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Objective: This study aimed to produce hyperimmune serum against genotype VII Newcastle disease virus (NDV) with several applications. Materials and Methods: Production of hyperimmune serum against genotype VII NDV was performed on eight New Zealand white rabbits divided into four groups. Rabbits were immunized three times on the 1st day, the 14th day, and the 30th day. Blood sampling was carried out on the 8th day after the third immunization. Results: All groups showed the same pattern of hemagglutination inhibition (HI) titer results. HI titers would peak on the 5th or the 9th day after the second immunization, then decrease until the 3rd day after the third immunization, and increase again on the 5th day after the third immunization. Rabbits immunized intravenously showed higher HI titers than the other groups. These results indicate that the intravenous route for hyperimmune serum production against genotype VII Newcastle disease virus greatly affects the immune response result. Conclusions: The production of hyperimmune serum by intravenous immunization three times was able to produce the highest titer of 210 at 38 days. The agar gel precipitation test and the Western blot assay showed that the hyperimmune serum was specific for the Newcastle disease antigen. [ABSTRACT FROM AUTHOR]

Background: Clonorchiasis, an infectious disease caused by the liver fluke Clonorchis sinensis, may lead to the development of liver and gallbladder diseases, and even cholangiocarcinoma (CCA). However, the pathogenesis, host-pathogen interaction, and diagnostic markers for clonorchiasis remain unclear. Methods: Eighteen rabbits were randomly divided into control group (n = 9) and C. sinensis-infected group (n = 9), and their plasma samples were collected at 7, 14, 28, and 63 days post-infection (dpi). Biochemical indices and metabolites in different infection periods were detected. A non-targeted ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) approach was employed to investigate the metabolic profiles of plasma in rabbits, and related metabolic pathways of differential metabolites and correlation between candidate biochemical indices and differential metabolites were analyzed. Finally, the candidate biomarkers were verified with human samples using a targeted metabolomics method. Results: The result of biochemical indices indicated C. sinensis infection would affect the liver function biochemical indices, especially alanine aminotransferase, aspartate transaminase (AST), glutamyl transpeptidase (GGT), total bile acid, high-density lipoprotein, and cholinesterase. The metabonomic results showed that 58, 212, 23, and 21 differential metabolites were identified in different phases of the infection. Multivariate statistical analysis of differential metabolites revealed distinct metabolic signatures during different phases of infection, with most of these signatures being observed at 14 dpi, which mainly influences the amino acid metabolisms. For metabolites and biochemical indices, AST, GGT, hypoxanthine, l-pipecolic acid, and d-glucuronate represented potential noninvasive biomarkers for the diagnosis of C. sinensis (P < 0.05 and AUC > 0.8). Furthermore, GGT and d-glucuronate levels were positively correlated with the infection (r(28) = 0.98, P < 0.0001) and showed excellent diagnostic performance (AUC = 0.972; 95% confidence interval, 0.921 to 1.000). Conclusions: The present results provide new insights into plasma metabolic changes in rabbits during C. sinensis infection, and the potential biomarker may be used for developing an effective method to diagnose clonorchiasis in the future. [ABSTRACT FROM AUTHOR]

The article presents a study which explores that Staphylococcus aureus endocarditis (SEC) as an antiangiogenic virulence factor that promotes Staphylococcus aureus endocarditis independent of superantigen activity. It mentions the SEC's ability to interfere with tissue revascularization and remodeling after injury serves as a mechanism to promote SAIE and its life-threatening systemic pathologies.

Appropriate animal model is the basis for the smooth development of scientific research, and also the guarantee of the experimental results. As a common clinical disease, the pathogenesis of KOA and the mechanism of action of various treatment methods need to be explored and verified by a large number of animal experiments. The selection and establishment of animal model is an important link, The selection of modeling methods in western medicine and the establishment of the model of combination of disease and syndrome in traditional Chinese medicine are the key points and difficulties. In this paper, the selection of KOA animal models was reviewed through literature retrieval, and the status quo of model establishment methods was summarized from the perspectives of western medicine and TCM. The main animal species include mice, chicken, rabbit, dog, sheep, horse, pig, monkey, emu and so on. The establishment methods of western medicine and TCM models are different. Western medicine models can be divided into spontaneous model induction model and transgenic model according to different establishment methods while TCM models are mainly established according to their syndromes. [ABSTRACT FROM AUTHOR]

Rabbit haemorrhagic disease (RHD) is a significant viral disease caused by infection with Rabbit haemorrhagic disease virus (RHDV). The first documented cases of RHDV in Singapore occurred in adult pet European rabbits (Oryctolagus cuniculus) in September 2020. Rabbits presented with acute hyporexia, lethargy, huddled posture, and varying degrees of pyrexia and tachypnoea. Clinical pathology consistently reflected markedly elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALKP). Hepatic lobe torsion was ruled out using ultrasonography and colour Doppler studies in all patients. A total of 11 rabbits owned by 3 families were presented to the clinics; 8/11 rabbits died within 48 hr of presentation, while the remaining two rabbits had recovered after prolonged hospitalization and one rabbit was aclinical. Histopathology revealed acute, marked diffuse hepatocellular necrosis and degeneration, findings which were suggestive for RHDV infection and prompted the undertaking of further molecular diagnostics. Subsequent polymerase chain reaction of the liver samples detected RHDV RNA. Molecular characterization of viral genomes by whole genome sequencing revealed that the outbreak strain was of the genotype GI.2 (RHDV2/RHDVb). Nucleotide sequences of the VP60 gene were compared with various RHDV variants using phylogenetic analysis. The sample genome shared highest sequence identity with a GI.2-genotyped virus from GenBank (RHDV isolate Algarve 1 polyprotein and minor structural protein (VP10) genes, GenBank accession KF442961). The combination of clinical, histopathological, molecular and sequencing technologies enabled rapid detection and detailed genetic characterization of the RHDV virus causing the present outbreak for prompt implementation of disease control measures in Singapore. Further epidemiological investigations of potential virus introduction into Singapore are ongoing. [ABSTRACT FROM AUTHOR]

Rabbit haemorrhagic disease (RHD) is a major threat to domestic and wild European rabbits. Presently, in Europe, the disease is caused mainly by Rabbit haemorrhagic disease virus 2 (RHDV2/b or Lagovirus europaeus GI.2), the origin of which is still unclear, as no RHDV2 reservoir hosts were identified. After the RHDV2 emergence in 2010, viral RNA was detected in a few rodent species. Furthermore, RHDV2 was found to cause disease in some hare species resembling the disease in rabbits, evidencing the ability of the virus to cross the species barrier. In this study, through molecular, histopathologic, antigenic and morphological evidences, we demonstrate the presence and replication of RHDV2 in Eurasian badgers (Meles meles) found dead in the district of Santarém, Portugal, between March 2017 and January 2020. In these animals, we further classify the RHDV2 as a Lagovirus europaeus recombinant GI.4P-GI. 2. Our results indicate that Meles meles is susceptible to RHDV2, developing systemic infection, and excreting the virus in the faeces. Given the high viral loads seen in several organs and matrices, we believe that transmission to the wild rabbit is likely. Furthermore, transmission electron microscopy data show the presence of calicivirus compatible virions in the nucleus of hepatocytes, which constitutes a paradigm shift for caliciviruses' replication cycle. [ABSTRACT FROM AUTHOR]

Rabbit haemorrhagic disease virus (RHDV) is highly pathogenic to European rabbits. Until recently, only one serotype of RHDV was known, GI.1/RHDV. RHDV2/GI.2 is a novel virus that has rapidly spread and become the dominant pathogenic calicivirus in wild rabbits worldwide. It is speculated that RHDV2 has three competitive advantages over RHDV: (a) the ability to partially overcome immunity to other variants; (b) the ability to clinically infect young rabbits; and (c) a wider host range. These differences would be expected to influence virus transmission dynamics. We used markers of recent infection (IgM/IgA antibodies) to investigate virus transmission dynamics pre and post the arrival of RHDV2. Our data set contained over 3,900 rabbits sampled across a 7-year period at 12 Australian sites. Following the arrival of RHDV2, seasonal peaks in IgM and IgA seropositivity shifted forward one season, from winter to autumn and spring to winter, respectively. Contrary to predictions, we found only weak effects of rabbit age, seropositivity to non-pathogenic calicivirus RCV-A1 and population abundance on IgM/IgA seropositivity. Our results demonstrate that RHDV2 enters rabbit populations shortly after the commencement of annual breeding cycles. Upon entering, the population RHDV2 undergoes extensive replication in young rabbits, causing clinical disease, high virus shedding, mortality and the creation of virus-laden carcasses. This results in high virus contamination in the environment, furthering the transmission of RHDV2 and initiating outbreaks, whilst simultaneously removing the susceptible cohort required for the effective transmission of RHDV. Although RHDV may enter the population at the same time point, it is sub-clinical in young rabbits, causing minimal virus shedding and low environmental contamination. Our results demonstrate a major shift in epidemiological patterns in virus transmission, providing the first evidence that RHDV2's ability to clinically infect young rabbits is a key competitive advantage in the field. [ABSTRACT FROM AUTHOR]

