Adaptive immunity and histopathology in frog virus 3-infected Xenopus

Robert, Jacques; Morales, Heidi; Buck, Wayne R.; Cohen, Nicholas; Marr, Shauna; Gantress, Jennifer

doi:10.1016/j.virol.2004.12.012

Cited by 82 publications

(89 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Considering that renal tubular epithelium is a target cell for Ranavirus (Gantress et al, 2003;Converse and Green, 2005;Robert et al, 2005), it is logical to assume that Ranavirus may be more likely to invade damaged cells. Such a relationship was expected in organisms with hyaline droplet degeneration of the renal tubules (e.g., observed with myxosporidia) but not found.…”

Section: Discussionmentioning

confidence: 99%

Pathologic Findings in Larval and Juvenile Anurans Inhabiting Farm Ponds in Tennessee, Usa

Miller

Gray

Rajeev

et al. 2009

Journal of Wildlife Diseases

View full text Add to dashboard Cite

ABSTRACT:Amphibian populations are declining globally, yet general pathologic surveys for freeranging amphibians are uncommon. Pathologic surveys are necessary to provide insight into the impacts of humans on emergence of pathogens in amphibian populations. During 2005, 104 American bullfrog (Rana catesbeiana) and 80 green frog (Rana clamitans) larvae and 40 green frog juveniles were collected from farm ponds in Tennessee, and complete necropsies were performed. Diagnostic testing included bacterial culture, virus testing, fecal parasite analysis, and histologic examination. Gross and histologic examination revealed that all individuals, except one bullfrog tadpole, could be classified as clinically normal. The clinically abnormal tadpole had swollen erythemic legs, and was positive for Aeromonas hydrophila but negative for Ranavirus. Parasites were common (43%) among specimens, with myxosporidium and trematodes most often noted. Commensal and opportunistic microorganisms were cultured from the tissues. Ranavirus was detected in 29% of individuals but generally not associated with significant histopathologic changes. Myxosporidia and Ranavirus coinfections occurred in 7 and 26% of green and bullfrog tadpoles, respectively, with the highest coinfection rate (83%) in bullfrog tadpoles during winter. Protozoans were most common in fecal examination. These data can serve as a baseline to evaluate the presence of clinical disease in larval and juvenile amphibians.

show abstract

Section: Discussionmentioning

confidence: 99%

Pathologic Findings in Larval and Juvenile Anurans Inhabiting Farm Ponds in Tennessee, Usa

Miller

Gray

Rajeev

et al. 2009

Journal of Wildlife Diseases

View full text Add to dashboard Cite

show abstract

“…Ranaviruses are known to infect many other organs, including skin, kidney, intestines and the nervous system ; thus, inferences from our results are limited to the liver. The results from different target organs may also differ depending on the amount of time between ranavirus exposure and testing (Robert et al 2005). In Xenopus laevis, the liver becomes infected after the kidneys (Robert et al 2005) so that liver infection may be indicative of multi-systemic infection.…”

Section: Methodsmentioning

confidence: 99%

“…The results from different target organs may also differ depending on the amount of time between ranavirus exposure and testing (Robert et al 2005). In Xenopus laevis, the liver becomes infected after the kidneys (Robert et al 2005) so that liver infection may be indicative of multi-systemic infection. Inasmuch as target organs may differ for different types of virus and host species, our results may be limited to American bullfrog tadpoles and the isolates used in our study.…”

Section: Methodsmentioning

confidence: 99%

Reliability of non-lethal surveillance methods for detecting ranavirus infection

Gray¹,

Miller²,

Hoverman³

2012

Dis. Aquat. Org.

View full text Add to dashboard Cite

Ranaviruses have been identified as the etiologic agent in many amphibian die-offs across the globe. Polymerase chain reaction (PCR) is commonly used to detect ranavirus infection in amphibian hosts, but the test results may vary between tissue samples obtained by lethal and non-lethal procedures. Testing liver samples for infection is a common lethal sampling technique to estimate ranavirus prevalence because the pathogen often targets this organ and the liver is easy to identify and collect. However, tail clips or swabs may be more practicable for ranavirus surveillance programs compared with collecting and euthanizing animals, especially for uncommon species. Using PCR results from liver samples for comparison, we defined false-positive test results as occurrences when a non-lethal technique indicated positive but the liver sample was negative. Similarly, we defined false-negative test results as occurrences when a non-lethal technique was negative but the liver sample was positive. Using these decision rules, we estimated false-negative and false-positive rates for tail clips and swabs. Our study was conducted in a controlled facility using American bullfrog Lithobates catesbeianus tadpoles; false-positive and falsenegative rates were estimated after different periods of time following exposure to ranavirus. False-negative and false-positive rates were 20 and 6%, respectively, for tail samples, and 22 and 12%, respectively, for swabs. False-negative rates were constant over time, but false-positive rates decreased with post-exposure duration. Our results suggest that non-lethal sampling techniques can be useful for ranavirus surveillance, although the prevalence of infection may be underestimated when compared to results obtained with liver samples. KEY WORDS: Iridovirus · Ranavirus · Molecular technique · PCR · Sampling · SurveillanceResale or republication not permitted without written consent of the publisher shipment in order to verify that they are not infected with ranavirus. Also, in order to better understand the threat that ranaviruses pose to native amphibians, surveillance for this pathogen is becoming more widespread in wild populations (e.g. Gray et al. 2007, 2009b, Greer et al. 2009, Hoverman et al. 2012. Given the increased need to test amphibians for rana virus infection, the usefulness of non-lethal sampling techniques needs to be determined.Common non-lethal techniques for pathogen testing include tail or toe clips and swabs of the oral cavity, cloaca and skin , Kriger et al. 2006, St-Amour & Lesbarrères 2007, Driskell et al. 2009, Gray et al. 2009b. Testing amphibians for infection using non-lethal techniques has several advantages -including, presumably, a low impact on wild or captive populations, the possibility of repeat sampling of the same individual, and generally, a lower cost compared to full necropsies of euthanized animals (Greer & Collins 2007, St-Amour & Lesbarrères 2007, Green et al. 2010. These advantages are particularly useful when monitoring infection in uncommo...

