scholarly journals The Effect Of Salinity On Enterocytozoon hepatopenaei Infection in Penaeus vannamei Under Experimental Conditions

2021 ◽  
Author(s):  
Luis Fernando Aranguren ◽  
Faris Alghamdi ◽  
Katrien De Belder ◽  
J. Lin ◽  
Hung N. Mai ◽  
...  
Keyword(s):  
Penaeus Monodon ◽  
Oral Route ◽  
Western Hemisphere ◽  
Penaeus Vannamei ◽  
Asian Countries ◽  
Experimental Conditions ◽  
Reliable Source ◽  
Specific Pathogen ◽  
Enterocytozoon Hepatopenaei ◽  
First Time

Abstract Background: Enterocytozoon hepatopenaei (EHP) is an enteric pathogen that affects Penaeus vannamei and Penaeus monodon shrimp in many SE Asian countries. In the western hemisphere, EHP was reported for the first time in 2016 in farmed P. vannamei in Venezuela. Anecdotal evidence suggests that EHP is more prevalent in grow-out ponds where the salinity is high (>15 parts per thousand (ppt)) compared to grow-out ponds with low salinities (<5 ppt). Considering that P. vannamei is an euryhaline species, we were interested in knowing if EHP can propagate in P. vannamei in low salinities. Results: In this study, we described an experimental infection using fecal strings as a source inoculum. Specific Pathogen Free (SPF) P. vannamei were maintained at three different salinities (2 ppt, 15 ppt, and 30 ppt) while continuously challenged using feces from known EHP-infected P. vannamei over a period of three weeks. The fecal strings, used as a source of EHP inocula in the challenges, was sufficient to elicit an infection in shrimp maintained at the three salinities. The infectivity of EHP in shrimp reared at 2 ppt, 15 ppt, and 30 ppt salinities was confirmed by PCR and histopathology. The prevalence and the severity of the EHP infection was higher at 30 ppt than at 2 ppt and 15 ppt. Conclusion: The data suggests that fecal strings are a reliable source of EHP inoculum to conduct experimental challenges via the fecal-oral route. An EHP infection can occur at a salinity as low as 2 ppt, however, the prevalence and the severity of the EHP infection is higher at a salinity of 30 ppt.

scholarly journals The effect of salinity on enterocytozoon hepatopenaei infection in Penaeus vannamei under experimental conditions

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
L. F. Aranguren Caro ◽  
F. Alghamdi ◽  
K. De Belder ◽  
J. Lin ◽  
H. N. Mai ◽  
...  
Keyword(s):  
Penaeus Monodon ◽  
Oral Route ◽  
Western Hemisphere ◽  
Penaeus Vannamei ◽  
Asian Countries ◽  
Experimental Conditions ◽  
Reliable Source ◽  
Specific Pathogen ◽  
Enterocytozoon Hepatopenaei ◽  
First Time

Abstract Background Enterocytozoon hepatopenaei (EHP) is an enteric pathogen that affects Penaeus vannamei and Penaeus monodon shrimp in many SE Asian countries. In the western hemisphere, EHP was reported for the first time in 2016 in farmed P. vannamei in Venezuela. Anecdotal evidence suggests that EHP is more prevalent in grow-out ponds where the salinity is high (> 15 parts per thousand (ppt)) compared to grow-out ponds with low salinities (< 5 ppt). Considering that P. vannamei is an euryhaline species, we were interested in knowing if EHP can propagate in P. vannamei in low salinities. Results In this study, we described an experimental infection using fecal strings as a source inoculum. Specific Pathogen Free (SPF) P. vannamei were maintained at three different salinities (2 ppt, 15 ppt, and 30 ppt) while continuously challenged using feces from known EHP-infected P. vannamei over a period of 3 weeks. The fecal strings, used as a source of EHP inocula in the challenges, was sufficient to elicit an infection in shrimp maintained at the three salinities. The infectivity of EHP in shrimp reared at 2 ppt, 15 ppt, and 30 ppt salinities was confirmed by PCR and histopathology. The prevalence and the severity of the EHP infection was higher at 30 ppt than at 2 ppt and 15 ppt. Conclusion The data suggests that fecal strings are a reliable source of EHP inoculum to conduct experimental challenges via the fecal-oral route. An EHP infection can occur at a salinity as low as 2 ppt, however, the prevalence and the severity of the EHP infection is higher at a salinity of 30 ppt.

scholarly journals The Effect of Salinity on Enterocytozoon hepatopenaei Infection in Penaeus vannamei Under Experimental Conditions

