Lethal Systemic Disease Research Articles

Carbon Dot-Loaded Apoptotic Vesicles Improve the Liver Kupffer Cell-Mediated Antibacterial Effect to Synergistically Alleviate Sepsis.

Sepsis is a lethal systemic inflammatory disease against infection that lacks effective therapeutic approaches. Liver resident macrophage Kupffer cell (KC)-initiated bacterial clearance is crucial for the host to defend against infection. However, it remains unclear whether this process also governs the antibacterial therapy of sepsis that would be used to improve therapeutic outcomes. Here, we found that copper-doped carbon dots (Cu-CDs) exhibited superior antibacterial capabilities in vitro but displayed limited therapeutic effects in septic mice due to their limited ability to target the liver and restore KC antimicrobial capacity. Thus, we developed a composite nanodrug of copper-doped carbon dot-loaded apoVs (CC-apoVs) that combined the antibacterial ability of Cu-CDs and liver KC targeting features of apoV. Moreover, intravenous injection of CC-apoVs markedly alleviated the systemic infection and decreased the mortality of septic mice compared to Cu-CD and apoV infusion alone. Mechanistically, CC-apoV injection rescued impaired liver KCs during sepsis and enhanced their ability to capture and kill bloodborne bacteria. In addition, apoV-promoted macrophage killing of bacteria could be blocked by the inhibition of small GTPase Rab5. This study reveals a liver KC-targeted therapeutic strategy for sepsis and provides a nanodrug CC-apoV to improve the host antibacterial defense and amplify the therapeutic effect of the nanodrug.

Visceral Leishmaniasis co-existing with Multisystem Inflammatory Syndrome in a child

Leishmaniasis is a zoonotic disease caused by an intracellular protozoan parasite. The clinical spectrum of leishmaniasis ranges from a self-resolving cutaneous ulcer to Visceral leishmaniasis which is a serious, progressive, and potentially lethal systemic disease. “Multisystem Inflammatory Syndrome in Children” (MIS-C), which develops after the infection rather than during the acute stage of COVID-19 is a novel systemic syndrome that includes fever, elevated inflammatory parameters and organ dysfunction not attributed to other infectious causes. Here is presented a case the case of a 3-years old girl presented with persistent fever, and elevated inflammatory markers which was found to suffer simultaneously two severe conditions; Visceralis leishmaniasis and MIS-C. As these diseases have some similar clinical and laboratory features a high index of suspicion should be kept for both of them while valuating an ill child with fever and increased inflammatory markers.

Tetraplex Fluorescent Microbead-Based Immunoassay for the Serodiagnosis of Newcastle Disease Virus and Avian Influenza Viruses in Poultry Sera.

Virulent Newcastle disease virus (NDV) as well as highly pathogenic avian influenza (HPAIV) subtypes H5 and H7 induce contagious and lethal systemic disease in poultry. In contrast, low pathogenic AIV H5 and H7 may circulate clinically unnoticed in poultry but eventually generate HPAIV. Low pathogenic NDV strains are widely used as live-attenuated vaccines against ND. Serological tools are essential to conduct active surveillance for infections with notifiable AIV-H5, -H7 and to control vaccination against NDV and HPAIV in poultry populations. Here, recombinant nucleocapsid proteins (NP) of AIV and NDV, and haemagglutinin protein fragment-1 (HA1) of AIV subtypes H5 and H7 were expressed in E. coli. Purification and refolding were required before coating fluorescent microspheres via streptavidin-biotin linkage. The tetraplexed inhibition fluorescent microsphere immunoassay (iFMIA) was then assembled for analysis on a Luminex®-like platform (Bioplex®) using murine monoclonal antibodies specific for each of the four targets. The assay was evaluated by testing galliform poultry sera derived from experimental infections (n = 257) and from farms (n = 250), respectively. The tetraplex iFMIA compared favorably with commercially available ELISAs and the “gold standard” hemagglutination inhibition assay. Tetraplexed iFMIA provided a specific and sensitive tool to detect and discriminate AIV- and NDV-specific antibodies in the sera of galliform poultry.

