A Combined Method Based on the FIPV N Monoclonal Antibody Immunofluorescence Assay and RT-nPCR Method for the Rapid Diagnosis of FIP-Suspected Ascites

Feline infectious peritonitis (FIP), which is caused by feline infectious peritonitis virus (FIPV), is a fatal and immunologically mediated infectious disease among cats. At present, due to the atypical clinical symptoms and clinicopathological changes, the clinical diagnosis of FIP is still difficult. The gold standard method for the differential diagnosis of FIP is immunohistochemistry (IHC) which is time-consuming and requires specialized personnel and equipment. Therefore, a rapid and accurate clinical diagnostic method for FIPV infection is still urgently needed. In this study, based on the etiological investigation of FIPV in parts of southern China, we attempted to explore a new rapid and highly sensitive method for clinical diagnosis. The results of the etiological investigation showed that the N gene of the FIPV BS8 strain had the highest homology with other strains. Based on this, a specific FIPV BS8 N protein monoclonal antibody was successfully prepared by expression of the recombinant proteins, immunization of mice, fusion and selection of hybridoma cell lines, and screening and purification of monoclonal antibodies. Furthermore, we carried out a time-saving combination method including indirect immunofluorescence assay (IFA) and nested reverse transcription polymerase chain reaction (RT-nPCR) to examine FIP-suspected clinical samples. These results were 100% consistent with IHC. The results revealed that the combined method could be a rapid and accurate application in the diagnosis of suspected FIPV infection within 24 hours. In conclusion, the combination of IFA and RT-nPCR was shown to be a fast and reliable method for clinical FIPV diagnosis. This study will provide insight into the exploitation of FIPV N antibodies for the clinical diagnosis of FIP-suspected ascites samples.

Two Multiplex PCR Methods for Detecting Several Pathogens Associated with Feline Respiratory and Intestinal Tracts.

Respiratory tract and intestinal diseases are common threats to feline health. Coinfection with multiple pathogens is not rare among clinical infectious cases. Rapid diagnosis of these coinfections is of great significance for timely and effective clinical treatment. In this study, two novel multiplex polymerase chain reactions (mPCRs) were established for simultaneous detection of four pathogens associated with the feline intestinal tract (feline coronavirus (FCoV), feline astrovirus (FeAstV), feline panleukopenia virus (FPV) and feline kobuvirus (FeKoV)) and five pathogens associated with the respiratory tract (feline calicivirus (FCV), feline herpesvirus 1 (FHV-1), feline leukemia virus (FeLV), Chlamydia felis (C. felis) and influenza A virus (IAV)). The results of sensitivity analysis revealed that the detection limits for FeKoV, FPV, FeAstV, FCoV, IAV, C. felis, FeLV, FHV-1 and FCV were 103, 104, 103, 103, 103, 104, 104, 105 and 105 copies/µL, respectively. Moreover, the specificity of the two mPCRs was high. When the two mPCRs were applied to clinical samples, the assay worked well. In conclusion, we established two mPCR methods that provide an excellent tool for the diagnosis and monitoring of pathogens associated with the feline respiratory and intestinal tracts.

Anatomic Repair of Left Main Coronary Artery Atresia: Coronary Ostioplasty With Autologous Pulmonary Artery.

BACKGROUND: Left main coronary arterial (LMCA) atresia is a rare coronary arterial anomaly with extremely limited data on the optimal management. We aimed to report our single-surgeon experience of the ostioplasty in patients with LMCA atresia. METHODS: From July 2018 to December 2019, pediatric patients who presented with LMCA atresia and subsequently underwent surgical coronary ostioplasty were recruited into this retrospective study. Concomitant mitral repair was applied when the regurgitation was moderate or more severe. RESULTS: A total of 9 patients diagnosed with LMCA atresia were included. Mitral regurgitation was found in all of them, including 6 (66.7%) severe, 1 (11.1%) moderate, and 2 (22.2%) mild. In addition to ischemic lesions, which were found in 7 (77.8%) patients, structural mitral problems were also common (presented in 7 [77.8%] patients). All the patients underwent coronary ostioplasty with autologous pulmonary arterial patch augmenting the anterior wall of the neo-ostium. Mean aortic cross clamp time and cardiopulmonary bypass time was 88.1 ± 18.9 and 124.6 ± 23.6 minutes, respectively. During a median of 10.9 (range: 3.3 to 17.2) months' follow-up, there was only 1 death at 5 months after surgery. All survivors were recovered uneventfully with normal left-ventricular function; however, with 4 (50.0%) having significant recurrence of mitral regurgitation. CONCLUSIONS: With favourable surgical outcomes, coronary ostioplasty for LMCA atresia may be an option of revascularization. Structural mitral problems presented in majority patients, resulting in the requirement of concomitant mitral repair. However, the optimal technique of mitral repair remains unclear.