• A reservoir species for the emerging amphibian pathogen Batrachochytrium dendrobatidis thrives in a landscape decimated by disease.

      Reeder, N.M.M.; Pessier, Allan P.; Vredenburg, V.T. (2012)
      Chytridiomycosis, a disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is driving amphibian declines and extinctions in protected areas globally. The introduction of invasive reservoir species has been implicated in the spread of Bd but does not explain the appearance of the pathogen in remote protected areas. In the high elevation (>1500 m) Sierra Nevada of California, the native Pacific chorus frog, Pseudacris regilla, appears unaffected by chytridiomycosis while sympatric species experience catastrophic declines. We investigated whether P. regilla is a reservoir of Bd by comparing habitat occupancy before and after a major Bd outbreak and measuring infection in P. regilla in the field, monitoring susceptibility of P. regilla to Bd in the laboratory, examining tissues with histology to determine patterns of infection, and using an innovative soak technique to determine individual output of Bd zoospores in water. Pseudacris regilla persists at 100% of sites where a sympatric species has been extirpated from 72% in synchrony with a wave of Bd. In the laboratory, P. regilla carried loads of Bd as much as an order of magnitude higher than loads found lethal to sympatric species. Histology shows heavy Bd infection in patchy areas next to normal skin, a possible mechanism for tolerance. The soak technique was 77.8% effective at detecting Bd in water and showed an average output of 68 zoospores per minute per individual. The results of this study suggest P. regilla should act as a Bd reservoir and provide evidence of a tolerance mechanism in a reservoir species....
    • AMPHIBIAN DISEASES-Batrachochytrium dendrobatidis in Adult Notophthalmus viridescens in North-Central Alabama, USA

      Bakkegard, K. A.; Pessier, Allan P.; (2010)
      ...We report on a haphazard collection of dead adult Notophthalmus viridescens discovered during a field zoology class trip conducted by KAB in Birmingham, Alabama....
    • Broad host range of SARS-CoV-2 predicted by comparative and structural analysis of ACE2 in vertebrates

      Damas, Joana; Hughes, Graham M.; Keough, Kathleen C.; Painter, Corrie A.; Persky, Nicole S.; Corbo, Marco; Hiller, Michael; Koepfli, Klaus-Peter; Pfenning, Andreas R.; Zhao, Huabin; et al. (2020)
      The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of COVID-19. The main receptor of SARS-CoV-2, angiotensin I converting enzyme 2 (ACE2), is now undergoing extensive scrutiny to understand the routes of transmission and sensitivity in different species. Here, we utilized a unique dataset of ACE2 sequences from 410 vertebrate species, including 252 mammals, to study the conservation of ACE2 and its potential to be used as a receptor by SARS-CoV-2. We designed a five-category binding score based on the conservation properties of 25 amino acids important for the binding between ACE2 and the SARS-CoV-2 spike protein. Only mammals fell into the medium to very high categories and only catarrhine primates into the very high category, suggesting that they are at high risk for SARS-CoV-2 infection. We employed a protein structural analysis to qualitatively assess whether amino acid changes at variable residues would be likely to disrupt ACE2/SARS-CoV-2 spike protein binding and found the number of predicted unfavorable changes significantly correlated with the binding score. Extending this analysis to human population data, we found only rare (frequency <0.001) variants in 10/25 binding sites. In addition, we found significant signals of selection and accelerated evolution in the ACE2 coding sequence across all mammals, and specific to the bat lineage. Our results, if confirmed by additional experimental data, may lead to the identification of intermediate host species for SARS-CoV-2, guide the selection of animal models of COVID-19, and assist the conservation of animals both in native habitats and in human care.
    • Characterization of progressive keratitis in Otariids: Otariid keratitis

      Colitz, Carmen M. H.; Renner, Michael S.; Manire, Charles A.; Doescher, Bethany; Schmitt, Todd L.; Osborn, Steven D.; Croft, Lara; Olds, June; Gehring, Erica; Mergl, June; et al. (2010)
      ... ‘Otariid Keratitis’ occurs in all populations of eared seals evaluated. A large‐scale epidemiological study is ongoing to identify the risk factors that contribute to this disease. Exposure to chronic sunlight appears to be an important risk factor as shade diminishes clinical signs; animals kept out of sunlight the majority of the time have less severe clinical signs....
    • Chlamydia pneumoniae polioencephalomyelitis and ganglionitis in captive Houston toads (Anaxyrus houstonensis)

