Prototype and BA.5 protein nanoparticle vaccines protect against Omicron BA.5 variant in Syrian hamsters.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with greater transmissibility or immune evasion properties has jeopardized the existing vaccine and antibody-based countermeasures. Here, we evaluated the efficacy of boosting pre-immune hamsters with protein nanoparticle vaccines (Novavax, Inc.) containing recombinant Prototype (Wuhan-1) or BA.5 S proteins against a challenge with the Omicron BA.5 variant of SARS-CoV-2. Serum antibody binding and neutralization titers were quantified before challenge, and viral loads were measured 3 days after challenge. Boosting with Prototype or BA.5 vaccine induced similar antibody binding responses against ancestral Wuhan-1 or BA.5 S proteins, and neutralizing activity of Omicron BA.1 and BA.5 variants. One and three months after vaccine boosting, hamsters were challenged with the Omicron BA.5 variant. Prototype and BA.5 vaccine-boosted hamsters had reduced viral infection in the nasal washes, nasal turbinates, and lungs compared to unvaccinated animals. Although no significant differences in virus load were detected between the Prototype and BA.5 vaccine-boosted animals, fewer breakthrough infections were detected in the BA.5-vaccinated hamsters. Thus, immunity induced by Prototype or BA.5 S protein nanoparticle vaccine boosting can protect against the Omicron BA.5 variant in the Syrian hamster model. IMPORTANCE: As SARS-CoV-2 continues to evolve, there may be a need to update the vaccines to match the newly emerging variants. Here, we compared the protective efficacy of the updated BA.5 and the original Wuhan-1 COVID-19 vaccine against a challenge with the BA.5 Omicron variant of SARS-CoV-2 in hamsters. Both vaccines induced similar levels of neutralizing antibodies against multiple variants of SARS-CoV-2. One and three months after the final immunization, hamsters were challenged with BA.5. No differences in protection against the BA.5 variant virus were observed between the two vaccines, although fewer breakthrough infections were detected in the BA.5-vaccinated hamsters. Together, our data show that both protein nanoparticle vaccines are effective against the BA.5 variant of SARS-CoV-2 but given the increased number of breakthrough infections and continued evolution, it is important to update the COVID-19 vaccine for long-term protection.

duper is a null mutation of Cryptochrome 1 in Syrian hamsters.

The duper mutation is a recessive mutation that shortens the period length of the circadian rhythm in Syrian hamsters. These animals show a large phase shift when responding to light pulses. Limited genetic resources for the Syrian hamster (Mesocricetus auratus) presented a major obstacle to cloning duper. This caused the duper mutation to remain unknown for over a decade. In this study, we did a de novo genome assembly of Syrian hamsters with long-read sequencing data from two different platforms, Pacific Biosciences and Oxford Nanopore Technologies. Using two distinct ecotypes and a fast homozygosity mapping strategy, we identified duper as an early nonsense allele of Cryptochrome 1 (Cry1) leading to a short, unstable protein. CRY1 is known as a highly conserved component of the repressive limb of the core circadian clock. The genome assembly and other genomic datasets generated in this study will facilitate the use of the Syrian hamster in biomedical research.

Cross-species metabolomic profiling reveals phosphocholine-mediated liver protection from cold and ischemia/reperfusion.

Cold and ischemia/reperfusion (IR)-associated injuries are seemingly inevitable during liver transplantation and hepatectomy. Because Syrian hamsters demonstrate intrinsic tolerance to transplantation-like stimuli, cross-species comparative metabolomic analyses were conducted with hamster, rat, and donor liver samples to seek hepatic cold and IR-adaptive mechanisms. Lower hepatic phosphocholine contents were found in recipients with early graft-dysfunction and with virus-caused cirrhosis or high model for end-stage liver disease scores (≥30). Choline/phosphocholine deficiency in cultured human THLE-2 hepatocytes and animal models weakened hepatocellular cold tolerance and recovery of glutathione and ATP production, which was rescued by phosphocholine supplements. Among the biological processes impacted by choline/phosphocholine deficiency, 3 lipid-related metabolic processes were downregulated, whereas phosphocholine elevated the expression of genes in methylation processes. Consistently, in THLE-2, phosphocholine enhanced the overall RNA m6A methylation, among which the transcript stability of fatty acid desaturase 6 (FADS6) was improved. FADS6 functioned as a key phosphocholine effector in the production of polyunsaturated fatty acids, which may facilitate the hepatocellular recovery of energy and redox homeostasis. Thus, our study reveals the choline-phosphocholine metabolism and its downstream FADS6 functions in hepatic adaptation to cold and IR, which may inspire new strategies to monitor donor liver quality and improve recipient recovery from the liver transplantation process.

