- Clinic for Birds and Reptiles, University of Leipzig, Germany
Volker Schmidt
Universität Leipzig, Veterinärmedizinische Fakultät, Faculty Member
- Birds (Ecology), Parasites of Birds, Passerine Birds, Pigeons, Poultry Science, Poultry Disease, and 12 morePoultry Pathology, Reptiles, Tortoises, Veterinary Pathology, Herpetology, Wildlife Diseases, Zoological Medicine, Exotic animals, Avian Pathology, Avian medicine, Reptiles Associated Fungal Pathogens, and Reptile Medicineedit
- PD Dr. med. vet. Dip ECZM (Avian&Herp), EBVS® European Veterinary Specialist in [Avian Medicine and Surgery]edit
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... more
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 patholog...
Research Interests:
A recent study revealed that organically raised Bronze turkeys showed a high prevalence of green liver discoloration. This alteration is commonly associated with the Turkey Osteomyelitis Complex and potentially caused by opportunistic... more
A recent study revealed that organically raised Bronze turkeys showed a high prevalence of green liver discoloration. This alteration is commonly associated with the Turkey Osteomyelitis Complex and potentially caused by opportunistic bacteria. Therefore, 360 organically fattened Bronze turkeys were examined post-mortem throughout two fattening trials with two examinations each to determine possible infectious risk factors and reduce disease prevalence. Clinical and pathoanatomical examinations were performed on every hen. Histopathological, bacteriological, parasitological, and virological examinations were performed on at least six hens without and, if applicable, six hens with green livers on each examination date. Overall, 9.0% of all hens had a green liver without a correlation with bacterial or parasitological findings but multiple health impairments. The discoloration correlated significantly with the detection of immunosuppressive turkey hemorrhagic enteritis virus at the ea...
Research Interests:
Research Interests:
Evaluating methods of hormone measurement in different specimens of male parrots in order to assess their reproductive status and stress axis. Cockatiels and rose-ringed parakeets were chosen as psittaciforme representatives and their... more
Evaluating methods of hormone measurement in different specimens of male parrots in order to assess their reproductive status and stress axis. Cockatiels and rose-ringed parakeets were chosen as psittaciforme representatives and their endocrine profiles were examined. In various pre-experiments, suitable techniques for the determination of testosterone in plasma, saliva and faeces of male parrots were established. Before analysing the samples by enzyme immunoassay, blood and faeces were extracted using diethyl ether, while saliva could be tested without extraction. Based on the excretion of mainly conjugated testosterone metabolites, parrots' faecal samples were also hydrolysed with β-glucuronidase/arylsulfatase before extraction. In addition, the levels of the stress hormone corticosterone were determined by radioimmunoassay in order to assess possible relationships between stress and the secretion of testosterone. The examined psittacine species displayed different seasonal se...
Research Interests:
An adult female Russian tortoise (Testudo horsfieldii) was admitted to a veterinary clinic with a 1-week history of anorexia and lethargy. Physical examination revealed significant dehydration and generalized dysecdysis. Blood parameters... more
An adult female Russian tortoise (Testudo horsfieldii) was admitted to a veterinary clinic with a 1-week history of anorexia and lethargy. Physical examination revealed significant dehydration and generalized dysecdysis. Blood parameters were all within species-reported limits. Radiography revealed an increased amount of soft tissue opacity within the coelomic cavity and a distinct loss of serosal detail. A large cavitated mass was detected ultrasonographically in the right coelom and a tentative diagnosis of kidney pathology was made. Using computed tomography and magnetic resonance imaging, a partly mineralized heterogeneous mass was seen in the right coelom. After stabilization, a transplastron coeliotomy was performed. A 7 Â 5 cm mass, including associated cysts, was removed. The tortoise died 8 h postoperatively and post-mortem examination revealed a urothelial carcinoma arising from the renal pelvis. To the authors' knowledge, this is the first report in a tortoise of urothelial carcinoma, which has rarely been reported in reptiles.