Pathology and epidemiology of fatal toxoplasmosis in free-ranging marmosets (Callithrix spp.) from the Brazilian atlantic forest.

Toxoplasmosis is an important zoonotic disease that affects a wide range of warm-blooded host species. Neotropical primates (New World Primates; NWP) are highly susceptible, developing a lethal acute systemic disease. Toxoplasmosis in free-ranging NWP is poorly described, with only a few studies based on serosurveys. Herein we performed a retrospective study focusing on the epidemiology and pathology of toxoplasmosis among 1,001 free-ranging marmoset (Callithrix spp.) deaths from the Brazilian Atlantic Forest. This study included marmosets necropsied at the Instituto Municipal de Medicina Veterinária Jorge Vaitsman (IJV) from January 2017 to July 2019, which were found dead from all regions in the State of Rio de Janeiro. Histopathology, immunohistochemistry, and transmission electron microscopy were performed to better characterize toxoplasmosis in this free-ranging population. All samples were also tested for Yellow Fever Virus (YFV) RT-qPCR by the official diagnostic service. A total of 1,001 free-ranging marmosets were included in this study, with 16 (1.6%) cases of lethal Toxoplasma gondii infections identified both as individual cases and in outbreaks. Presence of infection was not associated with sex, age, geographical distribution, or year of death, and no co-infection with YFV was observed. The main pathological feature in these cases was random necrotizing hepatitis with detection of intralesional T. gondii zoites in all infected cases. Interstitial pneumonia rich in alveolar foamy macrophages and fibrin deposition, necrotizing myocarditis and necrotizing splenitis were also pathological features in affected marmosets. Therefore, toxoplasmosis was considered the cause of death in 1.6% of free-ranging marmosets in this retrospective series, including some cases associated with outbreaks. Necrotizing random hepatitis was a consistent pathological finding in affected cases and sampling of liver should be ensured from Callitrichid post mortem cases.

Circulating T Cells Are Not Sufficient for Protective Immunity against Virulent Francisella tularensis.

Pulmonary infections elicit a combination of tissue-resident and circulating T cell responses. Understanding the contribution of these anatomically distinct cellular pools in protective immune responses is critical for vaccine development. Francisella tularensis is a highly virulent bacterium capable of causing lethal systemic disease following pulmonary infection for which there is no currently licensed vaccine. Although T cells are required for survival of F. tularensis infection, the relative contribution of tissue-resident and circulating T cells is not completely understood, hampering design of effective, long-lasting vaccines directed against this bacterium. We have previously shown that resident T cells were not sufficient to protect against F. tularensis, suggesting circulating cells may serve a critical role in host defense. To elucidate the role of circulating T cells, we used a model of vaccination and challenge of parabiotic mice. Intranasally infected naive mice conjoined to immune animals had increased numbers of circulating memory T cells and similar splenic bacterial burdens as vaccinated-vaccinated pairs. However, bacterial loads in the lungs of naive parabionts were significantly greater than those observed in vaccinated-vaccinated pairs, but despite early control of F. tularensis replication, all naive-vaccinated pairs succumbed to infection. Together, these data define the specific roles of circulating and resident T cells in defense against infection that is initiated in the pulmonary compartment but ultimately causes disseminated disease. These data also provide evidence for employing vaccination strategies that elicit both pools of T cells for immunity against F. tularensis and may be a common theme for other disseminating bacterial infections.