Amongst newly developed approaches to analyse molecular data, phylodynamic models are receiving much attention because of their potential to reveal changes to viral populations over short periods. This knowledge can be very important for understanding disease impacts. However, their accuracy needs to be fully understood, especially in relation to wildlife disease epidemiology, where sampling and prior knowledge may be limited. The release of the rabbit haemorrhagic disease virus (RHDV) as biological control in naïve rabbit populations in Australia in 1996 provides a unique data set with which to validate phylodynamic models. By comparing results obtained from RHDV sequence data with our current understanding of RHDV epidemiology in Australia, we evaluated the performances of these recently developed models. In line with our expectations, coalescent analyses detected a sharp increase in the virus population size in the first few months after release, followed by a more gradual increase. Phylodynamic analyses using a birth-death model generated effective reproductive number estimates (the average number of secondary infections per each infectious case, Re) larger than one for most of the epochs considered. However, the possible range of the initial Re included estimates lower than one despite the known rapid spread of RHDV in Australia. Furthermore, the analyses that accounted for geographical structuring failed to converge. We argue that the difficulties that we encountered most likely stem from the fact that the samples available from 1996 to 2014 were too sparse with respect to both geographic and within outbreak coverage to adequately infer some of the model parameters. In general, while these phylodynamic analyses proved to be greatly informative in some regards, we caution that their interpretation may not be straightforward. We recommend further research to evaluate the robustness of these models to assumption violations and sensitivity to sampling regimes. [ABSTRACT FROM AUTHOR]

Introduced rabbits are a continuing threat to native Australian flora and fauna. Three interventions using biological control agents, myxomatosis, European rabbit fleas, and rabbit hemorrhagic disease, have reduced rabbit abundance and kept numbers low over the last 70 years. We considered the benefits of biological control for native fauna to put the role of rabbits in influencing vegetation cover, food supply, and predation into better perspective. Numerous examples exist demonstrating increases in native vegetation and the expansion and recovery of native animal populations at landscape scales following intense rabbit suppression. Ongoing research on methods for supplementing the impact of biological control agents and managing introduced predators are needed to restore Australia's arid‐zone ecosystems. However, many biologists and rangeland managers first need to reevaluate the misconception that removing rabbits also introduces other serious and insurmountable problems such as prey‐switching by introduced cats and foxes. [ABSTRACT FROM AUTHOR]

The use of rabbit hemorrhagic disease virus (RHDV) as a biocontrol agent to control feral rabbit populations in Australia, in combination with circulating endemic strains, provides a unique environment to observe the interactions between different lagoviruses competing for the same host. Following the arrival of RHDV2 (GI.2) in Australia, it became necessary to investigate the potential for immunological cross-protection between different variants, and the implications of this for biocontrol programs and vaccine development. Laboratory rabbits of various immune status—(1) rabbits with no detectable immunity against RHDV; (2) rabbits with experimentally acquired immunity after laboratory challenge; (3) rabbits immunised with a GI.2-specific or a multivalent RHDV inactivated virus prototype vaccine; or (4) rabbits with naturally acquired immunity—were challenged with one of three different RHDV variants (GI.1c, GI.1a or GI.2). The degree of cross-protection observed in immune rabbits was associated with the variant used for challenge, infectious dose of the virus and age, or time since acquisition of the immunity, at challenge. The immune status of feral rabbit populations should be determined prior to intentional RHDV release because of the high survival proportions in rabbits with pre-existing immunity. In addition, to protect domestic rabbits in Australia, a multivalent RHDV vaccine should be considered because of the limited cross-protection observed in rabbits given monovalent vaccines. [ABSTRACT FROM AUTHOR]

Rab GTPases not only play a crucial role in the exocytosis and membrane transport of all eukaryotic cells, but are also gradually being found to be involved in innate immunity in mammals. However, the immunological function of Rab3a in fish remains unclear. In this study, two members of Rab3a, CiRab3aa and CiRab3ab, were cloned from grass carp (Ctenopharyngodon idella) for the first time. It was observed that CiRab3aa exhibited a prompt response to grass carp reovirus (GCRV) infection, and suppressing the expression of the CiRab3aa effectively inhibited GCRV replication, whereas the expression level of the CiRab3ab gene did not affect GCRV replication. Furthermore, overexpression of CiRab3aa significantly suppressed the mRNA levels of TLR9 , TNF-α , IL-1β , IL-6 , IL-10 , ERK , and IFN-I following stimulation with CpG ODN 1670 A, suggesting that CiRab3aa is a negative regulator of TLR9 signaling pathway. In conclusion, this study not only revealed functional differences between CiRab3aa and CiRab3ab in grass carp immunity, providing new sights into understanding their function in teleost fish, but also provided a new target for the treatment strategy of grass carp hemorrhagic disease. These results will help address the harm and economic losses caused by GCRV infection in grass carp breeding industry. • CiRab3aa and CiRab3ab genes were cloned and characterized in grass carp. • There are 7 amino acid differences in the Rab domain of Rab3aa and Rab3aa protein. • Knockdown of CiRab3aa significantly inhibited the replication of GCRV. • CiRab3aa was a negative regulator of the TLR9 signaling pathway. [ABSTRACT FROM AUTHOR]

A new virus known as snakehead rhabdovirus (SHRV-In) was discovered in South India in striped snakehead (Channa striata) that had hemorrhagic patches and cutaneous ulcerations. The virus is the most potentially harmful pathogen of snakehead because it could cause 100% mortality within 5 days. The goal of the current investigation was to evaluate the infectivity of rhabdovirus in freshwater fishes and to analyze the immune response in snakehead fish after challenge with SHRV-In. The infectivity study of SHRV-In against three freshwater fish such as tilapia, grass carp and loach showed that the virus could not induce mortality in any of them. Snakehead fish challenged with SHRV-In showed significant (p < 0.05) changes in haematological parameters such as red blood cell (RBC), haemoglobin (HGB), haematocrit (HCT), mean corpuscular haemoglobin concentration (MCHC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), white blood cell (WBC), total platelet (PLT) counts, mean platelet volume (MPV) and immunological markers such as respiratory burst, superoxide dismutase, catalase activity and myeloperoxidase activity at 6, 12, 24 and 48 hpi. Real time PCR was executed to examine the expression profile of innate immune genes such as IRF-7, IL-8 and IL-12 in Snakehead fish at 6, 12, 24 and 48 h post SHRV-In infection. Immune gene expression of IRF-7, IL-8 and IL-12 were up-regulated in the spleen when compared to kidney at 6 and 12 hpi. However, the expression level of all the genes was down-regulated at 24 and 48 hpi. The down regulation of innate immune genes after 24 hpi in these tissues may be the result of increased multiplication of SHRV-In by interfering with the immune signaling pathway. • Indian strain of snakehead rhabdovirus (SHRV-In) has host specificity to cause infection. • SHRV-In virus strain significantly altered the haematological and immunological profile of snakehead. • Earlier innate immune responses of snakehead were induced by SHRV-In infection. [ABSTRACT FROM AUTHOR]

