Pathology of Coronavirus Infections: A Review of Lesions in Animals in the One-Health Perspective

SARS-CoV-2 prevalence in domestic and wildlife animals: A genomic and docking based structural comprehensive review

The SARS-CoV-2 virus has been identified as the infectious agent that led to the COVID-19 pandemic, which the world has seen very recently. Researchers have linked the SARS-CoV-2 outbreak to bats for the zoonotic spread of the virus to humans. Coronaviruses have a crown-like shape and positive-sense RNA nucleic acid. It attaches its spike glycoprotein to the host angiotensin-converting enzyme 2 (ACE2) receptor. Coronavirus genome comprises 14 ORFs and 27 proteins, spike glycoprotein being one of the most critical proteins for viral pathogenesis. Many mammals and reptiles, including bats, pangolins, ferrets, snakes, and turtles, serve as the principal reservoirs for this virus. But many experimental investigations have shown that certain domestic animals, including pigs, chickens, dogs, cats, and others, may also be able to harbor this virus, whether they exhibit any symptoms. These animals act as reservoirs for SARS-CoV, facilitating its zoonotic cross-species transmission to other species, including humans. In this review, we performed a phylogenetic analysis with multiple sequence alignment and pairwise evolutionary distance analysis, which revealed the similarity of ACE2 receptors in humans, chimpanzees, domestic rabbits, house mice, and golden hamsters. Pairwise RMSD analysis of the spike protein from some commonly reported SARS-CoV revealed that bat and pangolin coronavirus shared the highest structural similarity with human coronavirus. In a further experiment, molecular docking confirmed a higher affinity of pig, bat, and pangolin coronavirus spike proteins' affinity to the human ACE2 receptor. Such comprehensive structural and genomic analysis can help us to forecast the next likely animal source of these coronaviruses that may infect humans. To combat these zoonotic illnesses, we need a one health strategy that considers the well-being of people and animals and the local ecosystem.

Antiviral Therapy of COVID-19

Since the beginning of the COVID-19 pandemic, the scientific community has focused on prophylactic vaccine development. In parallel, the experience of the pharmacotherapy of this disease has increased. Due to the declining protective capacity of vaccines against new strains, as well as increased knowledge about the structure and biology of the pathogen, control of the disease has shifted to the focus of antiviral drug development over the past year. Clinical data on safety and efficacy of antivirals acting at various stages of the virus life cycle has been published. In this review, we summarize mechanisms and clinical efficacy of antiviral therapy of COVID-19 with drugs based on plasma of convalescents, monoclonal antibodies, interferons, fusion inhibitors, nucleoside analogs, and protease inhibitors. The current status of the drugs described is also summarized in relation to the official clinical guidelines for the treatment of COVID-19. In addition, here we describe innovative drugs whose antiviral effect is provided by antisense oligonucleotides targeting the SARS-CoV-2 genome. Analysis of laboratory and clinical data suggests that current antivirals successfully combat broad spectra of emerging strains of SARS-CoV-2 providing reliable defense against COVID-19.

A Combined Method Based on the FIPV N Monoclonal Antibody Immunofluorescence Assay and RT-nPCR Method for the Rapid Diagnosis of FIP-Suspected Ascites