Chronic limb ischemia manifestation in COVID-19 infection: awareness and treatment in primary care

Chronic limb ischemia (CLI) is a type of peripheral arterial disease (PAD) that is still underdiagnosed and undertreated despite the increasing incidence, thus becoming a global health burden. And CLI reflects the local manifestations of a lethal systemic disease — atherosclerosis. If left untreated, chronic limb ischemia can result in major limb loss. In this pandemic era, limb ischemia has become one of several clinical manifestations that occur in patients with COVID-19 infection. Systemic inflammation in COVID-19 infection, direct viral infection, hypercoagulable state, and hyperinflammatory response are responsible for damage to the arterial system, causing endothelial dysfunction. Diagnosing PAD has become a challenge especially in the early stage and in the asymptomatic phase. The untreated condition could lead to the development of CLI. The primary physicians in the primary health facilities hold an important role in the early diagnosis and management of patients with CLI symptoms or with risk factors of CLI, especially in patients who have experienced COVID-19 infection. Due to the limitation of diagnostic testing modalities at primary health facilities, the physician can assess the ankle-brachial index (ABI) to determine the presence of CLI. Management of the disease is different for every patient and is customized based on the other comorbidities. Risk factors should be controlled in order to achieve a better outcome. A good management strategy will improve the quality of life of the patient. This review will discuss the occurrence of CLI in COVID-19 infection.

Comparative Virulence and Genomic Analysis of Streptococcus suis Isolates.

Streptococcus suis is a zoonotic bacterial swine pathogen causing substantial economic and health burdens to the pork industry. Mechanisms used by S. suis to colonize and cause disease remain unknown and vaccines and/or intervention strategies currently do not exist. Studies addressing virulence mechanisms used by S. suis have been complicated because different isolates can cause a spectrum of disease outcomes ranging from lethal systemic disease to asymptomatic carriage. The objectives of this study were to evaluate the virulence capacity of nine United States S. suis isolates following intranasal challenge in swine and then perform comparative genomic analyses to identify genomic attributes associated with swine-virulent phenotypes. No correlation was found between the capacity to cause disease in swine and the functional characteristics of genome size, serotype, sequence type (ST), or in vitro virulence-associated phenotypes. A search for orthologs found in highly virulent isolates and not found in non-virulent isolates revealed numerous predicted protein coding sequences specific to each category. While none of these predicted protein coding sequences have been previously characterized as potential virulence factors, this analysis does provide a reliable one-to-one assignment of specific genes of interest that could prove useful in future allelic replacement and/or functional genomic studies. Collectively, this report provides a framework for future allelic replacement and/or functional genomic studies investigating genetic characteristics underlying the spectrum of disease outcomes caused by S. suis isolates.

Coronavirus Infections in Companion Animals: Virology, Epidemiology, Clinical and Pathologic Features.

Coronaviruses are enveloped RNA viruses capable of causing respiratory, enteric, or systemic diseases in a variety of mammalian hosts that vary in clinical severity from subclinical to fatal. The host range and tissue tropism are largely determined by the coronaviral spike protein, which initiates cellular infection by promoting fusion of the viral and host cell membranes. Companion animal coronaviruses responsible for causing enteric infection include feline enteric coronavirus, ferret enteric coronavirus, canine enteric coronavirus, equine coronavirus, and alpaca enteric coronavirus, while canine respiratory coronavirus and alpaca respiratory coronavirus result in respiratory infection. Ferret systemic coronavirus and feline infectious peritonitis virus, a mutated feline enteric coronavirus, can lead to lethal immuno-inflammatory systemic disease. Recent human viral pandemics, including severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and most recently, COVID-19, all thought to originate from bat coronaviruses, demonstrate the zoonotic potential of coronaviruses and their potential to have devastating impacts. A better understanding of the coronaviruses of companion animals, their capacity for cross-species transmission, and the sharing of genetic information may facilitate improved prevention and control strategies for future emerging zoonotic coronaviruses. This article reviews the clinical, epidemiologic, virologic, and pathologic characteristics of nine important coronaviruses of companion animals.

Ex Vivo Virotherapy with Myxoma Virus to Treat Cancer.