Slow decrease in temperature produces readthrough transcripts in mammalian hibernation.

Accumulating evidence suggests that various cellular stresses interfere with the end processing of mRNA synthesis and lead to the production of abnormally long transcripts, known as readthrough transcripts (RTTs), which extend beyond the termination sites. Small mammalian hibernators repeatedly enter a state referred to as deep torpor (DT), where the metabolic rate, respiration rate, and core body temperature become extremely low, which produces various types of cellular stresses and therefore induces RTTs. However, the types of stresses and processes around the DT that cause RTTs are unclear. In the present study, we showed that RTTs are produced from different gene loci in the livers of Syrian hamsters under DT and summer-like conditions. Moreover, in vitro analysis using hamster primary hepatocytes revealed that DT-specific RTTs are induced by a slow decline in temperature, as seen in body temperature in the entrance phase of DT, but not by rapid cold treatment or hypoxia. In addition, it was observed that RTTs were not elongated under a significantly cold temperature (4 °C). These results indicate that DT-specific RTTs are produced during the entrance phase of torpor by a slow decrease in body temperature.

The Highly Conserved Stem-Loop II Motif Is Dispensable for SARS-CoV-2.

The stem-loop II motif (s2m) is an RNA structural element that is found in the 3' untranslated region (UTR) of many RNA viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Though the motif was discovered over 25 years ago, its functional significance is unknown. In order to understand the importance of s2m, we created viruses with deletions or mutations of the s2m by reverse genetics and also evaluated a clinical isolate harboring a unique s2m deletion. Deletion or mutation of the s2m had no effect on growth in vitro or on growth and viral fitness in Syrian hamsters in vivo. We also compared the secondary structure of the 3' UTR of wild-type and s2m deletion viruses using selective 2'-hydroxyl acylation analyzed by primer extension and mutational profiling (SHAPE-MaP) and dimethyl sulfate mutational profiling and sequencing (DMS-MaPseq). These experiments demonstrate that the s2m forms an independent structure and that its deletion does not alter the overall remaining 3'-UTR RNA structure. Together, these findings suggest that s2m is dispensable for SARS-CoV-2. IMPORTANCE RNA viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), contain functional structures to support virus replication, translation, and evasion of the host antiviral immune response. The 3' untranslated region of early isolates of SARS-CoV-2 contained a stem-loop II motif (s2m), which is an RNA structural element that is found in many RNA viruses. This motif was discovered over 25 years ago, but its functional significance is unknown. We created SARS-CoV-2 with deletions or mutations of the s2m and determined the effect of these changes on viral growth in tissue culture and in rodent models of infection. Deletion or mutation of the s2m element had no effect on growth in vitro or on growth and viral fitness in Syrian hamsters in vivo. We also observed no impact of the deletion on other known RNA structures in the same region of the genome. These experiments demonstrate that s2m is dispensable for SARS-CoV-2.

CSF1R inhibitor PLX3397 depletes microglia in Mongolian gerbil Meriones unguiculatus, but not in syrian hamster Mesocricetus auratus.

