Preliminary data about Paraoxonase-1 (PON-1) as a maker for Feline Infectious Peritonitis (FIP)

Feline infectious peritonitis (FIP) is a fatal disease in which the definitive diagnosis is achieved by immunohistochemistry (IHC) on post-mortem biopsies. The clinical suspicion is aroused by signalment, clinical signs and several laboratory tests, including alpha-1-acid glycoprotein measurement for which the only validated kit is no longer available. Paraoxonase-1 (PON-1) is a serum enzyme with antioxidant activity, considered as a negative acute phase protein in several species. Since inflammation plays a major role in FIP, and due to the high susceptibility of cats to oxidation, it could be of great interest the evaluation of this enzyme as a diagnostic marker for FIP. The aim of this study was to measure paraoxonase-1 in healthy cats and cats with clinical signs consistent with FIP (both wet or dry form), in order to evaluate the utility of this parameter in the diagnosis of FIP. Sixty-two cats were enrolled and divided into three groups: healthy (n=16), confirmed FIP (n=22) and NON FIP with similar clinical signs (n=24). PON-1 was measured on serum, using a paraoxon-based enzymatic method, already validated in cats. Results showed significantly lower PON-1 activity in FIP cats (mean ± SD: 29.1 ± 16.3 U/mL; median: 24.4; IQR: 16.6-38.3), compared with healthy cats (90.1 ± 24.1 U/mL; median: 86.0; IQR: 76.7-105.7; P<0.001) and with “non-FIP” cats (55.9 ± 28.3 U/mL; median: 51.9; IQR: 35.7-68.8, P<0.001). A significant difference was also found between healthy and “non-FIP” cats (P<0.001). The receiver operating characteristic (ROC) curve demonstrated that PON-1 may discriminate cats with and without FIP (Fig.1). At the cut-off that maximizes the diagnostic power of the test, sensitivity and specificity for FIP were 77% each, suggesting that PON-1 may be a reliable marker in association with other confirmatory tests and with signs consistent with the disease

The gut microbiome and mucosal defenses in cats with coronaviruses: a pilot study

Feline Infectious Peritonitis (FIP) develops from a mutation of enteric feline coronaviruses (FCoVs) and an imbalance of the host immune response. The wide polymorphism of FCoVs is associated with the viral replication rate (Licitra et al. 2013).  Changes in the composition of the gut microbiota may induce quali-quantitative modifications in FCoVs and/or different immune profiles (Weese et al., 2015). Few information is available on feline gut microbiome and the association between microbiota and the predisposition to pathological conditions (Ramadan et al., 2014).The aim of this study is to provide preliminary data about the composition of gut microbiota in healthy cats compared with FCoV infected cats (with and without  FIP), in order to evaluate whether changes of gut microbiota may induce changes in FCoV, in its genetic polymorphism and in the mucosal immunity.Screening analyses have been performed on 22 cats:- Routine hematology and biochemistry on EDTA and serum (included electrophoresis and alpha-1-acid glycoprotein measurement for cats suspected with FIP)- Nested RT-PCR-3’UTR on frozen faeces- Effusion evaluation- FIV/FeLV serologyDue to strict inclusion criteria (cats younger than 2.5 years old, indoor and not assuming antibiotics in the previous two months) and based on the results obtained from the complete set of analysis, only 15 cats, specifically 5 cats for each of the following 3 groups: FIP- affected, healthy negative and positive for FCoV, have been recruited to perform the following analyses: - microbiota analysis through NGS of 16S rRNA gene (V4 region) amplicons followed by bioinformatic analysis -  evaluation of secretory IgA (ELISA kit)- phylogenetic analysis of FCoVs S gene sequencesInnovative results will be provided on the feline gut microbiota composition. These will be correlated with the presence and genetic polymorphisms of FCoV and mucosal defenses to establish significant correlations between the analysed factors

Agreement between In-Clinics and Virus Neutralization Tests in Detecting Antibodies against Canine Distemper Virus (CDV)

Core vaccinations and specific antibody titer evaluations are strongly recommended worldwide by all the vaccination guidelines. Virus neutralization (VN) is considered the gold standard for measuring antibody titer against canine distemper virus, but it is complex and time consuming, and the use of in-clinics tests would allow to obtain quicker results. The aim of this study was to evaluate the agreement of the commercial in-clinics VacciCheck test compared to VN. A total of 106 canine sera were analyzed using both methods. The best agreement was obtained using a protective threshold of ≥1:32. VacciCheck showed 95.5% sensitivity, 87.2% specificity, and 92.5% accuracy. The Cohen’s kappa coefficient between methods was 0.84 (CI 95% 0.73 to 0.95), revealing an optimal agreement between the two methods (p = 0.0073). The evaluation of discordant results reveal that most samples had less than 1.5 dilution difference, and that usually did not affect the classification as protected or non-protected. Results also suggest that, in dubious cases, especially when a protective result is expected, retesting is advisable. In conclusion, VacciCheck may be considered as a reliable instrument that may help the clinician in identifying the best vaccine protocol, avoiding unnecessary vaccination, and thus reducing the incidence of adverse effects

Preliminary investigation on feline coronavirus presence in the reproductive tract of the tom cat as a potential route of viral transmission

Objectives: Feline infectious peritonitis (FIP) is an immune-mediated disease initiated by feline coronavirus (FCoV) infection. To date, the only proven route of transmission is the faecal\u2013oral route, but a possible localisation of FCoV in the reproductive tract of tom cats is of concern, owing to the involvement of the male reproductive tract during FIP and to the presence of reproduction disorders in FCoV-endemic feline catteries. The aim of the study was to investigate the presence and localisation of FCoV in semen and/or in the reproductive tract of tom cats, and its possible association with seroconversion and viraemic phase. Methods: Blood, serum, semen and/or testicle samples were obtained from 46 tom cats. Serology was performed on 38 serum samples, nested reverse transcriptase PCR (nRT-PCR) and reverse transcriptase quantitative PCR (RT-qPCR) were performed on 39 blood samples and on 17 semen samples, and histology, immunohistochemistry and nRT-PCR were performed on 39 testicles. Results: Twenty-four of 38 serum samples were positive on serology. Semen samples were negative on RT-PCR and RT-qPCR for FCoV, while all blood samples were negative at both molecular methods, except for one sample positive at RT-qPCR with a very low viral load. All testicles were negative at immunohistochemistry, while six were positive at nRT-PCR for FCoV. Serology and blood PCR results suggest that the virus was present in the environment, stimulating transient seroconversion. FCoV seems not to localise in the semen of tom cats, making the venereal route as a way of transmission unlikely. Although viral RNA was found in some testicles, it could not be correlated with the viraemic phase. Conclusions and relevance: In the light of these preliminary results, artificial insemination appears safer than natural mating as it eliminates the direct contact between animals, thus diminishing the probability of faecal\u2013oral FCoV transmission