MERS-CoV Found in Hyalomma dromedarii Ticks Attached to Dromedary Camels at a Livestock Market, United Arab Emirates, 2019

The main mode of transmission of Middle East respiratory syndrome-related coronavirus (MERS-CoV) between dromedaries is likely via the respiratory route. However, there must be other modes to explain how the infection is brought to MERS-CoV-negative closed herds, such as transmission by ticks. Here, we present a study performed at three different locations in the United Arab Emirates (UAE) involving 215 dromedary camels (Camelus dromedarius) and the ticks attached to them. We tested the camels and ticks via RT-(q)PCR for the presence of MERS-CoV nucleic acids, as well as flaviviruses that may be present in the region (e.g., Alkhumra hemorrhagic fever virus). Camel sera were additionally analyzed for evidence of previous exposure to MERS-CoV. In total, 8 out of 242 tick pools were positive for MERS-CoV RNA (3.3%; C_t 34.6-38.3), 7 of which contained Hyalomma dromedarii ticks, and one contained a Hyalomma sp. tick (species not identified). All of the virus-positive ticks' host camels were also positive for MERS-CoV RNA in their nasal swab samples. Short sequences established in the N gene region from two positive tick pools were identical to viral sequences from their hosts' nasal swabs. In total, 59.3% of dromedaries at the livestock market had MERS-CoV RNA in their nasal swabs (C_t 17.7-39.5). While dromedaries at all locations were negative for MERS-CoV RNA in their serum samples, antibodies were detected in 95.2% and 98.7% of them (tested by ELISA and indirect immunofluorescence test, respectively). Given the probably transient and/or low level of MERS-CoV viremia in dromedaries and the rather high C_t values observed in the ticks, it seems unlikely that Hyalomma dromedarii is a competent vector for MERS-CoV; however, its role in mechanical or fomite transmission between camels should be investigated.

Potentially Zoonotic Viruses in Wild Rodents, United Arab Emirates, 2019—A Pilot Study

The majority of emerging viral infectious diseases in humans originate from wildlife reservoirs, such as rodents and bats. We investigated a possible reservoir, namely wild gerbils and mice trapped in a desert reserve within the emirate of Dubai, United Arab Emirates (UAE). In total, 52 gerbils and 1 jird (Gerbillinae), 10 house mice (Mus musculus), and 1 Arabian spiny mouse (Acomys dimidiatus) were sampled. Oro-pharyngeal swabs, fecal samples, attached ticks, and organ samples (where available) were screened by (RT-q)PCR for the following viruses: Middle East respiratory syndrome-related coronavirus, Crimean-Congo hemorrhagic fever orthonairovirus, Alkhumra hemorrhagic fever virus, hantaviruses, Lymphocytic choriomeningitis mammarenavirus, Rustrela virus, poxviruses, flaviviruses, and herpesviruses. All of the samples were negative for all investigated viruses, except for herpesviruses: 19 gerbils (35.8%) and 7 house mice (70.0%) were positive. The resulting sequences were only partly identical to sequences in GenBank. Phylogenetic analysis revealed three novel betaherpesviruses and four novel gammaherpesviruses. Interestingly, species identification of the positive gerbils resulted in eight individuals clustering in a separate clade, most closely related to Dipodillus campestris, the North African gerbil, indicating either the expansion of the geographic range of this species, or the existence of a closely related, yet undiscovered species in the UAE. In conclusion, we could not find evidence of persistence or shedding of potentially zoonotic viruses in the investigated rodent cohorts of limited sample size.

Vaccination against Borna Disease: Overview, Vaccine Virus Characterization and Investigation of Live and Inactivated Vaccines

(1) Background: Vaccination of horses and sheep against Borna disease (BD) was common in endemic areas of Germany in the 20th century but was abandoned in the early 1990s. The recent occurrence of fatal cases of human encephalitis due to Borna disease virus 1 (BoDV-1) has rekindled the interest in vaccination. (2) Methods: The full genomes of the BD live vaccine viruses "Dessau" and "Giessen" were sequenced and analyzed for the first time. All vaccination experiments followed a proof-of-concept approach. Dose-titration infection experiments were performed in rabbits, based on both cell culture- and brain-derived viruses at various doses. Inactivated vaccines against BD were produced from concentrated cell culture supernatants and investigated in rabbits and horses. The BoDV-1 live vaccine "Dessau" was administered to horses and antibody profiles were determined. (3) Results: The BD live vaccine viruses "Dessau" and "Giessen" belong to clusters 3 and 4 of BoDV-1. Whereas the "Giessen" virus does not differ substantially from field viruses, the "Dessau" virus shows striking differences in the M gene and the N-terminal part of the G gene. Rabbits infected with high doses of cell-cultured virus developed neutralizing antibodies and were protected from disease, whereas rabbits infected with low doses of cell-cultured virus, or with brain-derived virus did not. Inactivated vaccines were administered to rabbits and horses, following pre-defined vaccination schemes consisting of three vaccine doses of either adjuvanted or nonadjuvanted inactivated virus. Their immunogenicity and protective efficacy were compared to the BD live vaccine "Dessau". Seventy per cent of horses vaccinated with the BD live vaccine "Dessau" developed neutralizing antibodies after vaccination. (4) Conclusion: Despite a complex evasion of immunological responses by bornaviruses, some vaccination approaches can protect against clinical disease. For optimal effectiveness, vaccines should be administered at high doses, following vaccination schemes consisting of three vaccine doses as basic immunization. Further investigations are necessary in order to investigate and improve protection against infection and to avoid side effects.

MERS-CoV in sheep, goats, and cattle, United Arab Emirates, 2019: Virological and serological investigations reveal an accidental spillover from dromedaries

The recent COVID-19 pandemic has demonstrated again the global threat posed by emerging zoonotic coronaviruses. During the past two decades alone, humans have experienced the emergence of several coronaviruses, such as SARS-CoV in 2003, MERS-CoV in 2012, and SARS-CoV-2 in 2019. To date, MERS-CoV has been detected in 27 countries, with a case fatality ratio of approximately 34.5%. Similar to other coronaviruses, MERS-CoV presumably originated from bats; however, the main reservoir and primary source of human infections are dromedary camels. Other species within the Camelidae family, such as Bactrian camels, alpacas, and llamas, seem to be susceptible to the infection as well, although to a lesser extent. In contrast, susceptibility studies on sheep, goats, cattle, pigs, chickens, and horses obtained divergent results. In the present study, we tested nasal swabs and/or sera from 55 sheep, 45 goats, and 52 cattle, collected at the largest livestock market in the United Arab Emirates, where dromedaries are also traded, for the presence of MERS-CoV nucleic acid by RT-qPCR, and for specific antibodies by immunofluorescence assay. All sera were negative for MERS-CoV-reactive antibodies, but the nasal swab of one sheep (1.8%) repeatedly tested positive for MERS-CoV nucleic acid. Next generation sequencing (NGS) of the complete N gene of the sheep-derived MERS-CoV revealed >99% nucleotide identity to MERS-CoV sequences of five dromedaries in nearby pens and to three reference sequences. The NGS sequence of the sheep-derived MERS-CoV was confirmed by conventional RT-PCR of a part of the N gene and subsequent Sanger sequencing. All MERS-CoV sequences clustered within clade B, lineage 5. In conclusion, our study shows that noncamelid livestock, such as sheep, goats, and cattle do not play a major role in MERS-CoV epidemiology. The one sheep that tested positive most likely reflects an accidental viral spillover event from infected dromedaries in nearby pens.

