This study represents the largest prospective analysis of FCV diversity and antigenic cross-reactivity at a European level. The scale and random nature of sampling used gives confidence that the FCV isolates used are broadly representative of FCVs that cats are exposed to in these countries. The in vitro neutralisation results suggest that antibodies raised to FCV-F9 remain broadly cross-reactive to contemporary FCV isolates across the European countries sampled.

Objectives Feline calicivirus (FCV) is a highly variable and globally important feline pathogen for which vaccination has been the mainstay of control. Here, we test whether the continued use of FCV-F9, one of the most frequently used vaccine strains globally, is driving the emergence of vaccine-resistant viruses in the field. Methods This study made use of two representative panels of field isolates previously collected from cats visiting randomly selected veterinary practices across the UK as part of separate cross-sectional studies from 2001 and 2013/2014. Phylogenetic analysis and in vitro virus neutralisation tests were used to compare the genetic and antigenic relationships between these populations and FCV-F9. Results Phylogenetic analysis showed a typically radial distribution dominated by 52 distinct strains, with strains from both 2001 and 2013/2014 intermingled. The sequence for FCV-F9 appeared to be integral to this phylogeny and there were no significant differences in the genetic distances within each studied population (intra-population distances), or between them (inter-population distances), or between each population and FCV-F9. A 1 in 8 dilution neutralised 97% and 100% of the 2001 and 2013/14 isolates, respectively, and a 1 in 16 dilution neutralised 87% and 75% of isolates, respectively. There was no significant difference either in variance between the FCV-F9 neutralising titres for the two populations, or in the distribution of neutralisation titres across the two populations. Conclusions and relevance Although FCV is a highly variable virus, we found no evidence for a progressive divergence of field virus from vaccine strain FCV-F9, either phylogenetically or antigenically, with FCV-F9 antisera remaining broadly and equally cross-reactive to two geographically representative and temporally separated FCV populations. We suggest this may be because the immunodominant region of the FCV capsid responsible for neutralisation may have structural constraints preventing its longer term progressive antigenic evolution.

This work evaluated in vivo performance of a tissue-engineered bone-like matrix obtained by culturing cell-scaffold constructs in a flow perfusion bioreactor, designed to enable culture of large constructs, envisioning the regeneration of critical-sized defects. A blend of starch with polycaprolactone scaffolds was seeded with goat bone marrow stromal cells (GBMSCs) cultured in the perfusion bioreactor for 14 days using osteogenic medium. Cell seeded scaffolds cultured in static conditions acted as controls. After 14 days, constructs (42 mm length and 16 mm in diameter) were implanted in critical size defects performed in the tibial bone of six adult goats from which the bone marrow had been collected previously. Explants were retrieved after six and 12 weeks of implantation and characterized using scanning electron microscopy, energy-dispersive spectroscopy, micro-computed tomography and radiographic analysis to assess tissue morphology and calcification. Explants were histologically analyzed, using Hematoxylin & Eosin and Masson Trichrome staining. Results provided relevant information about the performance and functionality of starch with polycaprolactone-goat bone marrow stromal cell constructs in a critical size orthotopic defect performed in a large animal model and demonstrated that culture of the starch with polycaprolactone scaffolds with the autologous cells in perfusion culture provide a good therapy for the healing and regenerative process of bone defects.

Background: There is a lack of national population data concerning infectious disease in companion animals. Here, we piloted the feasibility of linking diagnostic laboratories, population surveillance and modern sequencing approaches to extract targeted diagnostic samples from laboratories before they were discarded, as a novel route to better understand national epidemiology of major small animal pathogens. Methods: Samples tested for canine or feline parvovirus were requested from a national veterinary diagnostic laboratory and analysed by Sanger or next generation sequencing. Samples were linked to electronic health data held in the SAVSNET database. Results: Sequences obtained from positive samples, together with associated metadata, provided new insights into the recent geographical distribution of parvovirus strains in circulation in the United Kingdom (UK). Conclusions: This collaboration with industry represents a 'National Virtual Biobank' that can rapidly be called on, to efficiently add new layers of epidemiological information of relevance to animal, and potentially human, population health.

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