Wisconsin Veterinary Diagnostic Laboratory

Madison, WI, United States

Wisconsin Veterinary Diagnostic Laboratory

Madison, WI, United States
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News Article | October 24, 2015
Site: phys.org

The Wisconsin Department of Natural Resources (DNR) launched a quick response and, working with the Wisconsin Veterinary Diagnostic Laboratory (WVDL), quickly learned that a deadly virus was responsible: viral hemorrhagic septicemia virus, or VHSv. First detected in the U.S. among freshwater fish in 2005—including muskellunge, perch and walleye—VHSv had already caused mass fish die-offs in the Great Lakes and several regional waterways connected to them. The DNR subsequently encouraged anglers and boaters to adopt practices that have helped slow the spread of VHSv into other inland lakes in Wisconsin, but a new study led by Tony Goldberg, professor of epidemiology and pathobiological sciences at the University of Wisconsin-Madison School of Veterinary Medicine (SVM), shows the virus is still circulating in Lake Winnebago. It also shows that some fish actually survive VHSv infection but could be sources of future infections. "It's still possible to transmit the virus to fish in other lakes," says WVDL Virology Section Head Kathy Toohey-Kurth, a member of the research team and a clinical professor at the SVM. Though large numbers of dead fish are no longer washing up on shore, "it shows the virus is still transmitting and people still have to be careful to follow all the guidelines from the DNR, like not carrying buckets of bait between waters," she adds. Drum are a food source for popular game fish like walleye and sauger. VHSv does not infect people, but 28 species of fish are vulnerable to the virus, which causes them to bleed to death. Some of these species, like bass and muskellunge, are iconic fishes that help support Wisconsin's $2.3 billion-a-year sport fishing industry. The findings of the current study, and the new diagnostic test upon which it relied, are aiding the DNR in efforts to monitor game fish in waterways throughout the state, in addition to better informing its stocking efforts. The diagnostic test was developed by Toohey-Kurth—an expert in veterinary diagnostic testing—and Anna Wilson-Rothering, a WVDL scientist and lead author of the study. Wilson-Rothering is a former DNR employee who was involved in early VHSv surveillance efforts and earned her master's degree from UW-Madison studying the virus. Efforts to develop the test started in 2009, shortly after Goldberg joined the faculty of UW-Madison and became involved in measures to prevent the spread of VHSv. "I met with the DNR and we discussed some of the problems," says Goldberg, who is also associate director for research at the Global Health Institute and John D. MacArthur Chair at UW-Madison. "It was very difficult to diagnose. It required you to kill the fish and take its internal organs to isolate the virus. It was also a lengthy process and very labor intensive." The new test requires just a small blood sample from the fish, which can be caught, sampled and released back to the water. The researchers take the blood back to the lab and look for evidence the fish were once infected with the virus: a specific antibody produced by the fish in response to infection. Like fingerprints on a doorknob at the scene of a crime, antibodies show the virus was once there. The research team worked with the DNR to collect blood from nearly 600 drum in Lake Winnebago twice a year in 2011 and 2012—both spring and fall—and used the test to look for VHSv antibodies. The team also collected fish to look for those that may still harbor active virus, finding it in just one: a large, older female. This provided "proof that the virus is still present in the lake," Goldberg says. "Fish are still being exposed." The researchers believe that enough drum have been infected with and survived the virus, their antibodies providing protection from re-infection, that mass fish kills have probably not occurred. This phenomenon is referred to as "herd immunity" and is similar to what happens when a large group of people is vaccinated against a disease like measles. If enough individuals are protected, less of the virus circulates and infects the unprotected. But once levels of protected individuals fall, either from deaths from other causes, or as large numbers of new, unprotected fish are born, another wave of VHSv-induced deaths could occur. Researchers will continue to monitor for the virus and the study, they say, underscores the importance of collaborative scientific efforts with the DNR and the role these efforts play in addressing the needs of the state. "This test will continue to be useful to monitor VHSv transmission,"says Toohey-Kurth, "and with further refinements we will be able to better assist our state partners with management of the disease." The study is published in the Journal of Clinical Microbiology.