Grass carp reovirus (GCRV) infections and hemorrhagic disease (GCHD) outbreaks are typically seasonally periodic and temperature-dependent, yet the molecular mechanism remains unclear. Herein, we depicted that temperature-dependent IL-6/STAT3 axis was exploited by GCRV to facilitate viral replication via suppressing type Ⅰ IFN signaling. Combined multi-omics analysis and qPCR identified IL-6, STAT3, and IRF3 as potential effector molecules mediating GCRV infection. Deploying GCRV challenge at 18 °C and 28 °C as models of resistant and permissive infections and switched to the corresponding temperatures as temperature stress models, we illustrated that IL-6 and STAT3 expression, genome level of GCRV, and phosphorylation of STAT3 were temperature dependent and regulated by temperature stress. Further research revealed that activating IL-6/STAT3 axis enhanced GCRV replication and suppressed the expression of IFNs, whereas blocking the axis impaired viral replication. Mechanistically, grass carp STAT3 inhibited IRF3 nuclear translocation via interacting with it, thus down-regulating IFNs expression, restraining transcriptional activation of the IFN promoter, and facilitating GCRV replication. Overall, our work sheds light on an immune evasion mechanism whereby GCRV facilitates viral replication by hijacking IL-6/STAT3 axis to down-regulate IFNs expression, thus providing a valuable reference for targeted prevention and therapy of GCRV. [Display omitted] • GCRV-induced transcription and phosphorylation of STAT3 are temperature-dependent. • IL-6/STAT3 axis regulates transcription of type Ⅰ IFN and genome level of GCRV. • STAT3 interacts with IRF3. • STAT3 represses transcriptional activation of IFN promoter. • IL-6/STAT3 axis regulates nuclear translocation of IRF3. [ABSTRACT FROM AUTHOR]

Grass carp hemorrhagic disease is a significant problem in grass carp aquaculture. It releases highly oxidizing hemoglobin (Hb) into tissues, induces rapid autooxidation, and subsequently discharges cytotoxic reactive oxygen species (ROS). However, the mechanism underlying Hb damage to the teleost remains unclear. Here, we employed ferrylHb and heme to incubate L8824 (grass carp liver) cells and quantitatively analyzed the corresponding molecular regulation using the RNA-seq method. Based on the RNA-seq analysis data, after 12 h of incubation of the L8824 cells with ferrylHb, a total of 3738 differentially expressed genes (DEGs) were identified, 1824 of which were upregulated, and 1914 were downregulated. A total of 4434 DEGs were obtained in the heme treated group, with 2227 DEGs upregulated and 2207 DEGs downregulated. KEGG enrichment analysis data revealed that the incubation of ferrylHb and heme significantly activated the pathways related to Oxidative Phosphorylation, Autophagy, Mitophagy and Protein Processing in Endoplasmic Reticulum. The genes associated with NF-κB, autophagy and apoptosis pathways were selected for further validation by quantitative real-time RT-PCR (qRT-PCR). The results were consistent with the RNA-seq data. Taken together, the incubation of Hb and heme induced the molecular regulation of L8824, which consequently led to programmed cell death through multiple pathways. • The stimulation of ferrylHb induced abundant of DEGs in L8824 cellls. • The stimulation of ferrylHb and heme induced inflammation in L8824 cells. • The stimulation of ferrylHb and heme activated multiple cells programmed death pathways. [ABSTRACT FROM AUTHOR]

Lagomorpha coccidiosis, caused by coccidia, is a prevalent disease affecting rabbits, hares and pikas. This meta-analysis aimed to estimate the pooled prevalence of coccidia infection in lagomorphs and identify potential risk factors. A systematic search of six databases yielded 102 studies published between 1981 and 2023. The pooled prevalence of Eimeriidae, Sarcocystidae and Cryptosporidiidae in lagomorphs was 76.4%, 6.2% and 3.9%, respectively. Rabbits had the highest prevalence of Eimeriidae (76.8%) and Sarcocystidae (7.4%), while pikas had the highest prevalence of Cryptosporidiidae (6.2%). Juvenile rabbits exhibited the highest prevalence of Eimeriidae (84.6%) and Cryptosporidiidae (9.9%). Northwest China had the highest prevalence of Eimeriidae (87.8%). Over time, the prevalence of Eimeriidae declined (Coefficient: −0.0062; P<0.05), but remained high (65.0%) in the past five years. Our findings highlight the prevalence of Eimeriidae infection in lagomorphs and the need for further research on Sarcocystidae and Cryptosporidiidae infections. We emphasize the importance of developing lagomorpha coccidia vaccines and implementing vaccination schedules for juvenile rabbits to mitigate coccidia infections. • A systematic search of six databases identified 102 studies from 1981 to 2023. • Rabbits have highest Eimeriidae (76.8%) and Sarcocystidae (7.4%) prevalence. • Northwest China has highest Eimeriidae prevalence (87.8%). • Declining trend in Eimeriidae prevalence, yet high (65.0%) in the past five years. [ABSTRACT FROM AUTHOR]

Epizootic hemorrhagic disease (EHD) and bluetongue (BT) are vector-borne viral diseases that affect wild and domestic ruminants. Clinical signs of EHD and BT are similar; thus, the syndrome is referred to as hemorrhagic disease (HD). Syndromic surveillance and virus detection in North America reveal a northern expansion of HD. High mortalities at northern latitudes suggest recent incursions of HD viruses into northern geographic areas. We evaluated the occurrence of HD in wild Illinois white-tailed deer from 1982 to 2019. Our retrospective space–time analysis identified high-rate clusters of HD cases from 2006 to 2019. The pattern of northward expansion indicates changes in virus-host-vector interactions. Serological evidence from harvested deer revealed prior infection with BTV. However, BTV was not detected from virus isolation in dead deer sampled during outbreaks. Our findings suggest the value of capturing the precise geographic location of outbreaks, the importance of virus isolation to confirm the cause of an outbreak, and the importance of expanding HD surveillance to hunter-harvested wild white-tailed deer. Similarly, it assists in predicting future outbreaks, allowing for targeted disease and vector surveillance, helping wildlife agencies communicate with the public the cause of mortality events and viral hemorrhagic disease outcomes at local and regional scales. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) has caused the ongoing COVID-19 pandemic and there is a growing demand for safe and effective vaccines. The thermophilic Thermothelomyces heterothallica filamentous fungal host, C1-cell, can be utilized as an expression platform for the rapid production of large quantities of antigens for developing vaccines. The aim of this study was to evaluate the local tolerance and the systemic toxicity of a C1-cell expressed receptor-binding domain (C1-RBD) vaccine, following repeated weekly intramuscular injections (total of 4 administrations), in New Zealand White rabbits. The animals were sacrificed either 3 days or 3 weeks following the last dose. No signs of toxicity were observed, including no injection site reactions. ELISA studies revealed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific immunoglobulin G antibodies in the sera of C1-RBD-treated animals starting from day 13 post injection, that were further elevated. Histopathology evaluation and immunohistochemical staining revealed follicular hyperplasia, consisting of B-cell type, in the spleen and inguinal lymph nodes of the treated animals that were sustained throughout the recovery phase. No local or systemic toxicity was observed. In conclusion, the SARS-CoV-2 C1-RBD vaccine candidate demonstrated an excellent safety profile and a lasting immunogenic response against receptor-binding domain, thus supporting its further development for use in humans. [ABSTRACT FROM AUTHOR]

A three-year-old male German Shepherd dog was presented to Referral Veterinary Polyclinic, Indian Veterinary Research Institute (RVP, IVRI), with a history of anorexia, progressive weight loss and relapsing fever for 15 days. Anamnesis revealed that the dog often attacked Nilgai and other wild animals in the forest and consumed wild rabbit regularly. Clinical examination revealed pale oral and conjunctival mucous membranes, pyrexia (104.3 F) and popliteal lymphadenopathy. Haemato-biochemical examination revealed anaemia, increased alkaline phosphatase (ALP), serum glutamic pyruvic transaminase (SGPT), blood urea nitrogen (BUN) and creatinine levels suggestive of multiple organ involvement. Oral mode of transmission of trypanosomiasis was suspected in this case and blood sample was subjected to staining and molecular techniques for confirmation. Giemsa stained blood smear revealed leaf-like haemoparasite with free flagella, subterminal kinetoplast and well-developed undulating membrane characteristic of Trypanosoma spp. Additionally, infection was further confirmed by polymerase chain reaction (PCR) using two different sets of primers, namely, Tevans F2/R2 and Tryp1S/1R, targeting paraflagellar rod-2 (PFR-2) and internal transcribed spacer-1 (ITS-1) region, respectively. The dog was treated with diminazene aceturate with supportive therapy. Marked recovery in clinical signs and restoration of organ functions were noticed after completion of therapy. [ABSTRACT FROM AUTHOR]