Crimean-Congo Hemorrhagic Fever Virus Past Infections Are Associated with Two Innate Immune Response Candidate Genes in Dromedaries

Dromedaries are an important livestock, used as beasts of burden and for meat and milk production. However, they can act as an intermediate source or vector for transmitting zoonotic viruses to humans, such as the Middle East respiratory syndrome coronavirus (MERS-CoV) or Crimean-Congo hemorrhagic fever virus (CCHFV). After several outbreaks of CCHFV in the Arabian Peninsula, recent studies have demonstrated that CCHFV is endemic in dromedaries and camel ticks in the United Arab Emirates (UAE). There is no apparent disease in dromedaries after the bite of infected ticks; in contrast, fever, myalgia, lymphadenopathy, and petechial hemorrhaging are common symptoms in humans, with a case fatality ratio of up to 40%. We used the in-solution hybridization capture of 100 annotated immune genes to genotype 121 dromedaries from the UAE tested for seropositivity to CCHFV. Through univariate linear regression analysis, we identified two candidate genes belonging to the innate immune system: FCAR and CLEC2B. These genes have important functions in the host defense against viral infections and in stimulating natural killer cells, respectively. This study opens doors for future research into immune defense mechanisms in an enzootic host against an important zoonotic disease.

West Nile Virus and Tick-Borne Encephalitis Virus Are Endemic in Equids in Eastern Austria

The emergence of West Nile virus (WNV) and Usutu virus (USUV) in addition to the autochthonous tick-borne encephalitis virus (TBEV) in Europe causes rising concern for public and animal health. The first equine case of West Nile neuroinvasive disease in Austria was diagnosed in 2016. As a consequence, a cross-sectional seroprevalence study was conducted in 2017, including 348 equids from eastern Austria. Serum samples reactive by ELISA for either flavivirus immunoglobulin G or M were further analyzed with the plaque reduction neutralization test (PRNT-80) to identify the specific etiologic agent. Neutralizing antibody prevalences excluding vaccinated equids were found to be 5.3% for WNV, 15.5% for TBEV, 0% for USUV, and 1.2% for WNV from autochthonous origin. Additionally, reverse transcription quantitative polymerase chain reaction (RT-qPCR) was performed to detect WNV nucleic acid in horse sera and was found to be negative in all cases. Risk factor analysis did not identify any factors significantly associated with seropositivity.

Association of Dromedary Camels and Camel Ticks with Reassortant Crimean-Congo Hemorrhagic Fever Virus, United Arab Emirates

We previously detected a potentially novel reassortant of Crimean-Congo hemorrhagic fever virus in camels at the largest livestock market in the United Arab Emirates. A broader survey of large mammals at the site indicated zoonotic transmission is associated with dromedaries and camel ticks. Seroprevalence in cattle, sheep, and goats is minimal.

Diversity of West Nile and Usutu virus strains in mosquitoes at an international airport in Austria

Increased globalization and international transportation have resulted in the inadvertent introduction of exotic mosquitoes and new mosquito‐borne diseases. International airports are among the possible points of entry for mosquitoes and their pathogens. We established a mosquito and mosquito‐borne diseases monitoring programme at the largest international airport in Austria and report the results for the first two years, 2018 and 2019. This included weekly monitoring and sampling of adult mosquitoes, and screening them for the presence of viral nucleic acids by standard molecular diagnostic techniques. Additionally, we surveyed the avian community at the airport, as birds are potentially amplifying hosts. In 2018, West Nile virus (WNV) was detected in 14 pools and Usutu virus (USUV) was detected in another 14 pools of mosquitoes (minimum infection rate [MIR] of 6.8 for each virus). Of these 28 pools, 26 consisted of female Culex pipiens/torrentium, and two contained male Culex sp. mosquitoes. Cx. pipiens/torrentium mosquitoes were the most frequently captured mosquito species at the airport. The detected WNV strains belonged to five sub‐clusters within the sub‐lineage 2d‐1, and all detected USUV strains were grouped to at least seven sub‐clusters among the cluster Europe 2; all strains were previously shown to be endemic in Austria. In 2019, all mosquito pools were negative for any viral nucleic acids tested. Our study suggests that airports may serve as foci of arbovirus activity, particularly during epidemic years, and should be considered when designing mosquito control and arbovirus monitoring programmes.

Innate and Adaptive Immune Genes Associated with MERS-CoV Infection in Dromedaries

The recent SARS-CoV-2 pandemic has refocused attention to the betacoronaviruses, only eight years after the emergence of another zoonotic betacoronavirus, the Middle East respiratory syndrome coronavirus (MERS-CoV). While the wild source of SARS-CoV-2 may be disputed, for MERS-CoV, dromedaries are considered as source of zoonotic human infections. Testing 100 immune-response genes in 121 dromedaries from United Arab Emirates (UAE) for potential association with present MERS-CoV infection, we identified candidate genes with important functions in the adaptive, MHC-class I (HLA-A-24-like) and II (HLA-DPB1-like), and innate immune response (PTPN4, MAGOHB), and in cilia coating the respiratory tract (DNAH7). Some of these genes previously have been associated with viral replication in SARS-CoV-1/-2 in humans, others have an important role in the movement of bronchial cilia. These results suggest similar host genetic pathways associated with these betacoronaviruses, although further work is required to better understand the MERS-CoV disease dynamics in both dromedaries and humans.

Capillaria hepatica (syn. Calodium hepaticum) as a Cause of Asymptomatic Liver Mass

Capillaria hepatica (syn. Calodium hepaticum) is a parasitic nematode of rodents, rarely infecting humans. An asymptomatic Israeli adult male with extensive travel history was diagnosed with a liver mass on routine post-thymectomy follow-up. Imaging and computer tomography (CT) guided biopsy were inconclusive. Surgical excision revealed an eosinophilic granuloma with fragments of a nematode suspected to be C. hepatica. Molecular methods verified the diagnosis, and the patient was treated empirically. This is the first case of hepatic capillariasis described in Israel, and the first to be diagnosed using molecular methods.

