Khamsingnok Piyamat, Rapichai Witsanu, Rattanasrisomporn Amonpun, Rungsuriyawiboon Oumaporn, Choowongkomon Kiattawee, Rattanasrisomporn Jatuporn
Graduate Program in Animal Health and Biomedical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand.
Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand.
Animals (Basel). 2024 Aug 22;14(16):2432. doi: 10.3390/ani14162432.
Feline calicivirus (FCV) is a highly contagious virus that causes upper respiratory tract disease, commonly known as cat flu. It is widely distributed worldwide and poses a major threat to feline health. Therefore, it is essential to find an efficient and rapid method for detecting FCV. In this study, the colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay, using neutral red as an indicator, was developed and validated to target the ORF2 gene of FCV for the first time. Additionally, the study compared the diagnostic abilities of polymerase chain reaction (PCR), nested PCR, and RT-LAMP assays for detecting FCV in clinical samples. The optimized RT-LAMP amplification was carried out at 56.3 °C. The technique visually detected FCV within 70 min, with a limit of detection of 14.3 × 10 copies/µL, and showed no cross-reactivity with other feline pathogens. Out of 54 oropharyngeal swab samples, 17 tested positive for FCV using both nested PCR and RT-LAMP, while only one tested positive using conventional PCR. The positivity rate was higher with nested PCR and RT-LAMP (31.48%) compared to conventional PCR (1.85%). Consequently, these results demonstrated the effectiveness of the colorimetric RT-LAMP assay developed in this study as an alternative for diagnosing FCV in cats.
猫杯状病毒（FCV）是一种高度传染性病毒，可引起上呼吸道疾病，通常称为猫流感。它在全球广泛分布，对猫的健康构成重大威胁。因此，找到一种高效、快速检测FCV的方法至关重要。在本研究中，首次开发并验证了以中性红为指示剂的比色逆转录环介导等温扩增（RT-LAMP）检测法，用于靶向FCV的ORF2基因。此外，该研究比较了聚合酶链反应（PCR）、巢式PCR和RT-LAMP检测法在临床样本中检测FCV的诊断能力。优化后的RT-LAMP扩增在56.3℃下进行。该技术在70分钟内可直观检测到FCV，检测限为14.3×10拷贝/μL，且与其他猫病原体无交叉反应。在54份口咽拭子样本中，17份使用巢式PCR和RT-LAMP检测均为FCV阳性，而使用传统PCR检测仅1份阳性。与传统PCR（1.85%）相比，巢式PCR和RT-LAMP的阳性率更高（31.48%）。因此，这些结果证明了本研究中开发的比色RT-LAMP检测法作为诊断猫FCV的替代方法的有效性。