Xanthogranulomatosis is a common dermatological disease in birds. This form of inflammation, possibly associated with lipometabolic disorders, can also be seen in visceral organs, which as yet has only rarely been described in avian... more
Xanthogranulomatosis is a common dermatological disease in birds. This form of inflammation, possibly associated with lipometabolic disorders, can also be seen in visceral organs, which as yet has only rarely been described in avian medicine. In general, diseases related to impaired lipid metabolism are frequently reported in avian medicine, with hepatic steatosis and atherosclerosis being the most common. In human medicine, infectious agents—especially some strains of adenovirus—were implicated in contributing to lipometabolic disorders; this has also been described for chicken. Here, a case series of six Red-crowned Parakeets (Cyanoramphus novaezelandiae) is presented, all cases being characterized by psittacine adenovirus 2 (PsAdV-2) infection with or without disseminated xanthogranulomatosis. The affected individuals were examined alive by clinical examination. Total body radiographs were taken of two birds, haematology and blood biochemistry results were achieved in one bird. T...
Research Interests:
Biotyper analysis of Nannizziopsis guarroi, a fatal fungal pathogen in lizards, was described recently. Hypocrealean fungal infections in captive reptiles appear with an increasing frequency during the last decade. Therefore, the aim of... more
Biotyper analysis of Nannizziopsis guarroi, a fatal fungal pathogen in lizards, was described recently. Hypocrealean fungal infections in captive reptiles appear with an increasing frequency during the last decade. Therefore, the aim of this study was to proof Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) as diagnostic tool for the identification of reptile pathogenic hypocrealean fungi. Ten fungal isolates obtained from nine reptiles with fungal glossitis, disseminated visceral mycosis, pneumomycosis, and fungal keratitis were analyzed. Phylogeny consisted of fragments of the large subunit of nuclear encoded ribosomal DNA (D1/D2, LSU) and the internal transcribed spacer region 1 of nuclear encoded ribosomal DNA (ITS1) as well as the protein coding gene translation elongation factor 1 alpha (TEF). Results revealed unanimously two Metarhizium granulomatis genotypes in a total of three isolates, various M. viride genotypes (n = 3), two dif...
Research Interests:
Usutu virus (USUV) is an emerging mosquito-borne arbovirus within the genus Flavivirus, family Flaviviridae. Similar to the closely related West Nile virus (WNV), USUV infections are capable of causing mass mortality in wild and captive... more
Usutu virus (USUV) is an emerging mosquito-borne arbovirus within the genus Flavivirus, family Flaviviridae. Similar to the closely related West Nile virus (WNV), USUV infections are capable of causing mass mortality in wild and captive birds, especially blackbirds. In the last few years, a massive spread of USUV was present in the avian population of Germany and other European countries. To date, no specific antiviral therapies are available. Nine different approved drugs were tested for their antiviral effects on the replication of USUV in vitro in a screening assay. Ivermectin was identified as a potent inhibitor of USUV replication in three cell types from different species, such as simian Vero CCL-81, human A549 and avian TME R. A 2- to 7-log10 reduction of the viral titer in the supernatant was detected at a non-cytotoxic concentration of 5 µM ivermectin dependent on the applied cell line. IC50 values of ivermectin against USUV lineage Africa 3 was found to be 0.55 µM in Vero ...
Research Interests:
Lipometabolic disorders, such as xanthogranulomatosis, are common diseases in avian medicine. Various manifestations of lipometabolic disorders and risk factors for acquiring lipometabolic diseases have been described in the past years.... more
Lipometabolic disorders, such as xanthogranulomatosis, are common diseases in avian medicine. Various manifestations of lipometabolic disorders and risk factors for acquiring lipometabolic diseases have been described in the past years. Xanthogranulomas are usually limited to the skin and supposed to be associated with traumatic or inflammatory injuries in that area. Disseminated xanthogranulomatosis, appearing simultaneously in several internal organs, has been recently described in psittacine birds, the cause of the diseases was not known. Here, we describe a case series of disseminated xanthogranulomatosis in another psittacine species, the Red-crowned Parakeet (Cyanoramphus novaezelandiae) and a possible association with a concurrent psittacine adenovirus 2 (PsAdV-2) infection. Viral infections that trigger lipometabolic diseases have been described in human medicine in some species of small animals and in chickens. PsAdV-2- infections are widely
distributed in avian species. A possible association between PsAdV-2- infections and lipometabolic diseases in the Red-crowned Parakeet should be considered. Individual birds and flocks with both or
either of these diseases should be carefully examined and monitored.
distributed in avian species. A possible association between PsAdV-2- infections and lipometabolic diseases in the Red-crowned Parakeet should be considered. Individual birds and flocks with both or
either of these diseases should be carefully examined and monitored.