New World camelids are sentinels for the presence of Borna disease virus

Borna disease (BD), a frequently fatal neurologic disorder caused by Borna disease virus 1 (BoDV-1), has been observed for decades in horses, sheep, and other mammals in certain regions of Europe. The bicoloured white-toothed shrew (Crocidura leucodon) was identified as a persistently infected species involved in virus transmission. Recently, BoDV-1 attracted attention as a cause of fatal encephalitis in humans. Here, we report investigations on BoDV-1-infected llamas from a farm in a BD endemic area of Switzerland, and alpacas from holdings in a region of Germany where BD was last seen in the 1960s but not thereafter. All New World camelids showed apathy and abnormal behaviour, necessitating euthanasia. Histologically, severe non-suppurative meningoencephalitis with neuronal Joest-Degen inclusion bodies was observed. BoDV-1 was confirmed by immunohistology, RT-qPCR, and sequencing in selected animals. Analysis of the llama herd over 20 years showed that losses due to clinically suspected BD increased within the last decade. BoDV-1 whole-genome sequences from one Swiss llama and one German alpaca and-for comparison-from one Swiss horse and one German shrew were established. They represent the first published whole-genome sequences of BoDV-1 clusters 1B and 3, respectively. Our analysis suggests that New World camelids may have a role as a sentinel species for BoDV-1 infection, even when symptomatic cases are lacking in other animal species.

Peptidomic Analysis of Skin Secretions of the Caribbean Frogs Leptodactylus insularum and Leptodactylus nesiotus (Leptodactylidae) Identifies an Ocellatin with Broad Spectrum Antimicrobial Activity

Ocellatins are peptides produced in the skins of frogs belonging to the genus Leptodactylus that generally display weak antimicrobial activity against Gram-negative bacteria only. Peptidomic analysis of norepinephrine-stimulated skin secretions from Leptodactylus insularum Barbour 1906 and Leptodactylus nesiotus Heyer 1994, collected in the Icacos Peninsula, Trinidad, led to the purification and structural characterization of five ocellatin-related peptides from L. insularum (ocellatin-1I together with its (1–16) fragment, ocellatin-2I and its (1–16) fragment, and ocellatin-3I) and four ocellatins from L. nesiotus (ocellatin-1N, -2N, -3N, and -4N). While ocellatins-1I, -2I, and -1N showed a typically low antimicrobial potency against Gram-negative bacteria, ocellatin-3N (GIFDVLKNLAKGVITSLAS.NH₂) was active against an antibiotic-resistant strain of Klebsiella pneumoniae and reference strains of Escherichia coli, K. pneumoniae, Pseudomonas aeruginosa, and Salmonella typhimurium (minimum inhibitory concentrations (MICs) in the range 31.25–62.5 μM), and was the only peptide active against Gram-positive Staphylococcus aureus (MIC = 31.25 μM) and Enterococcus faecium (MIC = 62.5 μM). The therapeutic potential of ocellatin-3N is limited by its moderate hemolytic activity (LC₅₀ = 98 μM) against mouse erythrocytes. The peptide represents a template for the design of long-acting, non-toxic, and broad-spectrum antimicrobial agents for targeting multidrug-resistant pathogens.

Crimean-Congo Hemorrhagic Fever Virus Endemicity in United Arab Emirates, 2019

We conducted a cross-sectional survey of Crimean-Congo hemorrhagic fever virus (CCHFV) in dromedary camels and attached ticks at 3 locations in the United Arab Emirates. Results revealed a high prevalence of CCHFV-reactive antibodies in camels and viral RNA in ticks and camel serum, suggesting the virus is endemic in this country.

Emergence of West Nile virus lineage 2 in Europe: Characteristics of the first seven cases of West Nile neuroinvasive disease in horses in Austria

We report details of the first seven equine cases of confirmed West Nile neuroinvasive disease in Austria. The cases presented during summer and autumn of 2016 (n = 2), 2017 (n = 3) and 2018 (n = 2). All horses showed gait abnormalities and 6 of 7 horses exhibited fasciculations and/or tremors, and we provide video recordings of these. Three horses also showed cranial nerve involvement. Following rapid improvement, three horses were discharged. Four horses were euthanized due to the severity of clinical signs and subjected to neuropathological examination. West Nile virus (WNV) lineage 2 nucleic acid was detected in 5 of 7 horses, and WNV‐specific neutralizing antibodies in all 7 horses. In addition, serologic evidence of WNV infection was found in two out of fourteen in‐contact horses. Horses may be considered a sentinel species for human WNV infections, integrating human and veterinary medicine and thus contributing to the one health concept.

No Evidence of Mosquito Involvement in the Transmission of Equine Hepacivirus (Flaviviridae) in an Epidemiological Survey of Austrian Horses

Prevalence studies have demonstrated a global distribution of equine hepacivirus (EqHV), a member of the family Flaviviridae. However, apart from a single case of vertical transmission, natural routes of EqHV transmission remain elusive. Many known flaviviruses are horizontally transmitted between hematophagous arthropods and vertebrate hosts. This study represents the first investigation of potential EqHV transmission by mosquitoes. More than 5000 mosquitoes were collected across Austria and analyzed for EqHV ribonucleic acid (RNA) by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Concurrently, 386 serum samples from horses in eastern Austria were analyzed for EqHV-specific antibodies by luciferase immunoprecipitation system (LIPS) and for EqHV RNA by RT-qPCR. Additionally, liver-specific biochemistry parameters were compared between EqHV RNA-positive horses and EqHV RNA-negative horses. Phylogenetic analysis was conducted in comparison to previously published sequences from various origins. No EqHV RNA was detected in mosquito pools. Serum samples yielded an EqHV antibody prevalence of 45.9% (177/386) and RNA prevalence of 4.15% (16/386). EqHV RNA-positive horses had significantly higher glutamate dehydrogenase (GLDH) levels (p = 0.013) than control horses. Phylogenetic analysis showed high similarity between nucleotide sequences of EqHV in Austrian horses and EqHV circulating in other regions. Despite frequently detected evidence of EqHV infection in Austrian horses, no viral RNA was found in mosquitoes. It is therefore unlikely that mosquitoes are vectors of this flavivirus.

Increase in human West Nile and Usutu virus infections, Austria, 2018

Between 28 June and 17 September 2018, 27 cases of human West Nile virus infections were recorded in Austria; four cases of West Nile neuroinvasive disease, 11 cases of West Nile fever, six infections detected by blood donation screening and six imported cases. In addition, 18 cases of human Usutu virus infections (all blood donors) were recorded. This is the highest number of annual infections recorded in Austria since the introduction of both viruses.

Different dynamics of Usutu virus infections in Austria and Hungary, 2017-2018

Usutu virus (USUV), a mosquito‐borne flavivirus closely related to West Nile virus, emerged in Austria in 2001, when it caused a considerable mass‐mortality of Eurasian blackbirds. Cases in birds increased until 2003 and quickly declined thereafter, presumably due to developing herd immunity. Since 2006, no further cases were recorded, until two blackbirds were tested positive in 2016. In Hungary, USUV first appeared in 2005 and has caused only sporadic infections since then. Initially, the only genetic USUV lineage found across both countries was Europe 1. This changed in 2015/2016, when Europe 2 emerged, which has since then become the prevalent lineage. Due to dispersal of these strains and introduction of new genetic lineages, USUV infections are now widespread across Europe. In 2009, the first cases of USUV‐related encephalitis were described in humans, and the virus has been frequently detected in blood donations since 2016. To monitor USUV infections among the Austrian wild bird population in 2017/2018, 86 samples were investigated by RT‐PCR. In 67 of them, USUV nucleic acid was detected (17 in 2017, 50 in 2018). The majority of succumbed birds were blackbirds, found in Vienna and Lower Austria. However, the virus also spread westwards to Upper Austria and southwards to Styria and Carinthia. In Hungary, 253 wild birds were examined, but only six of them were infected with USUV (five in 2017, one in 2018). Thus, in contrast to the considerable increase in USUV‐associated bird mortality in Austria, the number of infections in Hungary declined after a peak in 2016. Except for one case of USUV lineage Africa 3 in Austria in 2017, Europe 2 remains the most prevalent genetic lineage in both countries. Since USUV transmission largely depends on temperature, which affects vector populations, climate change may cause more frequent USUV outbreaks in the future.