Feline infectious peritonitis (FIP), which is caused by feline infectious peritonitis virus (FIPV), is a fatal and immunologically mediated infectious disease among cats. At present, due to the atypical clinical symptoms and clinicopathological changes, the clinical diagnosis of FIP is still difficult. The gold standard method for the differential diagnosis of FIP is immunohistochemistry (IHC) which is time-consuming and requires specialized personnel and equipment. Therefore, a rapid and accurate clinical diagnostic method for FIPV infection is still urgently needed. In this study, based on the etiological investigation of FIPV in parts of southern China, we attempted to explore a new rapid and highly sensitive method for clinical diagnosis. The results of the etiological investigation showed that the N gene of the FIPV BS8 strain had the highest homology with other strains. Based on this, a specific FIPV BS8 N protein monoclonal antibody was successfully prepared by expression of the recombinant proteins, immunization of mice, fusion and selection of hybridoma cell lines, and screening and purification of monoclonal antibodies. Furthermore, we carried out a time-saving combination method including indirect immunofluorescence assay (IFA) and nested reverse transcription polymerase chain reaction (RT-nPCR) to examine FIP-suspected clinical samples. These results were 100% consistent with IHC. The results revealed that the combined method could be a rapid and accurate application in the diagnosis of suspected FIPV infection within 24 hours. In conclusion, the combination of IFA and RT-nPCR was shown to be a fast and reliable method for clinical FIPV diagnosis. This study will provide insight into the exploitation of FIPV N antibodies for the clinical diagnosis of FIP-suspected ascites samples.

Cross-species transmission of coronaviruses with a focus on severe acute respiratory syndrome coronavirus 2 infection in animals: a review for the veterinary practitioner

AbstractIn 2019 a novel coronavirus termed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged from an unidentified source and spread rapidly among humans worldwide. While many human infections are mild, some result in severe clinical disease that in a small proportion of infected people is fatal. The pandemic spread of SARS-CoV-2 has been facilitated by efficient human-to-human transmission of the virus, with no data to indicate that animals contributed to this global health crisis. However, a range of domesticated and wild animals are also susceptible to SARS-CoV-2 infection under both experimental and natural conditions. Humans are presumed to be the source of most animal infections thus far, although natural transmission between mink and between free-ranging deer has occurred, and occasional natural transmission between cats cannot be fully excluded. Considering the ongoing circulation of the virus among people, together with its capacity to evolve through mutation and recombination, the risk of the emergence of animal-adapted variants is not negligible. If such variants remain infectious to humans, this could lead to the establishment of an animal reservoir for the virus, which would complicate control efforts. As such, minimising human-to-animal transmission of SARS-CoV-2 should be considered as part of infection control efforts. The aim of this review is to summarise what is currently known about the species specificity of animal coronaviruses, with an emphasis on SARS-CoV-2, in the broader context of factors that facilitate cross-species transmission of viruses.

Diagnostic Approach to Enteric Disorders in Pigs

The diagnosis of enteric disorders in pigs is extremely challenging, at any age. Outbreaks of enteric disease in pigs are frequently multifactorial and multiple microorganisms can co-exist and interact. Furthermore, several pathogens, such as Clostridium perfrigens type A, Rotavirus and Lawsonia intracellularis, may be present in the gut in the absence of clinical signs. Thus, diagnosis must be based on a differential approach in order to develop a tailored control strategy, considering that treatment and control programs for enteric diseases are pathogen-specific. Correct sampling for laboratory analyses is fundamental for the diagnostic work-up of enteric disease in pigs. For example, histology is the diagnostic gold standard for several enteric disorders, and sampling must ensure the collection of representative and optimal intestinal samples. The aim of this paper is to focus on the diagnostic approach, from sampling to the aetiological diagnosis, of enteric disorders in pigs due to different pathogens during the different phases of production.

Evaluation of UVC Excimer Lamp (222 nm) Efficacy for Coronavirus Inactivation in an Animal Model

The current pandemic caused by severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) has encouraged the evaluation of novel instruments for disinfection and lowering infectious pressure. Ultraviolet subtype C (UVC) excimer lamps with 222 nm wavelength have been tested on airborne pathogens on surfaces and the exposure to this wavelength has been considered safer than conventional UVC. To test the efficacy of UVC excimer lamps on coronaviruses, an animal model mimicking the infection dynamics was implemented. An attenuated vaccine based on infectious bronchitis virus (IBV) was nebulized and irradiated by 222 nm UVC rays before the exposure of a group of day-old chicks to evaluate the virus inactivation. A control group of chicks was exposed to the nebulized vaccine produced in the same conditions but not irradiated by the lamps. The animals of both groups were sampled daily and individually by choanal cleft swabs and tested usign a strain specific real time RT-PCR to evaluate the vaccine replication. Only the birds in the control group were positive, showing an active replication of the vaccine, revealing the efficacy of the lamps in inactivating the vaccine below the infectious dose in the other group.