show abstract

“…Necrosis of the colonic mucosa seemed to have been associated with an accumulation of mucus and bacterial overgrowth in the colon of some individuals, which was shed as a cohesive pearly white mass approximately 24 h prior to death. Whereas the main lesion reported in immunocompromised X. laevis infected with FV3 was necrosis of the epithelium of renal proximal tubules (Robert et al, 2005), damage to the epithelium of the renal tubules in wood frogs was observed only in some individuals and it was often mild. Although there may be a true difference in the type of tissue targeted by FV3 in each species, the published histopathological images of FV3 infection in X. laevis appear to represent haematopoietic rather than tubular necrosis (Robert et al, 2005).…”

Section: J Forzá N and Othersmentioning

confidence: 97%

“…Whereas the main lesion reported in immunocompromised X. laevis infected with FV3 was necrosis of the epithelium of renal proximal tubules (Robert et al, 2005), damage to the epithelium of the renal tubules in wood frogs was observed only in some individuals and it was often mild. Although there may be a true difference in the type of tissue targeted by FV3 in each species, the published histopathological images of FV3 infection in X. laevis appear to represent haematopoietic rather than tubular necrosis (Robert et al, 2005). In some of the frogs that survived the infection, and particularly in the one survivor of the group that received 10 3.43 p.f.u.…”

Section: J Forzá N and Othersmentioning

confidence: 97%

Clinical signs, pathology and dose-dependent survival of adult wood frogs, Rana sylvatica, inoculated orally with frog virus 3 Ranavirus sp., Iridoviridae

Forzán

Jones

Vanderstichel

et al. 2015

Journal of General Virology

View full text Add to dashboard Cite

School of Veterinary and Biomedical Sciences, James Cook University, Townsville, Australia Amphibian populations suffer massive mortalities from infection with frog virus 3 (FV3, genus Ranavirus, family Iridoviridae), a pathogen also involved in mortalities of fish and reptiles. Experimental oral infection with FV3 in captive-raised adult wood frogs, Rana sylvatica (Lithobates sylvaticus), was performed as the first step in establishing a native North American animal model of ranaviral disease to study pathogenesis and host response. Oral dosing was successful; LD 50 was 10 2.93 (2.42-3.44) p.f.u. for frogs averaging 35 mm in length. Onset of clinical signs occurred 6-14 days post-infection (p.i.) (median 11 days p.i.) and time to death was 10-14 days p.i. (median 12 days p.i.). Each tenfold increase in virus dose increased the odds of dying by 23-fold and accelerated onset of clinical signs and death by approximately 15 %. Ranavirus DNA was demonstrated in skin and liver of all frogs that died or were euthanized because of severe clinical signs. Shedding of virus occurred in faeces (7-10 days p.i.; 3-4.5 days before death) and skin sheds (10 days p.i.; 0-1.5 days before death) of some frogs dead from infection. Most common lesions were dermal erosion and haemorrhages; haematopoietic necrosis in bone marrow, kidney, spleen and liver; and necrosis in renal glomeruli, tongue, gastrointestinal tract and urinary bladder mucosa. Presence of ranavirus in lesions was confirmed by immunohistochemistry. Intracytoplasmic inclusion bodies (probably viral) were present in the bone marrow and the epithelia of the oral cavity, gastrointestinal tract, renal tubules and urinary bladder. Our work describes a ranavirus-wood frog model and provides estimates that can be incorporated into ranavirus disease ecology models.

show abstract

Adaptive immunity and histopathology in frog virus 3-infected Xenopus

Cited by 82 publications

References 27 publications

Pathologic Findings in Larval and Juvenile Anurans Inhabiting Farm Ponds in Tennessee, Usa

Pathologic Findings in Larval and Juvenile Anurans Inhabiting Farm Ponds in Tennessee, Usa

Reliability of non-lethal surveillance methods for detecting ranavirus infection

Clinical signs, pathology and dose-dependent survival of adult wood frogs, Rana sylvatica, inoculated orally with frog virus 3 Ranavirus sp., Iridoviridae

Contact Info

Product

Resources

About