Pathology of animal models of COVID-19

This paper describes the pathogenesis and immunology of Macaca mulatta, Macaca fascicularis, ferrets, Syrian golden hamsters (Mesocricetus auratus), mice, cats, mink, pigs and rabbits used as models for SARS-CoV-2 infection.

Analysis of intermediate hosts and susceptible animals of SARS-CoV-2 by computational methods

COVID-19, a disease caused by SARS-CoV-2 that produces major symptoms of pneumonia, has been a disaster worldwide. The traceability of SARSCoV- 2 and the discovery of susceptible animal species is crucial to halt viral transmission and explore the mechanism of cross-species transmission. We selected 82 representative ACE2 sequences from the 1000 sequences with the closest homology to the hACE2 protein. All selected ACE2 proteins were subjected to homology modeling. Potential natural and intermediate hosts, as well as animal species susceptible to SARS-CoV-2, were analyzed systematically by calculation of the binding free energy of ACE2 protein to the RBD of SARSCoV- 2. Primates, some wild Felidae, civets, goats, spotted hyenas and golden hamsters are susceptible to SARS-CoV-2 and may be potential intermediate hosts, whereas pangolins, birds and reptiles are unlikely to be intermediate hosts. Mice, rats and guinea pig are not susceptible to SARS-CoV-2. Given their possible susceptibility, non-human primates, goats and golden hamsters could potentially be used as experimental models to examine SARS-CoV-2 infection without transgenesis. Herein, possible candidates for the natural and intermediate hosts of SARS-CoV-2 are suggested, to provide guidance for subsequent studies.

New evidence for aerosol transmission of SARS-CoV-2

Since the outbreak of COVID-19, the opinion that the aerosol plays a key role in the transmission of SARS-CoV-2 has been controversial. The COVID-19 pandemic has continued interpersonal transmission for more than two years, especially after the emergence of Delta and Omicron variants, making the situation of COVID-19 pandemic more severe. The transmission of SARS-COV-2 variants was significantly accelerated and the time of transmission between generations was significantly shortened. Therefore, it has been questioned to attribute the close-range infection to droplet transmission. The point that the aerosol can also has a close-range transmission and may play a dominant role is neglected under the influence of traditional transmission mode of respiratory infectious diseases. A large number of studies have shown that normal breath, talk and cough could release a large number of respiratory aerosol particles, and the virus particles were mainly tiny particles(=5.0 micro m). The biological activity and infectivity of the droplet nuclei have been questioned in the studies on their physicochemical properties. Animal models of ferrets and hamsters showed that SARS-COV-2 could transmit via aerosol. Therefore, the new evidence for the aerosol transmission of SARS-COV-2 was reviewed in the article so as to provide latest evidence-based evidence for prevention and control of COVID-19.

Research-Relevant Conditions and Pathology of Laboratory Mice, Rats, Gerbils, Guinea Pigs, Hamsters, Naked Mole Rats, and Rabbits.

Animals are valuable resources in biomedical research in investigations of biological processes, disease pathogenesis, therapeutic interventions, safety, toxicity, and carcinogenicity. Interpretation of data from animals requires knowledge not only of the processes or diseases (pathophysiology) under study but also recognition of spontaneous conditions and background lesions (pathology) that can influence or confound the study results. Species, strain/stock, sex, age, anatomy, physiology, spontaneous diseases (noninfectious and infectious), and neoplasia impact experimental results and interpretation as well as animal welfare. This review and the references selected aim to provide a pathology resource for researchers, pathologists, and veterinary personnel who strive to achieve research rigor and validity and must understand the spectrum of "normal" and expected conditions to accurately identify research-relevant experimental phenotypes as well as unusual illness, pathology, or other conditions that can compromise studies involving laboratory mice, rats, gerbils, guinea pigs, hamsters, naked mole rats, and rabbits.

Susceptibility of cell lines from different animal species to Porcine Deltacoronavirus

