Rhinotracheitis Research Articles

Detection of Mycoplasma spp. and feline calicivirus in cats with ocular surface disease.

To survey the prevalence of pathogens in shelter-housed cats with active ocular surface disease (OSD). A total of 255 shelter-housed domestic cats with evidence of active OSD. No normal, unaffected cats were sampled. OSD scoring was performed on cats with active OSD. Combined oropharyngeal/conjunctival swabs were submitted for rt-PCR/PCR for feline herpesvirus (FHV-1), feline calicivirus (FCV), Chlamydia spp. (CHL), Bordetella bronchiseptica (BORD), and Mycoplasma spp. (MYC). Pathogens were detected as follows: 76.4% (195/255) MYC, 57.6% (147/255) FHV-1, 42.7% (109/255) FCV, 26.7% (68/255) CHL, and 5.5% (14/255) BORD. Monoinfections affected 21.1% (54/255) animals, with MYC being the most common monoinfection (12.5%, 32/255), followed by FHV-1 (4.7%, 12/255), followed by CHL (2.4%, 6/255), followed by FCV (1.6%, 4/255), with no animals having a BORD monoinfection. Dual infections affected 36.4% of animals (93/255), with MYC detected in 30.1% (77/255) dual infections and FCV detected in 12.9% (33/255) dual infections. Dual infections with MYC and FCV together were detected in 9.8% (25/255) animals. Many animals (35.3%, 90/255) were found to be affected by 3 or more pathogens, and 7.1% (18/255) animals had no pathogens detected. OSD scores were not influenced by any variable assessed, including the number and type of pathogens detected. MYC, FHV-1, FCV, and CHL were commonly detected in this group of animals with OSD. Both MYC and FCV (alone or in combination with each other) were detected in multiple animals with active OSD, supporting prior evidence that either may independently act as a primary ocular surface pathogen.

Development of a Targeted NGS Assay for the Detection of Respiratory Pathogens including SARS-CoV-2 in Felines.

Acute respiratory diseases in felines can be attributed to a diverse range of pathogens. The recent emergence of novel viruses, particularly SARS-CoV-2 and its variants, has also been associated with respiratory ailments in cats and other pets, underscoring the need for a highly sensitive diagnostic assay capable of concurrently detecting multiple respiratory pathogens. In this study, we developed a targeted next generation sequencing panel using Ion Torrent Ampliseq technology to detect multiple respiratory pathogens, including recent SARS-CoV-2 variants and Feline herpesvirus-1, Feline calicivirus, Bordetella bronchiseptica, Mycoplasmopsis (previously Mycoplasma) felis, and Chlamydia felis. A PCR amplification-based library preparation, employing primers designed for pathogen target regions, was synthesized and divided into two pools, followed by sequencing and assembly to a repertoire of target pathogen genomes. Analytical sensitivity was assessed based on Ct values from real-time PCR for the corresponding pathogens, indicating an equivalent detection limit. Most of the pathogens under study were positively identified to a limit of approximately Ct 36, whereas for Feline herpesvirus-1 and SARS-CoV-2, positive reads were observed in samples with a Ct of 37. Based on a limited number of samples, the diagnostic sensitivity values for the SARS-CoV-2, Feline herpesvirus-1, and M. felis samples were 100% with no false negative results. The diagnostic specificity of SARS-CoV-2, Feline herpesvirus-1, Feline calicivirus, and C. felis were 100%. Importantly, none of the target primers exhibited non-specific amplification, ensuring the absence of false positive results for other pathogens within the study. Additionally, the assay's specificity was validated by cross-referencing the raw sequencing data with established databases like BLAST, affirming the high specificity of the targeted Next-Generation Sequencing (tNGS) assay. Variations in the sequencing reads of different pathogens were observed when subjected to diverse extraction methods. Rigorous assessment of the assay's reliability involved reproducibility across testing personnel and repeated runs. The developed assay's clinical applicability was tested using samples submitted to the diagnostic laboratory from cat shelters and suspected cases. The developed targeted next-generation sequencing methodology empowers the detection of multiple respiratory pathogens manifesting similar clinical symptoms while offering confirmation of results through genome sequencing.