Myxoma virus (MYXV) is a member of the Poxviridae family and the genus Leporipoxvirus. In nature MYXV tropism is restricted to lagomorphs, and is specifically pathogenic only for European rabbits (Oryctolagus cuniculus), in which this virus causes the lethal systemic disease called myxomatosis. Importantly, although MYXV cannot cause any disease pathology in humans, mice, or any other domestic animals other than rabbit, this virus can productively infect and kill a variety of human and murine cancer cells, from either primary sources or cultured cancer cell lines. Therefore, in the last decade, MYXV has emerged as a novel oncolytic virus against hematologic malignancies and various solid cancers. One novel aspect of MYXV virotherapy is a new systemic virus delivery strategy to cancer sites in the recipient, by which adsorption of the virus to isolated leukocytes is conducted prior to reinfusion of the virus-infected cells back into the recipient, via a procedure called ex vivo virotherapy (EVV, or simply EV2). The EV2 delivery strategy thus exploits the inherent migratory properties of leukocytes to ferry MYXV to tissue sites bearing cancer cells that are accessible to leukocyte chemotaxis. Here, we describe EV2 procedures with MYXV to systemically deliver the virus to sites of disseminated and/or metastatic cancer in situ via infected leukocytes derived from either bone marrow or peripheral blood.

Sterile Keratitis

Sterile keratitis shows multiple manifestations. It may occur as an ophthalmological problem but can also be part of a systemic disease, including potentially lethal systemic vasculitis. Diagnosis as well as management of this disease is a challenging task for the ophthalmologist. There are therapeutic principles which apply to all non-infectious cases of keratitis and corneal ulcerations. Specific treatments, however, are determined by the pathogenesis and may differ. Therefore, an accurate diagnosis must guide therapeutic decision making. The correct diagnosis and management of sterile ulcerative keratitis is able to restore the patient's vision in most cases. In potentially lethal systemic disease it may even be able to save the patient's life.

Bilateral Anterior Uveitis Revealing Relapsing Polychondritis

Relapsing polychondritis is a potentially lethal but rare systemic autoimmune disease. The major site of inflammation is the connective tissue, usually involving the ears, nose, larynx, tracheobronchial tree, and cardiovascular system. Although scleritis and episcleritis are known to be the most probable ocular manifestation, it may also present with uveitis. We present the case of a 22-year-old young lady who initially referred with bilateral red and painful eyes caused by anterior uveitis. Her right ear was also red and painful, consistent with cartilaginous inflammation. She was diagnosed with relapsing polychondritis with bilateral anterior uveitis and chondritis of the ear in conjunction with the rheumatology department. Bilateral anterior uveitis should evaluated and monitored carefully in patients with relapsing polychondritis.

Subinhibitory Concentrations of Amoxicillin, Lincomycin, and Oxytetracycline Commonly Used to Treat Swine Increase Streptococcus suis Biofilm Formation.

Streptococcus suis is a bacterial swine pathogen with a significant economic burden. It typically colonizes the tonsil and nasal cavity of swine causing a variety of symptoms ranging from asymptomatic carriage to lethal systemic disease. A key barrier toward the development of improved vaccines or interventions for S. suis infections is a gap in our understanding of the mechanisms contributing to persistence in the host, in which colonized pigs continue to shed and transmit S. suis. We hypothesized that exposure to sub-MICs of antibiotics commonly used by the swine industry would increase the biofilm capacity of S. suis strains. Using a 96-well plate MIC protocol, we experimentally determined the MIC for each of 12 antibiotics for a virulent strain of S. suis strain that consistently formed biofilms using a standard crystal violet assay. Using this static biofilm assay, we demonstrated that sub-MICs of bacitracin, carbadox, chlortetracycline, enrofloxacin, gentamicin, neomycin, sulfadimethoxine, tiamulin, and tylosin did not increase S. suis biofilms. In contrast, we demonstrated that sub-MICs of amoxicillin, lincomycin, and oxytetracycline increased overall biofilm formation under both static and flow conditions. The biofilm formation of 11 additional clinical isolates were measured using the relevant concentrations of amoxicillin, lincomycin, and oxytetracycline. Eight of the eleven strains increased the biofilm formation with lincomycin, seven with amoxicillin, and three with oxytetracycline. Collectively, our data demonstrate that exposure to sub-MICs of these commonly used antibiotics contributes to increased biofilm formation of S. suis, thereby potentially increasing survival and persistence within the respiratory tract of swine.