Microglia are the residential immune cells in the central nervous system. Their roles as innate immune cells and regulators of synaptic remodeling are critical to the development and the maintenance of the brain. Numerous studies have depleted microglia to elucidate their involvement in healthy and pathological conditions. PLX3397, a blocker of colony stimulating factor 1 receptor (CSF1R), is widely used to deplete mouse microglia due to its non-invasiveness and convenience. Recently, other small rodents, including Syrian hamsters (Mesocricetus auratus) and Mongolian gerbils (Meriones unguiculatus), have been recognized as valuable animal models for studying brain functions and diseases. However, whether microglia depletion via PLX3397 is feasible in these species remains unclear. Here, we administered PLX3397 orally via food pellets to hamsters and gerbils. PLX3397 successfully depleted gerbil microglia but had no effect on microglial density in hamsters. Comparative analysis of the CSF1R amino acid sequence in different species hints that amino acid substitutions in the juxtamembrane domain may potentially contribute to the inefficacy of PLX3397 in hamsters.

Characterization of humoral responses to Nipah virus infection in the Syrian Hamster model of disease.

Nipah virus (NiV) is a highly pathogenic paramyxovirus. The Syrian hamster model recapitulates key features of human NiV disease and is a critical tool for evaluating antivirals and vaccines. Here we describe longitudinal humoral immune responses in NiV-infected Syrian hamsters. Samples were obtained 1-28 days after infection and analyzed by ELISA, neutralization, and Fc-mediated effector function assays. NiV infection elicited robust antibody responses against the nucleoprotein and attachment glycoprotein. Levels of neutralizing antibodies were modest and only detectable in surviving animals. Fc-mediated effector functions were mostly observed in nucleoprotein-targeting antibodies. Antibody levels and activities positively correlated with challenge dose.

Human-to-Human Transmission of Andes Virus Modeled in Syrian Hamsters.

Several occurrences of human-to-human transmission of Andes virus, an etiological agent of hantavirus cardiopulmonary syndrome, are documented. Syrian hamsters consistently model human hantavirus cardiopulmonary syndrome, yet neither transmission nor shedding has been investigated. We demonstrate horizontal virus transmission and show that Andes virus is shed efficiently from both inoculated and contact-infected hamsters.

Spontaneous recurrence of a summer-like diel rhythm in the body temperature of the Syrian hamster after hibernation.

Mammalian hibernation is a survival strategy characterized by metabolic suppression and drastically lowering body temperature (Tb), used during harsh seasons with food shortages and cold. The Syrian hamster commences hibernation in response to a short photoperiod and cold but spontaneously concludes hibernation after several months without environmental cues. Little is known about the changes in diel rhythms during hibernation. Using long-term and high-resolution Tb data, we analysed the diel Tb rhythm time-course changes in Syrian hamsters raised under summer-like conditions (long photoperiod (LP) and warm; LP-warm) and transferred to winter-like conditions (short photoperiod (SP) and cold; SP-cold). The diel Tb rhythm was undetectable during the hibernation period (HIBP), reappearing after the HIBP. The phase of this returning rhythm reverted to the LP entrainment phase characteristics despite the ambient SP and then re-entrained to the ambient SP as if the hamsters were transferred from the LP-warm to SP-cold conditions. The diel Tb rhythm reverted from the SP- to LP-type in a hibernation-dependent manner. Under constant dark and cold conditions, the circadian Tb rhythm recovered without photic stimuli following the HIBP. These findings suggest that hibernation involves a program that anticipates the ambient photoperiod when animals emerge from hibernation.

Highly Neutralizing COVID-19 Convalescent Plasmas Potently Block SARS-CoV-2 Replication and Pneumonia in Syrian Hamsters.