To mitigate the negative impacts of invasive rabbits in Australia, land managers are permitted to release the biocontrol virus, rabbit hemorrhagic disease virus (RHDV), to reduce rabbit numbers. However, it is strongly recommended that RHDV is not released when young rabbits are present in the population as infection in this cohort is sublethal and induces life‐long virus immunity. The recruitment of these rabbits into the breeding population may make the population harder to control in future, potentially leading to increasing rather than decreased population size. To investigate whether the recommended release guidelines are followed, we obtained data on the supply and release of RHDV by land managers. We then used generalized additive models to investigate Australia‐wide and state‐specific annual and long‐term temporal trends in the supply and release of RHDV. Half of all RHDV supply (47%) and three quarters of reported releases (74%) Australia‐wide occurred during the anticipated major rabbit breeding seasons and when the risk of immunizing young rabbits is greatest. We found evidence of both RHDV supply and release during the anticipated major rabbit breeding seasons in almost all states for which data existed. RHDV supply increased with below average annual rainfall. This may indicate a tendency for land managers to notice, and want to control, rabbits and their impacts more following drier years when both rabbits and their impacts are potentially more damaging. Our study raises concerns regarding the inappropriate release of RHDV by land managers and whether its supply should be restricted to ensure ongoing and effective management of invasive rabbits. More broadly, our study serves as a warning to other conservation and pest management activities reliant on land managers or citizens following implementation guidelines. In some cases, good intentions may have adverse outcomes. [ABSTRACT FROM AUTHOR]

Introduction: Osteomyelitis is characterized by intensive inflammatory bone disease and remains a clinical challenge in orthopedic surgery, despite the advances made in medical and surgical therapies. Staphylococcus aureusis a major causative agent of osteomyelitis, causing the progressive inflammatory destruction of bone. Prophylaxis of osteomyelitis during orthopedic surgery is necessary. NFκB essential modulator–binding domain (NBD) peptides are cell-permeable peptide inhibitors of the IκB-kinase complex. The prophylactic effect of NBD peptides in relieving inflammation and inhibiting bone defects in osteomyelitis is still under investigation. Our purpose was to determine the preventive effect of NBD peptides in S. aureus infection–induced bone defects in osteomyelitis. Methods: An S. aureus osteomyelitis rabbit model was used in this study. The rabbits were divided into four groups: NBD, cefazolin, control, and PBS. Clinical and laboratory indicators of erythrocyte-sedimentation rate, CRP, and TNFα levels were assessed to monitor systemic reactions. The efficacy of NBD peptides in S. aureus–induced osteomyelitis was evaluated by radiological, histological, and microbiological examinations, immunohistochemistry, immunofluorescence, and micro-CT scans. Results: In general, NBD peptides effectively reduced clinical signs in rabbits when compared with the control group. Radiography indicated that there was more severe osteomyelitis in the bacterium-infection control group. There was no significance between cefazolin- and NBD-group average scores. The histological results of the lesion slices further confirmed different severity among the groups. Additionally, significant pathological differences were found between the cefazolin and NBD groups, and the PBS group showed no obvious pathological changes. Conclusion: Prophylactic administration of NBD peptides to bone-defect areas inhibited bacterial spread and promoted bone regeneration, making NBD peptides a possible treatment option for prophylaxis in bone infections. [ABSTRACT FROM AUTHOR]

Purpose: To study, blood components and some indicators of liver function were measured andCandida albicans was isolated and identified from infected cows' vagina with inflammatory signs then experimentally in rabbits treated with estradiol hormone. Introduction: Candidiasis is an infection caused by yeast,. Candida can multiply and cause an infection if the environment inside the vagina changes in a way that induces its growth. Materials and Methods: Isolation and identification of candida albicans isolate from cow' vaginitis (40 samples), duration in November 2020 till May 2021 then treated with saccharomyces cerevisiae. Candida albicans inoculums at 1.5 ×108 cell/ml, in non-pregnant vagainal' Rabbits a weight (2 kg) after treated with estradiol hormone for several days before the infection occurred. The experiment was carried out in the microbiology laboratories in College Veterinary Medicine-the University of Baghdad, the blood, liver parameters, and rabbits' vaginal histology was studied. Results: The Hb parameters in G2 showed higher significant differences (8.31±0.75107) compared with G1(12.80 ± 2.42782), G3 (13.26 ± 1.465), G4 (12.46 ± 1.987), G5 (12.75 ± 2.128) respectively, the effectiveness of the treatment with S.cerevisiae and its ability to return hemoglobin and liver functions to its normal value and the treatment cause inhibitory effect of C.albicans infection, the vagainal histological section in G4 showed narrow folding of mucosa thrown with mild MNCs infiltrate LP and submucosa, no inflammatory cells seen in a muscular layer or in the serosa. Conclusion: The study proved the effectiveness by using Saccharomyces cerevisiae and treating rabbits vaginal infection with pathogenic Candida albicans, that Injected estradiol hormone S\C then, recovery the blood and liver parameters to their normal condition, in addition, the treatment of vaginal tissue and its return to its normal state. [ABSTRACT FROM AUTHOR]

Rabbits have been widely used for studying ocular physiology and pathology due to their relatively large eye size and similar structures with human eyes. Various rabbit ocular disease models, such as dry eye, age-related macular degeneration, and glaucoma, have been established. Despite the growing application of proteomics in vision research using rabbit ocular models, there is no spectral assay library for rabbit eye proteome publicly available. Here, we generated spectral assay libraries for rabbit eye compartments, including conjunctiva, cornea, iris, retina, sclera, vitreous humor, and tears using fractionated samples and ion mobility separation enabling deep proteome coverage. The rabbit eye spectral assay library includes 9,830 protein groups and 113,593 peptides. We present the data as a freely available community resource for proteomic studies in the vision field. Instrument data and spectral libraries are available via ProteomeXchange with identifier PXD031194. Measurement(s) database type spectral library Technology Type(s) ion mobility spectrometry-mass spectrometry Sample Characteristic - Organism Oryctolagus cuniculus Sample Characteristic - Environment eye Sample Characteristic - Location United States of America [ABSTRACT FROM AUTHOR]

Simple Summary: Rabbit Haemorrhagic Disease is caused by a virus that affects the liver, the spleen and the lungs of rabbits, causing hepatitis, splenomegaly and haemorrhages. A new genotype of the virus was first reported in France in 2010 and has spread globally since then, replacing most of the circulating former viruses in many countries. The detection of the virus and the differentiation of both genotypes is of crucial importance for disease surveillance. In this article, a rapid test for antigen detection is described and evaluated, providing the first description of a quick and easy-to-use test that allows for the simultaneous detection and differentiation of the genotypes. A total of 136 samples, rabbit liver samples and liver exudates (liquid collected after freeze–thawing) classified as infected and non-infected, were analysed, with good results. These data confirm that the developed rapid test can be used as a reliable diagnostic test for disease surveillance, especially in farms and the field. Rabbit Haemorrhagic Disease Virus 2 (RHDV2, recently named Lagovirus europaeus/GI.2) was first reported in France in 2010 and has spread globally since then, replacing most of the circulating former RHDV (genotype GI.1) in many countries. The detection and differentiation of both genotypes is of crucial importance for the surveillance of the disease. In this article, a duplex lateral flow assay (LFA) for antigen detection is described and evaluated, providing the first description of a quick and easy-to-use test that allows for the simultaneous detection and differentiation of RHDV genotypes GI.1 and GI.2. A panel of GI.1- or GI.2-infected and non-infected rabbit liver samples and liver exudates (136 samples) was analysed, obtaining a total sensitivity of 94.4% and specificity of 100%. These data confirm that the developed duplex LFA can be used as a reliable diagnostic test for RHD surveillance, especially in farms and the field. [ABSTRACT FROM AUTHOR]

The European rabbit (Oryctolagus cuniculus) is one of the most devastating invasive species in Australia. Since the 1950s, myxoma virus (MYXV) and rabbit haemorrhagic disease virus (RHDV) have been used to manage overabundant rabbit populations. Resistance to MYXV was observed within a few years of the release. More recently, resistance to lethal RHDV infection has also been reported, undermining the efficiency of landscape‐scale rabbit control. Previous studies suggest that genetic resistance to lethal RHDV infection may differ locally between populations, yet the mechanisms of genetic resistance remain poorly understood. Here, we used genotyping by sequencing (GBS) data representing a reduced representation of the genome, to investigate Australian rabbit populations. Our aims were to understand the relationship between populations and identify possible genomic signatures of selection for RHDV resistance. One population we investigated had previously been reported to show levels of resistance to lethal RHDV infection. This population was compared to three other populations with lower or no previously reported RHDV resistance. We identified a set of novel candidate genes that could be involved in host–pathogen interactions such as virus binding and infection processes. These genes did not overlap with previous studies on RHDV resistance carried out in different rabbit populations, suggesting that multiple mechanisms are feasible. These findings provide useful insights into the different potential mechanisms of genetic resistance to RHDV virus which will inform future functional studies in this area. [ABSTRACT FROM AUTHOR]