Hermetic microfluidic device for point-of-care viral nucleic acid testing

There is an unmet clinical and public health need for rapid and accurate point-of-care (POC) diagnosis and management of infectious pathogens, especially in resource-limited environments. In this work, we present a microfluidic deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) rapid test (μDART) device for POC detection of various viral pathogens. This platform hermetically integrates the modules of extraction-free sample lysis, loop-mediated isothermal amplification (LAMP) with lyophilized reagent beads, and real-time colorimetric signal sensing to realize "sample-in and result-out" in 15–30 min. Test results can be sent to a mobile phone for remote monitoring. Automated high-precision liquid handling is achieved by a combination of negative-pressure-driven microchambers and self-sealing valves, thus simplifying manual operations and eliminating the leakage of nucleic acid aerosols. The limit of detection (LOD) of the device is as low as ∼53 copies/mL or ∼2 copies/reaction for SARS-CoV-2, which is as sensitive as the gold standard of nucleic acid testing. To validate our device’s clinical applications, we tested both DNA and RNA viruses as representative pathogens including 537 clinical nasal swab samples for SARS-CoV-2, 74 cervical swab samples for human papillomavirus 16/18 (HPV16/18) and 82 pet swab samples for feline cupripoxvirus (FCV) and feline herpesvirus (FHV). Across these tests, the clinical sensitivity and specificity were 92.5% - 97.7% and 99.7%-100%, respectively. We demonstrate that the μDART is able to provide a quick and accurate result for POCT and self-testing, and can connect to health care wirelessly to achieve remote monitoring.

Development and validation of multiplex one-step qPCR/RT-qPCR assays for simultaneous detection of SARS-CoV-2 and pathogens associated with feline respiratory disease complex.

Feline respiratory disease complex (FRDC) is caused by a wide range of viral and bacterial pathogens. Both Influenza A virus (IAV) and Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) also induce respiratory diseases in cats. Two one-step multiplex qPCR/RT-qPCR assays were developed and validated: FRA_1 (Feline respiratory assay 1) for the detection of four viral targets and FRA_2 for the detection of three bacteria associated with FRDC. Both multiplex assays demonstrated high specificity, efficiency (93.51%-107.8%), linearity (> 0.998), analytical sensitivity (≤ 15 genome copies/μl), repeatability (coefficient of variation [CV] < 5%), and reproducibility (CV < 6%). Among the 63 clinical specimens collected from FRDC-suspected cats, 92.1% were positive for at least one pathogen and co-infection was detected in 57.1% of samples. Mycoplasma felis (61.9%) was the most found pathogen, followed by feline herpesvirus-1 (30.2%), Chlamydia felis (28.7%) and feline calicivirus (27.0%). SARS-CoV-2 was detected in two specimens. In summary, this new panel of qPCR/RT-qPCR assays constitutes a useful and reliable tool for the rapid detection of SARS-CoV-2 and viral and bacterial pathogens associated with FRDC in cats.

Immunogenicity evaluation of a bivalent vaccine based on a recombinant rabies virus expressing gB protein of FHV-1 in mice and cats