West Nile virus (WNV) and Usutu virus (USUV) are important flaviviruses circulating in Germany. While USUV was first reported more than 10 years ago, WNV has only reached the country in 2018. Wild birds are important amplifying hosts for... more
West Nile virus (WNV) and Usutu virus (USUV) are important flaviviruses circulating in Germany. While USUV was first reported more than 10 years ago, WNV has only reached the country in 2018. Wild birds are important amplifying hosts for both viruses. Therefore, we have been monitoring the bird population in different regions of Germany by a previously established network for many years. This report summarizes the results of molecular and/or serological methods of 2345 blood samples from birds of 22 different orders and over 2900 bird carcasses from 2019 and 2020. USUV RNA circulation was found in different regions of Germany, with emphasis on USUV lineages Europe 3 and Africa 3. Increased evidence of USUV lineage Europe 2 was detected in eastern Germany. WNV RNA was found only in birds from the eastern part of the country. The seroprevalence for USUV was between 3.11% and 7.20% in all three regions investigated, whereas the WNV seroprevalence spanned from 14.77% to 16.15% in easter...
Research Interests:
Research Interests:
Der chronisch regurgitierende Wellensittich – eine diagnostische und therapeutische Herausforderung -
Research Interests:
The mosquito-borne flavivirus Usutu virus (USUV) is responsible for countless deaths in both resident populations and birds kept in outdoor aviaries. Since 2001, USUV outbreaks attract increased attention due to the rapid geographical... more
The mosquito-borne flavivirus Usutu virus (USUV) is responsible for countless deaths in both resident populations and birds kept in outdoor aviaries. Since 2001, USUV outbreaks attract increased attention due to the rapid geographical spread of the virus and its close relation to West Nile virus (WNV), an emerging pathogen in humans and animals. Similar to WNV, the USUV enzootic transmission cycle predominantly involves Culex spp. as vectors, whereas birds serve as amplifying reservoir hosts. In Europe, USUV-associated disease outbreaks in birds are nearly exclusively described during late spring and early autumn (early April to late October). Contagiousness of virus particles excreted by infected animals has not yet been proven, so that the role of non-vector-borne transmission, as it is known for the closely related WNV, remains unclear. Here we report the diagnosis of USUV infection in 15 of 24 birds from mortality outbreaks in eight different aviaries located in Germany, that occured during the cold season between late October 2018 and early April 2019. Detection of USUV was performed using standardized molecular biological methods and immunohistochemistry for verification of the infection. USUV infection in a parrot species, a tropical finch and two estrildid finches are reported for the first time. Further research on the occurrence of USUV infection during the cold season is key to understanding the dynamics of viral transmission as well as for a profound health risk assessment for aviary birds as well as humans.
Research Interests:
Objective Pigeon rotavirus A (RVA) isolates of genotype G18P[17] are causing disease outbreaks and fatalities in pigeon lofts in Australia, Germany, Belgium, Denmark and USA since 2016. Most disease outbreaks have been reported from... more
Objective Pigeon rotavirus A (RVA) isolates of genotype G18P[17] are causing disease outbreaks and fatalities in pigeon lofts in Australia, Germany, Belgium, Denmark and USA since 2016. Most disease outbreaks have been reported from juvenile pigeons (Columba livia forma domestica). However, reports on RVA-associated disease outbreaks in fancy pigeons in connection with fancy pigeon shows in Germany are rare. Material and methods Overall 18 pigeons (16 fancy pigeons and one racing pigeon from 9 pigeon fanciers, as well as one feral pigeon from a rescue center) were sent in for routine diagnostic necropsy including histopathologic, parasitologic and microbiologic examinations. Molecular biologic examinations for detection of RVA, circovirus, Usutu virus, West Nile virus and Chlamydia psittaci were also carried out on all pigeons. An accompanying questionnaire filled in by the senders was used to generate basic information on the affected pigeon lofts. Results Disease outbreaks in juve...
Research Interests:
Research Interests:
Aspergillosis is the most common fungal disease of the avian respiratory tract. Due to delayed diagnosis and treatment failure, the outcome of these infections is often poor. We investigate 159 cases of avian aspergillosis among captive... more
Aspergillosis is the most common fungal disease of the avian respiratory tract. Due to delayed diagnosis and treatment failure, the outcome of these infections is often poor. We investigate 159 cases of avian aspergillosis among captive birds in Germany to define clinical features as well as the frequency of in vitro triazole resistance. Adult birds were more likely to present with clinical signs compared to juvenile birds, and dyspnoea was the most common clinical sign, present in 53% of birds. Molecular species identification indicated that all infections were caused by Aspergillus fumigatus. Only one of 159 independent isolates was azole resistant.