A 4-y-old, spayed female, mixed-breed domesticated rabbit (Oryctolagus cuniculus domesticus) was presented because of progressive bilateral exophthalmos, with a large mediastinal mass in the cranial thorax. Palliative radiation therapy was elected, and 4 fractions of 5 Gy were delivered twice weekly under general anesthesia using 3-dimensional conformal radiation therapy for a total dose of 20 Gy, guided by an on-board cone beam CT scan. Quality-of-life and respiratory rate improved before sudden death that followed an episode of dyspnea. The overall survival time following initial diagnosis was 93 d, with 68 d after the first dose of radiation. An autopsy was performed, and the mass was diagnosed as a type A thymoma. The diagnosis was confirmed with positive immunohistochemical labeling of the neoplastic cells for cytokeratin 5/6 and cytokeratin 7. [ABSTRACT FROM AUTHOR]

In rabbits, a white-spotted liver can be indicative of one of several disease processes, frequently caused by parasites. To date, the prevalence of white-spotted liver in wild rabbits, Oryctolagus cuniculus, in the United Kingdom is undetermined. We evaluated the prevalence and main parasitic etiologies of this entity in a U.K. population of wild rabbits. Wild rabbits (n = 87) were shot in Cambridgeshire for population control, and cadavers were donated for research. Postmortem examination was undertaken, including gross and histologic hepatic examination. Macroscopic lesions consistent with white-spotted liver were found in 46 of 87 (53%) rabbits examined; most of these lesions were considered to be mild. For 28 of 46 (59%) rabbits with gross hepatic lesions, an etiologic agent was apparent histologically. Eimeria stiedae was detected in 21 of 87 (24%) rabbits, and Calodium hepaticum (syn. Capillaria hepatica) was detected in 7 of 87 (8%). In the subset of rabbits killed in the summer, there was a significant association between white-spotted liver and juvenile age class. There was also an association between white-spotted liver caused by E. stiedae and juvenile age class. When restricting analysis to rabbits with white-spotted liver caused by E. stiedae and submitted in the summer, both juvenile age class and female had significant effects. E. stiedae and C. hepaticum can be transmitted to pet lagomorphs via contaminated vegetation, and to humans in the case of the latter, which demonstrates the importance of monitoring the prevalence of these parasitic diseases in wild rabbits. [ABSTRACT FROM AUTHOR]

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Rabbit haemorrhagic disease virus 2 (RHDV2; GI.2) is a pathogenic lagovirus that emerged in 2010, and which now has a global distribution. Outbreaks have been associated with local population declines in several lagomorph species, due to rabbit haemorrhagic disease (RHD)-associated mortality raising concerns for its potential negative impact on threatened or vulnerable wild populations. The Irish hare (Lepus timidus hibernicus) is endemic to Ireland, and is of conservation interest. The first cases of RHDV2 in Ireland were reported in domestic rabbits (Oryctolagus cuniculus) in 2016, soon followed by the first known case in a wild rabbit also in 2016, from a population reported to be experiencing high fatalities. During summer 2019, outbreaks in wild rabbits were confirmed in several locations throughout Ireland. Six cases of RHDV2 in wild hares were confirmed between July and November 2019, at four locations. Overall, 27 cases in wildlife were confirmed in 2019 on the island of Ireland, with a predominantly southern distribution. Passive surveillance suggests that the Irish hare is susceptible to lethal RHDV2 infection, and that spillover infection to hares is geographically widespread in eastern areas of Ireland at least, but there is a paucity of data on epidemiology and population impacts. A literature review on RHD impact in closely related Lepus species suggests that intraspecific transmission, spillover transmission, and variable mortality occur in hares, but there is variability in reported resistance to severe disease and mortality amongst species. Several key questions on the impact of the pathogen in Irish hares remain. Surveillance activities throughout the island of Ireland will be important in understanding the spread of infection in this novel host. [ABSTRACT FROM AUTHOR]

Wild European rabbits (Oryctolagus cuniculus) give birth in an underground nursery burrow where the kits are hermetically closed into the nest chamber for several weeks except for the three minutes of daily nursing. Given this confinement, the nest quality seems to be crucial in affecting the kits' survival. The situation is less critical in rabbitries where the domesticated descendants are kept and give birth in separate nest boxes where the temperature and humidity conditions are less extreme and nests consist of fur and wood shavings or straw. However, nesting behaviour of domestic does still reflects several aspects of the ancestors, and providing conditions close to their biological needs is advised. The present study aimed to understand the factors contributing to the nest material choice of rabbits by analysing the composition of wild rabbit nests and testing naive domestic does in controlled laboratory settings for their preferences in constructing their nests. We were able to collect 21 just abandoned nests in their natural habitat and found they contained rabbit fur and hay, of which 85% was dry grass, mostly long leaves of Calamagrostis sp. Using domesticated rabbit does, we then tested if there is a preference for the features of the wild rabbit nests or whether the above-mentioned finding was either an accidental consequence of grass availability or ageing of the nest material. Two-way choice tests revealed that primiparous domestic does preferred the dry grass over green and long leaves over short grass bunches for nest building. Ageing of the nest material was rather negligible and did not contribute to the high level of dry grass content. We concluded that long dry grass is recommended as it seems to fulfil basic needs of this domesticated animal. [ABSTRACT FROM AUTHOR]

The use of parasites in conservation of other animal species may increase knowledge of natural parasite communities, elucidate parasite ecological function, and provide a baseline to better understand hosts and parasites. Climate change, habitat loss, invasive species, overexploitation, parasite conservation, animal conservation, pathogens, patógenos, cambio climático, conservación animal, conservación de parásitos, pérdida del hábitat, especie invasora, sobreexplotación For example, vertically transmitted parasites inform movement between groups (Kerr et al., 2018), parasites with slower evolutionary rates inform large-scale geographic movements (e.g., between islands; Whiteman et al., 2006), and host-specific, rapidly evolving parasites (e.g., RNA viruses) inform fine-scale connectivity across landscapes (Fountain-Jones et al., 2021). Keywords: animal conservation; climate change; habitat loss; invasive species; overexploitation; parasite conservation; pathogens; cambio climático; conservación animal; conservación de parásitos; especie invasora; patógenos; pérdida del hábitat; sobreexplotación EN animal conservation climate change habitat loss invasive species overexploitation parasite conservation pathogens cambio climático conservación animal conservación de parásitos especie invasora patógenos pérdida del hábitat sobreexplotación 1 12 12 03/02/22 20220201 NES 220201 Introduction Large anthropogenic disturbances that act in synergy to negatively affect biodiversity include overexploitation, habitat degradation, introduction and expansion of invasive species, and climate change (Bellard et al., 2016; Maxwell et al., 2016; Wilcove et al., 1998). The use of parasite genetics to identify host source populations is sometimes more informative than host genetics, can provide greater information regarding the host, and alleviates difficulty in identification of cryptic parasite species (Criscione et al., 2006). [Extracted from the article]