Feline viral rhinotracheitis (FVR) is caused by the feline herpesvirus-1 (FHV-1), which commonly results in upper respiratory symptoms, and can result in death in the kittens and weak cats. Rabies is an infectious disease with zoonotic characteristics highly relevant to public health and also poses a serious threat to cats. Vaccines are the most effective method to control the spread of both FHV-1 and RABV and have the advantage that they produce long-term specific immune responses. In this study, we constructed a bivalent vaccine against FHV-1 and rabies virus (RABV) simultaneously. The vaccine was constructed by cloning FHV-1 gB into a RABV based vector, and the recombinant RABV (SRV9-FHV-gB) expressing the FHV-1 gB protein was rescued. The growth characteristics of SRV9-FHV-gB were analyzed on NA and BSR cells. To assess the immunogenicity of the vaccine, mice and cats were immunized with SRV9-FHV-gB supplemented with Gel02 adjuvant.The SRV9-FHV-gB exhibited the same growth characteristics as the parent virus SRV9 in both BSR cells and NA cells. The safety of SRV9-FHV-gB was evaluated using 5-day-old and 14-day-old suckling mice. The results showed that mice infected with the SRV9-FHV-gB survived for longer than those in the SRV9 group. Mice immunized with inactivated SRV9-FHV-gB produced high titers of specific antibodies against FHV-1 and neutralizing antibodies against RABV. Cats that received three immunizations with SRV9-FHV-gB also produced neutralizing antibodies against both FHV-1 and RABV. This study represents the first time that a bivalent vaccine targeting FHV-1 and RABV has been constructed, laying the foundations and providing inspiration for the development of other multivalent vaccines.

Saikosaponin B2, Punicalin, and Punicalagin in Vitro Block Cellular Entry of Feline Herpesvirus-1.

In the realm of clinical practice, nucleoside analogs are the prevailing antiviral drugs employed to combat feline herpesvirus-1 (FHV-1) infections. However, these drugs, initially formulated for herpes simplex virus (HSV) infections, operate through a singular mechanism and are susceptible to the emergence of drug resistance. These challenges underscore the imperative to innovate and develop alternative antiviral medications featuring unique mechanisms of action, such as viral entry inhibitors. This research endeavors to address this pressing need. Utilizing Bio-layer interferometry (BLI), we meticulously screened drugs to identify natural compounds exhibiting high binding affinity for the herpesvirus functional protein envelope glycoprotein B (gB). The selected drugs underwent a rigorous assessment to gauge their antiviral activity against feline herpesvirus-1 (FHV-1) and to elucidate their mode of action. Our findings unequivocally demonstrated that Saikosaponin B2, Punicalin, and Punicalagin displayed robust antiviral efficacy against FHV-1 at concentrations devoid of cytotoxicity. Specifically, these compounds, Saikosaponin B2, Punicalin, and Punicalagin, are effective in exerting their antiviral effects in the early stages of viral infection without compromising the integrity of the viral particle. Considering the potency and efficacy exhibited by Saikosaponin B2, Punicalin, and Punicalagin in impeding the early entry of FHV-1, it is foreseeable that their chemical structures will be further explored and developed as promising antiviral agents against FHV-1 infection.

In vitro evaluation of a natural food supplement as inhibitors of feline herpesvirus replication

The feline herpesvirus (FHV) is a widely diffused and highly contagious virus that represents a common health problem in cats. It is frequently associated with diseases of different pathogenicity that can be particularly severe in young kittens determining viral pneumonia and sometimes, death. Unfortunately, there isn’t a well-defined therapeutic protocol against the virus. Several studies concerning the application of alternative treatments against herpesviruses have been performed with promising results, in both human and veterinary medicine. The present study aims to investigate in vitro antiviral effects against FHV of the commercially compound HELP-TH1 (Camon, S.p.A., Italy) mainly composed by Ganoderma lucidum, Cordyceps sinensis, and Trametes versicolor. The antiviral effect of HELP-TH1 was evaluated by the Plaque Reduction Assay and by the real time PCR quantifying and comparing the viral load of infected controls vs treated experimental samples. Our data indicate that HELP-TH1 inhibits the cytopathic effect of the virus and reduces the viral load in the experimental conditions demonstrating its antiviral effect.