2020 ◽  
Author(s):  
Luis Fernando Aranguren ◽  
Faris Alghamdi ◽  
Katrien De Belder ◽  
J. Lin ◽  
Hung N. Mai ◽  
...  
Keyword(s):  
Penaeus Monodon ◽  
Oral Route ◽  
Western Hemisphere ◽  
Penaeus Vannamei ◽  
Asian Countries ◽  
Experimental Conditions ◽  
Reliable Source ◽  
Specific Pathogen ◽  
Enterocytozoon Hepatopenaei ◽  
First Time

Abstract Background: Enterocytozoon hepatopenaei (EHP) is an enteric pathogen that affects Penaeus vannamei and Penaeus monodon shrimp in many SE Asian countries. In the western hemisphere, EHP was reported for the first time in 2016 in farmed P. vannamei in Venezuela. Anecdotal evidence suggests that EHP is more prevalent in grow-out ponds where the salinity is high (>15 parts per thousand (ppt)) compared to grow-out ponds with low salinities (<5 ppt). Considering that P. vannamei is an euryhaline species, we were interested in knowing if EHP can propagate in P. vannamei in low salinities.Results: In this study, we described an experimental infection using fecal strings as a source inoculum. Specific Pathogen Free (SPF) P. vannamei were maintained at three different salinities (2 ppt, 15 ppt, and 30 ppt) while continuously challenged using feces from known EHP-infected P. vannamei over a period of three weeks. The fecal strings, used as a source of EHP inocula in the challenges, was sufficient to elicit an infection in shrimp maintained at the three salinities. The infectivity of EHP in shrimp reared at 2 ppt, 15 ppt, and 30 ppt salinities was confirmed by PCR and histopathology. The prevalence and the severity of the EHP infection was higher at 30 ppt than at 2 ppt and 15 ppt.Conclusion: The data suggests that fecal strings are a reliable source of EHP inoculum to conduct experimental challenges via the fecal-oral route. An EHP infection can occur at a salinity as low as 2 ppt, however, the prevalence and the severity of the EHP infection is higher at a salinity of 30 ppt.

scholarly journals The Effect Of Salinity On Enterocytozoon Hepatopenaei  Infection In Penaeus Vannamei Under Experimental Conditions

2020 ◽  
Author(s):  
Luis Fernando Aranguren ◽  
Faris Alghamdi ◽  
Katrien De Belder ◽  
J. Lin ◽  
Hung N. Mai ◽  
...  
Keyword(s):  
Reliable Method ◽  
Oral Route ◽  
Western Hemisphere ◽  
Penaeus Vannamei ◽  
Specific Pathogen Free ◽  
Asian Countries ◽  
Experimental Conditions ◽  
Specific Pathogen ◽  
Enterocytozoon Hepatopenaei ◽  
First Time

Abstract Background: Enterocytozoon hepatopenaei (EHP) is an enteric pathogen that affects Penaeus vannamei and P. monodon shrimp in many SE Asian countries. In the western hemisphere, EHP was reported for the first time in 2016 in farmed P. vannamei in Venezuela. Anecdotal evidence suggests that EHP is more prevalent in grow-out ponds where the salinity is high (>15 parts per thousand (ppt) compared to grow-out ponds with low salinities (<5 ppt). Considering that P. vannamei is an euryhaline species, we were interested in knowing if EHP can propagate in P. vannamei in low salinities. Result: In this study, we described an experimental infection using fecal strings as a source inoculum. Specific Pathogen Free (SPF) P. vannamei were maintained at two different salinities including 2 ppt and 30 ppt, and continuously challenged using feces from known EHP-infected P. vannamei over a period of three weeks. The fecal strings, used as a source of EHP inocula in the challenges, was sufficient to elicit infection in shrimp maintained at both salinities. Infectivity of EHP in shrimp reared at 2 and 30 ppt salinities was confirmed by PCR and histopathology. The prevalence and the severity of EHP infection was higher at 30 ppt than 2 ppt. Conclusion: The data suggest that fecal strings is a reliable method to conduct EHP challenges via fecal-oral route. EHP infection can occur at a salinity as low as 2 ppt, although the prevalence and the severity of EHP infection is higher at a salinity of 30 ppt compared to 2 ppt.