Compartment syndrome generates an oxidative condition causing the death of skeletal muscle cells. Hirudin has antioxidant and anti-inflammatory properties. However, its correlation with the pathway of Nrf2/HO-1 for the protection of the skeletal muscle is unknown. We aimed to evaluate the protective efficacy of double-doses of hirudin in compartment syndrome and its association with Nrf2/HO-1 expression. Compartment syndrome was induced in rabbits and double-doses of hirudin (0-8 ATU/kg) were locally administered to select an optimal Hirudin concentration that protects skeletal muscle from damage. The tissue structural changes, W/D ratio, lipid peroxidation level by MDA assay and inflammatory factors were determined in the skeletal muscle. To determine the musculoprotective efficacy of H8 at 72 h timepoint after compartment syndrome, and its association with the Nrf2/HO-1 pathway, the following assays were performed by TUNEL assay and immunofluorescence: necrosis (high-mobility group box-1; HMGB1), Nrf2, and HO-1. In addition, the HO-1 mRNA was evaluated by qPCR. Hirudin in a dose of 8 ATU/kg (H8) presented the lowest levels of histological damage, fibrosis, W/D ratio and oxidative stress in the studied groups. Moreover, treatment with H8 markedly downregulated the level of inflammatory factors including TNF-a, IL-1β and IL-6. H8 showed a protective effect at 72 h timepoint after compartment syndrome, as revealed by a decrease in the levels of all damage markers. Nuclear translocation Nrf2 and HO-1 staining in cytoplasm were increased, and the levels of HO-1 mRNA were also increased. In conclusion, double-doses of H8 alleviate the death of muscle cells induced by oxidative stress 72 h after compartment syndrome in rabbits. This protective effect is associated with the nuclear translocation of Nrf2 and an elevated expression of HO-1. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to assess whether optic nerve sheath diameter (ONSD) measured by ultrasound could predict brain injury in sepsis associated encephalopathy (SAE). A total of 48 male New Zealand White rabbits were used to establish sepsis model. The levels of neuro-specific enolase (NSE), S100B, myeloperoxidase (MPO), and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immuno sorbent assay and ONSD were measured before modeling, 6 h, 12 h and 24 h after modeling. Sixteen rabbits were sacrificed for hematoxylin-eosin (HE) staining of brain tissue and the brain water content at above time points. Rabbits demonstrated brain injury by HE staining were included in the SAE group, the others were enrolled in the control group. The correlation between ONSD and MPO, NSE and S100B in the SAE group were analyzed. Receiver operator characteristic curves were generated to analyze the area under the curve (AUC), specificity and sensitivity of ONSD values for SAE. Twenty-nine of 48 rabbits had brain injury, while 19 cases were enrolled in the control group. The level of MPO, NSE, S100B, TNF-α at 6 h, 12 h and 24 h in SAE group were all higher than those of the control group with statistical significance. The ONSD in SAE group increased with time and significantly wider than those in the control group. Correlation analysis revealed that ONSD was positively correlated with MPO, NSE and S100B in the SAE group. The AUCs for the ONSD value in diagnosing SAE at 6 h, 12 h and 24 h were 0.864, 0.957, 0.877, respectively. Alterations in ONSD strongly correlated with MPO, NSE and S100B among SAE rabbits. Monitoring of ONSD exhibited a high predictive value for SAE. • SAE is a common complication of sepsis. • Some inflammatory factors and brain injury markers are helpful for the diagnosis of SAE. • Ultrasound measurement of ONSD could be used to evaluate brain injury. [ABSTRACT FROM AUTHOR]

Background: Neoadjuvant radiotherapy plays a vital role in the treatment of malignant bone tumors, and non-invasive imaging methods are needed to evaluate the response to treatment. Purpose: To assess the value of diffusion kurtosis imaging (DKI) for monitoring early response to radiotherapy in malignant bone tumors. Material and Methods: Treatment response was evaluated in a rabbit VX2 bone tumor model (n = 35) using magnetic resonance imaging (MRI), DKI, and histopathologic examinations. Subjects were divided into three groups: pre-treatment, post-treatment, and control groups. The post-treatment group was subclassified into good response and poor response groups according to the results of histopathologic examination. Apparent diffusion coefficient (ADC) and DKI parameters (mean diffusion coefficient [MD] and mean kurtosis [MK]) were recorded. The relationship between ADC, DKI parameters, and histopathologic changes after radiotherapy was determined using Pearson's correlation coefficient. The diagnostic performance of these parameters was assessed using receiver operating characteristic analysis. Results: MD in the good response group was higher after treatment than before treatment (P < 0.001) and higher than that in the poor response group (P = 0.009). MD was highly correlated with tumor cell density and apoptosis rate (r = −0.771, P < 0.001 and r = 0.625, P < 0.001, respectively). MD was superior to other parameters for determining the curative effect of radiotherapy, with a sensitivity of 75.0%, specificity of 100.0%, and area under the curve of 0.917 (P < 0.001). Conclusion: The correlations between MD, tumor cell density, and apoptosis suggest that MD could be useful for assessing the early response to radiotherapy in rabbit VX2 malignant bone tumors. [ABSTRACT FROM AUTHOR]

We present three cases fulfilling diagnostic criteria of hemorrhagic variants of acute disseminated encephalomyelitis (acute hemorrhagic encephalomyelitis, AHEM) occurring within 9 days after the first shot of ChAdOx1 nCoV-19. AHEM was diagnosed using magnetic resonance imaging, cerebrospinal fluid analysis and brain biopsy in one case. The close temporal association with the vaccination, the immune-related nature of the disease as well as the lack of other canonical precipitating factors suggested that AHEM was a vaccine-related adverse effect. We believe that AHEM might reflect a novel COVID-19 vaccine-related adverse event for which physicians should be vigilant and sensitized. [ABSTRACT FROM AUTHOR]

Background: An outbreak of salmonellosis due to Salmonella Typhimurium was detected coincidentally in a Swiss meat rabbitry, given that surveillance of Salmonella in rabbits is not mandatory in Switzerland. Methods: To assess the extent of potentially subclinical Salmonella carriage inmeat rabbits, faecal pool samples of 50 farms (90% of Swiss commercial rabbitries) with ground covering litter and group housing were bacteriologically tested. Additionally, 236 rabbits showing clinical signs compatible with intestinal diseases, such as salmonellosis, were examined postmortem and analysed bacteriologically. Salmonella isolates were serotyped and analysed bywhole genome sequencing (WGS). Results: Salmonella Typhimurium was detected in three commercial farms (6.0% of all tested farms). The affected farms were directly linked to the animal trade and Salmonella isolates were shown to be identical byWGS. Conclusion: There is no increased hazard for Salmonella carriage in the animalwelfarefriendly Swiss husbandry systems in general, despite risk factors such as ground covering litter. [ABSTRACT FROM AUTHOR]

Purpose: To develop a new interventional oncology technique using indocyanine green (ICG)-based interventional optical imaging (OI) to monitor the synergistic effect of radiofrequency hyperthermia (RFH)-enhanced oncolytic immunotherapy. Materials and Methods: This study included (1) optimization of ICG dose and detection time-window for intracellular uptake by VX2 tumor cells; (2) in-vitro confirmation of capability of using ICG-based OI to assess efficacy of RFH-enhanced oncolytic therapy (LTX-401) for VX2 cells; and (3) in-vivo validation of the interventional OI-monitored, intratumoral RFH-enhanced oncolytic immunotherapy using rabbit models with orthotopic liver VX2 tumors. Both in-vitro and in-vivo experiments were divided into four study groups (n=6/group) with different treatments: (1) combination therapy of RFH+LTX-401; (2) RFH alone at 42°C for 30 min; (3) oncolytic therapy with LTX-401; and (4) control with saline. For in-vivo validation, orthotopic hepatic VX2 tumors were treated using a new multi-functional perfusion-thermal radiofrequency ablation electrode, which enabled simultaneous delivery of both LTX-401 and RFH within the tumor and at the tumor margins. Results: In in-vitro experiments, taking up of ICG by VX2 cells was linearly increased from 0 μg/mL to 100 μg/mL, while ICG-signal intensity (SI) reached the peak at 24 hours. MTS assay and apoptosis analysis demonstrated the lowest cell viability and highest apoptosis in combination therapy, compared to three monotherapies (P <0.005). In in-vivo experiments, ultrasound imaging detected the smallest relative tumor volume for the combination therapy, compared to other monotherapies (P <0.005). In both in-vitro and in-vivo experiments, ICG-based interventional optical imaging detected a significantly decreased SI in combination therapy (P <0.005), which was confirmed by the "gold standard" optical/X-ray imaging (P <0.05). Pathologic/laboratory examinations further confirmed the significantly decreased cell proliferation with Ki-67 staining, significantly increased apoptotic index with TUNEL assay, and significantly increased quantities of CD8 and CD80 positive cells with immunostaining in the combination therapy group, compared to other three control groups (P <0.005). Conclusions: We present a new interventional oncology technique, interventional optical imaging-monitored RFH-enhanced oncolytic immunotherapy, which may open new avenues to effectively manage those patients with larger, irregular and unresectable malignancies, not only in liver but also the possibility in other organs. [ABSTRACT FROM AUTHOR]

In response to public health, it is necessary to write a review on COVID-19 disease as emerging zoonotic disease. Transmission of the new pathogen SARS-CoV-2 virus have several ways, spill - over or Evolutionary jump help virus to spread from one host to another with a rapid adaptation (Epidemiological cycling). Covid-19 can transmitted from animals to humans (Zoonotic disease) or from humans to animals (Zooanthroponosis) or from humans to humans (Emerging Infectious disease) or from animals to animals as infectious disease. On other hand some several wild animals considered reservoir host such as bats, snakes, frogs, hedge-hog, wild rats, marmots and rabbits.] 17, 16 [Since December 2019 when Covid-19 emerged in human from seafood market at Wuhan, Huanan city south China, rapidly transmitted all over the world as viral outbreak. [ABSTRACT FROM AUTHOR]