      Fratzke, Alycia; Howard, Lauren L.; Tocidlowski, Maryanne E.; Armién, Anibal; Oliveira, Fabiano; Ritchie, Branson; Berlin, Erin; Snook, Eric (2019)
      Chlamydia pneumoniae is a ubiquitous pathogen causing disease in humans, mammals, birds, reptiles, and amphibians. Since 2012, C. pneumoniae infection has caused neurologic disease and mortality in a breeding colony of endangered Houston toads (Anaxyrus houstonensis) at the Houston Zoo....
    • Clinical trials with itraconazole as a treatment for chytrid fungal infections in amphibians

      Brannelly, L.A.; Richards-Zawacki, C.L.; Pessier, Allan P. (2012)
      Due in large part to recent global declines and extinctions, amphibians are the most threatened vertebrate group. Captive assurance colonies may be the only lifeline for some rapidly disappearing species. Maintaining these colonies free of disease represents a challenge to effective amphibian conservation. The fungal disease chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), is one of the major contributors to global amphibian declines and also poses a serious threat to captive assurance colonies. Many treatment options for Bd infection have not been experimentally tested and the commonly administered dosages of some drugs are known to have negative side effects, highlighting a need for clinical trials. The objective of this study was to clinically test the drug itraconazole as a method for curing Bd infection. We bathed Bd-positive juveniles of 2 anuran amphibian species, Litoria caerulea and Incilius nebulifer, in aqueous itraconazole, varying the concentration and duration of treatment, to find the combination that caused the fewest side effects while also reliably ridding animals of Bd. Our results suggest that a bath in 0.0025% itraconazole for 5 min d?1 for 6 d reliably cures Bd infection and causes fewer side effects than the longer treatment times and higher concentrations of this drug that are commonly administered.
    • Cross-cultural consensus for waist–hip ratio and women's attractiveness

      Singh, Devendra; Dixson, B. J.; Jessop, T. S.; Morgan, Bethan J.; Dixson, Alan F.; (2010)
      In women of reproductive age, a gynoid body fat distribution as measured by the size of waist–hip ratio (WHR) is a reliable indicator of their sex hormone profile, greater success in pregnancy and less risk for major diseases. According to evolutionary mate selection theory, such indicators of health and fertility should be judged as attractive….
    • Depositional diseases

      Graham, E.A.; Burns, Rachel E.; Ossiboff, R. J.; Garner, Michael M.; Jacobson, Elliott R. (CRC Press, 2021)
      This book accompanies Infectious Diseases and Pathology of Reptiles, Second Edition to cover noninfectious diseases of reptiles, meeting the need for a similar, authoritative single-source reference. The volume features color photos of normal anatomy and histology, as well as gross, light, and electron microscopic imagery of diseases. Subjects range from neoplasia, nutrition, and metabolic disease, and deposition disorders to developmental anomalies, trauma, and physical diseases, and the unique contribution of paleopathology and diseases of bone. Each chapter is supported by numerous figures, many of which are unique and cannot be found in the published literature. Readers will note that some of the chapters are based on organ system, a trend that will continue into the next edition to encompass all of the basic organ systems. This book holds the most information ever accrued into one publication on noninfectious diseases and pathology of this class of animals, providing information on every aspect of the anatomy, pathophysiology, and differential diagnosis. With up-to-the-minute data, a never-before-seen collection of images, and a stellar panel of contributors, Noninfectious Diseases and Pathology of Reptiles is the definitive resource for veterinarians, biologists, and researchers involved in the study of reptile diseases.
    • Development of a case definition for clinical feline herpesvirus infection in cheetahs (acinonyx jubatus) housed in zoos

      Witte, Carmel L.; Lamberski, Nadine; Rideout, Bruce; Fields, Victoria; Teare, Cyd Shields; Barrie, Michael; Haefele, Holly; Junge, Randall; Murray, Suzan; Hungerford, Laura L. (2013)
      The identification of feline herpesvirus (FHV) infected cheetahs (Acinonyx jubatus) and characterization of shedding episodes is difficult due to nonspecific clinical signs and limitations of diagnostic tests. The goals of this study were to develop a case definition for clinical FHV and describe the distribution of signs. Medical records from six different zoologic institutions were reviewed to identify cheetahs with diagnostic test results confirming FHV….
    • Diagnosis and control of amphibian chytridiomycosis

      Pessier, Allan P.; Miller, R. Eric; Fowler, Murray E. (Elsevier SaundersSt. Louis, 2012)
      Chytridiomycosis is an emerging infectious disease associated with global amphibian population dec- lines. The causative agent, Batrachochytrium dendrobatidis (Bd), is a chytrid fungus with a broad host range documented to infect the skin of over 300 different frog and salamander species to date (www.spatialepidemiology.net/bd-maps)....
    • Epidemiology of tuberculosis in multi-host wildlife systems: Implications for black (Diceros bicornis) and white (Ceratotherium simum) rhinoceros

