Fowl adenoviruses (FAdV), detected during routine diagnostic investigations from 38 countries (5 continents) over a decade, were partially sequenced and grouped by phylogenetic analysis. The partial polymerase gene nucleotide sequences of the 365 fowl adenovirus isolates resulted in the following species distribution: 11% FAdV-A; 3% FAdV-B; 2% FAdV-C; 34% FAdV-D; and 50% FAdV-E. Noticeably, only 79 of the detected strains could be associated with adenovirus-specific pathologic conditions: 62 (79%) with inclusion body hepatitis; 9 (11%) with gizzard erosion; and 8 (10%) with hepatitis hydropericardium syndrome. The remainder of the FAdV strains was detected as concomitant infection from other disease conditions almost exclusively in boilers of 27 to 42 d of age: the majority of them was FAdV-E followed by FAdV-D, and to a lesser extent of FAdV-A, B, and C, the latter ones have not been associated with any of the established adenovirus-caused syndromes in our collection. The highest ratio of coinfections was observed for FAdV-B (62%), while it was about 30% for the rest of the FAdV species. The most frequent coinfection, in connection with all FAdV species, was with the avian infectious bronchitis virus. The presented database will serve as the basis for comparative whole genome and cross-neutralization analysis of selected FAdV isolates.

As a result of their rather uniform external appearance and gross cranial morphology, the systematics of blind mole\ud rats has been hotly debated over the last century; however, the separation of the large-bodied and small-bodied\ud blind mole rats at the genus level (Spalax and Nannospalax, respectively), suggested earlier on morphological\ud grounds, is strongly supported by recent molecular biological evidence. The species of Spalax have so far been\ud distinguished from each other by cranial traits only, especially the outline of sutures of the cranium, and the shape\ud and relative size of the nasal and parietal bones. Based on mitochondrial DNA sequences (with the widest\ud taxonomic and geographic coverage so far) and detailed anatomical comparisons of museum specimens, we\ud herewith provide a revision of the taxonomic and phylogenetic status of the westernmost representative of the\ud genus, Spalax graecus s.l. We clarify that antiquus and istricus – presently regarded as synonyms of graecus – are\ud well-defined species, and they together form a separate clade within Spalax. The robustness of our conclusions is\ud supported by the combined evidence of morphology, multilocus phylogeny, species distribution, and taxon history\ud (species congruence with past tectonic and climate events)

Newcastle Disease is one of the most important infectious poultry diseases worldwide and is associated with high morbidity, mortality, and economic loss. In several countries, vaccination is applied to prevent and control outbreaks; however, information on the ability of vaccines to reduce transmission of ND virus (NDV) is sparse. Here we quantified the transmission of velogenic NDV among 42-day-old broilers. Chickens were either vaccinated with a single dose of a vector vaccine expressing the F protein (rHVT-ND) at day-old in the presence of maternally derived antibodies or kept unvaccinated. Seeders were challenged 8 h before the co-mingling with the corresponding contacts from the same group. Infection was monitored by daily testing of cloacal and oro-nasal swabs with reverse transcription-real-time PCR and by serology. Vaccinated birds were completely protected against clinical disease and virus excretion was significantly reduced compared to the unvaccinated controls that all died during the experiment. The reproduction ratio, which is the average number of secondary infections caused by an infectious bird, was significantly lower in the vaccinated group (0.82 (95% CI 0.38–1.75)) than in the unvaccinated group (3.2 (95% CI 2.06–4.96)). Results of this study demonstrate the potential of rHVT-ND vaccine in prevention and control of ND outbreaks.

Piglets from a porcine circovirus type 2 (PCV2) stable farm of low and high levels of maternally derived antibodies (MDA) against PCV2 were vaccinated either with a whole virus type or a PCV2 ORF2 antigen-based commercial subunit vaccine at three weeks of age. Two non-vaccinated groups served as low and high MDA positive controls. At four weeks post vaccination, all piglets were challenged with a PCV2d-2 type virus strain and were checked for parameters related to vaccine protection over a four-week observation period. MDA levels evidently impacted the outcome of the PCV2d-2 challenge in non-vaccinated animals, while it did not have a significant effect on vaccine-induced protection levels. The humoral immune response developed faster in the whole virus vaccinates than in the subunit vaccinated pigs in the low MDA groups. Further, high MDA levels elicited a stronger negative effect on the vaccine-induced humoral immune response for the subunit vaccine than for the whole virus vaccine. The group-based oral fluid samples and the group mean viraemia and faecal shedding data correlated well, enabling this simple, and animal welfare-friendly sampling method for the evaluation of the PCV2 viral load status of these nursery piglets.

Infectious laryngotracheitis is an economically significant viral disease of chickens, that mainly affects the upper respiratory tract, and is present worldwide. This case reports the first outbreak of infectious laryngotracheitis in a four-week-old organic broiler farm and surrounding flocks in Greece, with typical clinical symptoms and lesions, allegedly provoked by a wild strain of infectious laryngotracheitis virus. Our findings contradict the general perception indicating that the disease appears mainly in older birds and that vaccine strains are the primary cause of infectious laryngotracheitis outbreaks in most continents. A recombinant vectored vaccine was administered, supplementary to biosecurity measures, containing the viral spread. The responsible strain was potentially circulating in the area; therefore, an industry-wide holistic approach was applied, including the vaccination of neighboring broilers and breeders with the same vaccine, the rapid molecular diagnosis of the disease, and strict biosecurity protocols. The results of this holistic effort were effective because, following the application of vaccine and management protocols, manifestations of the disease in regional flocks dropped significantly, and there was no recurrence to date. These findings suggest that vaccination protocols should be modified, especially for organic broilers, to include vaccination against infectious laryngotracheitis.

Fowl adenovirus 1 (FAdV-1) is the main cause of gizzard erosion in chickens. Whole genome sequencing and sequence analyses of 32 FAdV-1 strains from a global collection provided evidence that multiple recombination events have occurred along the entire genome. In gene-wise phylogenies, only the adenoviral pol gene formed a tree topology that corresponded to whole genome-based phylogeny. Virus genetic features that were clearly connected to gizzard erosion were not identified in our analyses. However, some genome variants tended to be more frequently identified from birds with gizzard erosion and strains isolated from healthy birds or birds with non-specific pathologies tended to form common clusters in multiple gene phylogenies. Our data show that the genetic diversity is greater, and the evolutionary mechanisms are more complex within FAdV-1 than previously thought. The implications of these findings for viral pathogenesis and epidemiology await further investigation.