Purpose: Dry eye disease (DED) is classified as aqueous deficient, evaporative, or mixed. We investigated the therapeutic effect of the novel anti-inflammatory drug phosphosulindac (PS) in rabbit models of DED encompassing its pathogenesis, and its transition to chronicity. Methods: We treated three rabbit models of DED with PS (hydrogel formulation) or vehicle topically applied 1 × /day. We induced aqueous-deficient DED (acute and chronic) by injecting Concanavalin A into lacrimal glands; evaporative DED by injecting into the upper eyelid inactivated Mycobacterium tuberculosis in complete Freund's adjuvant; and mixed DED through desiccative stress, induced by holding open the eye for 3 h. We determined corneal sensitivity, tear break-up time (TBUT), Schirmer's tear test (STT), tear osmolality, and fluorescein staining of the ocular surface. Results: PS reversed all abnormal DED parameters. In acute DED, PS dose dependently normalized corneal sensitivity and tear osmolality; and improved TBUT, STT, and fluorescein staining. PS normalized corneal sensitivity and improved all other parameters in chronic aqueous-deficient DED. In evaporative DED, PS normalized corneal sensitivity and improved TBUT and fluorescein staining (osmolality and STT were not significantly changed in this model). In the desiccative stress model, PS improved TBUT and fluorescein staining but had no effect on STT or tear osmolality. Conclusions: PS rapidly reversed almost all DED parameters in its three subtypes. The normalization of the suppressed corneal sensitivity suggests the possibility of marked symptomatic relief by PS. The hydrogel formulation allows once-daily dosing. PS merits further development as a potential treatment for DED. [ABSTRACT FROM AUTHOR]

• The growth inhibitory effect of the anti- killed whole cell IgY was higher than anti-pilQ-pilA IgY. • Intravenous administration of specific IgY was non protective against Pseudomonas aeruginosa sepsis in a rabbit model. • No bacteria were found in the spleen and liver samples from infected rabbit. Pseudomonas aeruginosa sepsis is associated with unacceptably high mortality and, for many of those who survive, long-term morbidity. The aims of this study were to production of IgY against chimeric protein pilQ-pilA-DSL region and killed- whole cell Pseudomonas aeruginosa O1 (PAO1) strain and their efficacy for immunoprophylaxis of sepsis caused by P. aeruginosa in a rabbit model. Specific IgY was obtained by immunization of hens. The purity of IgY was determined by SDS-PAGE analysis. The effect of IgY on growth and hydrophobicity of P. aeruginosa were performed through time-kill assay and microbial adhesion to hydrocarbons test (MATH), respectively. The efficacy of specific IgYs was examined against P. aeruginosa sepsis in a rabbit model. The rabbits were monitored for 72 h to record physiological characters and survival. Hematologic factors, C-reactive protein, pro-inflammatory cytokines, and bacterial count from blood and solid organs were measured, periodically. We found that the growth inhibitory effect of the anti- killed whole cell IgY was higher than anti-pilQ-pilA IgY (P < 0.001). The hydrophobicity effect of PAO1 increased when bacteria were opsonized by anti- killed whole cell IgY while the hydrophobicity activity was decreased following incubation of PAO1 with anti-pilQ-pilA IgY in a broth medium (P < 0.001). Following intravenous (IV) administration of produced IgYs, no significant difference was observed in the survival, decrease in inflammatory mediators and clinical symptoms between the groups 48h post infection (P > 0.05). Moreover, no considerable decrease was observed in the bacterial load of blood, lungs and kidneys in rabbits treated with specific IgYs and control groups (P > 0.05). No bacteria were found in the spleen and liver samples from infected rabbits. Although produced IgYs had a good immunoreactivity, IV immunization of IgYs was not protective against P. aeruginosa sepsis in the rabbit model. Further studies are needed to assess the immune response and decreasing mortality rate using the rabbit sepsis model. [ABSTRACT FROM AUTHOR]

Pasteurellosis is one of the most serious bacterial diseases of rabbits, causes considerable economic damage in production systems worldwide and is a widely proven zoonosis with cases in humans infected by companion animals. The activated complement system causes lysis of various pathogenic microorganisms by the formation of the membrane attack complex. The objective of the present work was to evaluate the survivability of a virulent isolate of Pasteurella multocida type A to human serum complement activity. A female rabbit was referred as a clinical case of pneumonic pasteurellosis, a nasal swab was performed for isolation and identification. P. multocida was isolated in pure culture, characterized by standard biochemical identification tests, then challenged for 30 min at 37°C with normal serum and heatinactivated serum. Lysis by complement action had a significant reduction in the viability of the microorganism with respect to the culture challenged with inactivated complement (p< 0.05), however, a significant percentage 51.07 ± 1.70 % managed to evade complement lytic activity. In the context of health, it is concluded that the complement system offers partial protection against infections by P. multocida serotype A causing pneumonic pasteurellosis in rabbits. [ABSTRACT FROM AUTHOR]

Formalin-fixed, paraffin-embedded tissues from European rabbits (Oryctolagus cuniculus) that succumbed to rabbit hemorrhagic disease virus 2 (RHDV2; Lagovirus GI.2) during the 2019 outbreak in Washington, USA, were utilized for in situ hybridization via RNAscope (ACDBio). This detection method was both sensitive and specific, with no staining in tissues from RHDV- (Lagovirus GI.1) and RHDV2-negative rabbits, and only slight background staining of RHDV-positive rabbits; RHDV2-positive tissues had bright-red cytoplasmic staining. Although much of the viral mRNA detection was consistent with previously described antigen detection via immunohistochemistry of the liver, lungs, and spleen, there was also significant glomerular staining in the kidneys, and endothelial staining within blood vessels of almost all organs. We validated the RNAscope technique for detection of RHDV2 mRNA in formalin-fixed, paraffin-embedded tissues, with increased sensitivity from previous techniques, and identified additional affected cell types that may contribute to the understanding of pathogenesis. [ABSTRACT FROM AUTHOR]

Until the early 1980s, it was totally unknown that lagomorphs were the hosts of several caliciviruses, which were included in the genus Lagovirus by the International Committee on Taxonomy of Viruses (ICTV) in 2000. In those years, two new diseases appeared, with very similar clinical and pathological profiles and associated high mortality rates: rabbit haemorrhagic disease (RHD) in rabbits and European Brown Hare Syndrome (EBHS) in European brown hares. It took a few years to ascertain that both diseases, actually acute and fatal forms of hepatitis, were caused by two genetically related caliciviruses, but they were finally classified by ICTV into two distinct viral species on the basis of their molecular characterisation and epidemiological data: RHDV in rabbit and EBHSV in brown hare. RHD has had a devastating effect on rabbit farms, causing great economic damage, especially in China, where RHD was first noticed around 1982, and in Europe. RHD has also severely affected wild rabbit populations, whose drastic decline has caused serious ecological imbalances in territories such as Spain, where rabbits are a central link in the wildlife food chain. Since the early 1990s, with the increased availability on the market of RHDV vaccines effective in protecting rabbits from RHD, the impact of the disease on rabbit farms has been significantly reduced. In the following years, also considering that RHDV is an endemic virus that cannot be eradicated, farmers learned how to manage the continuous use of RHDV vaccine in relation to the epidemiological situation, the type of breeding farm and the costs of vaccination prophylaxis. Although precarious, management of the RHD risk for rabbit farmers reached an acceptable equilibrium, which was, however, completely upset starting from 2010 by the emergence of another lagovirus also causing RHD. The genome of the newly emerged virus shows limited differences from that of RHDV, but the phenotypic traits of the two viruses are distinctive in at least three main respects: 1) The antigenic profile of the virus (the "face" of the virus recognised by the antibodies) is largely different from that of RHDV. 2) Newborn rabbits only a couple of weeks old die of RHD when infected with the new virus, while RHDV infections run asymptomatic until 7-8 wk of age. 3) The new virus, which started in Europe, has spread over the years to several continents, affecting wild and/or domestic rabbit populations. During this worldwide distribution, the new virus infected several lagomorph species and was shown to cause RHD in most of them. Considering these marked differences and the fact that the new virus is not a variant of RHDV, we proposed the name RHDV type 2 (RHDV2). All these main distinctive traits that differentiate RHDV from RHDV2 have the following consequences in practice: 1) The antigenic difference between RHDV and RHDV2 (their 'faces') is so great that we need "new" specific vaccines to control RHDV2 (i.e. RHDV2 is a new serotype). 2) In the event of an RHDV2 infection in suckling rabbits, the presence of maternal antibodies to RHDV2 in the blood is the only way to prevent RHD. In contrast, newborns are naturally resistant to RHD if infected with RHDV and therefore, in terms of protection, the presence of maternal antibodies is useless. 3) When RHD outbreaks occur in territories where rabbits live in sympatry with populations of other lagomorphs, viral contamination in the environment reaches sufficiently high levels to facilitate the transmission of RHDV2 to other lagomorphs, including those with a lower susceptibility to infection than the rabbit. Taken together, these phenotypic traits characteristic of RHDV2 are the reason for its rapid spread across the territory and the concomitant disappearance of RHDV. Probably the most striking example of the epidemiological consequences related to the peculiar features of RHDV2 is its rapid spread in the USA and Mexico, where it is now practically endemic. There, despite repeated isolated outbreaks of RHD caused by RHDV from 2000 onwards in small rabbit farms, RHDV has never been able to become endemic. [ABSTRACT FROM AUTHOR]