Despite various attempts to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients with COVID-19 convalescent plasmas, neither appropriate approach nor clinical utility has been established. We examined the efficacy of administration of highly neutralizing COVID-19 convalescent plasma (hn-plasmas) and such plasma-derived IgG administration using the Syrian hamster COVID-19 model. Two hn-plasmas, which were in the best 1% of 340 neutralizing activity-determined convalescent plasmas, were intraperitoneally administered to SARS-CoV-2-infected hamsters, resulting in a significant reduction of viral titers in lungs by up to 32-fold compared to the viral titers in hamsters receiving control nonneutralizing plasma, while with two moderately neutralizing plasmas (mn-plasmas) administered, viral titer reduction was by up to 6-fold. IgG fractions purified from the two hn-plasmas also reduced viral titers in lungs more than those from the two mn-plasmas. The severity of lung lesions seen in hamsters receiving hn-plasmas was minimal to moderate as assessed using microcomputerized tomography, which histological examination confirmed. Western blotting revealed that all four COVID-19 convalescent plasmas variably contained antibodies against SARS-CoV-2 components, including the receptor-binding domain and S1 domain. The present data strongly suggest that administering potent neutralizing activity-confirmed COVID-19 convalescent plasmas would be efficacious in treating patients with COVID-19. IMPORTANCE Convalescent plasmas obtained from patients who recovered from a specific infection have been used as agents to treat other patients infected with the very pathogen. To treat using convalescent plasmas, despite that more than 10 randomized controlled clinical trials have been conducted and more than 100 studies are currently ongoing, the effects of convalescent plasma against COVID-19 remained uncertain. On the other hand, certain COVID-19 vaccines have been shown to reduce the clinical COVID-19 onset by 94 to 95%, for which the elicited SARS-CoV-2-neutralizing antibodies are apparently directly responsible. Here, we demonstrate that highly neutralizing effect-confirmed convalescent plasmas significantly reduce the viral titers in the lung of SARS-CoV-2-infected Syrian hamsters and block the development of virally induced lung lesions. The present data provide a proof of concept that the presence of highly neutralizing antibody in COVID-19 convalescent plasmas is directly responsible for the reduction of viral replication and support the use of highly neutralizing antibody-containing plasmas in COVID-19 therapy with convalescent plasmas.

Establishment of multicenter COVID-19 therapeutics preclinical test system in Republic of Korea.

Throughout the recent COVID-19 pandemic, South Korea led national efforts to develop vaccines and therapeutics for SARS-CoV-2. The project proceeded as follows: 1) evaluation system setup (including Animal Biosafety Level 3 (ABSL3) facility alliance, standardized nonclinical evaluation protocol, and laboratory information management system), 2) application (including committee review and selection), and 3) evaluation (including expert judgment and reporting). After receiving 101 applications, the selection committee reviewed pharmacokinetics, toxicity, and efficacy data and selected 32 final candidates. In the nonclinical efficacy test, we used golden Syrian hamsters and human angiotensin-converting enzyme 2 transgenic mice under a cytokeratin 18 promoter to evaluate mortality, clinical signs, body weight, viral titer, neutralizing antibody presence, and histopathology. These data indicated eight new drugs and one repositioned drug having significant efficacy for COVID-19. Three vaccine and four antiviral drugs exerted significant protective activities against SARS-CoV-2 pathogenesis. Additionally, two anti-inflammatory drugs showed therapeutic effects on lung lesions and weight loss through their mechanism of action but did not affect viral replication. Along with systematic verification of COVID-19 animal models through large-scale studies, our findings suggest that ABSL3 multicenter alliance and nonclinical evaluation protocol standardization can promote reliable efficacy testing against COVID-19, thus expediting medical product development.

Hamster polyomavirus-associated T-cell lymphomas in Syrian hamsters (Mesocricetus auratus).