Evidences supporting Enterocytozoon hepatopenaei association with white feces syndrome in farmed Penaeus vannamei in Venezuela and Indonesia

2020 ◽  
Vol 141 ◽  
pp. 71-78
Author(s):  
LF Aranguren Caro ◽  
HN Mai ◽  
O Pichardo ◽  
R Cruz-Flores ◽  
B Hanggono ◽  
...  
Keyword(s):  
Latin America ◽  
Gastrointestinal Tract ◽  
Strong Association ◽  
Penaeus Monodon ◽  
Penaeus Vannamei ◽  
Asian Countries ◽  
Emerging Pathogen ◽  
First Case ◽  
History Of ◽  
Enterocytozoon Hepatopenaei

White feces syndrome (WFS) is an emerging and poorly described disease characterized by the presence of floating white fecal strings in shrimp (Penaeus monodon and P. vannamei) grow-out ponds. WFS has been associated with several pathogens, including Enterocytozoon hepatopenaei. This association is based on the fact that in areas where E. hepatopenaei has been reported, there was also a high WFS prevalence. E. hepatopenaei is an emerging pathogen that has affected cultured shrimp in Indonesia, Vietnam, China, Thailand, and India. In 2016, we reported the presence of E. hepatopenaei in farmed P. vannamei in Venezuela. In this study, we describe the first case of WFS in Venezuela associated with E. hepatopenaei. The white fecal strings and shrimp displaying white feces along the gastrointestinal tract observed in this study were similar to the gross signs found in WFS-impacted P. vannamei in SE Asian countries. Furthermore, we describe a strong association between WFS and E. hepatopenaei in the samples obtained from Venezuela and Indonesia. Quantification of E. hepatopenaei in WFS-affected ponds, ponds with a history of WFS, and ponds with no WFS showed that E. hepatopenaei loads were significantly higher in WFS-affected ponds. Furthermore, these findings constitute the first report of WFS being associated with E. hepatopenaei in farmed shrimp in Latin America. Additionally, we propose that the gross signs of WFS such as floating whitish fecal strings can be used as an indicator of the presence of E. hepatopenaei in countries where E. hepatopenaei is endemic.

scholarly journals Comparative investigation of lasing and amplification performance in cryogenic Yb:YLF systems

2021 ◽  
Vol 127 (3) ◽  
Author(s):  
Umit Demirbas ◽  
Martin Kellert ◽  
Jelto Thesinga ◽  
Yi Hua ◽  
Simon Reuter ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Estimation Method ◽  
Laser Cavity ◽  
Comparative Investigation ◽  
Limiting Factor ◽  
Experimental Conditions ◽  
Temperature Estimation ◽  
Transverse Temperature ◽  
First Time

AbstractWe present detailed experimental results with cryogenic Yb:YLF gain media in rod-geometry. We have comparatively investigated continuous-wave (cw) lasing and regenerative amplification performance under different experimental conditions. In the cw lasing experiments effect of crystal doping, cw laser cavity geometry and pump wavelength on lasing performance were explored. Regenerative amplification behavior was analyzed and the role of depolarization losses on performance was investigated. A recently developed temperature estimation method was also employed for the first time in estimating average crystal temperature under lasing conditions. It is shown that the thermal lens induced by transverse temperature gradients is the main limiting factor and strategies for future improvements are discussed. To the best of our knowledge, the achieved results in this study (375 W in cw, and 90 W in regenerative amplification) are the highest average powers ever obtained from this system via employing the broadband E//a axis.

scholarly journals Genetic and Antigenic Characterization of Avian Avulavirus Type 6 (AAvV-6) Circulating in Canadian Wild Birds (2005–2017)

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 543
Author(s):  
Tamiko Hisanaga ◽  
Catherine Soos ◽  
Nicola Lewis ◽  
Oliver Lung ◽  
Matthew Suderman ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Fusion Gene ◽  
Full Genome ◽  
Genome Sequences ◽  
Viral Shedding ◽  
Genetic Groups ◽  
Antigenic Characterization ◽  
Specific Pathogen ◽  
First Time

We describe for the first time the genetic and antigenic characterization of 18 avian avulavirus type-6 viruses (AAvV-6) that were isolated from wild waterfowl in the Americas over the span of 12 years. Only one of the AAvV-6 viruses isolated failed to hemagglutinate chicken red blood cells. We were able to obtain full genome sequences of 16 and 2 fusion gene sequences from the remaining 2 isolates. This is more than double the number of full genome sequences available at the NCBI database. These AAvV-6 viruses phylogenetically grouped into the 2 existing AAvV-6 genotype subgroups indicating the existence of an intercontinental epidemiological link with other AAvV-6 viruses isolated from migratory waterfowl from different Eurasian countries. Antigenic maps made using HI assay data for these isolates showed that the two genetic groups were also antigenically distinct. An isolate representing each genotype was inoculated in specific pathogen free (SPF) chickens, however, no clinical symptoms were observed. A duplex fusion gene based real-time assay for the detection and genotyping of AAvV-6 to genotype 1 and 2 was developed. Using the developed assay, the viral shedding pattern in the infected chickens was examined. The chickens infected with both genotypes were able to shed the virus orally for about a week, however, no significant cloacal shedding was detected in chickens of both groups. Chickens in both groups developed detectable levels of anti-hemagglutinin antibodies 7 days after infection.