A potential dual protection vaccine: Recombinant feline herpesvirus-1 expressing feline parvovirus VP2 antigen

Recently, herpesvirus viral vectors that stimulate strong humoral and cellular immunity have been demonstrated to be the most promising platforms for the development of multivalent vaccines, because they contain various nonessential genes and exhibit long-life latency characteristics. Previously, we showed that the feline herpesvirus-1 (FHV-1) mutant WH2020-ΔTK/gI/gE, which was safe for felines and provided efficacious protection against FHV-1 challenge, can be used as a vaccine vector. Moreover, previous studies have shown that the major neutralizing epitope VP2 protein of feline parvovirus (FPV) can elicit high levels of neutralizing antibodies. Therefore, to develop a bivalent vaccine against FPV and FHV-1, we first generated a novel recombinant virus by CRISPR/Cas9-mediated homologous recombination, WH2020-ΔTK/gI/gE-VP2, which expresses the VP2 protein of FPV. The growth characteristics of WH2020-ΔTK/gI/gE-VP2 were similar to those of WH2020-ΔTK/gI/gE, and WH2020-ΔTK/gI/gE-VP2 was stable for at least 30 generations in CRFK cells. As expected, we found that the felines immunized with WH2020-ΔTK/gI/gE-VP2 produced FPV-neutralizing antibody titers (27.5) above the positive cutoff (26) on day 14 after single inoculation. More importantly, recombinant WH2020-ΔTK/gI/gE-VP2 exhibited severely impaired pathogenicity in inoculated and cohabiting cats. The kittens immunized with WH2020-ΔTK/gI/gE and WH2020-ΔTK/gI/gE-VP2 produced similar levels of FHV-specific antibodies and IFN-β. Furthermore, felines immunized with WH2020-ΔTK/gI/gE-VP2 were protected against challenge with FPV and FHV-1. These data showed that WH2020-ΔTK/gI/gE-VP2 appears to be a potentially safe, effective, and economical bivalent vaccine against FPV and FHV-1 and that WH2020-ΔTK/gI/gE can be used as a viral vector to develop feline multivalent vaccines.

Advancements, challenges, and future perspectives in developing feline herpesvirus 1 as a vaccine vector.

As the most prevalent companion animal, cats are threatened by numerous infectious diseases and carry zoonotic pathogens such as Toxoplasma gondii and Bartonella henselae, which are the primary causes of human toxoplasmosis and cat-scratch disease. Vaccines play a crucial role in preventing and controlling the spread of diseases in both humans and animals. Currently, there are only three core vaccines available to prevent feline panleukopenia, feline herpesvirus, and feline calicivirus infections, with few vaccines available for other significant feline infectious and zoonotic diseases. Feline herpesvirus, a major component of the core vaccine, offers several advantages and a stable genetic manipulation platform, making it an ideal model for vaccine vector development to prevent and control feline infectious diseases. This paper reviews the technologies involved in the research and development of the feline herpesvirus vaccine vector, including homologous recombination, CRISPR/Cas9, and bacterial artificial chromosomes. It also examines the design and effectiveness of expressing antigens of other pathogens using the feline herpesvirus as a vaccine vector. Additionally, the paper analyzes existing technical bottlenecks and challenges, providing an outlook on its application prospects. The aim of this review is to provide a scientific basis for the research and development of feline herpesvirus as a vaccine vector and to offer new ideas for the prevention and control of significant feline infectious and zoonotic diseases.

Antiviral Activity of Nitazoxanide and Miltefosine Against FeHV-1 In Vitro.