Comparative genomic and methylome analysis of non-virulent D74 and virulent Nagasaki Haemophilus parasuis isolates.

Haemophilus parasuis is a respiratory pathogen of swine and the etiological agent of Glässer's disease. H. parasuis isolates can exhibit different virulence capabilities ranging from lethal systemic disease to subclinical carriage. To identify genomic differences between phenotypically distinct strains, we obtained the closed whole-genome sequence annotation and genome-wide methylation patterns for the highly virulent Nagasaki strain and for the non-virulent D74 strain. Evaluation of the virulence-associated genes contained within the genomes of D74 and Nagasaki led to the discovery of a large number of toxin-antitoxin (TA) systems within both genomes. Five predicted hemolysins were identified as unique to Nagasaki and seven putative contact-dependent growth inhibition toxin proteins were identified only in strain D74. Assessment of all potential vtaA genes revealed thirteen present in the Nagasaki genome and three in the D74 genome. Subsequent evaluation of the predicted protein structure revealed that none of the D74 VtaA proteins contain a collagen triple helix repeat domain. Additionally, the predicted protein sequence for two D74 VtaA proteins is substantially longer than any predicted Nagasaki VtaA proteins. Fifteen methylation sequence motifs were identified in D74 and fourteen methylation sequence motifs were identified in Nagasaki using SMRT sequencing analysis. Only one of the methylation sequence motifs was observed in both strains indicative of the diversity between D74 and Nagasaki. Subsequent analysis also revealed diversity in the restriction-modification systems harbored by D74 and Nagasaki. The collective information reported in this study will aid in the development of vaccines and intervention strategies to decrease the prevalence and disease burden caused by H. parasuis.

A global regulatory system links virulence and antibiotic resistance to envelope homeostasis in Acinetobacter baumannii.

The nosocomial pathogen Acinetobacter baumannii is a significant threat due to its ability to cause infections refractory to a broad range of antibiotic treatments. We show here that a highly conserved sensory-transduction system, BfmRS, mediates the coordinate development of both enhanced virulence and resistance in this microorganism. Hyperactive alleles of BfmRS conferred increased protection from serum complement killing and allowed lethal systemic disease in mice. BfmRS also augmented resistance and tolerance against an expansive set of antibiotics, including dramatic protection from β-lactam toxicity. Through transcriptome profiling, we showed that BfmRS governs these phenotypes through global transcriptional regulation of a post-exponential-phase-like program of gene expression, a key feature of which is modulation of envelope biogenesis and defense pathways. BfmRS activity defended against cell-wall lesions through both β-lactamase-dependent and -independent mechanisms, with the latter being connected to control of lytic transglycosylase production and proper coordination of morphogenesis and division. In addition, hypersensitivity of bfmRS knockouts could be suppressed by unlinked mutations restoring a short, rod cell morphology, indicating that regulation of drug resistance, pathogenicity, and envelope morphogenesis are intimately linked by this central regulatory system in A. baumannii. This work demonstrates that BfmRS controls a global regulatory network coupling cellular physiology to the ability to cause invasive, drug-resistant infections.

Visceral leishmaniasis in Lebanon a report of four cases: case series and review.