scholarly journals Extrusion Processing of Amaranth and Quinoa into Gluten-Free Snack Foods for Celiac and Gluten-Free Diets

2017 ◽  
Vol 6 (5) ◽  
pp. 107
Author(s):  
Caitlin Gearhart ◽  
Kurt A. Rosentrater
Keyword(s):  
Scale Up ◽  
Food Products ◽  
Poor Quality ◽  
Expansion Ratio ◽  
Gluten Free ◽  
Experimental Conditions ◽  
Snack Foods ◽  
Extrusion Processing ◽  
Nutritional Benefits ◽  
First Time

Because of the growth of gluten intolerance and Celiac disease, there is growing interest in development of gluten-free foods. Beyond just being gluten-free, such foods can also have other positive nutritional benefits to human health. Extrusion processing is commonly used to produce a wide variety of human food products. Gluten-free grains can be a processing challenge, however, due to lack of proper binding, which can lead to poor quality food products. This research explores how extrusion parameters impacted the quality of amaranth- and quinoa-based extrudates. The specific objectives of this project included extruding each of the grains, then measuring extrudate properties, such as color, unit density, expansion ratio, and durability. Both the quinoa and amaranth were extruded as raw grain, as well as ground to 2mm and 1mm particle sizes. Other experimental conditions included moisture contents of 20% and 40% (d.b.), and extruder screw speeds of 50 rpm and 100 rpm. All treatments were successfully extruded, and all extrudates had high quality attributes, making this the first time either quinoa or amaranth was extruded without any binding ingredients. This study provides information useful for commercial scale-up.

scholarly journals Survival of Gastric and Enterohepatic Helicobacter spp. in Water: Implications for Transmission

2008 ◽  
Vol 74 (6) ◽  
pp. 1805-1811 ◽  
Author(s):  
N. F. Azevedo ◽  
C. Almeida ◽  
I. Fernandes ◽  
L. Cerqueira ◽  
S. Dias ◽  
...  
Keyword(s):  
Membrane Integrity ◽  
Hierarchical Cluster ◽  
Culture Method ◽  
Oral Route ◽  
Human Stomach ◽  
Aquatic Environments ◽  
Integrity Assessment ◽  
Environmental Reservoir ◽  
H Pylori ◽  
First Time

ABSTRACT Part of the reason for rejecting aquatic environments as possible vectors for the transmission of Helicobacter pylori has been the preference of this microorganism to inhabit the human stomach and hence use a direct oral-oral route for transmission. On the other hand, most enteric bacterial pathogens are well known for being able to use water as an environmental reservoir. In this work, we have exposed 13 strains of seven different Helicobacter spp. (both gastric and enterohepatic) to water and tracked their survival by standard plating methods and membrane integrity assessment. The influence of different plating media and temperatures and the presence of light on recovery was also assessed. There was good correlation between cultivability and membrane integrity results (Pearson's correlation coefficient = 0.916), confirming that the culture method could reliably estimate differences in survival among different Helicobacter spp. The species that survived the longest in water was H. pylori (>96 h in the dark at 25°C), whereas H. felis appeared to be the most sensitive to water (<6 h). A hierarchical cluster analysis demonstrated that there was no relationship between the enterohepatic nature of Helicobacter spp. and an increased time of survival in water. This work assesses for the first time the survival of multiple Helicobacter spp., such has H. mustelae, H. muridarum, H. felis, H. canadensis, H. pullorum, and H. canis, in water under several conditions and concludes that the roles of water in transmission between hosts are likely to be similar for all these species, whether enterohepatic or not.

scholarly journals Pedicularis L. Genus: Systematics, Botany, Phytochemistry, Chemotaxonomy, Ethnopharmacology and Other

2019 ◽  
Author(s):  
Claudio Frezza ◽  
Alessandro Venditti ◽  
Chiara Toniolo ◽  
Daniela De Vita ◽  
Ilaria Serafini ◽  
...  
Keyword(s):  
Traditional Medicine ◽  
Natural Compounds ◽  
Asian Countries ◽  
Comprehensive Review ◽  
Points Of View ◽  
First Time

In this review, the relevance of plants belonging to the Pedicularis L. genus was explored from different points of view. Particular emphasys was given especially to the phytochemistry and the ethnopharmacology of the genus since several classes of natural compounds have been evidenced within it and several Pedicularis species are well known to be employed in the traditional medicine of many Asian countries. Nevertheless, some important conclusions on the chemotaxonomic and chemosystematic aspects of the genus were also provided for the first time. This work represents the first total comprehensive review on the genus Pedicularis.

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