Kyasanur Forest disease virus (KFDV) and the closely related Alkhurma hemorrhagic disease virus (AHFV) are emerging flaviviruses that cause severe viral hemorrhagic fevers in humans. Increasing geographical expansion and case numbers, particularly of KFDV in southwest India, class these viruses as a public health threat. Viral pathogenesis is not well understood and additional vaccines and antivirals are needed to effectively counter the impact of these viruses. However, current animal models of KFDV pathogenesis do not accurately reproduce viral tissue tropism or clinical outcomes observed in humans. Here, we show that pigtailed macaques (Macaca nemestrina) infected with KFDV or AHFV develop viremia that peaks 2 to 4 days following inoculation. Over the course of infection, animals developed lymphocytopenia, thrombocytopenia, and elevated liver enzymes. Infected animals exhibited hallmark signs of human disease characterized by a flushed appearance, piloerection, dehydration, loss of appetite, weakness, and hemorrhagic signs including epistaxis. Virus was commonly present in the gastrointestinal tract, consistent with human disease caused by KFDV and AHFV where gastrointestinal symptoms (hemorrhage, vomiting, diarrhea) are common. Importantly, RNAseq of whole blood revealed that KFDV downregulated gene expression of key clotting factors that was not observed during AHFV infection, consistent with increased severity of KFDV disease observed in this model. This work characterizes a nonhuman primate model for KFDV and AHFV that closely resembles human disease for further utilization in understanding host immunity and development of antiviral countermeasures. Author summary: Kyasanur Forest disease virus (KFDV) and Alkhurma hemorrhagic disease virus (AHFV) are tick-borne flaviviruses that cause viral hemorrhagic fevers in India and the Arabian Peninsula, respectively. Bonnet macaques and black-faced langurs are susceptible to KFDV infection, but these animals do not experience hemorrhagic signs as seen in human cases with KFDV. This work characterizes for the first time experimental infection of KFDV and AHFV in pigtailed macaques (PTMs). Infected PTMs can develop moderate to severe disease that models multiple features of human disease, including some hemorrhagic signs. Together these data describe the PTM model for KFDV and AHFV as a valuable tool for future work to study viral pathogenesis and for assessing the efficacy of vaccines and antivirals. [ABSTRACT FROM AUTHOR]

The rabbit industry in El Salvador is a little explored area, since the rabbit considered more as a pet and not as a protein of high nutritional value for the human being, which has advantages over other species such as the high rate of fertility and the lit tle space needed for its development. However, as in every exploitation the aspect of costs per feed and the respective gain in weight of the animal is one of the factors considered since it represents one of the highest costs of production. Alternatives to concentrate feeding such as hydroponic crops, specifically corn (Zea mays), can have a positive impact on local producers because the country does not have well established dry and rainy seasons, making it difficult for farmers to harvest. The research carried out using three groups of four rabbits each one of the age of a month and a half. Since at this age a greater food conversion obtained with the diet based on concentrate. The control group assigned a unique diet of concentrated super rabbit of grea ter commercial consumption to a ration of 120 grams per day. The experimental group, which given a diet based on hydroponic cultivation of corn (Zea mays) of, own elaboration to a ration of 120 grams. A third group to which added concentrated 60 grams and hydroponic cultivation of corn (Zea mays) 60 grams; this with the objective of determining which of the three groups gains greater weight and meat quality. [ABSTRACT FROM AUTHOR]

The diversity of lagoviruses (Caliciviridae) in Australia has increased considerably in recent years. By the end of 2017, five variants from three viral genotypes were present in populations of Australian rabbits, while prior to 2014 only two variants were known. To understand the evolutionary interactions among these lagovirus variants, we monitored their geographical distribution and relative incidence over time in a continental-scale competition study. Within 3 years of the incursion of rabbit haemorrhagic disease virus 2 (RHDV2, denoted genotype GI.1bP-GI.2 [polymerase genotype]P-[capsid genotype]) into Australia, two novel recombinant lagovirus variants emerged: RHDV2-4e (genotype GI.4eP-GI.2) in New South Wales and RHDV2-4c (genotype GI.4cP-GI.2) in Victoria. Although both novel recombinants contain non-structural genes related to those from benign, rabbit-specific, enterotropic viruses, these variants were recovered from the livers of both rabbits and hares that had died acutely. This suggests that the determinants of host and tissue tropism for lagoviruses are associated with the structural genes, and that tropism is intricately connected with pathogenicity. Phylogenetic analyses demonstrated that the RHDV2-4c recombinant emerged independently on multiple occasions, with five distinct lineages observed. Both the new RHDV2-4e and -4c recombinant variants replaced the previous dominant parental RHDV2 (genotype GI.1bP-GI.2) in their respective geographical areas, despite sharing an identical or near-identical (i.e. single amino acid change) VP60 major capsid protein with the parental virus. This suggests that the observed replacement by these recombinants was not driven by antigenic variation in VP60, implicating the non-structural genes as key drivers of epidemiological fitness. Molecular clock estimates place the RHDV2-4e recombination event in early to mid-2015, while the five RHDV2-4c recombination events occurred from late 2015 through to early 2017. The emergence of at least six viable recombinant variants within a 2-year period highlights the high frequency of these events, detectable only through intensive surveillance, and demonstrates the importance of recombination in lagovirus evolution. [ABSTRACT FROM AUTHOR]

Epstein-Barr virus (EBV) is a common herpesvirus associated with malignant and non-malignant conditions. An accumulating body of evidence supports a role for EBV in the pathogenesis of multiple sclerosis (MS), a demyelinating disease of the CNS. However, little is known about the details of the link between EBV and MS. One obstacle which has hindered research in this area has been the lack of a suitable animal model recapitulating natural infection in humans. We have recently shown that healthy rabbits are susceptible to EBV infection, and viral persistence in these animals mimics latent infection in humans. We used the rabbit model to investigate if peripheral EBV infection can lead to infection of the CNS and its potential consequences. We injected EBV intravenously in one group of animals, and phosphate-buffered saline (PBS) in another, with and without immunosuppression. Histopathological changes and viral dynamics were examined in peripheral blood, spleen, brain, and spinal cord, using a range of molecular and histopathology techniques. Our investigations uncovered important findings that could not be previously addressed. We showed that primary peripheral EBV infection can lead to the virus traversing the CNS. Cell associated, but not free virus in the plasma, correlated with CNS infection. The infected cells within the brain were found to be B-lymphocytes. Most notably, animals injected with EBV, but not PBS, developed inflammatory cellular aggregates in the CNS. The incidence of these aggregates increased in the immunosuppressed animals. The cellular aggregates contained compact clusters of macrophages surrounded by reactive astrocytes and dispersed B and T lymphocytes, but not myelinated nerve fibers. Moreover, studying EBV infection over a span of 28 days, revealed that the peak point for viral load in the periphery and CNS coincides with increased occurrence of cellular aggregates in the brain. Finally, peripheral EBV infection triggered temporal changes in the expression of latent viral transcripts and cytokines in the brain. The present study provides the first direct in vivo evidence for the role of peripheral EBV infection in CNS pathology, and highlights a unique model to dissect viral mechanisms contributing to the development of MS. [ABSTRACT FROM AUTHOR]