Leishmaniasis comprises a complex of vector-borne diseases, caused by more than 20 species of the protozoan genus Leishmania, and ranging from localized skin ulcers to lethal systemic disease. It is endemic in Asia, Africa, the Americas, and the Mediterranean region. In the Middle East countries like Syria reports high incidence of the disease. In addition to the endemicity of the region for leishmaniasis, the Middle East has seen a great deal of human migration either for earning of livelihood or due to political upheaval in the region. Cutaneous form can be disfiguring but visceral form can be lethal. In this article we report the clinical presentation of 4 cases of visceral leishmaniasis; 3 cases were pediatrics and one immunosuppressed adult patient all of them were from Syria from different regions. The diagnosis was made by bone marrow aspirate; PCR was made for 2 of them and was positive for leishmania infantum. All of them were treated with Amphotericn B lipid formulation (ABELCET) with complete response (definite cure). We report in this article 4 cases of visceral leishmaniasis treated with amphotericin B lipid complex (Abelcet) following the guidelines with complete remission. Visceral leishmaniasis is a serious disease and if not treated can lead to death. Lebanon is not known to be endemic for leishmania but since the war the ministry of health reported an outbreak of leishmania and mainly cutaneous leishmania. Here we present 4 cases of visceral leishmania and a review of the latest guidelines on the treatment modalities and protocols.

Analysis of gene expression in filamentous cells of Candida albicans grown on agar plates.

Candida albicans (C. albicans) is a commensal organism of the human gastrointestinal and genitourinary tracts. C. albicans is also a major human pathogen, causing disease ranging from cutaneous infections to lethal systemic disease. The ability of this fungus to switch between yeast and filamentous forms of growth has long been linked to its pathogenesis. Filamentation can be induced by a variety of distinct environmental cues and can occur in either liquid or solid media. While some evidence suggests that there are differences between filamentation in solid and liquid media, gene expression analysis of filamentation in C. albicans has focused strictly on cells grown in liquid media. We have developed a method for analyzing gene expression of filamentous cells grown on solid induction media at early stages of filamentation, establishing cell plating densities, ideal collection times, and collection techniques. We have also demonstrated the utility of the approach not only in qRT-PCR assays, but high-throughput RNAseq assays as well. These assays will allow for comparison studies of C. albicans filamentation initiation in solid and liquid media.

Engineered recombinant protein products of the avian paramyxovirus type-1 nucleocapsid and phosphoprotein genes for serological diagnosis

BackgroundVirulent Newcastle disease virus (NDV, avian Avulavirus-1, APMV-1) induces a highly contagious and lethal systemic disease in gallinaceous poultry. APMV-1 antibody detection is used for surveillance and to control vaccination, but is hampered by cross-reactivity to other subtypes of avian Avulaviruses. Data are lacking concerning the applicability of NDV V proteins as differential diagnostic marker to distinguish vaccinated from virus-infected birds (DIVA strategy).MethodsFull length and C-terminally truncated nucleocapsid (NP) protein, and the unique C-terminal regions of the phospho- (P) and V proteins of the NDV LaSota strain were bacterially expressed as fusion proteins with the multimerization domain of the human C4 binding protein, and used as diagnostic antigens in indirect ELISA.ResultsWhen used as diagnostic antigen in indirect ELISAs, recombinant full-length proved to be a sensitive target to detect seroconversion in chickens after APMV-1 vaccination and infection, but revealed some degree of cross reactivity with sera raised against other APMV subtypes. Cross reactivity was abolished but also sensitivity decreased when employing a C-terminal fragment of the NP of NDV as diagnostic antigen. Antibodies to the NDV V protein were mounted in poultry following NDV infection but also, albeit at lower rates and titers, after vaccination with attenuated NDV vaccines. V-specific seroconversion within the flock was incomplete and titers in individual bird transient.ConclusionsIndirect ELISA based on bacterially expressed recombinant full-length NP compared favorably with a commercial NDV ELISA based on whole virus antigen, but cross reactivity between the NP proteins of different APMV subtypes could compromise specificity. However, specificity increased when using a less conserved C-terminal fragment of NP instead. Moreover, a serological DIVA strategy built on the NDV V protein was not feasible due to reduced immunogenicity of the V protein and frequent use of live-attenuated NDV vaccines.