Springer D.J.,New York State Department of Health | Springer D.J.,University at Albany | Springer D.J.,Duke University | Ren P.,New York State Department of Health | And 12 more authors.
PLoS ONE | Year: 2010

Cryptococcus gattii, an emerging fungal pathogen of humans and animals, is found on a variety of trees in tropical and temperate regions. The ecological niche and virulence of this yeast remain poorly defined. We used Arabidopsis thaliana plants and plant-derived substrates to model C. gattii in its natural habitat. Yeast cells readily colonized scratch-wounded plant leaves and formed distinctive extracellular fibrils (40-100 nm diameter ×500-3000 nm length). Extracellular fibrils were observed on live plants and plant-derived substrates by scanning electron microscopy (SEM) and by high voltage-EM (HVEM). Only encapsulated yeast cells formed extracellular fibrils as a capsule-deficient C. gattii mutant completely lacked fibrils. Cells deficient in environmental sensing only formed disorganized extracellular fibrils as apparent from experiments with a C. gattii STE12α mutant. C. gattii cells with extracellular fibrils were more virulent in murine model of pulmonary and systemic cryptococcosis than cells lacking fibrils. C. gattii cells with extracellular fibrils were also significantly more resistant to killing by human polymorphonuclear neutrophils (PMN) in vitro even though these PMN produced elaborate neutrophil extracellular traps (NETs). These observations suggest that extracellular fibril formation could be a structural adaptation of C. gattii for cell-to-cell, cell-to-substrate and/or cell-to-phagocyte communications. Such ecological adaptation of C. gattii could play roles in enhanced virulence in mammalian hosts at least initially via inhibition of host PMN-mediated killing. © 2010 Springer et al.

Appler K.K.,New York State Department of Health | Brown A.N.,New York State Department of Health | Brown A.N.,University at Albany | Brown A.N.,Ordway Research Institute | And 11 more authors.
PLoS ONE | Year: 2010

Most acute infections with RNA viruses are transient and subsequently cleared from the host. Recent evidence, however, suggests that the RNA virus, West Nile virus (WNV), not only causes acute disease, but can persist long term in humans and animal models. Our goal in this study was to develop a mouse model of WNV persistence. We inoculated immunocompetent ice subcutaneously (s.c.) with WNV and examined their tissues for infectious virus and WNV RNA for 16 months (mo) post-inoculation (p.i.). Infectious WNV persisted for 1 mo p.i. in all mice and for 4 mo p.i. in 12% of mice, and WNV RNA persisted for up to 6 mo p.i. in 12% of mice. The frequency of persistence was tissue dependent and was in the following order: skin, spinal cord, brain, lymphoid tissues, kidney, and heart. Viral persistence occurred in the face of a robust antibody response and in the presence of inflammation in the brain. Furthermore, persistence in the central nervous system (CNS) and encephalitis were observed even in mice with subclinical infections. Mice were treated at 1 mo p.i. with cyclophosphamide, and active viral replication resulted, suggesting that lymphocytes are functional during viral persistence. In summary, WNV persisted in the CNS and periphery of mice for up to 6 mo p.i. in mice with subclinical nfections. These results have implications for WNV-infected humans. In particular, immunosuppressed patients, organ transplantation, and long term sequelae may be impacted by WNV persistence. © 2010 Appler et al.

Grodsky S.M.,University of Wisconsin - Madison | Behr M.J.,University of Wisconsin - Madison | Behr M.J.,Wisconsin Veterinary Diagnostic Laboratory | Gendler A.,University of Wisconsin - Madison | And 4 more authors.
Journal of Mammalogy | Year: 2011

Wind turbine-associated bat mortality is occurring at unanticipated rates, yet our understanding of the causes of these fatalities is limited. The prominent proximate causes of bat deaths at wind turbines are direct collision (i.e., blunt-force trauma) and barotrauma. The objectives of this study were to use veterinary diagnostic procedures to determine the lesions associated with bats killed by wind turbines and investigate relationships between patterns of injuries and proximate causes of death. A majority of the bats (74%; 29 of 39) examined by radiology had bone fractures; most of these fractures were in the wings and none was in the hind limbs. Visual inspection resulted in 33% fewer detected bone fractures when compared with radiology results. Bats dropped from a turbine nacelle (91.44 m) to determine extent and type(s) of bone fracture did not show signs of significant bone damage. Approximately one-half (52%; 12 of 23) of bats whose ears were examined had mild to severe hemorrhaging in the middle or inner ears (or both). None of the bats found during this study had any pre-existing disease. It is difficult to attribute individual fatalities exclusively to either direct collision or barotrauma. Gross necropsy, histopathology, and radiology complement each others' deficiencies and together give the best insight into cause of death. Delayed lethal effects after nonlethal contact with wind turbines are poorly understood and difficult to quantify by mortality searches alone but can result in underestimating bat mortality caused by wind energy facilities. © 2011 American Society of Mammalogists.