Hamster polyomavirus (HaPyV) infection has been associated with lymphomas in Syrian hamsters. In the present study, 14 cases of lymphoma in pet Syrian hamsters were pathologically examined and the involvement of HaPyV was investigated. Among 14 cases, 11 were abdominal and 3 were cutaneous lymphomas. The average ages of hamsters with abdominal lymphoma and cutaneous lymphoma were 7 months (range: 4-12 months) and 14 months (range: 6-23 months), respectively. Histologically, abdominal lymphomas were characterized by the diffuse growth of tumor cells with intermediate or large nuclei, low mitotic rates, the presence of tingible body macrophages, and the T-cell immunophenotype. Furthermore, 4/11 abdominal lymphomas were immunopositive for T-cell intracellular antigen-1, suggesting cytotoxic T-cell lymphomas. Cutaneous lymphomas were diagnosed as nonepitheliotropic T-cell lymphoma. Polymerase chain reaction (PCR) detected HaPyV DNA in 12/14 samples, and a sequence analysis of PCR amplicons confirmed >99% nucleotide identity to the published HaPyV sequences. In situ hybridization (ISH) for HaPyV DNA resulted in diffuse nuclear signals within tumor cells in 10/14 cases. Consistent with previous findings, all HaPyV-associated lymphomas were observed in the abdominal cavity of young hamsters. Polymerase chain reaction and ISH were useful for identifying the involvement of HaPyV in lymphomas, and ISH results indicated the presence of episomal HaPyV in neoplastic lymphocytes. The present study suggests that HaPyV infection is highly involved in abdominal lymphomas in young pet Syrian hamsters in Japan and provides diagnostic information on HaPyV-associated lymphoma.

Acute vaping in a golden Syrian hamster causes inflammatory response transcriptomic changes.

E-cigarette vaping is a major aspect of nicotine consumption, especially for children and young adults. Although it is branded as a safer alternative to cigarette smoking, murine and rat models of subacute and chronic e-cigarette vaping exposure have shown many proinflammatory changes in the respiratory tract. An acute vaping exposure paradigm has not been demonstrated in the golden Syrian hamster, and the hamster is a readily available small animal model that has the unique benefit of becoming infected with and transmitting respiratory viruses, including SARS-CoV-2, without genetic alteration of the animal or virus. Using a 2-day, whole body vaping exposure protocol in male golden Syrian hamsters, we evaluated serum cotinine, bronchoalveolar lavage cells, lung, and nasal histopathology, and gene expression in the nasopharynx and lung through reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Depending on the presence of nonnormality or outliers, statistical analysis was performed by ANOVA or Kruskal-Wallis tests. For tests that were statistically significant (P < 0.05), post hoc Tukey-Kramer and Dunn's tests, respectively, were performed to make pairwise comparisons between groups. In nasal tissue, RT-qPCR analysis revealed nicotine-dependent increases in gene expression associated with type 1 inflammation (CCL-5 and CXCL-10), fibrosis [transforming growth factor-ß (TGF-ß)], nicotine-independent increase oxidative stress response (SOD-2), and a nicotine-independent decrease in vasculogenesis/angiogenesis (VEGF-A). In the lung, nicotine-dependent increases in the expression of genes involved in the renin-angiotensin pathway [angiotensin-converting enzyme (ACE), ACE2], coagulation (tissue factor, Serpine-1), extracellular matrix remodeling (MMP-2, MMP-9), type 1 inflammation (IL-1ß, TNF-α, and CXCL-10), fibrosis (TGF-ß and Serpine-1), oxidative stress response (SOD-2), neutrophil extracellular traps release (ELANE), and vasculogenesis and angiogenesis (VEGF-A) were identified. To our knowledge, this is the first demonstration that the Syrian hamster is a viable model of e-cigarette vaping. In addition, this is the first report that e-cigarette vaping with nicotine can increase tissue factor gene expression in the lung. Our results show that even an acute exposure to e-cigarette vaping causes significant upregulation of mRNAs in the respiratory tract from pathways involving the renin-angiotensin system, coagulation, extracellular matrix remodeling, type 1 inflammation, fibrosis, oxidative stress response, neutrophil extracellular trap release (NETosis), vasculogenesis, and angiogenesis.

Anticancer and antioxidant profiling effects of Nerolidol against DMBA induced oral experimental carcinogenesis.