Research Interests:
Research Interests:
In contrast to fungal dermatitis, fungal glossitis and disseminated visceral mycosis, fungal infection of the lung has so far rarely been described in reptiles. Pulmonary fungal granulomas were diagnosed histopathologically within the... more
In contrast to fungal dermatitis, fungal glossitis and disseminated visceral mycosis, fungal infection of the lung has so far rarely been described in reptiles. Pulmonary fungal granulomas were diagnosed histopathologically within the scope of post mortem examinations. Fragments of the 18S-internal transcribed spacer1-5.8S rDNA (SSU-ITS1-5.8S) and 28S rDNA (LSU), including domains (D)1 and D2 as well as the protein coding gene translation elongation factor 1 alpha (TEF) were used for phylogenetical analysis after isolation of the fungal pathogen by culturing. Ten reptiles, including lizards (n = 6), snakes (n = 1), crocodilians (n = 2) and tortoises (n = 1) presented with pulmonary fungal granulomas (n = 8) and fibrinous pneumonia (n = 2) caused by different non-clavicipitaceous and clavicipitaceous species of the order Hypocreales. Purpureocillium lavendulum (n = 2) and Metarhizium robertsii (n = 1) as the etiologic agents of pneumonia in reptile species are described for the first time. Fungal pulmonary granulomas caused by clavicipitaceous fungi (n = 6) were all associated with disseminated visceral mycosis as well as oral fungal granulomas (n = 4) and/or fungal dermatitis (n = 1). Differing infection routes being likely for clavicipitaceous and non-clavicipitaceous fungal pathogens. A potential zoonotic health risk should be taken into account during necropsy or lung sampling in live reptiles with pulmonary fungal granulomas, since human infections, mainly keratitis and sclerokeratitis, caused by Beauveria bassiana, Metarhizium robertsii and Purpureocillium lilacinum, have occasionally been described.
Research Interests:
Research Interests:
Sindbis virus (SINV) is an arbovirus causing clinical symptoms such as arthritis, rash and fever following human infections in Fennoscandia. Its transmission cycle involves mosquito species as vectors as well as wild birds that act as... more
Sindbis virus (SINV) is an arbovirus causing clinical symptoms such as arthritis, rash and fever following human infections in Fennoscandia. Its transmission cycle involves mosquito species as vectors as well as wild birds that act as natural reservoir hosts. In Germany, SINV was first time observed in 2009 in different mosquito species in the Upper Rhine valley and one year later in a hooded crow in Berlin. Recently, SINV was also detected repeatedly at various locations in Germany in the context of a mosquitoes monitoring program for arboviruses. In this study, we detected for just the second time a SINV infection in a diseased wild bird (common wood pigeon) from Central Europe. SINV was isolated by cell culture and the complete SINV genome sequence was determined. Phylogenetic analyses revealed a close affiliation to SINV genotype I with a high similarity to human isolate sequences from Finland, Sweden and Russia. The isolate was genetically distinct from the first avian isolate suggesting the circulation of at least two different SINV strains in Germany. In order to reveal the infection frequency in SINV positive mosquito regions 749 bird blood samples were assayed serologically and SINV antibodies found primarily in resident birds. SINV is therefore endemically circulating in mosquitoes in Germany, which results in occasional bird infections. No data are yet available on zoonotic transmission to humans.