Feline herpesvirus type 1 (FeHV-1) is a primary pathogen in cats responsible for respiratory and ocular signs. There are presently no antiviral drugs that are officially licensed for veterinary use in several countries. Consequently, veterinarians must depend on off-label antivirals designed for human use. Recent advances in virus-host cell interaction have resulted in new insights into FeHV-1 replication, establishing the importance of the PI3K/Akt axis. The aim of this study was to employ this new information to assess the efficacy of two compounds whose activities involve this pathway. The antiviral properties of miltefosine and nitazoxanide were examined using seven different concentrations, evaluating cell viability and viral titers after 24 h of infection. Furthermore, selected concentrations were supplied at different time points to investigate the influence of the timing of the addition. The best results were obtained when the drugs were added both before and after viral adsorption (in particular for nitazoxanide). Each compound was further investigated by real-time PCR, western blot, and immunofluorescence. Nitazoxanide was the most effective treatment, reducing the expression of viral glycoproteins as measured by western blot and immunofluorescence, as well as reducing the release of virions in the supernatant (measured by real-time PCR). Moreover, treatment with nitazoxanide and miltefosine was associated with a decrease in Akt phosphorylation. This work emphasized the significance of comprehending the pathways necessary for viral replication and their use in the assessment of novel and effective antivirals.

Feline herpesvirus-1 (FeHV-1) in cats with ophthalmic problems: attempted propagation in CRFK cell lines

Feline herpesvirus-1 (FeHV-1) is classified within the Varicellovirus genus and is frequently seen in cats. Ocular complications, such as conjunctivitis, keratitis, and corneal ulcers, are common and have the potential to result in latency and permanent visual loss if not appropriately diagnosed and monitored. This study aimed to isolate FeHV-1 from cats with ocular lesions using the CRFK cell line.&#x0D; This study included a total of ten cats that tested positive for FeHV-1 and showed symptoms, including ocular and nasal discharge (8/10), conjunctivitis (6/10), and keratitis (5/10). Conjunctival samples were collected and processed for nucleic acid extraction. The CRFK cell line was propagated, and all positive samples were inoculated in 6-well plates. Surprisingly, no CPE was observed in the CRFK cell cultures during the observation period. Following post-inoculation in cell culture, the PCR analysis conducted on the supernatants obtained from the cultures found negative for FeHV-1. &#x0D; This study points out the challenges faced in isolating FeHV-1 in the CRFK from ocular samples of naturally infected cats. This highlights the requirement for future comprehensive in vitro studies to enhance the efficacy of FeHV-1 isolation techniques and explore potential approaches for FeHV-1 diagnosis.

Feline panleukopenia (review)

Feline panleukopenia, a disease globally known since the beginning of the last century and originally attributed to canine distemper, has expanded its range of hosts since its discovery as a result of successful infections (both natural and experimental) in mustelids, raccoons and even primates. Evolutionarily, the disease pathogen gave rise to anew infectious agent– canine parvovirus, which, despite its DNA structure, demonstrates a relatively high mutation rate and the emergence of new variants. The disease is in most cases fatal to newborn kittens and causes severe manifestations in adult cats, severely affecting the vital systems of the body. The prognosis is often (up to50%) unfavorable, while the animal’s age plays a key role. Current preventive measures can ensure protection, however, vaccines are used in the absence of adequate testing on cats and dogs (for ethical reasons) and have a number of limitations in use. The persistence of the infectious agent in the environment and the growing number of stray animals allow the infectious agent to circulate unhindered in these populations, threatening the health of domestic cats and endangered felines in nature reserves and zoos. Easing of legislation for leading research centers, regulation of the number of stray animals, adequate prevention measures for target groups in animal shelters, nurseries and zoos can contribute to a significant reduction in the circulation insusceptible populations of pathogens not only of this disease, but also of the majority of other dangerous infections, such as rabies, feline rhinotracheitis, canine distemper and others.

