysts in fecal and environmental samples. In this study, we examined the use of a real-time polymerase chain reaction (PCR) assay for detecting and quantifying Cryptosporidium parvum in three distinct and progressively more complex matrices: phosphate-buffered saline (PBS), HCT-8 cells (human ileocecal carcinoma), and human fecal specimens. A reliable standard curve was generated using the PBS samples spiked with pure oocysts, and oocyst starting quantities were calculated for the infected HCT-8 cell and spiked fecal samples. The assay detected Cryptosporidium in samples infected/spiked with > or =10(3) oocysts/sample and detected both C. hominis and C. parvum in clinical specimens. This assay is useful in a variety of samples in the research laboratory and will likely prove to be a useful tool in the clinical laboratory.
Insights
A new real-time polymerase chain reaction (PCR) assay can detect and quantify Cryptosporidium oocysts in various samples. This method offers a faster, more accessible diagnostic tool for identifying this common cause of diarrheal illness.
Area of Science:
- Medical Microbiology
- Molecular Diagnostics
- Parasitology
Background:
- Cryptosporidium causes significant global diarrheal illness, particularly in vulnerable populations.
- Current diagnostic methods are labor-intensive, require expertise, and lack quantification capabilities.
- Accurate detection and quantification are crucial for managing Cryptosporidium infections and environmental monitoring.
Purpose of the Study:
- To evaluate a real-time polymerase chain reaction (PCR) assay for detecting and quantifying Cryptosporidium parvum.
- To assess the assay's performance across different sample types, from simple buffers to complex biological matrices.
- To establish the assay's sensitivity and specificity for clinical and research applications.
Main Methods:
- Development and validation of a real-time PCR assay for Cryptosporidium detection.
- Generation of a standard curve using spiked phosphate-buffered saline (PBS) samples with known oocyst concentrations.
- Application of the assay to quantify oocysts in HCT-8 cell cultures and human fecal specimens.
Main Results:
- A reliable standard curve was established, enabling accurate oocyst quantification.
- The real-time PCR assay detected Cryptosporidium at levels of 10(3) oocysts per sample or higher.
- The assay successfully identified both Cryptosporidium hominis and Cryptosporidium parvum in clinical samples.
Conclusions:
- The developed real-time PCR assay is effective for detecting and quantifying Cryptosporidium in diverse sample matrices.
- This molecular method offers a significant improvement over traditional diagnostic techniques in terms of speed and accessibility.
- The assay holds promise as a valuable tool for both research and clinical laboratories in diagnosing and managing Cryptosporidium infections.
