Vaccination With a Gamma Irradiation-Inactivated African Swine Fever Virus Is Safe But Does Not Protect Against a Challenge.

African swine fever (ASF) is among the most devastating viral diseases of pigs and wild boar worldwide. In recent years, the disease has spread alarmingly. Despite intensive research activities, a commercialized vaccine is still not available, and efficacious live attenuated vaccine candidates raise safety concerns. From a safety perspective, inactivated preparations would be most favourable. However, both historical and more recent trials with chemical inactivation did not show an appreciable protective effect. Under the assumption that the integrity of viral particles could enhance presentation of antigens, we used gamma irradiation for inactivation. To this means, gamma irradiated ASFV "Estonia 2014" was adjuvanted with either Polygen™ or Montanide™ ISA 201 VG, respectively. Subsequently, five weaner pigs per preparation were immunized twice with a three-week interval. Six weeks after the first immunization, all animals were challenged with the highly virulent ASFV strain "Armenia 2008". Although ASFV p72-specific IgG antibodies were detectable in all vaccinated animals prior challenge, no protection could be observed. All animals developed an acute lethal course of ASF and had to be euthanized at a moderate humane endpoint within six days. Indeed, the vaccinated pigs showed even higher clinical scores and a higher inner body temperature than the control group. However, significantly lower viral loads were detectable in spleen and liver of immunized animals at the time point of euthanasia. This phenomenon suggests an immune mediated disease enhancement that needs further investigation.

Poult Enteritis and Mortality Syndrome in Turkey Poults: Causes, Diagnosis and Preventive Measures.

Poult enteritis and mortality syndrome (PEMS) is one of the most significant problem affecting turkeys and continues to cause severe economic losses worldwide. Although the specific causes of PEMS remains unknown, this syndrome might involve an interaction between several causative agents such as enteropathogenic viruses (coronaviruses, rotavirus, astroviruses and adenoviruses) and bacteria and protozoa. Non-infectious causes such as feed and management are also interconnected factors. However, it is difficult to determine the specific cause of enteric disorders under field conditions. Additionally, similarities of clinical signs and lesions hamper the accurate diagnosis. The purpose of the present review is to discuss in detail the main viral possible causative agents of PEMS and challenges in diagnosis and control.

Streptococcus catagoni sp. nov., isolated from the respiratory tract of diseased Chacoan peccaries (Catagonus wagneri).

Novel catalase-negative, Gram-stain-positive, beta-haemolytic, coccus-shaped organisms were isolated from Chacoan peccaries that died from respiratory disease. The initial API 20 Strep profiles suggested Streptococcus agalactiae with acceptable identification scores, but the 16S rRNA gene similarity (1548 bp) to available sequences of streptococci was below 98 %. Next taxa of the genus Streptococcus, displaying highest similarities to the strains from this study, were S. bovimastitidis NZ1587T (97.5 %), S. iniae ATCC 29178T (97.5 %), S. hongkongensis HKU30T (97.4 %), S. parauberis DSM 6631T (97.1 %), S. penaeicida CAIM 1838T (97.1 %), S. pseudoporcinus DSM 18513T (97.0 %), S. didelphis DSM 15616T (96.6 %), S. ictaluri 707-05T (96.6 %), S. uberis JCM 5709T (96.5 %) and S. porcinus NCTC 10999T (96.4 %). All other Streptococcus species had sequence similarities of below 96.4 %. A sodA gene as well as whole genome-based core genome phylogeny of three representative strains and 145 available Streptococcus genomes confirmed the unique taxonomic position. Interstrain average nucleotide identity (ANI) and amino acid identity (AAI) values were high (ANI >96 %; AAI 100%), but for other streptococci clearly below the proposed species boundary of 95-96 % (ANI <75 %; AAI <83 %). Results were confirmed by genome-to-genome distance calculations. Pairwise digital DNA-DNA hybridization estimates were high (>90 %) between the novel strains, but well below the species boundary of 70 % for closely related Streptococcus type strains (23.5-19.7 %). Phenotypic properties as obtained from extended biochemical profiles and MALDI-TOF mass spectrometry supported the outstanding rank. Based on the presented molecular and physiological data of the six strains, we propose a novel taxon for which we suggest the name Streptococcus catagoni sp. nov. with the type strain 99-1/2017T (=DSM 110457T=CCUG 74072T) and five reference strains.