[Objective] To explore whether porcine deltacoronavirus (PDCoV) can infect and proliferate in different animal species-derived cell lines. [Methods] The Sichuan isolate CHN-SC2015of PDCoV was inoculated in twelve cell lines derived from hamster,poultry,monkey, human and swine. After at least five blindly passages in each cell line, the virus was identified by RT-PCR,RT-q PCR, indirect immunofluorescence assay (IFA), and sequencing. [Results] PDCoV caused distinct cytopathic effect (CPE) in Vero,PAM,PK15,ST, and LLC-PK1 cells at the 1st passage (P1) and proliferated to various degrees in PAM,PK15,ST, and LLC-PK1 cells, while the CPE gradually disappeared during subsequent passages in Vero and PAM cells. Except that in the three susceptible cell lines (PK15,LLC-PK1, and ST), the viral copies of the infected cell lines gradually decreased with the increase in passages, and PDCoV could not be detected at P4 or P5 of DEF,Marc-145,HEK-293,ZYM-SIEC02, and PAM cells. PCR results showed that PDCoV could be detected only in CEF and Vero cells at P5. The IFA results showed that PDCoV could infect other cell lines except BHK-21 and ZYM-SIEC02, and specific immunofluorescence was observed in PK15,LLC-PK1, and ST cells at P1,P3, and P9. Therefore, only three cell lines (PK15,LLC-PK1, and ST) were suitable for serial passage, with the virus titers up to 107.11,107.00, and 107.37 TCID50/mL at P9,respectively. After passage in different cell lines,CHN-SC2015 accumulated 14 nucleotide mutations corresponding to 12 amino acid mutations. [Conclusion] This study indicates that PDCoV can infect a variety of cells in vitro, suggesting that it may have the potential of cross-species transmission.

Animal role in the COVID-19 pandemic

The first cases of human disease from COVID-19 were recorded in December 2019 in China, from where it spread rapidly around the world. COVID-19, the third emerging coronavirus infection in humans, is caused by the new SARS-CoV-2 virus, which can cause a severe acute respiratory syndrome in some infected individuals. Previous research has revealed the possible animal origin of SARS-CoV-2, with bats considered as natural reservoirs and pangolins as intermediate hosts. To better understand COVID-19 and more successfully control the spread, domestic and wild animals have been infected in experimental conditions. On the other hand, in some species, infections have been recorded in field conditions. Natural infections have been reported in dogs, cats, tigers, lions, and minks, who have been in contact with SARS-CoV-2 positive humans. The reverse transmission of the pathogen, from infected animals to humans, has only been recorded on intensive mink farms. To better understand the pathogenesis of this disease's causative agent, drugs and vaccine trials, some experimental infections were performed on animal models, of which ferrets, rhesus macaques, and hamsters proved to be the most suitable. This article aimed to consolidate known data on the potential origin of SARS-CoV-2, its transmission to humans, infections in animals, and their significance in the epidemiology of COVID-19.

64th Annual Meeting of the Pathology Section of the German Veterinary Medical Association

These proceedings contain 25 papers from the 64th Annual Meeting of the Pathology Section of the German Veterinary Medical Association. Topics include tumour infiltrating lymphocytes in mammary carcinomas in domestic rabbits;what decides good or bad? - global gene expression analysis of the adenoma of the hepatoid perianal glands and adenocarcinoma the canine apocrine anal sac glands;the canine cutaneous histiocytoma - boring or perspective in immuno-oncology?;impact of antibiotic pretreatment on ventilator-induced lung injury: contradiction between histology and transcriptome analysis?;characterization of murine satellite glial cells of the dorsal root ganglia - a unique cell population with potential regenerative capacities;impact of antibiotic pretreatment on ventilator-induced lung injury: contradiction between histology and transcriptome analysis?;primary diffuse leptomeningeals oligodendrogliomatosis in a cat;pathomorphological studies of fibroadnexal dysplasia in dogs;pyogranulomatous inflammation in multiple Organs of a dog with evidence of Corynebacterium tuberculostearicum;ovary tumors in cats - overview of the examination material from 2009-2020 and case report of a recurrent dysgerminoma;atherosclerosis in the dog;spinal neuroenteric cyst in one Saint Bernard;MENX - an endogenous model for pseudohypoxic pheochromocytomas;molecular Level Evolution II: similarities of CLCA2 in sauropsids and mammals;in vivo detection of double-stranded Ribonucleic acid (RNA) as an early detection marker unclear viral infections using the example of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) in experimental infected hamsters;the role of different mast cell subtypes in the context of intestinal carcinogenesis - a species-comparative approach;an underestimated treasure in paraffin - establishment of a global transcriptome analysis canine tumors from FFPE material based on QuantSeq 3' technology;well researched? - an approximation of the role of CLCA1 in joints through usage molecular databases;integration of digitized historical and cytopathology into an open source DICOM database and viewer system;3R 3D: skin model for the study of viral infections;CARD9 signaling promotes hippocampal neurogenesis and cytokine balance in a mouse model of virus-induced encephalitis;neuropathological changes after intranasal infection with Rift Valley fever virus - a murine model for human encephalitis;a T-cell a day keeps Theiler away - the influence non-reactive T-cells on the course of a Theiler virus infection in mice with C57BL/6 background;digitization in pathology - new opportunities and their obstacles;and specific features of satellite glial cells of dog and pig.