Research Interests:
Abstract: Macrorhabdosis is a debilitating disease condition that affects budgerigars (Melopsittacus undulatus), cockatiels (Nymphicus hollandicus), and many other bird species worldwide. Macrorhabdus ornithogaster is a pathogen which... more
Abstract: Macrorhabdosis is a debilitating disease condition that affects budgerigars (Melopsittacus undulatus), cockatiels (Nymphicus hollandicus), and many other bird species worldwide. Macrorhabdus ornithogaster is a pathogen which leads to nonspecific clinical signs, and to date, diagnosis as well as therapy are still challenging. In this study, medical histories of 32 budgerigars and 7 cockatiels with macrorhabdosis diagnosed clinically and by polymerase chain reaction (PCR) within a period of 24 months (from January 2016 to January 2018) were retrospectively analyzed. Macrorhabdus ornithogaster was diagnosed through fecal samples collected over several days and analyzed by microscopic examination or PCR. The effectiveness of 2 different amphotericin B treatment regimens were investigated by PCR. In 23 cases, treatment was performed with amphotericin B via drinking water at 0.1 mg/mL for 28 days. For the remaining 16 birds, an alternative treatment regimen of amphotericin B at 100 mg/kg PO q12h for 10 days was combined with administration of amphotericin B via drinking water at 0.1 mg/mL for 28 days. Fecal samples of all treated flocks were reexamined by PCR 10–14 days post-amphotericin B treatment. More than half (56.4%) of the treated birds tested negative for M ornithogaster irrespective of the treatment regimen. In addition to clinical improvement and microscopic examination of droppings, PCR was used for the first time to evaluate treatment response in birds diagnosed with M ornithogaster. Administration of amphotericin B via drinking water proved to be effective in more than 50% of cases, indicating a less stressful alternative to the oral administration of amphotericin B twice daily.
Research Interests:
Wild birds play an important role as reservoir hosts and vectors for zoonotic arboviruses and foster their spread. Usutu virus (USUV) has been circulating endemically in Germany since 2011, while West Nile virus (WNV) was first diagnosed... more
Wild birds play an important role as reservoir hosts and vectors for zoonotic arboviruses and foster their spread. Usutu virus (USUV) has been circulating endemically in Germany since 2011, while West Nile virus (WNV) was first diagnosed in several bird species and horses in 2018. In 2017 and 2018, we screened 1709 live wild and zoo birds with real-time polymerase chain reaction and serological assays. Moreover, organ samples from bird carcasses submitted in 2017 were investigated. Overall, 57 blood samples of the live birds (2017 and 2018), and 100 organ samples of dead birds (2017) were positive for USUV-RNA, while no WNV-RNA-positive sample was found. Phylogenetic analysis revealed the first detection of USUV lineage Europe 2 in Germany and the spread of USUV lineages Europe 3 and Africa 3 towards Northern Germany. USUV antibody prevalence rates were high in Eastern Germany in both years. On the contrary, in Northern Germany, high seroprevalence rates were first detected in 2018,...
Research Interests:
Research Interests:
Zusammenfassung Gegenstand und Ziel: Darstellung der Durchführbarkeit und des Nutzens der nichtinvasiven Schnittbildtechniken Computertomographie (CT) und Magnetresonanztomographie (MRT) zur Untersuchung der Schlangenlunge. Material und... more
Zusammenfassung Gegenstand und Ziel: Darstellung der Durchführbarkeit und des Nutzens der nichtinvasiven Schnittbildtechniken Computertomographie (CT) und Magnetresonanztomographie (MRT) zur Untersuchung der Schlangenlunge. Material und Methoden: Zur Verfügung standen drei Tigerpythons (Python molurus), bei denen hochgradige respiratorische Symptome und entsprechende Krankheitserreger gefunden wurden und die Sektionsbefunde eine hochgradige Pneumonie bestätigten. Die Tiere wurden röntgenologisch sowie mittels CT und MRT untersucht. Die Befunde wurden mit denen gesunder Schlangen verglichen. Ergebnisse: Röntgenologisch bestanden nur wenige Hinweise auf eine Pneumonie. Dagegen konnten mittels Computertomographie deutliche Verschattungen und eine erhöhte Gewebedichte im Bereich der Lunge nachgewiesen werden. In der magnetresonanztomographischen Untersuchung wurde ein hyperintenses Signalverhalten des Lungengewebes festgestellt (T2-Gewichtung), was ebenfalls als Hinweis auf entzündliche...
Research Interests:
Avian intestinal spirochetosis (AIS), an important but neglected disease in laying hens, is caused by Brachyspira pilosicoli, B. intermedia, and B. alvinipulli. Poultry are also frequently colonized by putatively nonpathogenic species... more
Avian intestinal spirochetosis (AIS), an important but neglected disease in laying hens, is caused by Brachyspira pilosicoli, B. intermedia, and B. alvinipulli. Poultry are also frequently colonized by putatively nonpathogenic species such as B. murdochii and B. innocens. We evaluated the differentiation of Brachyspira species by 3 methods: sequencing of the reduced nicotinamide adenine dinucleotide (NADH) oxidase gene ( nox), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and a new multiplex (m)PCR targeting genes such as the tryptophanase A gene ( tnaA) and the p-aminobenzoyl-glutamate hydrolase subunit B gene ( abgB). Sequencing of 414 bp of the nox PCR amplification products generated from 41 pure cultures of avian Brachyspira isolates allowed presumptive species identification in 33 isolates with at least 99% identity in basic local alignment search tool analysis, including B. pilosicoli, B. intermedia, B. murdochii, B. innocens, an...