Targeted surveillance reveals native and invasive mosquito species infected with Usutu virus

Background

The emergence of Usutu virus (USUV) in Europe was first reported in Austria, 2001, and the virus has since spread to many European countries. Initial outbreaks are marked by a mass die-off of European blackbirds (Turdus merula) and other bird species. During outbreaks, the virus has been detected in pools of Culex pipiens mosquitoes, and these mosquitoes are probably the most important enzootic vectors. Beginning in 2017, a second wave of blackbird deaths associated with USUV was observed in eastern Austria; the affected areas expanded to the Austrian federal states of Styria in the south and to Upper Austria in the west in 2018. We sampled the potential vector population at selected sites of bird deaths in 2018 in order to identify infected mosquitoes.

Results

We detected USUV RNA in 16 out of 19 pools of Cx. pipiens/Cx. torrentium mosquitoes at sites of USUV-linked blackbird mortality in Linz and Graz, Austria. A disseminated virus infection was detected in individuals from selected pools, suggesting that Cx. pipiens form pipiens was the principal vector. In addition to a high rate of infected Cx. pipiens collected from Graz, a disseminated virus infection was detected in a pool of Aedes japonicus japonicus.

Conclusions

We show herein that naturally-infected mosquitoes at foci of USUV activity are primarily Cx. pipiens form pipiens. In addition, we report the first natural infection of Ae. j. japonicus with USUV, suggesting that it may be involved in the epizootic transmission of USUV in Europe. Ae. j. japonicus is an invasive mosquito whose range is expanding in Europe.

Peptidomic analysis of the host-defense peptides in skin secretions of Rana graeca provides insight into phylogenetic relationships among Eurasian Rana species

Peptidomic analysis of norepinephrine-stimulated skin secretions from the Greek stream frog Rana graeca Boulenger, 1891 led to the identification and structural characterization of a range of host-defense peptides. These comprised brevinin-1GRa, brevinin-1GRb and an N-terminally extended form of brevinin-1GRb, ranatuerin-2GR together with its oxidized form and (11-28) fragment, temporin-GRa, temporin-GRb and its non-amidated form, and a melittin-related peptide, MRP-GR and its (1-18) fragment. The most abundant peptide, MRP-GR significantly (P < 0.001) stimulated insulin release from BRIN-BD11 clonal β-cells at concentrations ≥0.1 nM. Rana graeca (formerly Rana graeca graeca) and the morphologically similar Italian stream frog Rana italica Dubois, 1987 (formerly Rana graeca italica) were originally regarded as sub-species. However, the primary structures of the host defense peptides from both frogs support the claim based upon comparisons of the nucleotide sequences of S1 satellite DNA that R. graeca and R. italica are separate species. Cladistic analyses based upon the primary structures of the brevinin-1 and ranatuerin-2 peptides from Eurasian frogs indicate a close phylogenetic relationship between R. graeca and Rana latastei whereas R. italica is most closely related to Rana dalmatina.

Usutu virus infections among blood donors, Austria, July and August 2017 - Raising awareness for diagnostic challenges

Between July and August 2017, seven of 12,047 blood donations from eastern Austria, reacted positive to West Nile virus (WNV) in the cobas test (Roche). Follow-up investigations revealed Usutu virus (USUV) nucleic acid in six of these. Retrospective analyses of four blood donors diagnosed as WNV-infected in 2016 showed one USUV positive. Blood transfusion services and public health authorities in USUV-endemic areas should be aware of a possible increase of human USUV infections.

Infections of horses and shrews with Bornaviruses in Upper Austria: a novel endemic area of Borna disease

Borna disease, a lethal infection with Borna disease virus-1 (BoDV-1), was diagnosed in four horses from Upper Austria in 2015 and 2016. All cases occurred in winter (two cases in February 2015 and two cases in December 2016), and the maximal distance of the affected stables was 17 km. To demonstrate whether the causative agent was also harbored by its reservoir host, the bicolored white-toothed shrew (Crocidura leucodon), 28 shrews from this geographic area were collected in 2015 and investigated for the presence of BoDV-1. The shrew species were identified according to taxonomic clues and molecular barcodes. Affected horses and all shrews were investigated using histology, immunohistochemistry (IHC) and reverse transcription PCR. The horses exhibited severe nonpurulent encephalitis. Large amounts of BoDV-1 antigen were identified in their CNS. Among the 28 shrews, nine were identified as C. leucodon and 13 as Sorex araneus (Common shrew; Eurasian shrew). Six C. leucodon (66.7%) and one S. araneus (7.7%) had BoDV-1 infections. In accordance with previous findings, the IHC of C. leucodon exhibited a high amount of viral antigen in many neural and extraneural tissues. By contrast, the single positive S. araneus had an exclusively neural staining pattern. Of all positive samples, whole-genome BoDV-1 sequences were generated. The acquired sequences of the affected shrews were not identical to each other and clustered around the sequences of the diseased horses belonging, surprisingly, to the German ‘strain V’ cluster.

A novel HRM assay for the simultaneous detection and differentiation of eight poxviruses of medical and veterinary importance

Poxviruses belonging to the Orthopoxvirus, Capripoxvirus and Parapoxvirus genera share common host species and create a challenge for diagnosis. Here, we developed a novel multiplex PCR method for the simultaneous detection and differentiation of eight poxviruses, belonging to three genera: cowpox virus (CPXV) and camelpox virus (CMLV) [genus Orthopoxvirus]; goatpox virus (GTPV), sheeppox virus (SPPV) and lumpy skin disease virus (LSDV) [genus Capripoxvirus]; orf virus (ORFV), pseudocowpox virus (PCPV) and bovine papular stomatitis virus (BPSV) [genus Parapoxvirus]. The assay is based on high-resolution melting curve analysis (HRMCA) of PCR amplicons produced using genus specific primer pairs and dsDNA binding dye. Differences in fragment size and GC content were used as discriminating power. The assay generated three well separated melting regions for each genus and provided additional intra-genus genotyping allowing the differentiation of the eight poxviruses based on amplicon melting temperature. Out of 271 poxviral DNA samples tested: seven CPXV, 25 CMLV, 42 GTPV, 20 SPPV, 120 LSDV, 33 ORFV, 20 PCPV and two BPSV were detected; two samples presented co-infection with CMLV and PCPV. The assay provides a rapid, sensitive, specific and cost-effective method for the detection of pox diseases in a broad range of animal species and humans.