      Dwyer, Rebecca A.; Witte, Carmel L.; Buss, Peter; Goosen, Wynand J.; Miller, Michele (2020)
      Cases of tuberculosis (TB) resulting from infection with Mycobacterium tuberculosis complex (MTBC) have been recorded in captive white (Ceratotherium simum) and black (Diceros bicornis) rhinoceros. More recently, cases have been documented in free-ranging populations of both species in bovine tuberculosis (bTB) endemic areas of South Africa. There is limited information on risk factors and transmission patterns for MTBC infections in African rhinoceros, however, extrapolation from literature on MTBC infections in other species and multi-host systems provides a foundation for understanding TB epidemiology in rhinoceros species. Current diagnostic tests include blood-based immunoassays but distinguishing between subclinical and active infections remains challenging due to the lack of diagnostic techniques. In other species, demographic risk factors for MTBC infection include sex and age, where males and adults are generally at higher risk than females and younger individuals. Limited available historical information reflects similar age- and sex-associated patterns for TB in captive black and white rhinoceros, with more reports of MTBC-associated disease in black rhinoceros than in white rhinoceros. The degree of MTBC exposure in susceptible wildlife depends on their level of interaction, either directly with other infected individuals or indirectly through MTBC contaminated environments, which is dependent on the presence and abundance of infected reservoir hosts and the amount of MTBC shed in their excreta. Captive African rhinoceros have shown evidence of MTBC shedding, and although infection levels are low in free-ranging rhinoceros, there is a risk for intraspecies transmission. Free-ranging rhinoceros in bTB endemic areas may be exposed to MTBC from other infected host species, such as the African buffalo (Syncerus caffer) and greater kudu (Tragelaphus strepsiceros), through shared environmental niches, and resource co-utilization. This review describes current knowledge and information gaps regarding the epidemiology of TB in African rhinoceros.
    • Epidemiology of ulcerative shell disease in Colombian slider turtles (Trachemys callirostris) in a wildlife facility in Colombia between 2005 and 2009

      Castro, Andrés Alejandro; Vivas, Zoila A.; Brieva, Claudia I.; Witte, Carmel L. (2014)
      ...This is the first epidemiological study of this disease in turtles in a wildlife rehabilitation facility anywhere in the world.
    • Genetic characterization and epidemiology of Helicobacters in non-domestic animals

      Schrenzel, Mark D.; Witte, Carmel L.; Bahl, J.; Tucker, Tammy A.; Fabian, Niora; Greger, Heidi; Hollis, Chrissie; Hsia, Gary; Siltamaki, Erin; Rideout, Bruce; et al. (2010)
      ... To better understand the ecology of helicobacters, we did a PCR survey and epidemiologic analysis of 154 captive or wild vertebrate taxa originating from 6 continents....
    • Granulomatous myositis associated with a novel alveolate pathogen in an adult southern leopard frog (Lithobates sphenocephalus)

      Jones, Megan E. B.; Armién, Aníbal G.; Rothermel, Betsie B.; Pessier, Allan P. (2012)
      Since 1999, infections with an incompletely characterized alveolate protozoan variously reported as a Dermocystidium-like organism, a Perkinsus-like agent, and Dermomycoides sp. have been associated with mortality events in tadpoles of ranid frogs from the USA. However, disease or mortality events due to this organism have not been described in post-metamorphic animals. We describe infection with a morphologically similar protozoan presenting itself as a leg mass in a free-ranging adult southern leopard frog Lithobates sphenocephalus….
    • Investigation of factors predicting disease among zoo birds exposed to avian mycobacteriosis

      Witte, Carmel L.; Hungerford, L.L.; Papendick, Rebecca; Stalis, Ilse H.; Rideout, Bruce; (2010)
      Objective—To characterize infection patterns and identify factors associated with avian mycobacteriosis among zoo birds that were housed with infected enclosure mates. Design—Matched case-control study. Animals—79 birds with avian mycobacteriosis (cases) and 316 nondiseased birds (controls) of similar age and taxonomic group that were present in the bird collection of the Zoological Society of San Diego from 1991 through 2005….
    • IOD in rhinos--epidemiology group report: report from the Epidemiology Working Group of the International Workshop on Iron Overload Disorder in Browsing Rhinoceros

      Dennis, Pam; Ellis, Susie; Mellen, Jill; Lee, Pauline; Olea-Popelka, Francisco; Petric, Ann; Ryder, Oliver A. (2012)
      The Epidemiology Working Group, a subgroup of the participants of the International Workshop on Iron Storage Disease (renamed iron overload disorder, IOD), identified several areas in which information is lacking regarding IOD in browser rhinoceros. One of the first steps necessary in understanding iron overload disorder (IOD) is to define the parameters by which to identify IOD....
    • Koala retrovirus diversity, transmissibility, and disease associations