News Article | October 24, 2015
Site: www.sciencedaily.com

In May 2007, hundreds of freshwater drum — also known as sheepshead — turned up dead in Lake Winnebago and nearby Little Lake Butte des Morts, both inland lakes near Oshkosh, Wisconsin. The fish were splotched with red and their eyes were swollen and bulging. The Wisconsin Department of Natural Resources (DNR) launched a quick response and, working with the Wisconsin Veterinary Diagnostic Laboratory (WVDL), quickly learned that a deadly virus was responsible: viral hemorrhagic septicemia virus, or VHSv.

Muller L.K.,U.S. Geological Survey | Lorch J.M.,University of Wisconsin - Madison | Lindner D.L.,U.S. Department of Agriculture | O'Connor M.,Wisconsin Veterinary Diagnostic Laboratory | And 2 more authors.
Mycologia | Year: 2013

The fungus Geomyces destructans is the causative agent of white-nose syndrome (WNS), a disease that has killed millions of North American hibernating bats. We describe a real-time TaqMan PCR test that detects DNA from G. destructans by targeting a portion of the multicopy intergenic spacer region of the rRNA gene complex. The test is highlysensitive, consistently detecting as little as 3.3 fg genomic DNA from G. destructans. The real-time PCR test specifically amplified genomic DNA from G. destructans but did not amplify target sequence from 54 closely related fungal isolates (including 43 Geomyces spp. isolates) associated with bats. The test was qualified further by analyzing DNA extracted from 91 bat wing skin samples, and PCR results matched histopathology findings. These data indicate the real-time TaqMan PCR method described herein is a sensitive, specific and rapid test to detect DNA from G. destructans and provides a valuable tool for WNS diagnostics and research. © 2013 by The Mycological Society of America.

Lorch J.M.,University of Wisconsin - Madison | Muller L.K.,U.S. Geological Survey | Russell R.E.,U.S. Geological Survey | O'Connor M.,Wisconsin Veterinary Diagnostic Laboratory | And 2 more authors.
Applied and Environmental Microbiology | Year: 2013

White-nose syndrome (WNS) is an emerging disease of hibernating bats caused by the recently described fungus Geomyces destructans. First isolated in 2008, the origins of this fungus in North America and its ability to persist in the environment remain undefined. To investigate the correlation between manifestation of WNS and distribution of G. destructans in the United States, we analyzed sediment samples collected from 55 bat hibernacula (caves and mines) both within and outside the known range of WNS using a newly developed real-time PCR assay. Geomyces destructans was detected in 17 of 21 sites within the known range of WNS at the time when the samples were collected; the fungus was not found in 28 sites beyond the known range of the disease at the time when environmental samples were collected. These data indicate that the distribution of G. destructans is correlated with disease in hibernating bats and support the hypothesis that the fungus is likely an exotic species in North America. Additionally, we examined whether G. destructans persists in infested bat hibernacula when bats are absent. Sediment samples were collected from 14 WNS-positive hibernacula, and the samples were screened for viable fungus by using a culture technique. Viable G. destructans was cultivated from 7 of the 14 sites sampled during late summer, when bats were no longer in hibernation, suggesting that the fungus can persist in the environment in the absence of bat hosts for long periods of time. © 2013, American Society for Microbiology.

