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Transmission electron microscopic images of reptilian ferlavirus in the snake epididymis. Representative TEM images from a big-eyed pit viper snake from colony A. (A). Intracytoplasmic, large, electron-dense viral factories (arrowheads) were observed in multiple degenerated epithelial cells represented by cellular vacuolation and a disrupted nuclear membrane (N). (B) A cytoplasmic inclusion body contains numerous pleomorphic, electron-dense viral nucleocapsid particles displacing the nucleus (N). (C) Ferlaviral ribonucleocapsid particle was seen in the nucleus (N). (D) Pleomorphic ribonuleocapsid with herringbone-like structure. Bars indicate as described in figures. CM cellular membrane.
Source publication
Reptilian ferlavirus, a pathogen of serious concern in snakes, has been reported in Western countries, but little is known about its prevalence in Thailand, where many snake breeding farms are located. In this study, we investigated the reptilian ferlavirus via swab samples derived from 49 diseased snakes and 77 healthy snakes as well as tissue sam...
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... demonstration of reptilian ferlavirus. As evidence of strong ISH signals were observed in the male reproductive tract and to provide additional support for our ISH results, transmission electron microscopy (TEM) was used to ultrastructurally demonstrate the ferlaviral particles in the male reproductive tract (Fig. 4). Overall, the observed cells in the epididymis of both snakes (big-eyed pit viper No. 1 from colony A and cobra No. 1 from colony E) revealed severe degeneration and necrosis, represented by cellular vacuolation and disrupted epithelial membrane (Fig. 4A). The interpretation of those tissues was cofounded by degenerative changes. ...
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... used to ultrastructurally demonstrate the ferlaviral particles in the male reproductive tract (Fig. 4). Overall, the observed cells in the epididymis of both snakes (big-eyed pit viper No. 1 from colony A and cobra No. 1 from colony E) revealed severe degeneration and necrosis, represented by cellular vacuolation and disrupted epithelial membrane (Fig. 4A). The interpretation of those tissues was cofounded by degenerative changes. Numerous densely aggregated intracytoplasmic electron-dense materials were found frequently in the tubular basement membrane of the epididymis and efferent duct (Fig. 4B). Electron-dense nucleocapsid particles that packed and eccentrically replaced the ...
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... degeneration and necrosis, represented by cellular vacuolation and disrupted epithelial membrane (Fig. 4A). The interpretation of those tissues was cofounded by degenerative changes. Numerous densely aggregated intracytoplasmic electron-dense materials were found frequently in the tubular basement membrane of the epididymis and efferent duct (Fig. 4B). Electron-dense nucleocapsid particles that packed and eccentrically replaced the round-to-oval flattened nucleus were seen in the freely floating cells in the efferent tubules and in the lumen of the epididymis (Fig. 4C). The materials contained numerous pleomorphic nucleocapsid filaments with estimated sizes ranging from 200-400 nm. ...
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... electron-dense materials were found frequently in the tubular basement membrane of the epididymis and efferent duct (Fig. 4B). Electron-dense nucleocapsid particles that packed and eccentrically replaced the round-to-oval flattened nucleus were seen in the freely floating cells in the efferent tubules and in the lumen of the epididymis (Fig. 4C). The materials contained numerous pleomorphic nucleocapsid filaments with estimated sizes ranging from 200-400 nm. Freely floating virions were seen in the vas deferens of both examined snake tissues (Fig. ...
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... the round-to-oval flattened nucleus were seen in the freely floating cells in the efferent tubules and in the lumen of the epididymis (Fig. 4C). The materials contained numerous pleomorphic nucleocapsid filaments with estimated sizes ranging from 200-400 nm. Freely floating virions were seen in the vas deferens of both examined snake tissues (Fig. ...
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... demonstration of reptilian ferlavirus. As evidence of strong ISH signals were observed in the male reproductive tract and to provide additional support for our ISH results, transmission electron microscopy (TEM) was used to ultrastructurally demonstrate the ferlaviral particles in the male reproductive tract (Fig. 4). Overall, the observed cells in the epididymis of both snakes (big-eyed pit viper No. 1 from colony A and cobra No. 1 from colony E) revealed severe degeneration and necrosis, represented by cellular vacuolation and disrupted epithelial membrane (Fig. 4A). The interpretation of those tissues was cofounded by degenerative changes. ...
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... used to ultrastructurally demonstrate the ferlaviral particles in the male reproductive tract (Fig. 4). Overall, the observed cells in the epididymis of both snakes (big-eyed pit viper No. 1 from colony A and cobra No. 1 from colony E) revealed severe degeneration and necrosis, represented by cellular vacuolation and disrupted epithelial membrane (Fig. 4A). The interpretation of those tissues was cofounded by degenerative changes. Numerous densely aggregated intracytoplasmic electron-dense materials were found frequently in the tubular basement membrane of the epididymis and efferent duct (Fig. 4B). Electron-dense nucleocapsid particles that packed and eccentrically replaced the ...