Host-defense and trefoil factor family peptides in skin secretions of the Mawa clawed frog Xenopus boumbaensis (Pipidae)

Peptidomic analysis of norepinephrine-stimulated skin secretions from the octoploid Mawa clawed frog Xenopus boumbaensis Loumont, 1983 led to the identification and characterization of 15 host-defense peptides belonging to the magainin (two peptides), peptide glycine-leucine-amide (PGLa; three peptides), xenopsin precursor fragment (XPF; three peptides), caerulein precursor fragment (CPF; two peptides), and caerulein precursor fragment-related peptide (CPF-RP; five peptides) families. In addition, caerulein and three peptides with structural similarity to the trefoil factor family (TFF) peptides, xP2 and xP4 from Xenopus laevis were also present in the secretions. Consistent with data from comparisons of the nucleotides sequence of mitochondrial and nuclear genes, the primary structures of the peptides suggest a close phylogenetic relationship between X. boumbaensis and the octoploid frogs Xenopus amieti and Xenopus andrei. As the three species occupy disjunct ranges within Cameroon, it is suggested that they diverged from a common ancestor by allopatric speciation.

Keratoconjunctivitis in a group of Icelandic horses with suspected γ-herpesvirus involvement

REASONS FOR PERFORMING STUDY

The role of equid γ-herpesviruses on ocular surface diseases has been disputed, because the diagnosis is usually based on clinical symptoms and detection of viral DNA from samples obtained from live animals.

OBJECTIVES

To describe the clinical course, results of polymerase chain reaction (PCR) analysis, in situ hybridisation, cell culture and pathohistological findings of select cases in a presumed outbreak of herpesvirus infection in a group of 15 Icelandic horses.

STUDY DESIGN

Case series.

METHODS

Pooled ocular and nasal swabs and peripheral blood mononuclear cells of horses diagnosed clinically with herpesvirus-associated keratoconjunctivitis were analysed for presence of equine herpesviruses (EHV)-2 and EHV-5 nucleic acid using real-time PCR. Necropsy specimens from one horse, subjected to euthanasia due to deterioration of clinical symptoms were examined histopathologically, and analysed for presence of EHV-2 and EHV-5 nucleic acid using real-time PCR. In situ hybridisation and cell culture of select samples were performed.

RESULTS

All horses with symptoms of severe keratoconjunctivitis were positive for presence of either EHV-2 and/or EHV-5 nucleic acid using real-time PCR. Assessment of necropsy specimens of the most severely affected case, revealed presence of EHV-2 and/or EHV-5 nucleic acid in several ocular and extraocular anatomical locations. The remaining horses responded favourably to symptomatic treatment.

CONCLUSIONS

This case series illustrates a severe outbreak of keratoconjunctivitis in a group of Icelandic horses, with suspected γ-herpesvirus involvement. For the first time equid γ-herpesviruses were detected in intraocular anatomical locations.

West Nile virus positive blood donation and subsequent entomological investigation, Austria, 2014

The detection of West Nile virus (WNV) nucleic acid in a blood donation from Vienna, Austria, as well as in Culex pipiens pupae and egg rafts, sampled close to the donor’s residence, is reported. Complete genomic sequences of the human- and mosquito-derived viruses were established, genetically compared and phylogenetically analyzed. The viruses were not identical, but closely related to each other and to recent Czech and Italian isolates, indicating co-circulation of related WNV strains within a confined geographic area. The detection of WNV in a blood donation originating from an area with low WNV prevalence in humans (only three serologically diagnosed cases between 2008 and 2014) is surprising and emphasizes the importance of WNV nucleic acid testing of blood donations even in such areas, along with active mosquito surveillance programs.

Complex epidemiology of a zoonotic disease in a culturally diverse region: phylogeography of rabies virus in the Middle East

The Middle East is a culturally and politically diverse region at the gateway between Europe, Africa and Asia. Spatial dynamics of the fatal zoonotic disease rabies among countries of the Middle East and surrounding regions is poorly understood. An improved understanding of virus distribution is necessary to direct control methods. Previous studies have suggested regular trans-boundary movement, but have been unable to infer direction. Here we address these issues, by investigating the evolution of 183 rabies virus isolates collected from over 20 countries between 1972 and 2014. We have undertaken a discrete phylogeographic analysis on a subset of 139 samples to infer where and when movements of rabies have occurred. We provide evidence for four genetically distinct clades with separate origins currently circulating in the Middle East and surrounding countries. Introductions of these viruses have been followed by regular and multidirectional trans-boundary movements in some parts of the region, but relative isolation in others. There is evidence for minimal regular incursion of rabies from Central and Eastern Asia. These data support current initiatives for regional collaboration that are essential for rabies elimination.

Host-defense peptides from skin secretions of Fraser's clawed frog Xenopus fraseri (Pipidae): Further insight into the evolutionary history of the Xenopodinae

Peptidomic analysis of norepinephrine-stimulated skin secretions of the tetraploid frog Xenopus fraseri Boulenger, 1905 (Pipidae) led to identification of 13 host-defense peptides. The primary structures of the peptides demonstrate that they belong to the magainin (3 peptides), peptide glycine-leucine-amide, PGLa (4 peptides), and xenopsin-precursor fragment, XPF (2 peptides) families, first identified in Xenopus laevis, together with caerulein precursor fragment-related peptides, CPF-RP (4 peptides), first identified in Silurana tropicalis. In addition, the secretions contain a molecular variant of xenopsin displaying the substitution Arg(4)→Lys compared with X. laevis xenopsin and peptide glycine-tyrosine-amide (PGYa) (GRIIPIYPEFERVFA KKVYPLY.NH2) whose function is unknown. The most potent antimicrobial peptide identified is CPF-RP-F1 (GFGSVLGKALKFGANLL.NH2) with MIC=12.5μM against Staphylococcus aureus and 50μM against Escherichia coli. On the basis of similarities in morphology and advertisement calls, X. fraseri has been placed in a species group that includes the octoploids Xenopus amieti and Xenopus andrei, and the tetraploid Xenopus pygmaeus. Cladistic analyses based upon the primary structures of magainin, PGLa, and CPF-RP peptides support a close evolutionary relationship between X. fraseri, X. amieti and X. andrei but suggest a more distant relationship with X. pygmaeus.

Middle East respiratory syndrome coronavirus (MERS-CoV) in dromedary camels, Oman, 2013

A countrywide survey in Oman revealed Middle Eastrespiratory syndrome coronavirus (MERS-CoV) nucleicacid in five of 76 dromedary camels. Camel-derivedMERS-CoV sequences (3,754 nucleotides assembled from partial sequences of the open reading frame (ORF)1a, spike, and ORF4b genes) from Oman and Qatar were slightly different from each other, but closely related to human MERS-CoV sequences from the same geographical areas, suggesting local zoonotic transmission. High viral loads in nasal and conjunctival swabs suggest possible transmission by the respiratory route.