In Silico Drug Repositioning to Target the SARS-CoV-2 Main Protease as Covalent Inhibitors Employing a Combined Structure-Based Virtual Screening Strategy of Pharmacophore Models and Covalent Docking

The epidemic caused by the SARS-CoV-2 coronavirus, which has spread rapidly throughout the world, requires urgent and effective treatments considering that the appearance of viral variants limits the efficacy of vaccines. The main protease of SARS-CoV-2 (M^pro) is a highly conserved cysteine proteinase, fundamental for the replication of the coronavirus and with a specific cleavage mechanism that positions it as an attractive therapeutic target for the proposal of irreversible inhibitors. A structure-based strategy combining 3D pharmacophoric modeling, virtual screening, and covalent docking was employed to identify the interactions required for molecular recognition, as well as the spatial orientation of the electrophilic warhead, of various drugs, to achieve a covalent interaction with Cys145 of M^pro. The virtual screening on the structure-based pharmacophoric map of the SARS-CoV-2 M^pro in complex with an inhibitor N3 (reference compound) provided high efficiency by identifying 53 drugs (FDA and DrugBank databases) with probabilities of covalent binding, including N3 (Michael acceptor) and others with a variety of electrophilic warheads. Adding the energy contributions of affinity for non-covalent and covalent docking, 16 promising drugs were obtained. Our findings suggest that the FDA-approved drugs Vaborbactam, Cimetidine, Ixazomib, Scopolamine, and Bicalutamide, as well as the other investigational peptide-like drugs (DB04234, DB03456, DB07224, DB7252, and CMX-2043) are potential covalent inhibitors of SARS-CoV-2 M^pro.

Nature of viruses and pandemics: Coronaviruses

Coronaviruses (CoVs) have the largest genome among RNA viruses and store large amounts of information without genome integration as they replicate in the cell cytoplasm. The replication of the virus is a continuous process, whereas the transcription of the subgenomic mRNAs is a discontinuous one, involving a template switch, which resembles a high frequency recombination mechanism that may favor virus genome variability. The origin of the three deadly human CoVs SARS-CoV, MERS-CoV and SARS-CoV-2 are zoonotic events. SARS-CoV-2 has incorporated in its spike protein a furine proteolytic site that facilitates the activation of the virus in any tissue, making this CoV strain highly polytropic and pathogenic. Using MERS-CoV as a model, a propagation-deficient RNA replicon was generated by removing E protein gene (essential for viral morphogenesis and involved in virulence), and accessory genes 3, 4a, 4b and 5 (responsible for antagonism of the innate immune response) to attenuate the virus: MERS-CoV-Δ[3,4a,4b,5,E]. This RNA replicon is strongly attenuated and elicits sterilizing protection after a single immunization in transgenic mice with the receptor for MERS-CoV, making it a promising vaccine candidate for this virus and an interesting platform for vector-based vaccine development. A strategy could be developed for the design of RNA replicon vaccines for other human pathogenic coronaviruses.

•

CoV RNA transcription is a discontinuous high-frequency recombination process.

•

Human CoVs have a zoonotic origin.

•

Replication-competent propagation-defective CoVs are the bases for vaccines.

•

Single immunization with CoV RNA replicon vaccines elicits sterilizing immunity.

