Development and evaluation of loop-mediated isothermal amplification assay for rapid and sensitive detection of canine parvovirus DNA directly in faecal specimens.

Aims:  To develop a specific and highly sensitive loop-mediated isothermal amplification (LAMP) technique for the rapid detection of canine parvovirus (CPV) DNA directly in suspected faecal samples of dogs by employing a simple method of template preparation.

Methods And Results:  LAMP reaction was developed by designing two sets of outer and inner primers, which target a total of six distinct regions on VP2 gene of CPV. The template DNA was prepared by a simple boiling and chilling method. Of the 140 faecal samples screened by the developed LAMP and the conventional PCR assays, 104 samples (74·28%) were found positive by LAMP, whereas 81 samples (57·85%) were found positive by PCR. The specificity of the LAMP assay was tested by cross-examination of common pathogens of dogs and further confirmed by sequencing. The detection limit of the LAMP was 0·0001 TCID₅₀ ml⁻¹, whereas the detection limit of the PCR was 1000 TCID₅₀ ml⁻¹.

Conclusions:  The developed LAMP assay detects CPV DNA in faecal specimens directly within an hour by following a simple and rapid boiling and chilling method of template preparation. The result also shows that the developed LAMP assay is specific and highly sensitive in detecting CPV.

Significance And Impact Of The Study:  The result indicates the potential usefulness of LAMP which is a simple, rapid, specific, highly sensitive and cost-effective field-based method for direct detection of CPV from the suspected faecal samples of dogs.