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... degeneration and necrosis, represented by cellular vacuolation and disrupted epithelial membrane (Fig. 4A). The interpretation of those tissues was cofounded by degenerative changes. Numerous densely aggregated intracytoplasmic electron-dense materials were found frequently in the tubular basement membrane of the epididymis and efferent duct (Fig. 4B). Electron-dense nucleocapsid particles that packed and eccentrically replaced the round-to-oval flattened nucleus were seen in the freely floating cells in the efferent tubules and in the lumen of the epididymis (Fig. 4C). The materials contained numerous pleomorphic nucleocapsid filaments with estimated sizes ranging from 200-400 nm. ...
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... electron-dense materials were found frequently in the tubular basement membrane of the epididymis and efferent duct (Fig. 4B). Electron-dense nucleocapsid particles that packed and eccentrically replaced the round-to-oval flattened nucleus were seen in the freely floating cells in the efferent tubules and in the lumen of the epididymis (Fig. 4C). The materials contained numerous pleomorphic nucleocapsid filaments with estimated sizes ranging from 200-400 nm. Freely floating virions were seen in the vas deferens of both examined snake tissues (Fig. ...
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... the round-to-oval flattened nucleus were seen in the freely floating cells in the efferent tubules and in the lumen of the epididymis (Fig. 4C). The materials contained numerous pleomorphic nucleocapsid filaments with estimated sizes ranging from 200-400 nm. Freely floating virions were seen in the vas deferens of both examined snake tissues (Fig. ...
Citations
... Previous work has shown that ferlaviruses are capable of infecting a wide range of reptile species [5,10,11,14,[20][21][22], while some evidence has suggested that a number of factors may influence the course of clinical disease and pathological changes in infected animals. Ferlavirus infections have most often been documented in viperid species [1,3,4,[23][24][25][26][27][28], often during severe disease outbreaks in collections. They have also been found in wild-caught viperids from South America [29]. ...
... They have also been found in wild-caught viperids from South America [29]. Reports of infection in colubrids are slightly rarer, and include colubrid infections in mixed collections together with viperid snakes as well as in cases in which no contact with viperid snakes was reported [6,10,24,28,30,31]. There are a number of studies reporting detection of ferlaviruses in pythons. ...
... In cases in which virus characterization has been reported, genogroup B viruses have been associated with respiratory or CNS disease or sudden death in boas, colubrids, pythons, and vipers in various collections in Europe [20]; with an outbreak of respiratory disease and high mortality in a mixed collection of elapids, vipers, and pythons in Croatia [35]; with colubrids or elapids experiencing respiratory disease in snake farms in China [31]; and with viperids, colubrids, elapids, and pythons with respiratory disease (but not in clinically healthy snakes) in several collections in Thailand [28]. Virus detection by at least one of the methods used was successful in 75% of the lung samples, 50% of the intestinal samples, 42% of the pancreas samples, 75% of the kidney samples, and 67% of the brain samples. ...
Ferlaviruses are a cause of respiratory disease in snakes. Four genogroups (A, B, C, and tortoise) have been described. Disease development is believed to depend on virus, host, and environment-specific factors. There is evidence of transmission of individual strains between genera and families of reptiles. A genogroup B virus previously used in a transmission study with corn snakes (Pantherophis guttatus) was applied intratracheally in ball pythons (Python regius) using the same protocol as for the corn snakes. Ball pythons became infected, with initial mild clinical signs noted four days post infection (p.i.), and the virus was detected first in the lungs on day 4 and spread to the intestine, pancreas, kidney and brain. Hematology showed an increase in circulating lymphocytes which peaked on day 28 p.i. Antibodies were detected beginning on day 16 and increased steadily to the end of the study. In comparison to corn snakes, ball pythons exhibited milder clinical signs and pathological changes, faster development of and higher antibody titers, and a hematological reaction dominated by lymphocytosis in contrast to heterophilia in corn snakes. These differences in host reaction to infection are important to understand ferlavirus epidemiology as well as for clinical medicine and diagnostic testing.
... B. constrictor are susceptible to a wide range of viral, bacterial and parasitic infections. Important viral agents reported in this species are reptarenaviruses (the causative agents of Boid inclusion body disease, BIBD) (Hetzel et al., 2013) and the ophidian paramyxovirus (Piewbang et al. 2021). Parasitic infections are also of relevance; reported are, for example, arthropods (mites, e.g. ...
The common boa (Boa constrictor) belongs to the family Boidae and represents one of the most popular traded and kept snake species in captivity. The early diagnosis, prevention and prophylaxis of diseases in this species, and in reptiles in general, still pose major challenges, also due to the lack of reliable reference values. This prompted us to conduct a study on clinically healthy captive B. constrictor to assess their basic health parameters in the blood (haematological and biochemical values, stress markers). Several parameters differed significantly between younger (<3 years) and older (≥3 years) boas; in the latter, the percentages of eosinophils, the haemoglobin and haematocrit levels, as well as the albumin and total protein levels, were higher. In male snakes, cholesterol levels were significantly higher than in females. Light and electron microscopy as well as immunohistochemistry served to identify and determine the morphological features of peripheral blood cells, that is, heterophils, basophils, eosinophils, azurophils, monocytes, lymphocytes, thrombocytes and erythrocytes. Leukocyte subpopulations, that is, T and B cells and monocytes, were also identified based on specific marker expression. The study provides data on haematological, biochemical and stress hormone levels, suitable as reference values, and on the blood cell morphology of B. constrictor which can serve as a guideline for further research on this species.