Research Interests:
Fatal clostridial infections and clostridial toxicoses are common in birds. Most fatalities are associated with toxin production and progress rapidly, often within 24 hours of infection. We describe an unusual and protracted course of... more
Fatal clostridial infections and clostridial toxicoses are common in birds. Most fatalities are associated with toxin production and progress rapidly, often within 24 hours of infection. We describe an unusual and protracted course of disease in 6 captive brown pelicans ( Pelecanus occidentalis), which was believed to result from toxicosis by toxovar A produced by a mixed infection with Clostridium sordellii and Clostridium perfringens. Although the first death in the group occurred 3 days after signs of illness were documented, the remaining birds died over a 38-day period despite aggressive antibiotic and supportive therapy. Although the birds presented with classic signs of botulism, Clostridium botulinum was not identified in any tissues or environmental samples. Postmortem findings in all pelicans included extensive subacute myonecrosis, enteritis, and nonsuppurative hepatitis. Alpha-toxins and sordellilysin genes from C perfringens and C sordelli isolates, respectively, were d...
Research Interests:
A 24-year-old female secretary bird ( Sagittarius serpentarius) was presented with acute, mild dyspnea occurring only during feeding times. Despite initial conservative therapy consisting of antibiotics and antifungal, antiparasitic, and... more
A 24-year-old female secretary bird ( Sagittarius serpentarius) was presented with acute, mild dyspnea occurring only during feeding times. Despite initial conservative therapy consisting of antibiotics and antifungal, antiparasitic, and anti-inflammatory drugs, the dyspnea worsened progressively, resulting in severe respiratory distress. Radiographs of the trachea suggested stenosis in the caudal one-third of the trachea. Tracheal endoscopy revealed an obstruction of approximately 90% of the tracheal lumen, in addition to mild suspected aspergillosis of the air sacs. Tracheal resection and anastomosis were performed, during which 1.5 cm of abnormal trachea was removed. Histopathologic examination showed severe granulomatous tracheitis, most likely induced by foreign body material. Respiratory signs resolved immediately postoperatively. Antibiotic and anti-inflammatory therapy continued for another 7 days and the bird was treated with antifungals for a total of 45 days. The bird rec...
Research Interests:
Metarhizium (M.) granulomatis (formerly Chamaeleomyces granulomatis) invariably causes fatal fungal glossitis and systemic mycosis in veiled chameleons (Chamaeleo calyptratus). Isolation of M. granulomatis in other lizards thus far has... more
Metarhizium (M.) granulomatis (formerly Chamaeleomyces granulomatis) invariably causes fatal fungal glossitis and systemic mycosis in veiled chameleons (Chamaeleo calyptratus). Isolation of M. granulomatis in other lizards thus far has not been described. The aim of this study therefore was to obtain information on the presence of M. granulomatis in reptiles kept as pets, and to examine whether there was an association between specific genotypes and clinical/pathological outcomes. Besides 18S ribosomal (r) DNA (SSU) and internal transcribed spacer1-5.8S (ITS1-5.8S) rDNA, a fragment of the large subunit of the 28S rDNA (LSU), including the domains 1 (D1) and D2, were sequenced for identification of the fungus and phylogenetic analysis. Metarhizium granulomatis was isolated from 23 veiled chameleons, two panther chameleons (Furcifer pardalis) and one central bearded dragon (Pogona vitticeps). Only the veiled chameleons revealed corresponding pathological findings in the form of glossal hemorrhage, granulomatous glossitis, pharyngitis, dermatitis and/or visceral mycosis. The infection site correlated to survival times of infected veiled chameleons. Combined long-term treatment with terbinafine and nystatin based on susceptibility testing may be helpful for prevention of disease and visceral spreading of the fungus, but elimination of the fungal pathogen or successful treatment of diseased veiled chameleons have not been achieved yet. Sequencing of the ribosomal genes yielded five different genotypes, with genotype A being strongly correlated with dermatitis, and remaining genotypes with pharyngitis and glossitis. However, disseminated visceral mycosis developed irrespective of the genotypes.