Crystal Structure of Feline Infectious Peritonitis Virus Main Protease in Complex with Synergetic Dual Inhibitors.

Coronaviruses (CoVs) can cause highly prevalent diseases in humans and animals. Feline infectious peritonitis virus (FIPV) belongs to the genus Alphacoronavirus, resulting in a lethal systemic granulomatous disease called feline infectious peritonitis (FIP), which is one of the most important fatal infectious diseases of cats worldwide. No specific vaccines or drugs have been approved to treat FIP. CoV main proteases (M(pro)s) play a pivotal role in viral transcription and replication, making them an ideal target for drug development. Here, we report the crystal structure of FIPV M(pro) in complex with dual inhibitors, a zinc ion and a Michael acceptor. The complex structure elaborates a unique mechanism of two distinct inhibitors synergizing to inactivate the protease, providing a structural basis to design novel antivirals and suggesting the potential to take advantage of zinc as an adjunct therapy against CoV-associated diseases. Coronaviruses (CoVs) have the largest genome size among all RNA viruses. CoV infection causes various diseases in humans and animals, including severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). No approved specific drugs or vaccinations are available to treat their infections. Here, we report a novel dual inhibition mechanism targeting CoV main protease (M(pro)) from feline infectious peritonitis virus (FIPV), which leads to lethal systemic granulomatous disease in cats. M(pro), conserved across all CoV genomes, is essential for viral replication and transcription. We demonstrated that zinc ion and a Michael acceptor-based peptidomimetic inhibitor synergistically inactivate FIPV M(pro). We also solved the structure of FIPV M(pro) complexed with two inhibitors, delineating the structural view of a dual inhibition mechanism. Our study provides new insight into the pharmaceutical strategy against CoV M(pro) through using zinc as an adjuvant therapy to enhance the efficacy of an irreversible peptidomimetic inhibitor.

Transcriptome analysis of feline infectious peritonitis virus infection.

Feline infectious peritonitis (FIP) is a lethal systemic disease caused by FIP virus (FIPV). There are no effective vaccines or treatment available, and the virus virulence determinants and pathogenesis are not fully understood. Here, we describe the sequencing of RNA extracted from Crandell Rees Feline Kidney (CRFK) cells infected with FIPV using the Illumina next-generation sequencing approach. Bioinformatics analysis, based on Felis catus 2X annotated shotgun reference genome, using CLC bio Genome Workbench is used to map both control and infected cells. Kal’s Z test statistical analysis is used to analyze the differentially expressed genes from the infected CRFK cells. In addition, RT-qPCR analysis is used for further transcriptional profiling of selected genes in infected CRFK cells and Peripheral Blood Mononuclear Cells (PBMCs) from healthy and FIP-diagnosed cats.

Crystallization and preliminary crystallographic study of Feline infectious peritonitis virus main protease in complex with an inhibitor.

Feline infectious peritonitis virus (FIPV) causes a lethal systemic granulomatous disease in wild and domestic cats around the world. Currently, no effective vaccines or drugs have been developed against it. As a member of the genus Alphacoronavirus, FIPV encodes two polyprotein precursors required for genome replication and transcription. Each polyprotein undergoes extensive proteolytic processing, resulting in functional subunits. This process is mainly mediated by its genome-encoded main protease, which is an attractive target for antiviral drug design. In this study, the main protease of FIPV in complex with a Michael acceptor-type inhibitor was crystallized. The complex crystals diffracted to 2.5 Å resolution and belonged to space group I422, with unit-cell parameters a = 112.3, b = 112.3, c = 102.1 Å. There is one molecule per asymmetric unit.