... The slides were counterstained with nuclear fast red, dried at room temperature, and mounted with a coverslip. For the negative controls, two sets of TiPV qPCR-positive sections were incubated with a canine protoparvovirus-1 (CPPV-1) probe (Piewbang et al., 2021b) or a reptilian ferlavirus probe (Piewbang et al., 2021c). The TiLV-infected sections derived from experimental infection (Yamkasem et al., 2021d) that tested negative for TiPV using qPCR were used as additional negative controls for TiPV probe incubation. ...
... The sections were then deparaffinized, rehydrated, and bulk stained in a staining solution containing 2% (v/v) OsO4. Then, a pre-TEM process was performed using modified pop-off techniques, as previously described (Piewbang et al., 2021c;Piewbang et al., 2020). The sections were cut at 80 nm, placed on a copper grid, and visualized using a TEM system with the same settings as described above. ...
Tilapia culture is an essential protein-rich food production sector worldwide. The emergence of pathogens is sometimes associated with fatal outbreaks in tilapia, which dramatically slow production and result in severe economic losses. While tilapia lake virus (TiLV) infection has been associated with fatal diseases in tilapia, the novel tilapia parvovirus (TiPV) has been recently identified and reported to be associated with mass mortality events in tilapia farming. In this study, we identified the coinfection of a novel TiPV and TiLV in multiple independent tilapia farms in Thailand, thus causing significant losses. The full-length genomes of the TiPV were characterized, and a phylogenetic analysis was performed, indicating the genetic diversity of the TiPV and multiple amino acid mutations found in the structural protein VP1. Using the in situ hybridization (ISH) technique, TiPV was localized in the gills, heart, brain, liver, pancreas, spleen, intestine, kidney, eyes, and muscles of tilapia, with evidence of cellular tropism. The TiLV localization was confirmed using a dual ISH/immunohistochemistry protocol and transmission electron microscopy, which indicated a potential association with pathological alterations. Both TiPV and TiLV were successfully propagated in tilapia brain cells and the fish cell line E-11. This study also provided an indication of the potential cellular roles of the pathological features of TiPV coinfection with TiLV in red hybrid tilapia. Since mutations in the parvovirus structural protein led to virulence and extensive infection in susceptible hosts, several point mutations in the VP1 gene with amino acid signatures of TiPV found in tilapia in Thailand warrant future observations. Although the synergism between TiPV and TiLV coinfection remains undetermined, the contributory role of these two viruses requires intensive focus. Further investigations should lead to a suitable strategy for disease control.
Feline bocaviruses (FBoVs) have been recognized as novel feline pathogens associated with gastrointestinal diseases. Although bocavirus infections in humans and animals present a broad range of clinical symptoms including neurologic diseases, the neuropathology caused by FBoV infection in cats is unknown. This study aims to investigate the presence of bocavirus in the brain samples of 78 cats showing neurologic deficits and 41 healthy cats using polymerase chain reaction (PCR) and to present the pathological findings of FBoV infection in brain tissues. Only 5 (6.41%, 5/78) cats with neurological deficit were FBoV‐positive on PCR screening and were characterized as FBoV‐1 (4/5) and FBoV‐3 (1/5) by sequencing. Among FBoV‐positive cases, viral DNA were detected by PCR in the cerebrum and brain stem of all FBoV‐positive cases and rarely detected in the cerebellum of some cases. Histologically, all FBoV‐positive cases revealed a variety of inflammatory responses. Among these, 80% (4/5 cases) showed multifocal neuronal vacuolation, mainly found in the cerebrum and brain stem. Eosinophilic inclusion‐like materials were found within the nuclei of glial cells in the FBoV‐3 positive case. In situ hybridization revealed FBoV DNA in oligodendroglia and vacuolated neurons detected using dual labeling with Olig‐2 and NeuN immunohistochemistry, respectively. Transmission electron microscopy confirmed the presence of FBoV‐3 virions in the nuclei of glial cells. Apart from localization in brain tissues, the FBoV DNA were also detected in multiple lymph nodes (5/5) and some intestines (2/5) of such positive cases, suggesting both parenteral and enteral infections. Complete genome sequence analysis revealed genetic diversity of detected FBoV‐1, which were closely related to the strains found in China and Hong Kong, while the detected FBoV‐3 presented distant monophyletic clade to previously detected FBoV‐3 sequences. The FBoVs, together, should be considered a neurotropic virus and a possible cause for neuronal vacuolation in cats with neurologic deficits. This article is protected by copyright. All rights reserved
