Natural or experimental infection of domestic cats and virus transmission from humans to captive predatory cats suggest that felids are highly susceptible to SARS-CoV-2 infection. However, it is ...unclear which cells and compartments of the respiratory tract are infected. To address this question, primary cell cultures derived from the nose, trachea, and lungs of cat and lion were inoculated with SARS-CoV-2. Strong viral replication was observed for nasal mucosa explants and tracheal air-liquid interface cultures, whereas replication in lung slices was less efficient. Infection was mainly restricted to epithelial cells and did not cause major pathological changes. Detection of high ACE2 levels in the nose and trachea but not lung further suggests that susceptibility of feline tissues to SARS-CoV-2 correlates with ACE2 expression. Collectively, this study demonstrates that SARS-CoV-2 can efficiently replicate in the feline upper respiratory tract ex vivo and thus highlights the risk of SARS-CoV-2 spillover from humans to felids.
Culturing respiratory epithelial cells at an air-liquid interface (ALI) represents an established method for studies on infection or toxicology by the generation of an in vivo-like respiratory tract ...epithelial cellular layer. Although primary respiratory cells from a variety of animals have been cultured, an in-depth characterization of canine tracheal ALI cultures is lacking despite the fact that canines are a highly relevant animal species susceptible to various respiratory agents, including zoonotic pathogens such as severe acute respiratory coronavirus 2 (SARS-CoV-2). In this study, canine primary tracheal epithelial cells were cultured under ALI conditions for four weeks, and their development was characterized during the entire culture period. Light and electron microscopy were performed to evaluate cell morphology in correlation with the immunohistological expression profile. The formation of tight junctions was confirmed using transepithelial electrical resistance (TEER) measurements and immunofluorescence staining for the junctional protein ZO-1. After 21 days of culture at the ALI, a columnar epithelium containing basal, ciliated and goblet cells was seen, resembling native canine tracheal samples. However, cilia formation, goblet cell distribution and epithelial thickness differed significantly from the native tissue. Despite this limitation, tracheal ALI cultures could be used to investigate the pathomorphological interactions of canine respiratory diseases and zoonotic agents.
Several animal species are susceptible to SARS-CoV-2 infection, as documented by case reports and serological and in vivo infection studies. However, the susceptibility of many animal species remains ...unknown. Furthermore, the expression patterns of SARS-CoV-2 entry factors, such as the receptor angiotensin-converting enzyme 2 (ACE2), as well as transmembrane protease serine subtype 2 (TMPRSS2) and cathepsin L (CTSL), cellular proteases involved in SARS-CoV-2 spike protein activation, are largely unexplored in most species. Here, we generated primary cell cultures from the respiratory tract of domestic and wildlife animals to assess their susceptibility to SARS-CoV-2 infection. Additionally, the presence of
,
and
within respiratory tract compartments was investigated in a range of animals, some with unknown susceptibility to SARS-CoV-2. Productive viral replication was observed in the nasal mucosa explants and precision-cut lung slices from dogs and hamsters, whereas culture models from ferrets and multiple ungulate species were non-permissive to infection. Overall, whereas
and
were equally expressed in the respiratory tract, the expression levels of
were more variable, suggesting that a restricted availability of ACE2 may contribute to reduced susceptibility. Summarized, the experimental infection of primary respiratory tract cell cultures, as well as an analysis of entry-factor distribution, enable screening for SARS-CoV-2 animal reservoirs.
Multicentric B cell lymphoma in an 8-week-old calf Frischkorn, Marie; Fortelny, Michael; Ciurkiewicz, Malgorzata ...
Tierärztliche Praxis. Ausgabe G, Grosstiere/Nutztiere
51, Številka:
2
Journal Article
The presented report describes a case of sporadic bovine leukosis and its disease progression in an 8-week old, male cross-breed calf (Red Holstein Fleckvieh). The calf was initially presented due to ...suspect pulmonary infection. However, generalized enlargement of the subcutaneous lymph nodes was noticed, which is untypical for this disease. Based on the hematologic findings of highly increased numbers of lymphoblasts in peripheral blood as well as the sonographic examination of the lymph nodes, sporadic bovine leukosis was suspected. The calf died suddenly, three weeks after initial presentation. Pathohistological examination revealed a high-degree enlargement of all lymph nodes as well as an infiltration of nearly all organs and tissues with a monomorphic round cell population. These cells were also detected in bone marrow cytology. Immunhistochemical examination was performed and the cells reacted positive for the B-cell markers Pax 5 and CD20. Virologic examination for enzootic bovine leukosis was negative. In conjunction with the diagnosis of multicentric B-cell lymphoma, the test results indicated a juvenile form of sporadic bovine lymphoma.
Canine distemper virus (CDV), belonging to the genus
, is a highly contagious pathogen. It is infectious in a wide range of host species, including domestic and wildlife carnivores, and causes severe ...systemic disease with involvement of the respiratory tract. In the present study, canine precision-cut lung slices (PCLSs) were infected with CDV (strain R252) to investigate temporospatial viral loads, cell tropism, ciliary activity, and local immune responses during early infection ex vivo. Progressive viral replication was observed during the infection period in histiocytic and, to a lesser extent, epithelial cells. CDV-infected cells were predominantly located within the bronchial subepithelial tissue. Ciliary activity was reduced in CDV-infected PCLSs, while viability remained unchanged when compared to controls. MHC-II expression was increased in the bronchial epithelium on day three postinfection. Elevated levels of anti-inflammatory cytokines (interleukin-10 and transforming growth factor-β) were observed in CDV-infected PCLSs on day one postinfection. In conclusion, the present study demonstrates that PCLSs are permissive for CDV. The model reveals an impaired ciliary function and an anti-inflammatory cytokine response, potentially fostering viral replication in the lung during the early phase of canine distemper.