Research Interests:
Ophidian paramyxovirus (ferlavirus) is a global threat to reptilian sauropsids in herpetological collections, with occasional but fatal effects. This study characterizes the effects of three different genetic strains of ferlavirus on the... more
Ophidian paramyxovirus (ferlavirus) is a global threat to reptilian sauropsids in herpetological collections, with occasional but fatal effects. This study characterizes the effects of three different genetic strains of ferlavirus on the dynamic changes of histology and morphometry of the lung of corn snakes (Pantherophis guttatus). Lungs from 42 corn snakes were either sham-infected or infected experimentally under standardized conditions. From 4 to 49 days after intratracheal inoculation, the lungs were examined qualitatively and quantitatively. Progressive microscopical changes were seen in the lung. Initially, increased numbers of heterophils were observed in the interstitium followed by proliferation and vacuolation of epithelial cells lining faveoli. Electron microscopy revealed loss of type-I pneumocytes, hyperplasia of type-II pneumocytes, and interstitial infiltrates of heterophils and mononuclear cells. With progression of disease the respiratory epithelium was initially overgrown by transformed type-II pneumocytes and later became multilayered. The results of the study suggest that the respiratory capacity of the lungs declines with disease development. The dynamics of disease development and histopathology differed in snakes infected with different ferlavirus genogroups. Animals infected with virus genogroup B developed histopathological changes and morphometric changes more rapidly and of greater intensity than snakes infected with viruses from genogroups A or C.
Research Interests:
Abstract Dermatomycoses as well as disseminated systemic mycoses are caused by emerging obligate pathogenic fungi of the families Onygenaceae and Clavicipitaceae in captive as well as in free-living reptiles. Isolation and differentiation... more
Abstract Dermatomycoses as well as disseminated systemic mycoses are caused by emerging obligate pathogenic fungi of the families Onygenaceae and Clavicipitaceae in captive as well as in free-living reptiles. Isolation and differentiation of fungal agents and evaluation of their pathogenicity in diseased reptiles using histopathological examination are necessary to determine the pathogenicity of a fungal isolate in the disease process. Fungi formerly known as Chrysosporium anamorph of Nannizziopsis vriesii have recently been reassigned to the family Onygenaceae , order Onygenales (Eurotiomycetidae, Eurotiomycetes, and Ascomycota), based on phylogenetic studies. To date, 9 different reptile pathogenic species are known from this family, grouped in 3 phylogenetic lineages. The most relevant are Nannizziopsis guarroi affecting inland bearded dragons ( Pogona viticeps ) and green iguanas ( Iguana iguana ), as well as Ophidiomyces ophiodiicola in free-living snakes, which cause deep fungal dermatitis. Treatment with voriconazole is possible in bearded dragons and girdled lizards ( Cordylus giganteus ). Other obligate pathogenic fungi belong to the family Clavicipitaceae , which causes granulomatous glossitis, pharyngitis, and dermatitis, as well as disseminated visceral mycosis, in various lizards, tortoises, turtles, and crocodilians. No reports exist about successful treatments against fungal pathogens in the family Clavicipitaceae . Also, voriconoazole should be used carefully in chameleons, as it does not seem to be well tolerated in these species.
Research Interests:
A 49-year-old female scarlet macaw ( Ara macao ) was presented with a mass in the cervical region. The bird showed no evidence of pain or discomfort, it swallowed food normally, and its breathing pattern was unremarkable. Results of... more
A 49-year-old female scarlet macaw ( Ara macao ) was presented with a mass in the cervical region. The bird showed no evidence of pain or discomfort, it swallowed food normally, and its breathing pattern was unremarkable. Results of contrast radiographic imaging revealed a well-demarcated mass in the right cervical region not related to the crop. After surgical resection and histopathologic evaluation, a malignant nodular stage of an epithelioid cortical-type thymoma was diagnosed. One year later, metastasis of the thymoma to the lung was diagnosed and confirmed at postmortem examination. The final diagnosis was corrected to malignant nodular stage of an epithelioid cortical-type thymoma with metastasis to the lung. This is the first report in an avian species of a malignant thymoma with metastasis to the lung after complete resection of the initial cervical thymoma and a survival time of 1 year.