Host defense peptides from Lithobates forreri, Hylarana luctuosa, and Hylarana signata (Ranidae): phylogenetic relationships inferred from primary structures of ranatuerin-2 and brevinin-2 peptides

The primary structures of host-defense peptides present in frog skin secretions constitute useful molecular markers for establishing taxonomic classifications and investigating phylogenetic relationships between species within a particular genus. Peptidomic analysis has led to the characterization of multiple host-defense peptides in norepinephrine-stimulated skin secretions of three species of frogs from the family Ranidae: Lithobates forreri (Boulenger, 1883), Hylarana luctuosa (Peters, 1871), and Hylarana signata (Günther, 1872). The L. forreri secretions contain ranatuerin-2 (2 peptides), brevinin-1 (4 peptides), and temporin (1 peptide). The H. luctuosa secretions contain brevinin-2 (4 peptides), esculentin-1 (1 peptide), esculentin-2 (1 peptide), palustrin-2 (2 peptides), and temporin (2 peptides). The H. signata secretions contain brevinin-2 (4 peptides), brevinin-1 (5 peptides), palustrin-2 (1 peptide), and temporin (2 peptides). Cladistic analysis based upon the primary structures of 44 ranatuerin-2 peptides from 20 Lithobates species indicates a close phylogenetic relationship between L. forreri, Lithobates onca, and Lithobates yavapaiensis. A similar cladistic analysis based upon the primary structures of 27 brevinin-2 peptides from 8 Hylarana species provides support for a close phylogenetic relationship between H. signata and Hylarana picturata, while showing that the species are not conspecific, with H. luctuosa more distantly related.

Clinical course of ophthalmic findings and potential influence factors of herpesvirus infections: 18 month follow-up of a closed herd of lipizzaners

BACKGROUND

To date the influence of herpesviruses on the development of equine ocular diseases has not been clearly determined.

OBJECTIVE

The purpose of this study was to illustrate the course of equine ocular findings over a period of 18 months at 6 month intervals, in correlation with the results of herpesvirus detection.

METHODS

266 Lipizzaners in 3 federal states of Austria underwent complete ophthalmologic examination 4 times. Blood samples, nasal- and conjunctival swabs were obtained at the same time and used for the detection of the equid gammaherpesviruses EHV-2 and EHV-5 using consensus herpesvirus PCR and type-specific qPCRs. Ophthalmic findings and results of herpesvirus PCRs were recorded and statistically analysed using one-way ANOVA, and multiple logistic regression analysis to determine the influence of herpesvirus infections and other contributing factors on the presence of ophthalmic findings.

RESULTS

In the first, second, third and fourth examination period 266, 261, 249 and 230 horses were included, respectively. Ophthalmic findings consistent with herpesvirus infections included conjunctival- and corneal pathologies. Statistical analysis revealed that the probability of positive herpesvirus PCR results decreased with progressing age; however the presence of corneal findings increased over time. At the time of each examination 45.1%, 41.8%, 43.0%, and 57.0% of horses with conjunctival or corneal findings, respectively, were positive for EHV-2 and/or EHV-5. However, 31.6%, 17.6%, 20.1%, and 13.0% of clinically sound horses were positive for these herpesviruses at each examination period, too.

CONCLUSION

Based on the results of our study there is a significant influence of young age on EHV-2 and/or EHV-5 infection. Corneal pathologies increased over time and with progressing age. Whether the identified findings were caused by herpesviruses could not be unequivocally determined.

Prevalence of asinine herpesvirus type 5 (AsHV-5) infection in clinically normal Lipizzaner horses

The aim of this study was to assess the extent of asinine herpesvirus (AsHV) type 5 infection in 'closed' populations of clinically normal Lipizzaner horses. Peripheral blood mononuclear cells plus nasal and conjunctival swabs were obtained on four occasions over an 18 month period from 266 animals as part of a health surveillance programme. Sequence analysis of samples that were positive by nested consensus herpesvirus PCR but negative using quantified equid herpesvirus (EHV) type 2 and 5 PCR, revealed a total of 51 samples from 39 horses positive for AsHV-5. No statistically significant association between animal age, gender or geographical location and infection status was identified. The findings suggest sub-clinical AsHV-5 infection may be encountered more frequently than previously reported.

Prevalence of linear keratopathy in a herd of Lipizzaners over an 18-month period

The prevalence of linear keratopathy with progressing age in a closed population of a single horse breed is reported. All Lipizzaners in three federal states in Austria underwent complete ophthalmic examination four times over a period of 18 months, with six-month intervals. Findings consistent with linear keratopathy were recorded, and associated with factors such as sex, location, boarding system and level of performance throughout the study period. Logistic regression was applied to determine the influence of age on ophthalmic findings. On the first, second, third and fourth examinations, 0.8 per cent, 3.1 per cent, 4.4 per cent and 4.8 per cent (of 266, 261, 249 and 230 horses, respectively) of the study population, were diagnosed with linear keratopathy. This finding was consistently identified in the same horses, and once identified, no further progression was noted. Horses with this finding had no history of previous ocular problems or concurrent ocular abnormalities. Statistical analysis did not reveal any influence of sex, location, boarding, or level of performance; however the prevalence of linear keratopathy was found to increase with progressive age (P<0.5). The results of this study indicate that linear keratopathy was not congenital and was non-progressive in the Lipizzaner over a period of 18 months.

Barkedji virus, a novel mosquito-borne flavivirus identified in Culex perexiguus mosquitoes, Israel, 2011

Barkedji virus, named after the area of its first identification in Senegal, is a newly discovered flavivirus (FV), for which we propose the abbreviation BJV. In the present study, we report the first-time detection of BJV in Culex perexiguus mosquitoes in Israel in 2011 and determination of its almost complete polyprotein gene sequence. We characterized the BJV genome and defined putative mature proteins, conserved structural elements and potential enzyme motifs along the polyprotein precursor. By comparing polyproteins and individual proteins of BJV with several other FVs, a distant relationship of BJV to Nounane virus (NOUV), a recently described African FV, is demonstrated. Phylogenetic analysis of 55 selected flaviviral polyprotein gene sequences exhibits two major clusters, one made up of the classical three clades of FVs: mosquito-borne, tick-borne and those without known vectors. The other cluster exclusively contains so-called 'insect-specific' FVs, which do not replicate in vertebrate cells. Based on our phylogenetic analysis, BJV is related to other members of the mosquito-borne clade with yet unknown vertebrate hosts, such as NOUV, Donggang virus, Chaoyang virus and Lammi virus. However, with a maximum identity of only 54 % to NOUV, BJV represents a distinct new virus species.

