Characterization of neurotropic HPAI H5N1 viruses with novel genome constellations and mammalian adaptive mutations in free-living mesocarnivores in Canada.

The GsGd lineage (A/goose/Guangdong/1/1996) H5N1 virus was introduced to Canada in 2021/2022 through the Atlantic and East Asia-Australasia/Pacific flyways by migratory birds. This was followed by unprecedented outbreaks affecting domestic and wild birds, with spillover into other animals. Here, we report sporadic cases of H5N1 in 40 free-living mesocarnivore species such as red foxes, striped skunks, and mink in Canada. The clinical presentations of the disease in mesocarnivores were consistent with central nervous system infection. This was supported by the presence of microscopic lesions and the presence of abundant IAV antigen by immunohistochemistry. Some red foxes that survived clinical infection developed anti-H5N1 antibodies. Phylogenetically, the H5N1 viruses from the mesocarnivore species belonged to clade 2.3.4.4b and had four different genome constellation patterns. The first group of viruses had wholly Eurasian (EA) genome segments. The other three groups were reassortant viruses containing genome segments derived from both North American (NAm) and EA influenza A viruses. Almost 17 percent of the H5N1 viruses had mammalian adaptive mutations (E627 K, E627V and D701N) in the polymerase basic protein 2 (PB2) subunit of the RNA polymerase complex. Other mutations that may favour adaptation to mammalian hosts were also present in other internal gene segments. The detection of these critical mutations in a large number of mammals within short duration after virus introduction inevitably highlights the need for continually monitoring and assessing mammalian-origin H5N1 clade 2.3.4.4b viruses for adaptive mutations, which potentially can facilitate virus replication, horizontal transmission and posing pandemic risks for humans.

Gastric neuroendocrine carcinoma (carcinoid) in a ferret (Mustela putorius furo).

A well-differentiated neuroendocrine carcinoma of the stomach (gastric carcinoid) with transcoelomic and lymph node metastasis was confirmed on post-mortem examination of a 3-year-old, spayed female, domestic ferret (Mustela putorius furo). The animal was initially presented with a history of persistent vomiting which progressed to weight loss, a palpable abdominal mass, and melena. The ferret received palliative treatment and was euthanized 9 mo after initial presentation. The clinical, ultrasonographical, cytological, gross pathological, histopathological, and immunohistochemical findings are described. Gastric neuroendocrine carcinomas are rarely reported in animals; this is the first description in a ferret. Key clinical message: Veterinary practitioners and diagnosticians should include neuroendocrine carcinoma as a differential diagnosis when encountering gastric neoplasms in ferrets and be aware of the potential for aggressive behavior and widely spread metastasis.

Carcinome neuroendocrine gastrique (carcinoïde) chez un furet ( Mustela putorius furo ). Un carcinome neuroendocrinien bien différencié de l'estomac (carcinoïde gastrique) avec des métastases transcoelomiques et ganglionnaires a été confirmé lors de l'autopsie d'une femelle furet domestique (Mustela putorius furo) stérilisée de 3 ans. L'animal a été initialement présenté avec des antécédents de vomissements persistants qui ont évolué vers une perte de poids, une masse abdominale palpable et un méléna. Le furet a reçu un traitement palliatif et a été euthanasié 9 mois après la présentation initiale. Les résultats cliniques, échographiques, cytologiques, de pathologie macroscopique, histopathologiques et immunohistochimiques sont décrits. Les carcinomes neuroendocriniens gastriques sont rarement rapportés chez les animaux; c'est la première description chez un furet.Message clinique clé:Les praticiens vétérinaires et les diagnosticiens doivent inclure le carcinome neuroendocrinien comme diagnostic différentiel lorsqu'ils rencontrent des néoplasmes gastriques chez les furets et être conscients du potentiel de comportement agressif et de métastases largement disséminées.(Traduit par Dr Serge Messier).

Phylogenetic analysis of porcine circovirus 3 circulating in Canadian pigs.

INTRODUCTION: Porcine circovirus 3 (PCV3) has been detected in pigs worldwide and associated with several clinical signs. METHODS: To investigate the genetic diversity of PCV3 strains circulating in Canada, 44 PCV3 positive samples from Saskatchewan (2/44), Manitoba (2/44), Quebec (4/44), Alberta (11/44) and Ontario (25/44) submitted to diagnostic laboratories in Canada between 2019 and 2021 were sequenced and analyzed. RESULTS: Phylogenetic analysis of capsid genes showed that all of the 44 Canadian strains classified into PCV3a and segregated into seven lineages with common amino acid changes observed at A24V, R27K, N56D, T77S, Q98R, L150I (F) and R168K positions. CONCLUSION: Future studies are required to determine whether the polymorphisms in capsid proteins, as revealed in this study, could be associated with differences in the pathogenicity or antigenicity of PCV3 strains. This is the first phylogenetic analysis of PCV3 strains among different provinces in Canada.

Bovine Adenovirus-3 Tropism for Bovine Leukocyte Sub-Populations.

A number of characteristics including lack of virulence and the ability to grow to high titers, have made bovine adenovirus-3 (BAdV-3) a vector of choice for further development as a vaccine-delivery vehicle for cattle. Despite the importance of blood leukocytes, including dendritic cells (DC), in the induction of protective immune responses, little is known about the interaction between BAdV-3 and bovine blood leukocytes. Here, we demonstrate that compared to other leukocytes, bovine blood monocytes and neutrophils are significantly transduced by BAdV404a (BAdV-3, expressing enhanced yellow green fluorescent protein [EYFP]) at a MOI of 1-5 without a significant difference in the mean fluorescence of EYFP expression. Moreover, though expression of some BAdV-3-specific proteins was observed, no progeny virions were detected in the transduced monocytes or neutrophils. Interestingly, addition of the "RGD" motif at the C-terminus of BAdV-3 minor capsid protein pIX (BAV888) enhanced the ability of the virus to enter the monocytes without altering the tropism of BAdV-3. The increased uptake of BAV888 by monocytes was associated with a significant increase in viral genome copies and the abundance of EYFP and BAdV-3 19K transcripts compared to BAdV404a-transduced monocytes. Our results suggest that BAdV-3 efficiently transduces monocytes and neutrophils in the absence of viral replication. Moreover, RGD-modified capsid significantly increases vector uptake without affecting the initial interaction with monocytes.

Combating Vaccine Hesitancy: Teaching the Next Generation to Navigate Through the Post Truth Era.

Despite scientific evidence supporting the fact that vaccines are fundamental tools for preventing infectious diseases, a percentage of the population still refuses some or all of them. Vaccine hesitancy has become a widespread issue, and its complexity lies in the great variety of factors that can influence decisions about immunization, which are not just vaccine-related concerns, but also involve personal and societal levels. Our research group performed an extensive literature review to analyze: (1) different age groups, their relation to the problem and their characteristics; (2) the most important information (key messages) about immunization that could be used to counteract hesitancy; and (3) best approaches to transmit the messages to the target groups. We propose a long-term approach to overcome vaccine hesitancy that involves the education of children and adolescents on the basics about immunization and critical thinking, using different communication channels.