The objective of this study is to examine the chemopreventive effects of Nerolidol (NER) on hamster buccal pouch carcinogenesis (HBC) induced by 7,12-dimethylbenz(a)anthracene (DMBA) in male golden Syrian hamsters. In this study, oral squamous cell carcinoma was developed in the buccal pouch of an oral painted hamster with 0.5% DMBA in liquid paraffin three times weekly for 12 weeks. To assess DMBA-induced hamster buccal tissue carcinogenesis, biochemical endpoints such as Phase I and II detoxification enzymes, antioxidants, lipid peroxidation (LPO) by-products, and renal function markers, as well as histopathological examinations, were used. Furthermore, the immunohistochemical studies of interleukin-6 were investigated to find the inflammatory link in the HBC carcinogenesis. In our results, DMBA alone exposed hamsters showed 100% tumor growth, altered levels of antioxidants, detoxification agents, LPO, and renal function identifiers as compared to the control hamsters. The outcome in  present biochemical, histopathological, and immunohistochemistry studies has been found a reverse in NER-treated hamsters against the tumor. This study concluded that NER modulated the biochemical profiles (antioxidants, detoxification, LPO, and renal function markers) and inhibited tumor development in DMBA induced oral carcinogenesis.

SARS-CoV-2 Infection Dysregulates Cilia and Basal Cell Homeostasis in the Respiratory Epithelium of Hamsters.

Similar to many other respiratory viruses, SARS-CoV-2 targets the ciliated cells of the respiratory epithelium and compromises mucociliary clearance, thereby facilitating spread to the lungs and paving the way for secondary infections. A detailed understanding of mechanism involved in ciliary loss and subsequent regeneration is crucial to assess the possible long-term consequences of COVID-19. The aim of this study was to characterize the sequence of histological and ultrastructural changes observed in the ciliated epithelium during and after SARS-CoV-2 infection in the golden Syrian hamster model. We show that acute infection induces a severe, transient loss of cilia, which is, at least in part, caused by cilia internalization. Internalized cilia colocalize with membrane invaginations, facilitating virus entry into the cell. Infection also results in a progressive decline in cells expressing the regulator of ciliogenesis FOXJ1, which persists beyond virus clearance and the termination of inflammatory changes. Ciliary loss triggers the mobilization of p73+ and CK14+ basal cells, which ceases after regeneration of the cilia. Although ciliation is restored after two weeks despite the lack of FOXJ1, an increased frequency of cilia with ultrastructural alterations indicative of secondary ciliary dyskinesia is observed. In summary, the work provides new insights into SARS-CoV-2 pathogenesis and expands our understanding of virally induced damage to defense mechanisms in the conducting airways.

Therapeutic Efficacy of Human Monoclonal Antibodies against Andes Virus Infection in Syrian Hamsters.

Andes virus, an orthohantavirus endemic to South America, causes severe hantavirus cardiopulmonary syndrome associated with human-to-human transmission. No approved treatments or vaccines against this virus are available. We show that a combined treatment with 2 monoclonal antibodies protected Syrian hamsters when administered at midstage or late-stage disease.

Disruption of Adaptive Immunity Enhances Disease in SARS-CoV-2-Infected Syrian Hamsters.

Animal models recapitulating human COVID-19 disease, especially severe disease, are urgently needed to understand pathogenesis and to evaluate candidate vaccines and therapeutics. Here, we develop novel severe-disease animal models for COVID-19 involving disruption of adaptive immunity in Syrian hamsters. Cyclophosphamide (CyP) immunosuppressed or RAG2 knockout (KO) hamsters were exposed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by the respiratory route. Both the CyP-treated and RAG2 KO hamsters developed clinical signs of disease that were more severe than those in immunocompetent hamsters, notably weight loss, viral loads, and fatality (RAG2 KO only). Disease was prolonged in transiently immunosuppressed hamsters and was uniformly lethal in RAG2 KO hamsters. We evaluated the protective efficacy of a neutralizing monoclonal antibody and found that pretreatment, even in immunosuppressed animals, limited infection. Our results suggest that functional B and/or T cells are not only important for the clearance of SARS-CoV-2 but also play an early role in protection from acute disease.IMPORTANCE Syrian hamsters are in use as a model of disease caused by SARS-CoV-2. Pathology is pronounced in the upper and lower respiratory tract, and disease signs and endpoints include weight loss and viral RNA and/or infectious virus in swabs and organs (e.g., lungs). However, a high dose of virus is needed to produce disease, and the disease resolves rapidly. Here, we demonstrate that immunosuppressed hamsters are susceptible to low doses of virus and develop more severe and prolonged disease. We demonstrate the efficacy of a novel neutralizing monoclonal antibody using the cyclophosphamide transient suppression model. Furthermore, we demonstrate that RAG2 knockout hamsters develop severe/fatal disease when exposed to SARS-CoV-2. These immunosuppressed hamster models provide researchers with new tools for evaluating therapies and vaccines and understanding COVID-19 pathogenesis.