Partial genetic characterization of Sedlec virus (Orthobunyavirus, Bunyaviridae)

Sedlec virus (SEDV) was isolated from the blood of a reed warbler (Acrocephalus scirpaceus) in July 1984 in South Moravia, Czech Republic. In this study first genetic data of SEDV are presented which allow an estimate on its phylogenetic and taxonomic positioning within the genus Orthobunyavirus. The phylogenetic analysis of a 369 nt long stretch within the S segment (nucleocapsid protein gene and non-structural S protein gene) indicates genetic relatedness of SEDV to Leanyer virus and Simbu group viruses, while the phylogenetic tree based on 1796nt long sequences of the L segment (RNA-dependent RNA polymerase gene) demonstrates genetic relationship of SEDV to two yet unclassified orthobunyaviruses: I612045 virus (isolated in India in 1961) and Oyo virus (isolated in Nigeria in 1964). Considering the genetic distances and the phylogenetic analyses, SEDV might represent a novel serogroup of the Orthobunyavirus genus.

Detection of Plasmodium sp.-infested Anopheles hyrcanus (Pallas 1771) (Diptera: Culicidae) in Austria, 2012

On July 15, 2012, adult Anopheles hyrcanus (Pallas 1771) mosquitoes were caught next to a farm barn near Rust, Burgenland, close to Lake Neusiedl National Park in eastern Austria. Six weeks later, adults of this invasive species were also found in a sheep shelter outside the village of Oggau and another 2 weeks later, in a horse barn in Mörbisch. The morphological typing was confirmed genetically by amplification and sequencing of a 1,404-bp-long fragment within the 5.8S ribosomal RNA gene, the internal transcribed spacer 2, and the 28S ribosomal RNA gene. Out of two A. hyrcanus pools analyzed, one was found positive for Plasmodium sp. A 460-bp-long sequence within the mitochondrial cytochrome b region revealed 100 % identity to a sequence of a Plasmodium parasite identified in a New Zealand bellbird (Anthornis melanura). The Austrian finding sites are close to the Hungarian border. In Hungary, the occurrence of A. hyrcanus was already reported in 1963. A. hyrcanus is considered the most important potential vector of malaria in southern France today. In Austria, sporadic autochthonous malaria cases could emerge, caused by immigration from malaria-endemic countries and heavy tourism. However, the broad population coverage of the Austrian health care system makes the reestablishment of endemic areas for malaria unlikely.

Detection of equid herpesviruses 2 and 5 in a herd of 266 Lipizzaners in association with ocular findings

A herd of Lipizzaners (n=266) in three locations [Federal stud Piber (Styria), Heldenberg (Lower Austria) and the Spanish Riding School Vienna (Vienna)] were examined for ocular diseases and tested for herpesviruses (HVs) in PBMCs, nasal- and conjunctival swabs. In 167 (62.8%) horses equid herpesvirus-2 (EHV-2) nucleic acid was identified in at least one of the investigated samples, and 136 (51.1%) horses were positive for equid herpesvirus-5 (EHV-5) nucleic acid in at least one of the samples. One hundred and five (39.5%) of the horses mentioned above were identified with EHV-2/EHV-5 double infections. The results were correlated with potential influence factors such as age, gender, location, and housing. Statistical analysis demonstrated a significantly higher percentage of horses diagnosed with HV infections stabled in one location (Piber); also, housing in free stalls was associated with a higher rate of HV infections. Horses carrying EHV-2 or EHV-5 nucleic acid were significantly younger than the negative group. Statistical analysis of PCR results and ophthalmic findings did not prove a significant association between any disease pattern and presence of the equid gammaherpesviruses EHV-2 and EHV-5. The results of this herd survey indicate that horses younger than eight years of age, housed in free stalls with high population densities have a significantly increased risk for infection with EHV-2 and EHV-5. However no prediction can be made whether this results in ophthalmic disease. This is the first ophthalmic-virologic survey of this magnitude in a single horse breed.

Characterization of antimicrobial peptides in skin secretions from discrete populations of Lithobates chiricahuensis (Ranidae) from central and southern Arizona

Populations of the Chiricahua leopard frog Lithobates chiricahuensis (Ranidae) occupying regions in southern Arizona (southern range) are morphologically distinct from those from the Mogollon Rim of central Arizona (northern range) and a comparison of DNA sequences of mitochondrial genes has suggested that they may represent separate species. Peptidomic analysis of norepinephrine-stimulated skin secretions has led to the identification of six peptides with antimicrobial activity in samples from specimens from both groups. The primary structure of the peptides (esculentin-2 CHa, ranatuerin-2 CHa, -CHb, and -CHc, and brevinin-1 CHa and -CHb) isolated from both southern and northern range frogs are identical consistent with the proposal that the two populations are conspecific. However, palustrin-2CHa and the atypical brevinin-1 CHc (FFPTIAG*****LTKLFCA ITKKC), containing a five amino acid residue deletion, were identified only in secretions from southern range specimens. Consequently, there is some support for the proposal that the two populations are closely related but separate species but this support is relatively weak. Esculentin-2 CHa (GFSSIFRGVAKFASKGLG KDLAKLGVDLVACKISKQC) displayed the highest antimicrobial potency (MIC ≤ 10μM) against a variety of microorganisms and was only moderately hemolytic (LC(50) = 150 μM). Cladistic analysis based upon the primary structures of brevinin-1 peptides indicates a close phylogenetic relationship between L. chiricahuensis, L. onca, and L. yavapaiensis.

Natural zoonotic infections of two marmosets and one domestic rabbit with herpes simplex virus type 1 did not reveal a correlation with a certain gG-, gI- or gE genotype

Infections with herpes simplex virus type 1 (HSV-1) are not restricted to humans but infrequently may be transmitted to certain animal species, in some cases resulting in severe disease, including encephalitis and death. Recent studies demonstrate that humanderived HSV-1 field isolates can be typed according to their gG- gIand gE gene sequences. We investigated whether HSV-1 infections of animals were predominantly caused by a certain genotype. Isolates derived from two marmosets and one domestic rabbit, however, revealed different genotypes. Despite the very limited number of investigated animal-derived HSV-1 strains, this result does not point towards the existence of certain HSV-1 genotypes with a higher potential of being transmitted to animals.

Antimicrobial peptides from the skin secretions of the South-East Asian frog Hylarana erythraea (Ranidae)

Peptidomic analysis of norepinephrine-stimulated skin secretions of the South-East Asian frog Hylarana erythraea (formerly Rana erythraea partim) has led to the identification of multiple peptides with antimicrobial activity. Structural characterization of the peptides demonstrated that they belong to the brevinin-1 (3), brevinin-2 (2), esculentin-2 (4), and temporin (1) families. The values in parentheses indicate the number of paralogs. In addition, a peptide (GVIKSVLKGVAKTVALG ML.NH(2)) was isolated that shows some structural similarity to the brevinin-2-related peptides (B2RP) previously isolated from North American frogs of the genus Lithobates. A synthetic replicate of the species B2RP showed broad-spectrum growth inhibitory activity against reference strains of Escherichia coli (MIC=12.5 microM), Staphylococcus aureus (MIC=12.5 microM) and Candida albicans (MIC=50 microM) and was active against multidrug-resistant clinical isolates of Acetinobacter baumannii (MIC in the range 6-12.5 microM). The hemolytic activity of the peptide was relatively low (LC(50)=280 microM). Phylogenetic analysis based upon the amino acid sequences of 47 brevinin-2 peptides from 17 Asian species belonging to the family Ranidae provides support for the placement of H. erythraea in the genus Hylarana.

