Detection of transmissible gastroenteritis virus using cDNA probes

Area of Science:

• Veterinary Virology
• Molecular Diagnostics
• Coronaviridae

Background:

• Transmissible gastroenteritis virus (TGEV) causes significant economic losses in swine production.
• Accurate and sensitive detection methods for TGEV are crucial for disease control.
• Existing diagnostic methods may have limitations in sensitivity or specificity.

Purpose of the Study:

• To develop and evaluate novel cDNA probes for the detection of TGEV.
• To assess the sensitivity and specificity of these probes in various sample types.
• To compare the performance of the new probes with conventional diagnostic techniques.

Main Methods:

• Preparation of five cDNA probes from molecular clones of the TGEV genome.
• Dot blot hybridization assay using 32P-labeled cDNA probes.
• Testing probes against TGEV strains, mock-infected cultures, porcine rotavirus, and unrelated coronaviruses.
• Evaluation of probe performance on field samples using immunofluorescence assay and electron microscopy.

Main Results:

• All five cDNA probes hybridized to virulent, attenuated, and field strains of TGEV.
• Probes detected as little as 200 pg of TGEV RNA and showed no cross-reactivity with other viruses.
• Specific probes (pB4 and Hpa-1600) detected TGEV in 79-88% of field samples.
• The pD24 clone differentiated TGEV from related coronaviruses and performed comparably to conventional methods.

Conclusions:

• Developed cDNA probes are sensitive and specific for TGEV detection.
• These probes can reliably identify TGEV in cell cultures and fecal specimens.
• The pD24 probe offers a valuable tool for differentiating TGEV from other coronaviruses.