Ovine gammaherpesvirus 2 infections in cattle without typical manifestations of sheep-associated malignant catarrhal fever and concomitantly infected with bovine coronavirus

Sheep-associated malignant catarrhal fever (SA-MCF) is a severe, frequently fatal, lymphoproliferative disease that affects a wide variety of ruminants and is caused by ovine gammaherpesvirus 2 (OvHV-2), a member of the MCF virus (MCFV) complex. The typical clinical manifestations of SA-MCF are well known and easily recognized by veterinarians, resulting in clinical diagnosis of MCF when characteristic clinical signs are present. This article describes the findings observed in cattle infected with OvHV-2 but without typical clinical manifestations of SA-MCF. Three calves with episodes of diarrhea before death and a yearling that died suddenly were investigated. Gross alterations were not suggestive of SA-MCF. Histopathology revealed a combination of proliferating vascular lesions (PVLs) and necrotizing vasculitis in three animals (two calves and the yearling); with PVLs being identified only at the carotid rete mirabile of two calves infected with OvHV-2. Additional significant histopathologic lesions included atrophic enteritis, portal lymphocytic hepatitis, interstitial pneumonia, suppurative bacterial bronchopneumonia, and pulmonary hemorrhage. An immunohistochemical assay designed to identify only antigens of MCFV revealed, positive, intralesional, intracytoplasmic immunoreactivity within epithelial cells of multiple tissues of all animals with PVLs. PCR assays amplified OvHV-2 DNA from multiple tissues of the animals that contained MCFV proteins, confirming the MCFV identified as OvHV-2. Additionally, bovine coronavirus (BCoV) nucleic acids were amplified from tissues of all animals, including the animal not infected by OvHV-2. Collectively, these findings confirmed the participation of OvHV-2 in the development of the disease patterns observed in these animals that were concomitantly infected by BCoV and provide additional confirmation that cattle can be subclinically infected with OvHV-2. Consequently, the real occurrence of OvHV-2-related disease may be more elevated than reported, since asymptomatic or subclinically infected animals are not likely to be investigated for OvHV-2. Furthermore, PVLs should be included as possible histologic indicators of OvHV-2-related diseases in ruminants.

Transforming the Emotional Intelligence of the Feeders in Agribusinesses into the Development of Task Performance and Counterproductive Work Behaviors during the COVID-19 Pandemic

Simple Summary

This research proposes a psychological model to describe how leadership can deal with the work burnout of feeders in livestock production agribusinesses to solve the important problems of mental health and well-being, thereby increasing the sustainable work of feeders. The empirical evidence comes from 240 livestock feeders from 80 Taiwanese livestock production agribusinesses. The research results can push the literature of emotional intelligence and implementation methods to livestock production agribusinesses.

Abstract

The present research poses a novel multilevel model to describe how transformational leadership can significantly affect task performance and counterproductive work behavior through intermediary effects of emotional intelligence, work engagement, and work burnout. The empirical data is from 240 livestock feeders from 80 Taiwanese livestock production agribusinesses. The empirical results demonstrate that leadership could indeed transform the emotional intelligence of livestock feeders into positive task performance and negative counterproductive work behavior. The research results can provide an implementation method for livestock production agribusinesses to achieve the sustainable work of feeders in agribusinesses through handling task performance and counterproductive work behavior of feeders.

Middle East respiratory syndrome coronavirus vaccine based on a propagation-defective RNA replicon elicited sterilizing immunity in mice

Self-amplifying RNA replicons are promising platforms for vaccine generation. Their defects in one or more essential functions for viral replication, particle assembly, or dissemination make them highly safe as vaccines. We previously showed that the deletion of the envelope (E) gene from the Middle East respiratory syndrome coronavirus (MERS-CoV) produces a replication-competent propagation-defective RNA replicon (MERS-CoV-ΔE). Evaluation of this replicon in mice expressing human dipeptidyl peptidase 4, the virus receptor, showed that the single deletion of the E gene generated an attenuated mutant. The combined deletion of the E gene with accessory open reading frames (ORFs) 3, 4a, 4b, and 5 resulted in a highly attenuated propagation-defective RNA replicon (MERS-CoV-Δ[3,4a,4b,5,E]). This RNA replicon induced sterilizing immunity in mice after challenge with a lethal dose of a virulent MERS-CoV, as no histopathological damage or infectious virus was detected in the lungs of challenged mice. The four mutants lacking the E gene were genetically stable, did not recombine with the E gene provided in trans during their passage in cell culture, and showed a propagation-defective phenotype in vivo. In addition, immunization with MERS-CoV-Δ[3,4a,4b,5,E] induced significant levels of neutralizing antibodies, indicating that MERS-CoV RNA replicons are highly safe and promising vaccine candidates.