Dietary Supplementation with Nucleotides, Short-Chain Fructooligosaccharides, Xylooligosaccharides, Beta-Carotene and Vitamin E Influences Immune Function in Kittens

Nucleotides, short-chain fructooligosaccharides (scFOS), xylooligosaccharides (XOS), β-carotene and vitamin E are reported to enhance immune function; however, the evidence of this in cats is limited. The aim of this study was to determine the immunomodulatory effects of these ingredients in kittens. Forty domestic short hair kittens were designated in litters to control or test diet for 28 weeks. Test diet was fortified with 0.33 g nucleotides, 0.45 g scFOS, 0.3 g XOS, 0.7 mg β-carotene and 66.5 mg vitamin E per 100 g diet. Kittens were vaccinated against feline parvovirus (FPV) and herpesvirus (FHV) at 10, 14 and 18 weeks. Kittens remained healthy, with no measured evidence of adverse health. Serum FPV and FHV antibody titres were significantly (p &lt; 0.05) higher in the test diet group at week 23 and 27, respectively. A significantly (p &lt; 0.05) higher proportion of test diet group kittens demonstrated an adequate response (four-fold titre increase) to FHV vaccination and a significantly (p &lt; 0.05) higher proportion reached a protective antibody titre for FHV. Serum IgM was significantly (p &lt; 0.05) higher in the test diet group. The test diet group demonstrated a stronger humoral immune response to vaccination, suggesting the diet supports immune defence, enabling a greater response to immune challenges.

Prevalence of Serum Antibody Titers against Core Vaccine Antigens in Italian Cats.

Feline core vaccines strongly recommended for all cats are against Feline panleukopenia virus (FPV), Felid herpesvirus type 1 (FeHV-1), and Feline calicivirus (FCV), but cats can be classified as low- and high-risk based on their lifestyle. The aim of this study was to determine the actual seroprotection against FPV, FeHV-1, and FCV in a large cohort of Italian cats by using the VacciCheck test. A total of 740 cats (567 owned and 173 stray cats; 435 vaccinated and 305 unvaccinated) were analyzed for Protective Antibody Titers (PATs). Differences related to origin, sex, age, breed, FIV/FeLV status, health status, and time elapsed since last vaccination were evaluated. Less than half of the entire cohort (36.4%) had PATs for all three diseases simultaneously, increasing to 48.6% if weak positive values were also considered and 50.3% when considering only the 435 vaccinated cats. Particularly, antibodies were detected against FCV, FPV, and FeHV-1 at protective titers (PATs) in 78.6%, 68.1, and 49.1% of the cats, respectively. In general, owned, neutered, and adult FIV- and/or FeLV-negative cats were the most protected categories, even if not always for the three viruses. Most cats maintained high PATs for 3 years or longer after vaccination against FPV and FCV but not FeHV-1. Long-lasting protective immunity persisted for many years after the last vaccination (more than 18 years in the oldest cats). Nevertheless, since not all cats were protected after so many years and for all pathogens, checking protection via antibody titration could be the best choice to prevent immunity breakdowns. The discussion also focuses on the reliability of antibody titration for the two URTD (upper respiratory tract disease) viruses which, unlike for FPV, is not widely accepted as a valid index of protection.

CHRONIC RHINITIS IN CAT

A rescue female cat named Hanji aged 2 years with a body weight of 2.3 kg was examined at the Veterinary Internal Medicine Laboratory, Faculty of Veterinary Medicine, Udayana University. The purpose of the study was to diagnose, treat and evaluate the success of therapy in a case cat. Based on anamnesis, the cat had recurrent sneezing and nasal discharge and the cat had experienced eye pain so that the cat's left eye was broken and lost. On physical examination, there were oozing spots on both nostrils, sneezing and oozing. On palpation the right and left lymphonoduses were swollen, and on auscultation of the lungs there was stridor or abnormal lung sounds in general. Skin and nails, limbs, musculoskeletal, circulation, nerves, urogenital, and mucosa were normal. Supporting examination by conducting hematological examination, test kit, and isolation of bacterial and fungal identification. The test kit results showed that the case cat was negative for calicivirus infection or rhinotracheitis. The case cat was diagnosed with chronic rhinitis with a prognosis of fausta from the series of examinations performed. The therapy given to the case cat consisted of anti-inflammatory methylprednisolone (4 mg preparation, given orally (PO) with ½ tab once a day for 5 days), antibiotic doxycycline (100 mg preparation, given PO once a day for 6 days with ¼ tab, and supportive therapy in the form of vitamins and feed supplementation. On the 8th day of therapy showed success in treating chronic rhinitis and the eyes had begun to dry out. After supporting examinations such as negative test kit results showed no other indications such as Feline Calicivirus (FCV) or Feline Herpesvirus (FHV) disease so that the case animal was diagnosed with chronic rhinitis due to Chlamydia felis infection. Advice to owners if there are animals experiencing similar symptoms, immediately take them to the veterinarian for treatment so that the infection does not continue and severe and always maintain animal hygiene and surroundings.