Streptobacillus canis sp. nov. isolated from a dog.

From a phlegmon in a dog an aerobic and facultatively anaerobic, indole-, oxidase- and catalase-negative, non-motile bacterium was isolated in 2019 in Germany that stained Gram-negative and showed a pleomorphic, rod-shaped, non-spore-forming appearance. Based on the results of 16S rRNA gene sequence analyses, strain IHIT1603-19T was assigned to the genus Streptobacillus with sequence similarities of 98.6, 98.0, 97.9, 97.1 and 94.4 % to the type strains of Streptobacillus felis, Streptobacillus notomytis, Streptobacillus ratti, Streptobacillus moniliformis and Streptobacillus hongkongensis, respectively. Strain IHIT1603-19T could also clearly be differentiated from other Streptobacillus species by rpoB, groEL and recA gene, nucleotide and amino acid sequence analyses as well as by core genome phylogeny. Regarding DNA-DNA relatedness, strain IHIT1603-19T demonstrated an average nucleotide identity of 83.00 and 82.28 % compared to S. felis 131000547T and S. moniliformis DSM 12112T, respectively. Chemotaxonomic and physiological data of strain IHIT1603-19T were in congruence with other closely related members of the family Leptotrichiaceae, represented by highly similar enzyme profiles and fatty acid patterns. MALDI-TOF MS analysis also proved suitable in unequivocally discriminating strain IHIT1603-19T from all currently described taxa of the genus Streptobacillus. On the basis of these data, we propose the novel species Streptobacillus canis sp. nov. with the type strain IHIT1603-19T (=DSM 110501T=CCUG 74118T=CIP 111795T). The G+C content of the DNA of the type strain is 26.6 mol%, genome size is 1.60 Mbp.

Improvement of a diagnostic procedure in surveillance of the listed fish diseases IHN and VHS.

Infectious haematopoietic necrosis (IHN) and viral haemorrhagic septicaemia (VHS) are OIE-listed and notifiable viral fish diseases which are controlled by eradication and surveillance programmes globally. The present study provides improved RT-qPCR procedures based on recently described OIE protocols. Improvements comprise the design of a new TaqMan® probe, replacing a TaqMan® MGB probe that turned out to show impaired binding. Reason for this is SNPs detected in the nucleoprotein N gene sequences of IHNV strains targeted by the RT-qPCR. Furthermore, the IHNV and VHSV RT-qPCR assays were realized as one-step and one-run procedures supplemented by an endogenous control system. The IHNV and VHSV RT-qPCR assays are characterized by a technical sensitivity of 19 and 190 gene equivalents (cRNA) and an analytical sensitivity of 2-7 and 13 TCID50 /ml, respectively. For verification purposes, 105 IHNV and 165 VHSV isolates and several non-targeted viral and bacterial pathogens were included and returned adequate results. However, in field samples divergent results left 14 samples of 154 undetected for IHNV and one sample of 127 for VHSV using cell culture. The study shows that RT-qPCR assays ensure facilitated and reliable testing on IHNV and VHSV in eradication and surveillance programmes.

Identification of a novel clade of group A rotaviruses in fatally diseased domestic pigeons in Europe.