Fatal Boomslang bite in the Northern Cape Krüger, Hendrik Johannes; Lemke, Franz Gustav
African Journal of Emergency Medicine,
03/2019, Letnik:
9, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The authors describe an atypical presentation after a Boomslang bite with rapid progression of symptoms and death.
A young gentleman was bitten and rapidly decompensated before monovalent antivenom ...could be administered, with fatal results.
This case highlights the importance of having monovalent Boomslang antivenom rapidly available in all referral centres that may be involved in the management of Boomslang bite victims.
The emergence of the coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inspired rapid research efforts targeting the host range, ...pathogenesis and transmission mechanisms, and the development of antiviral strategies. Genetically modified mice, rhesus macaques, ferrets, and Syrian golden hamsters have been frequently used in studies of pathogenesis and efficacy of antiviral compounds and vaccines. However, alternatives to in vivo experiments, such as immortalized cell lines, primary respiratory epithelial cells cultured at an air–liquid interface, stem/progenitor cell-derived organoids, or tissue explants, have also been used for isolation of SARS-CoV-2, investigation of cytopathic effects, and pathogen–host interactions. Moreover, initial proof-of-concept studies for testing therapeutic agents can be performed with these tools, showing that animal-sparing cell culture methods could significantly reduce the need for animal models in the future, following the 3R principles of replace, reduce, and refine. So far, only few studies using animal-derived primary cells or tissues have been conducted in SARS-CoV-2 research, although natural infection has been shown to occur in several animal species. Therefore, the need for in-depth investigations on possible interspecies transmission routes and differences in susceptibility to SARS-CoV-2 is urgent. This review gives an overview of studies employing alternative culture systems like primary cell cultures, tissue explants, or organoids for investigations of the pathophysiology and reverse zoonotic potential of SARS-CoV-2 in animals. In addition, future possibilities of SARS-CoV-2 research in animals, including previously neglected methods like the use of precision-cut lung slices, will be outlined.
On millennial or even centennial time scales, the activity of rapid flowing ice can affect climate variability and global sea level through release of meltwater into the ocean and positive feedback ...loops to the climate system. At the surge-type glacier Brúarjökull, an outlet of the Vatnajökull ice cap, eastern Iceland, extremely rapid ice flow was sustained by overpressurized water causing decoupling beneath a thick sediment sequence that was coupled to the glacier. This newly discovered mechanism has far reaching consequences for our understanding of fast-flowing ice and its integration with sediment discharge and meltwater release.
The purpose of this paper is to investigate the geographical distribution of pH values in Danish soils of different ages representing the main Saalian and Weichselian ice advances. The investigation ...is based on soil sampling from top- and subsoils in soil profiles located in a nationwide 7-km grid. The data have been analysed using statistical spatial analysis methods, and a model has been erected demonstrating areas of homogeneous low, high, or inhomogeneous pH values relative to deposits from different ice advances and regional variations in land use.
Purpose - Beyond critique of current maturity models, the research literature has neglected to supply empirical evidence of the value knowledge management (KM) holds for organizations. The majority ...of studies, in common with other emergent business philosophies, are focused on large organizations of developed economies, where readily available implementation resources are an underlying assumption. This paper aims to address this issue and to assess the correlation between the successful institutionalization of KM and organizational performance (OP) in a developing economy.Design methodology approach - From a large urban South African university engaged in numerous collaboration programs with industry, the authors gained insight into KM maturity and organizational performance (OP) of three industry groups, over a five-year period. The authors apply an inventory developed by Kruger and Snyman to a set of nine organisations distributed over three economic sectors in South Africa.Findings - By evaluating the relationship between KM maturity and OP from within three "time dependent" perspectives, insight was gained to answer the aim of the research undertaken, "Is there a correlation between KM maturity and OP in South Africa?" Diagrammatic presentation of OP scores and KM maturity growth revealed that in five out of the nine organizations there is a clearly identifiable relationship between KM maturity and OP in South Africa in both entities over the period under investigation. In certain instances, the correlations were not easily noticeable and or were non-existent. From a mathematical perspective, in comparing the correlation between growth in KM maturity and year-on-year growth in OP, it was revealed that six of the eight companies that recorded positive growth in KM maturity also recorded positive (year-on-year) growth in OP. In a similar manner, it was established that the company recording negative growth in KM maturity also recorded negative (year-on-year) growth in OP.Research limitations implications - Because the South African scenario can be considered a benchmark for developing economies characterized by continued change, diversity and even elements of silent intolerance and conflict, this study may be viewed as a "pilot study" to provide a baseline and insight into future research of KM for enabling OP.Originality value - This paper is of relevance to strategic managers and KM practitioners interested in gaining insight into the correlation between KM maturity and organisational performance.
PDF