Distribution of Borna disease virus antigen and RNA in tissues of naturally infected bicolored white-toothed shrews, Crocidura leucodon, supporting their role as reservoir host species

Borna disease is a severe viral-induced disorder of the central nervous system of horses, sheep, and a few other animal species, occurring in certain areas of central Europe. Pathogenesis and epidemiology of natural Borna disease virus (BDV) infections are still not fully understood; several unique epidemiologic features, however, point toward the existence of BDV reservoir populations other than the final hosts. In this study, 69 mice and 12 shrews were trapped and examined. The virus distribution was investigated in detail in 2 BDV-positive bicolored white-toothed shrews, Crocidura leucodon, by immunohistochemistry and TaqMan real-time reverse transcription polymerase chain reaction (RT-PCR). RT-PCR amplification products were sequenced, and the sequences were compared. These shrews had been collected in a BDV-endemic geographical region using live traps and did not show obvious clinical or pathological disease signs. BDV antigen and nucleic acid were identified in several organs, including the brain, mainly in nerve tissue and neurons, respectively, but also in parenchymal cells (eg, hepatocytes, Leydig cells) and epithelial cells, particularly of the respiratory and urogenital tract.

Avian bornaviruses in psittacine birds from Europe and Australia with proventricular dilatation disease

Birds with this disease display bornaviral antigen in neural and extraneural tissues.

To determine whether avian bornaviruses (ABVs) were a factor in proventricular dilatation disease (PDD), we used immunohistochemistry, reverse transcription–PCR, and nucleotide sequence analysis to examine paraffin wax–embedded or frozen tissue samples of 31 psittacine birds with this disease. PDD is a fatal disease of psittacine birds associated with nonsuppurative encephalitis and ganglioneuritis of the upper intestinal tract. Tissue samples had been collected from 1999 through 2008 in Austria, Switzerland, Hungary, and Australia. Immunohistochemical demonstration of viral antigen within the brain and vegetative nerve system of the gastrointestinal tract provides strong evidence for a causative role of ABVs in this condition. Partial sequences of nucleoprotein (p40) and matrix protein (gp18) genes showed that virus in most of our cases belonged to the ABV-2 and ABV-4 groups among the 5 genogroups described so far. Viral sequences of 2 birds did not match any of the described sequences and clustered together in a new branch termed ABV-6.

Antimicrobial peptides from the skin secretions of the New World frogs Lithobates capito and Lithobates warszewitschii (Ranidae)

Taxonomic revisions within the anuran family Ranidae have established the genus Lithobates that currently comprises 49 species of frogs from the New World. Peptidomic analysis, using reversed-phase HPLC with on-line detection by electrospray mass spectrometry, has led to the identification of multiple antimicrobial peptides in norepinephrine-stimulated skin secretions of the North American frog Lithobates capito and the Central American frog Lithobates warszewitschii. Structural characterization of the peptides demonstrated that the L. capito secretions contained brevinin-1 (1), esculentin-1 (1), esculentin-2 (1), ranatuerin-2 (3), and temporin (2) peptides. L. warszewitschii secretions contained brevinin-1 (1), esculentin-2 (1), ranatuerin-2 (2), and temporin (1) peptides. Values in parentheses indicate number of peptides in each family. Temporin-CPa from L. capito, with the atypical structure IPPFIKKVLTTVF.NH(2), also showed atypical growth-inhibitory activity having greater potency against Escherichia coli (MIC=25 microM) and Candida albicans (MIC=25 microM) than against Staphylococcus aureus (MIC=50 microM). Phylogenetic analysis based upon the amino acid sequences of 37 ranatuerin-2 peptides from 17 species belonging to the genus Lithobates provides support for currently accepted taxonomic relationships. L. capito is sister-group to Lithobates sevosus in a clade that also contains Lithobates areolatus, and Lithobates palustris. L. warszewitschii is most closely related to the Central American species Lithobates tarahumarae and Lithobates vaillanti.

[Detection of Dirofilaria in Austrian dogs]

A recent increase in the occurrence of Dirofilaria repens and Dirofilaria immitis has been reported from the eastern neighbouring countries of Austria (Slovakia, Hungary). In order to obtain data from Austria--especially from the areas bordering these countries--blood samples of dogs from Gänserndorf (northeastern Austria, bordering Slovakia) and Neusiedl (eastern Austria, bordering Hungary) were examined for the presence of Dirofilaria spp.-DNA by quantitative real-time PCR (qPCR). For D. repens one (out of eight) and six (out of ninety) positive dogs were found, respectively. D. immitis-DNA was not detected. Most of the positive dogs had previously been abroad in known Dirofilaria endemic areas. Two dogs, however, had never been abroad and presumably became infected in Austria. To investigate an autochthonous focus, 1366 mosquitoes from the eastern part of Austria were also examined by qPCR. Although positive mosquitoes could not be found, an emerging endemic occurrence of D. repens in Austria due to positive dogs seems possible.

Uterine involution and endometrial function in postpartum pony mares

OBJECTIVE

To determine endometrial regeneration in postpartum mares by analysis of histologic features, apoptosis and cell proliferation markers, lectin binding, cytokines, and progesterone and estrogen receptors in endometrial biopsy specimens.

ANIMALS

9 postpartum mares.

PROCEDURES

Mares were examined on postpartum days 1, 9, and 16, and uterine biopsy specimens were obtained for histologic examination. Lectin binding was analyzed histochemically, and expressions of Ki-67 antigen (proliferation marker), lysozyme, and caspase 3 (apoptosis marker) were studied immunohistochemically. Gene expressions for cytokines (interleukin-1beta, -6 and -8 and tumor necrosis factor-alpha), cyclooxygenase 2, prostaglandin-E-synthase, and estrogen and progesterone receptors were determined by use of quantitative real-time PCR assay.

RESULTS

On day 1, neutrophils predominated but by day 9 had largely been replaced by lymphocytes and macrophages. High numbers of cells with staining for caspase 3 were found on day 1, but numbers decreased by day 9. In contrast, the number of cells with staining for Kiel 67 antigen increased between days 1 and 9. Lectin binding to the endometrium changed over time. Relative mRNA expressions for cytokines and prostaglandin-E-synthase did not differ among days. Expressions of progesterone and estrogen receptors were minimal on day 1 and increased by day 9.

CONCLUSIONS AND CLINICAL RELEVANCE

Early postpartum endometrial cells underwent apoptosis, but during the second week, postpartum proliferation of cells predominated. Lectin binding reflected changes in endometrial glycocalyx patterns. Increased expression of estrogen receptors allowed the endometrium to respond to estrogen during foal heat, and in subsequent diestrus, the endometrium was able to respond to progesterone.