Rotaviruses are well-known causative agents of enteric disorders in humans and other mammals, but little is known about their virulence and pathogenic role in pigeons and other birds. Starting in summer 2017, a series of outbreaks of an acute disease with high mortalities was reported in domestic pigeons in Germany, Belgium and Denmark. The clinical picture was characterized by diarrhoea, vomiting, hepatic necrosis and sudden fatalities. From these severe outbreaks, we discovered several previously unknown group A rotavirus (RVA) lineages of genotype G18P[17]-I4-R4-C4-M4-A4-T4-N4-E19-H4, which were closely related but not identical to an RVA variant identified in cases of fatal hepatic necrosis in Australian pigeon lofts in 2016. Retrospective analysis demonstrated that the predecessors of the highly virulent variants have circulated in Europe since at least 2010. Our data indicate that reassortment and intercontinental spread has led to the emergence of novel RVA variants, which may constitute a major threat to animal welfare and health of domestic pigeon populations worldwide.

Porcine Epidemic Diarrhea in Europe: In-Detail Analyses of Disease Dynamics and Molecular Epidemiology.

Porcine epidemic diarrhea (PED) is an acute and highly contagious enteric disease of swine caused by the eponymous virus (PEDV) which belongs to the genus Alphacoronavirus within the Coronaviridae virus family. Following the disastrous outbreaks in Asia and the United States, PEDV has been detected also in Europe. In order to better understand the overall situation, the molecular epidemiology, and factors that might influence the most variable disease impact; 40 samples from swine feces were collected from different PED outbreaks in Germany and other European countries and sequenced by shot-gun next-generation sequencing. A total of 38 new PEDV complete coding sequences were generated. When compared on a global scale, all investigated sequences from Central and South-Eastern Europe formed a rather homogeneous PEDV S INDEL cluster, suggesting a recent re-introduction. However, in-detail analyses revealed two new clusters and putative ancestor strains. Based on the available background data, correlations between clusters and location, farm type or clinical presentation could not be established. Additionally, the impact of secondary infections was explored using the metagenomic data sets. While several coinfections were observed, no correlation was found with disease courses. However, in addition to the PEDV genomes, ten complete viral coding sequences from nine different data sets were reconstructed each representing new virus strains. In detail, three pasivirus A strains, two astroviruses, a porcine sapelovirus, a kobuvirus, a porcine torovirus, a posavirus, and an enterobacteria phage were almost fully sequenced.

Herpes B virus replication and viral lesions in the liver of a cynomolgus macaque which died from severe disease with rapid onset.

Herpes B virus (BV, Macacine alphaherpesvirus 1) infects macaques asymptomatically, with rare exceptions, but can cause fatal encephalitis in humans. Here, we report disseminated BV infection in a cynomolgus macaque that had died within 12 hour after the onset of unspecific symptoms. Multifocal lesions surrounded by viral antigen were detected in liver while other organs remained inconspicuous, indicating that the liver is a major target. Moreover, high copy numbers of viral DNA were found in feces, underlining the excrements are a potential source of transmission.

Approved and novel strategies in diagnostics of rat bite fever and other Streptobacillus infections in humans and animals.

Rat bite fever (RBF), a worldwide occurring and most likely under-diagnosed zoonosis caused by Streptobacillus moniliformis, represents the most prominent disease of Streptobacillus infections. Recently, novel members have been described, from which a reservoir in rats and other animal species and a zoonotic potential can be assumed. Despite regularly published case reports, diagnostics of RBF continues to represent a 'diagnostic dilemma', because the mostly applied 16S rRNA sequence analysis may be uncertain for proper pathogen identification. Virtually nothing is known regarding prevalence in humans and animal reservoirs. For a realistic assessment of the pathogen's spread, epidemiology and virulence traits, future studies should focus on the genomic background of Streptobacillus. Full genome sequence analyses of a representative collection of strains might facilitate to unequivocally identify and type isolates. Prevalence studies using selective enrichment mechanisms may also enable the isolation of novel strains and candidate species of this neglected group of microorganisms.

Comparison of porcine epidemic diarrhea viruses from Germany and the United States, 2014.

Since 2013, highly virulent porcine epidemic diarrhea virus has caused considerable economic losses in the United States. To determine the relation of US strains to those recently causing disease in Germany, we compared genomes and found that the strain from Germany is closely related to variants in the United States.