Cross-reactivity of Can f 1 with Syrian hamster and Fel d 1 in children.

Introduction and objectives: With increasing pet allergies among pediatric patients, the need for precise environmental care is increasing. We investigated the clinical, immunological, and environmental characteristics of pediatric patients sensitized to a dog to evaluate the cross-antigenicity of canine lipocalin Can f 1 with feline lipocalin Fel d 1 and Syrian hamster extract.Materials and methods: The protein fractions of the processed and commercial Syrian hamster extracts were compared using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). An enzyme-linked immunosorbent assay (ELISA) inhibition test was performed on Can f 1, Fel d 1, and processed Syrian hamster extract, and the antigen-specific immunoglobulin E (IgE)-binding capacity for each antigen was analyzed using serum samples from patients.Results: Twelve of 19 patients with a median age of 40.5 months were symptomatic when exposed to dogs. Eleven (91.7%) patients showed a positive IgE response to Can f 1. Two patients were positive for Fel d 1-specific IgE antibody, and one was positive for hamster-specific IgE antibody. SDS-PAGE confirmed the presence of different patterns of protein bands between the commercial and processed hamster extracts. There was no cross-antigenicity among Can f 1, Fel d 1, and processed Syrian hamster extract.

Alterations in Blood Chemistry Levels Associated With Nipah Virus Disease in the Syrian Hamster Model.

Nipah virus (NiV; family Paramyxoviridae, genus Henipavirus) infection can cause severe respiratory and neurological disease in humans. The pathophysiology of disease is not fully understood, and it may vary by presentation and clinical course. In this study, we investigate changes in blood chemistry in NiV-infected Syrian hamsters that survived or succumbed to disease. Increased sodium and magnesium and decreased albumin and lactate levels were detected in animals euthanized with severe clinical disease compared with mock-infected controls. When subjects were grouped by clinical syndrome, additional trends were discernable, highlighting changes associated with either respiratory or neurological disease.

A Novel Field-Deployable Method for Sequencing and Analyses of Henipavirus Genomes From Complex Samples on the MinION Platform.

Viruses in the genus Henipavirus encompass 2 highly pathogenic emerging zoonotic pathogens, Hendra virus (HeV) and Nipah virus (NiV). Despite the impact on human health, there is currently limited full-genome sequence information available for henipaviruses. This lack of full-length genomes hampers our ability to understand the molecular drivers of henipavirus emergence. Furthermore, rapidly deployable viral genome sequencing can be an integral part of outbreak response and epidemiological investigations to study transmission chains. In this study, we describe the development of a reverse-transcription, long-range polymerase chain reaction (LRPCR) assay for efficient genome amplification of NiV, HeV, and a related non-pathogenic henipavirus, Cedar virus (CedPV). We then demonstrated the utility of our method by amplifying partial viral genomes from 6 HeV-infected tissue samples from Syrian hamsters and 4 tissue samples from a NiV-infected African green monkey with viral loads as low as 52 genome copies/mg. We subsequently sequenced the amplified genomes on the portable Oxford Nanopore MinION platform and analyzed the data using a newly developed field-deployable bioinformatic pipeline. Our LRPCR assay allows amplification and sequencing of 2 or 4 amplicons in semi-nested reactions. Coupled with an easy-to-use bioinformatics pipeline, this method is particularly useful in the field during outbreaks in resource-poor environments.