The establishment and application of a dual Nano-PCR detection method for feline calicivirus and feline herpesvirus type I.

Feline calicivirus (FCV) and Feline herpesvirus type I (FHV-I) are the main pathogens causing upper respiratory tract infections in cats, and some wild animals. These two viruses always coinfection and cause serious harm to pet industry and wild animals protection. Established a rapid and accurate differential diagnosis method is crucial for prevention and control of disease, however, the current main detection method for these two viruses, either is low sensitivity (immunochromatographic strip), or is time-consuming and cannot differential diagnosis (conventional single PCR). Nanoparticle-assisted polymerase chain reaction (Nano-PCR) is a recently developed technique for rapid detection method of virus and bacteria. In this study, we described a dual Nano-PCR assay through combining the nanotechnology and PCR technology, which for the clinical simultaneous detection of FCV and FHV-I and differential diagnosis of upper respiratory tract infections in cats or other animals. Under optimized conditions, the optimal annealing temperature for dual Nano-PCR was 51.5°C, and specificity test results showed it had no cross reactivity to related virus, such as feline panleukopenia virus (FPV), feline Infectious peritonitis virus (FIPV) and rabies virus (RABV). Furthermore, the detection limit of dual Nano-PCR for FCV and FHV-I both were 1 × 10-8 ng/μL, convert to number of copies of virus DNA was 6.22 × 103copies/μL (FCV) and 2.81 × 103copies/μL (FHV-I), respectively. The dual Nano-PCR detected result of 52 cat clinical samples, including ocular, nasal and faecal swabs, and (3 FCV-positive samples), was consistent with ordinary PCR and the clinical detection results. The dual Nano-PCR method established in this study with strong specificity and high sensitivity can be used for virus nucleic acid (FCV and FHV-I) detection of clinical samples of feline upper respiratory tract infections feline calicivirus and feline herpesvirus while providing support for the early diagnosis of cats that infected by FCV and FHV-I.

Clinical evaluation of antiviral combination treatment in cats with feline herpesvirus-1 infection

Clinical evaluation of antiviral combination treatment in cats with feline herpesvirus-1 infection

A bacterium-like particle vaccine displaying protective feline herpesvirus 1 antigens can induce an immune response in mice and cats

Feline herpesvirus 1 (FHV-1) is a highly transmissible virus that mainly causes ocular and upper respiratory infections in cats and seriously threatens the health of domestic cats and captive or wild cats (such as tigers, cheetahs, and lions). Vaccination is crucial to reduce the incidence rate and mortality of cats infected with FHV-1. In this study, three bacterium-like particles (BLPs) displaying the gB, gC, and gD proteins of FHV-1 were constructed based on a gram-positive enhancer matrix-protein anchor (GEM-PA) surface display system. Indirect immunofluorescence assay, western blot, and electron microscopy results showed that gB, gC or gD protein of FHV-1 was successfully displayed on the surface of GEM particles. Additionally, we designed one more BLPs, designated gB&gC&gD-GEM, which consisted of a mixture of gB-GEM, gC-GEM, and gD-GEM at a protein content ratio of 1:1:1. Mice were immunized with the four BLPs mixed with Gel02 adjuvant, and the results indicated that neutralizing antibody level in the gB&gC&gD-GEM group was superior than those in the other groups. Moreover, gB&gC&gD-GEM significantly increased the secretion of cytokines, as well as the activation and maturation of B cells. It also boosted the production of central memory T cells among CD4 + and CD8 + T cells. Moreover, gB&gC&gD-GEM mixed with Gel02 adjuvant provoked an antibody response in cats. In conclusion, the BLPs vaccine prepared from gB&gC&gD-GEM induced specific humoral and cellular immune responses to FHV-1 and be used as a potential vaccine candidate for the control of FHV-1 infection in cats.