Brower A.I.,Wisconsin Veterinary Diagnostic Laboratory | Cigel F.,Wisconsin Veterinary Diagnostic Laboratory | Radi C.,Wisconsin Veterinary Diagnostic Laboratory | Toohey-Kurth K.,Wisconsin Veterinary Diagnostic Laboratory
Avian Pathology | Year: 2010

Proliferative growth, consistent with poxvirus infection, encapsulated plastic beak-bits and covered the dorsal portion of the upper beak and nares of adult male and female captive-raised Hungarian partridges. Three representative birds were submitted to the Wisconsin Veterinary Diagnostic Laboratory for necropsy. Lesions in the necropsied birds extended through the nares, where the plastic bit ends are designed to rest. The lesions also variably extended caudally into the oropharynx and cranially within the beak epithelium, and included palate deformity and beak necrosis. Poxvirus was diagnosed in all of the birds examined based on histopathology, electron microscopy, and polymerase chain reaction amplification and sequencing. This report is the first to describe avian pox lesions associated with the application of beak-bits and the resulting beak and oral pathology. © 2010 Houghton Trust Ltd.

Wang Y.,University of Wisconsin - Madison | Zeng S.,University of Wisconsin - Madison | Lin T.-M.,University of Wisconsin - Madison | Krugner-Higby L.,University of Wisconsin - Madison | And 3 more authors.
Pharmaceutical Research | Year: 2014

Purpose: Although Cu complexes have been investigated as anticancer agents, there has been no description of Cu itself as a cancer killing agent. A stealth liposomal Cu formulation (LpCu) was studied in vitro and in vivo.Methods: LpCu was evaluated in prostate cancer origin PC-3 cells by a metabolic cytotoxicity assay, by monitoring ROS, and by flow cytometry. LpCu efficacy was evaluated in vivo using intratumoral and intravenous injections into mice bearing PC-3 xenograft tumors. Toxicology was assessed by performing hematological and blood biochemistry assays, and tissue histology and Cu distribution was investigated by elemental analysis.Results: LpCu and free Cu salts displayed similar levels of cell metabolic toxicity and ROS. Flow cytometry indicated that the mechanisms of cell death were both apoptosis and necrosis. Animals injected i.t. with 3.5 mg/kg or i.v. with 3.5 and 7.0 mg/kg LpCu exhibited significant tumor growth inhibition. Kidney and eye were the main organs affected by Cu-mediated toxicities, but spleen and liver were the major organs of Cu deposition.Conclusions: LpCu was effective at reducing tumor burden in the xenograft prostate cancer model. There was histological evidence of Cu toxicity in kidneys and eyes of animals treated at the maximum tolerated dose of LpCu 7.0 mg/kg. © 2014 Springer Science+Business Media New York.

PubMed | Madison 53706., University of Wisconsin - Madison and Wisconsin Veterinary Diagnostic Laboratory
Type: | Journal: Journal of dairy science | Year: 2016

Salmonellosis on the dairy continues to have a significant effect on animal health and productivity and in the United States. Additionally, Salmonella enterica subspecies enterica causes an estimated 1.2 million cases of human illness annually. Contributing to the morbidity and mortality in both human and domestic animal species is emergence of antimicrobial resistance by Salmonella species and increased incidence of multidrug-resistant isolates. This study describes serotype distribution and the antimicrobial resistance patterns for various Salmonella serotypes isolated from bovine samples submitted to the Wisconsin Veterinary Diagnostic Laboratory (WVDL) over the past 10 yr. Salmonella serotyping and antimicrobial susceptibility testing data were obtained from the laboratory information management system at WVDL. Data from accessions were limited to bovine samples submitted to the WVDL between January 2006 and June 2015 and those that had both a definitive serotype and complete results for antimicrobial susceptibility testing. A total of 4,976 isolates were identified. Salmonella enterica ser. Dublin was the most prevalent serotype identified among bovine samples submitted to the WVDL, accounting for a total of 1,153 isolates (23% of total isolates) over the study period. Along with Dublin, Salmonella enterica ser. Cerro (795, 16%), Newport (720, 14%), Montevideo (421, 8%), Kentucky (419, 8%), and Typhimurium (202, 4%) comprised the top 6 most commonly isolated serotypes during that time. Overall, resistance of bovine Salmonella isolates in the study population remained stable; although, decreases in resistance were noted for gentamicin, neomycin, and trimethoprim sulfamethoxazole during the study period. All isolates remained susceptible to enrofloxacin. These data show that antimicrobial susceptibility for bovine Salmonella has changed in the population served by WVDL in the past 10 yr. This information is important for understanding Salmonella disease ecology in Wisconsin. Our findings are also relevant for animal and public health by improving informed antimicrobial use, new drug development, and regulation of their use in food animals.

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