The use of high-resolution melting analysis to distinguish feline enteric and feline infectious peritonitis coronaviruses

Abstract

Objectives: Feline coronavirus (FCoV) infections are a widespread occurrence among feline populations globally. The FCoV family encompasses two distinct biotypes: feline enteric coronavirus (FECV) and feline infectious peritonitis viruses (FIPV). FECV infections are asymptomatic or result in only mild enteric disease, whereas FIPV can cause a high mortality rate. Distinguishing FIPV from FCoV is crucial for prompt treatment. High resolution Melting (HRM) technology can accurately solve this problem.

Methods: In our work, one pair of primers was designed from the 7b gene of FCoV. There are three mutations specific for the same fragment amplification between FECV and FIPV. Thus, these mutations causes different dissociation curves and Tm values.

Results: HRM analysis showed that Tm values of FIPV was about 2 °C higher than that of FECV. Our assay had high specificity, sensitivity and reproducibility. We have tested the high accuracy of this method in 11 clinical samples and confirmed it with DNA sequencing. The high-resolution melting curve assay provides an alternative mean to distinguish FIPV from FCoV.

Conclusions and relevance: This HRM-based assay provides a rapid (< 2 h), cost-effective alternative to sequencing for discriminating FIPV from FECV. Its high accuracy and suitability for routine diagnostics could significantly improve early FIPV identification, enabling timely therapeutic decisions in veterinary practice.

Keywords: Cats; Feline coronavirus (FCoV); Feline enteric coronavirus (FECV); Feline infectious peritonitis viruses (FIPV); High resolution melting (HRM).