Assessing vaccine hesitancy and support for vaccination requirements for pets and potential Spillovers from humans

BackgroundGrowing vaccination hesitancy is well-document among humans. However, we know very little about vaccination hesitancy for pets as well as whether the two phenomena are interconnected. Moreover, support for pet vaccination requirements also remain underassessed. MethodsWe fielded a large, national survey (N = 3,958) on August 18 and August 19, 2023, to assess U.S. public opinion about the vaccination status of dogs (rabies, canine parvovirus, canine distemper, canine influenza, and Lyme disease) and cats (rabies, feline panleukopenia (parvo), feline herpesvirus-1, feline chlamydia, and feline Bordetella) in the United States. We also queried respondents about their support for vaccination requirements for the 10 diseases. ResultsWe find that the vast majority of cats and dogs are vaccinated. However, a substantial minority of pets is not, particularly for cats and for non-core vaccines. We find that attitudinal measures of human and pet vaccine hesitancy are closely related to each other. Moreover, they are strong predictors of vaccine behavior. Measures of vaccine hesitancy are also strong predictors of support for vaccination mandates. Common measures used to assess human vaccine hesitancy showed inconsistent effects. However, pet vaccinations appear to be less politically polarizing. ConclusionThe high correlation between pet and human measures raises the stake for public health efforts to improve attitudes about vaccines and vaccination rates across the board. Strong support for vaccination requirements should encourage policymakers to explore policy change. Moreover, veterinarians and their associations should consider expanding the number of core vaccinations.

Relationship between the bacterial ocular surface microbiota and outcomes for cats with feline herpesvirus type 1 ocular surface disease.

Feline herpesvirus 1 (FHV-1) causes ocular surface disease in domestic cats. The purpose of this study was to assess the relationship between bacterial ocular surface microbiota and outcomes for cats with FHV-1 ocular surface disease. Twenty-two shelter-housed cats with confirmed FHV-1 ocular surface disease. Animals were grouped according to FHV-1 shedding and ocular clinical scores following intervention: worsened outcome (WorOut, n = 11) or improved outcome (ImpOut, n = 11). Scoring and conjunctival sampling were completed on Days 1 and 8 of twice daily antiviral treatment. Bacterial DNA was extracted and submitted for 16S rRNA gene sequencing. Real-time polymerase chain reaction was performed for selected bacterial species. Overall DNA concentration between groups was assessed. Bacterial microbiota relative abundance composition was significantly different between ImpOut and WorOut groups (weighted UniFrac p = .006). Alpha diversity was significantly higher in the ImpOut group compared with the WorOut group (Shannon p = .042, Simpson's p = .022, Pielou's p = .037). Differences in the relative abundance of various phyla and species were detected between groups. Total DNA concentration was higher in the WorOut group compared with the ImpOut group (p = .04). Feline GAPDH (p = .001) and Bilophila wadsworthia (p = .024) copy number was significantly higher in the ImpOut group compared with the WorOut group. The results highlight the important relationship between the bacterial ocular surface microbiota and FHV-1 infection outcomes in cats treated with antiviral medications. Low bacterial species diversity, higher overall DNA (presumed predominantly bacterial) load, and certain bacterial phyla/species were associated with poor outcomes for cats with FHV-1 ocular disease.