Research Interests:
Usutu virus (USUV) is a mosquito-borne flavivirus accounting for large-scale deaths in resident bird populations. In this study, we show the introduction of USUV to Eastern Germany resulting in massive death of birds, particularly... more
Usutu virus (USUV) is a mosquito-borne flavivirus accounting for large-scale deaths in resident bird populations. In this study, we show the introduction of USUV to Eastern Germany resulting in massive death of birds, particularly blackbirds (Turdus merula). We found that three diverse USUV lineages ("Europe 3," "Africa 2," and "Africa 3-like") circulated simultaneously. Moreover, we detected USUV in Culex pipiens in a region where no dead birds were reported, strengthening the need for mosquito monitoring to uncover the spread of arboviruses. Furthermore, phylogenetic analyses revealed that mutations accumulated, in particular, in the NS3 region within short time periods. In addition, comparison of whole-genome sequences showed that diverse isolates of the cluster "Africa 3-like" are cocirculating in Germany due to independent introduction events.
Research Interests:
In the summer of 2016, Belgium, France, Germany and the Netherlands reported widespread Usutu virus (USUV) activity based on live and dead bird surveillance. The causative USUV strains represented four lineages, of which two putative... more
In the summer of 2016, Belgium, France, Germany and the Netherlands reported widespread Usutu virus (USUV) activity based on live and dead bird surveillance. The causative USUV strains represented four lineages, of which two putative novel lineages were most likely recently introduced into Germany and spread to other western European countries. The spatial extent of the outbreak area corresponded with R0 values > 1. The occurrence of the outbreak, the largest USUV epizootic registered so far in Europe, allowed us to gain insight in how a recently introduced arbovirus with potential public health implications can spread and become a resident pathogen in a naïve environment. Understanding the ecological and epidemiological factors that drive the emergence or re-emergence of USUV is critical to develop and implement timely surveillance strategies for adequate preventive and control measures. Public health authorities, blood transfusion services and clinicians in countries where USUV...
Research Interests:
Metarhizium viride has been associated with fatal systemic mycoses in chameleons but subsequent data on mycoses caused by this fungus in reptiles are lacking. The aim of the investigation was therefore to obtain information on the... more
Metarhizium viride has been associated with fatal systemic mycoses in chameleons but subsequent data on mycoses caused by this fungus in reptiles are lacking. The aim of the investigation was therefore to obtain information on the presence of M. viride kept as pets in captivity, and its association to clinical signs, pathological findings as well as improvement of diagnostically procedures. Beside 18S rDNA (SSU) and internal transcribed spacer region-1 (ITS-1), a fragment of the large subunit of the 28S rDNA (LSU), including the domains 1 and 2 (D1/D2) have been sequenced for identification of the fungus and phylogenetic analysis. Cultural isolation and histopathological examinations as well as pattern of antifungal drug resistance, using agar diffusion testing, were additional used for comparison of the isolates. In total 20 isolates from eight inland bearded dragons (Pogona vitticeps), six veiled chameleons (Chamaeleo calyptratus) and six panther chameleons (Furcifer pardalis) wer...
Research Interests:
Research Interests: Evolutionary Biology, Genetics, Horizontal Gene Transfer, Multidisciplinary, DNA, and 15 moreGermany, Drosophila, Animals, Molecular biology and evolution, Biological evolution, Oxford university, Diptera, Passeriformes, Base Sequence, Avian Virology, Biochemistry and cell biology, Molecular Sequence Data, Nucleotide sequence, canaries, and Bird diseases
Research Interests:
Ferlaviruses are important pathogens of snakes. However, factors influencing the pathogenicity of individual isolates as well as optimal protocols for virus detection in tissues of infected snakes have been insufficiently studied. The... more
Ferlaviruses are important pathogens of snakes. However, factors influencing the pathogenicity of individual isolates as well as optimal protocols for virus detection in tissues of infected snakes have been insufficiently studied. The objectives of this study were to compare virus detection using previously described PCR and cell culture protocols following infection with three genetically distinct ferlaviruses in corn snakes (Pantherophis guttatus) as a model species. Groups of 12 corn snakes were each inoculated intratracheally with a genogroup A, B, or C ferlavirus. Tracheal washes and cloacal swabs were tested for virus shedding on days 16 and 28. Three animals were each euthanized on days 4, 16, 28, and 49. Beside immunohistochemistry of lung tissue, several organs (lung, intestine, pancreas, kidney, brain) were tested for the presence of ferlavirus. Distinct differences were noted in the pathogenicity of the three viruses, with a genotype B isolate causing the greatest patholo...
Research Interests:
ABSTRACT