      Zheng, HaoQiang; Pan, Yi; Tang, Shaohua; Pye, Geoffrey W.; Stadler, Cynthia K; Vogelnest, Larry; Herrin, Kimberly Vinette; Rideout, Bruce; Switzer, William M. (2020)
      Background Koalas are infected with the koala retrovirus (KoRV) that exists as exogenous or endogenous viruses. KoRV is genetically diverse with co-infection with up to ten envelope subtypes (A-J) possible; KoRV-A is the prototype endogenous form. KoRV-B, first found in a small number of koalas with an increased leukemia prevalence at one US zoo, has been associated with other cancers and increased chlamydial disease. To better understand the molecular epidemiology of KoRV variants and the effect of increased viral loads (VLs) on transmissibility and pathogenicity we developed subtype-specific quantitative PCR (qPCR) assays and tested blood and tissue samples from koalas at US zoos (n=78), two Australian zoos (n=27) and wild-caught (n=21) in Australia. We analyzed PCR results with available clinical, demographic, and pedigree data. Results All koalas were KoRV-A-infected. A small number of koalas (10.3%) at one US zoo were also infected with non-A subtypes, while a higher non-A subtype prevalence (59.3%) was found in koalas at Australian zoos. Wild koalas from one location were only infected with KoRV-A. We observed a significant association of infection and plasma VLs of non-A subtypes in koalas that died of leukemia/lymphoma and other neoplasias and report cancer diagnoses in KoRV-A-positive animals. Infection and VLs of non-A subtypes was not associated with age or sex. Transmission of non-A subtypes occurred from dam-to-offspring and likely following adult-to-adult contact, but associations with contact type were not evaluated. Brief antiretroviral treatment of one leukemic koala infected with high plasma levels of KoRV-A, -B, and -F did not affect VL or disease progression. Conclusions Our results show a significant association of non-A KoRV infection and plasma VLs with leukemia and other
    • Pandemic (H1N1) 2009 virus in 3 wildlife species, San Diego, California, USA

      Schrenzel, Mark D.; Tucker, Tammy A.; Stalis, Ilse H.; Kagan, Rebecca A.; Burns, Russell P.; Denison, Amy M.; Drew, Clifton P.; Paddock, Christopher D.; Rideout, Bruce (2011)
      The influenza A pandemic (H1N1) 2009 virus rapidly created a global pandemic among humans and also appears to have strong infectivity for a broad range of animal species (1–3). The virus has been found repeatedly in swine and has been detected in a dog, cats, turkeys, and domestic ferrets and in nondomestic animals, including skunks, cheetahs, and giant anteaters (2–4). In some cases, animal-to-animal transmission may have occurred, raising concern about the development of new wildlife reservoirs. In 2009, the first recognized occurrence of pandemic (H1N1) 2009 in southern California in April was followed by a surge of cases during October through November (4). During this time, respiratory illness developed in a 12-year-old male American badger (Taxidea taxus taxus), a 19-year-old female Bornean binturong (Arctictis binturong penicillatus), and a 7-year-old black-footed ferret (Mustela nigripes) housed in a San Diego zoological garden....
    • Reducing the extinction risk of populations threatened by infectious diseases

      Glassock, Gael L.; Grueber, Catherine E.; Belov, Katherine; Hogg, Carolyn J. (2021)
      Extinction risk is increasing for a range of species due to a variety of threats, including disease. Emerging infectious diseases can cause severe declines in wild animal populations, increasing population fragmentation and reducing gene flow. Small, isolated, host populations may lose adaptive potential and become more susceptible to extinction due to other threats. Management of the genetic consequences of disease-induced population decline is often necessary. Whilst disease threats need to be addressed, they can be difficult to mitigate. Actions implemented to conserve the Tasmanian devil (Sarcophilus harrisii), which has suffered decline to the deadly devil facial tumour disease (DFTD), exemplify how genetic management can be used to reduce extinction risk in populations threatened by disease. Supplementation is an emerging conservation technique that may benefit populations threatened by disease by enabling gene flow and conserving their adaptive potential through genetic restoration. Other candidate species may benefit from genetic management via supplementation but concerns regarding outbreeding depression may prevent widespread incorporation of this technique into wildlife disease management. However, existing knowledge can be used to identify populations that would benefit from supplementation where risk of outbreeding depression is low. For populations threatened by disease and, in situations where disease eradication is not an option, wildlife managers should consider genetic management to buffer the host species against inbreeding and loss of genetic diversity.