A Review of the Neutrophil Extracellular Traps (NETs) from Cow, Sheep and Goat Models

This review provides insight into the importance of understanding NETosis in cows, sheep, and goats in light of the importance to their health, welfare and use as animal models. Neutrophils are essential to innate immunity, pathogen infection, and inflammatory diseases. The relevance of NETosis as a conserved innate immune response mechanism and the translational implications for public health are presented. Increased understanding of NETosis in ruminants will contribute to the prediction of pathologies and design of strategic interventions targeting NETs. This will help to control pathogens such as coronaviruses and inflammatory diseases such as mastitis that impact all mammals, including humans. Definition of unique attributes of NETosis in ruminants, in comparison to what has been observed in humans, has significant translational implications for one health and global food security, and thus warrants further study.

SARS-CoV-2, a Threat to Marine Mammals? A Study from Italian Seawaters

Zoonotically transmitted coronaviruses were responsible for Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), causing the dramatic Coronavirus Disease-2019 (CoViD-19) pandemic, which affected public health, the economy, and society on a global scale. The impact of the SARS-CoV-2 pandemic permeated into our environment and wildlife as well; in particular, concern has been raised about the viral occurrence and persistence in aquatic and marine ecosystems. The discharge of untreated wastewaters carrying infectious SARS-CoV-2 into natural water systems that are home to sea mammals may have dramatic consequences on vulnerable species. The efficient transmission of coronaviruses raises questions regarding the contributions of virus-receptor interactions. The main receptor of SARS-CoV-2 is Angiotensin Converting Enzyme-2 (ACE-2), serving as a functional receptor for the viral spike (S) protein. This study aimed, through the comparative analysis of the ACE-2 receptor with the human one, at assessing susceptibility to SARS-CoV-2 for different species of marine mammals living in Italian waters. We also determined, by means of immunohistochemistry, ACE-2 receptor localization in the lung tissue from different cetacean species, in order to provide a preliminary characterization of ACE-2 expression in the marine mammal respiratory tracts. Furthermore, to evaluate if and how Italian wastewater management and coastal exposition to extreme weather events may led to susceptible marine mammal populations being exposed to SARS-CoV-2, geomapping data were carried out and overlapped. The results showed the potential SARS-CoV-2 exposure for marine mammals inhabiting Italian coastal waters, putting them at risk when swimming and feeding in specific risk areas. Thus, we highlighted the potential hazard of the reverse zoonotic transmission of SARS-CoV-2 infection, along with its impact on marine mammals regularly inhabiting the Mediterranean Sea, while also stressing the need for appropriate action in order to prevent further damage to specific vulnerable populations.

New Brazilian variant of the SARS-CoV-2 (P1/Gamma) of COVID-19 in Alagoas state

Since the beginning of 2020, health authorities have been monitoring the cases of Coronavirus Disease 2019 (COVID-19), which has grown every day in Brazil and around the world, becoming pandemic. The new coronavirus, also called SARS-CoV-2 by scientists spreads rapidly, causing fear, deaths, and threats for the economy of several countries. This work aimed to describe the clinical characterization of the first cases of a new Brazilian variant of SARS-CoV-2 (P1) in the State of Alagoas, which occurred on February 16th, 2021. Two cases are described: first, a person infected in Amazonas State, where the new variant P1 was first described, who migrated to Alagoas State, and second, a case of probable community transmission within Alagoas, since the patient had no history of recent travel. In both confirmed cases the symptoms were mild. Further studies are necessary to better understand the clinical behavior of P1 SARS-CoV-2 variant and also the associated sequelae in the context of COVID-19.