Canadian Food Inspection Agency

We describe hepatic infections by giant liver fluke (Fascioloides magna) in free-ranging muskoxen (Ovibos moschatus) in Nunavik, Québec, Canada. Whole livers and feces were collected from 51 muskoxen (37 males, 14 females) harvested from 2007 to 2011. Prevalence of F. magna was very high (48/51, 94%; 95% confidence interval, 84-99), with the intensity of infection reaching up to 40 adult trematodes per liver (median, 4 flukes). The estimated percentage of macroscopically altered liver, which was evaluated in serial 1-cm-thick slices, ranged from 0.1% to 57.3% and was positively correlated with the number of parasites detected. Animals harvested near Tasiujaq had higher mean fluke intensity (7.2) than those near Kuujjuaq (2.6) in Nunavik, Québec, Canada. Despite the extent of the hepatic alterations in some individuals, no association was found between intensity of infection or liver alteration and the examined nutritional condition indices (depth of back fat, femur marrow fat percentage, and kidney fat index). Field observations suggest that infections by F. magna did not have a significant clinical impact on sampled muskoxen. The mean fluke intensity and the percentage of altered liver did not vary between sex and age. Fecal shedding of F. magna eggs was documented in some individuals, indicating that muskoxen could be characterized as a definitive host. Further research is needed to define the reservoir species and characterize the life cycle of this parasite in the Canadian Arctic.

Abstract Crimean-Congo hemorrhagic fever orthonairovirus (CCHFV) is a tick-borne RNA virus that can cause a severe hemorrhagic disease in humans. In animals, CCHFV infection is known to produce a transient viremia followed by host recovery and thus a short window in which animals can serve as potential intermediate hosts. Here we report that, in domestic sheep experimentally infected with CCHFV Kosovo Hoti, viral whole genome sequences were recovered from tissues long after the clearance of viremia. While viral RNA persistence in tissues was largely characterized by a lack of continuous and extensive viral replication, the sporadic presence of replication products (RNA transcripts and proteins) was detected. These findings suggest that the biology of CCHFV in animals goes far beyond an acute infection. A possibility of viral reactivation from a dormant state, akin to that observed in other RNA viruses, warrants further investigation.

Abstract The spongy moth ( Lymantria dispar dispar ) and several of its close relatives (subspecies L . d . asiatica and L . d . japonica , and the species L . umbrosa and L . albescens ) are defoliators that pose an invasion threat in Canada and around the world. Members of this group can disperse far beyond their native ranges on vehicles and freight, and they can attack a wide array of deciduous and coniferous plant species globally. Occasional population outbreaks can also defoliate large geographic areas over multiple years, resulting in widespread tree decline or mortality and a variety of other ecological impacts. As a result, these moths pose a serious threat to natural and urban forests. We summarize the history of Lymantria moth incursions into the province of British Columbia, Canada, since the start of regular surveillance and eradication began in that region near the end of the 1970s. Proactive public policy and a science-based management approach have contributed to a successful partnership between the federal and BC provincial governments to thwart a Lymantria moth invasion for nearly 50 years. Information © His Majesty the King in Right of Canada, as represented by the Minister of Natural Resources

Clubroot, caused by the obligate parasite Plasmodiophora brassicae, is a soilborne disease affecting canola (Brassica napus) and other crucifers. Although planting resistant cultivars remains the primary strategy for managing clubroot, the emergence of resistance-breaking P. brassicae pathotypes continues to threaten canola production. In this context, soil and root microorganisms may play a role in suppressing the disease. This study investigated the impact of P. brassicae infection on the microbial communities of soil, seeds, roots, and the rhizosphere in susceptible and resistant canola lines, with the aim of analyzing host–pathogen–microbiome interactions and identifying microbial taxa potentially associated with disease resistance. Our findings showed that resistant canola lines inoculated with P. brassicae (pathotype 3A) exhibited reduced disease severity compared to their susceptible counterparts. Diversity analyses of microbial communities revealed that clubroot-resistant canola lines tended to maintain more stable and diverse fungal communities, with a higher Shannon index than susceptible lines. Inoculation with P. brassicae induced more pronounced changes in the root microbiome than in the rhizosphere. Additionally, the seed microbiomes of resistant and susceptible lines displayed distinct bacterial and fungal profiles, suggesting that clubroot susceptibility may influence seed-associated microbial community composition. Differential abundance analysis of root and rhizosphere microbiomes indicated that certain microbial taxa, including bacterial genera such as Acidovorax, Bacillus, Cupriavidus, Cytophaga, Duganella, Flavobacterium, Fluviicola, Luteimonas, Methylotenera, Pedobacter, and Peredibacter, as well as fungal genera such as Aspergillus, Candida, Fusicolla, Paecilomyces, and Rhizophlyctis, may be recruited or enriched in resistant canola lines following P. brassicae inoculation, potentially contributing to reduced clubroot severity.

ABSTRACT The Japanese beetle (JB) Popillia japonica (Coleoptera: Scarabaeidae) has been a significant invasive pest for over a century in North America. Several studies have reported that plants under direct sunlight are preferred and trap colour affects the number of beetles captured, indicating that visual stimuli influence JB behaviour. Despite this, the influence of visual cues on trap efficiency remains poorly understood, and its visual system has not been characterised. To address this knowledge gap, we conducted a field trial using panels to manipulate sun exposure of traps to test the effect of sunlight intensity on JB trap performance. Our results indicate that JB flight activity is reduced under lower sunlight conditions and that visual cues influence trap performance. Fully shaded traps consistently captured fewer beetles when cloud cover was below 85%. To better understand JB colour perception, we investigated its genome for visual opsin genes and analysed its photoreceptor sensitivity with an electroretinogram. We found evidence for a UV‐green dichromatic visual system, lacking the orange‐sensitive photoreceptor found in some Coleoptera. This may explain inconsistencies in trap colour preference reported in the literature and indicates that JB may not have been able to differentiate some of the colour treatments tested in published studies. To optimise JB trap capture, future studies should evaluate UV‐reflecting traps, control for spectral reflectance intensity, and investigate whether JB avoids low‐light conditions due to environmental risks or visual limitations.

Nipah virus (NiV) and Hendra virus (HeV), which both belong to the genus henipavirus, are zoonotic pathogens that cause severe systemic, neurological, and/or respiratory disease in humans and a variety of mammals. Therefore, monitoring viral prevalence in natural reservoirs and rapidly diagnosing cases of henipavirus infection are critical to limiting the spread of these viruses. Current laboratory methods for detecting NiV and HeV include virus isolation, reverse transcription quantitative real-time PCR (RT-qPCR), and antigen detection via an enzyme-linked immunosorbent assay (ELISA), all of which require highly trained personnel and specialized equipment. Here, we describe the development of a point-of-care customized immunochromatographic lateral flow (ILF) assay that uses recombinant human ephrin B2 as a capture ligand on the test line and a NiV-specific monoclonal antibody (mAb) on the conjugate pad to detect NiV and HeV. The ILF assay detects NiV and HeV with a diagnostic specificity of 94.4% and has no cross-reactivity with other viruses. This rapid test may be suitable for field testing and in countries with limited laboratory resources.

A high-throughput sequencing-based grapevine metagenomic survey was conducted across all grape-growing Canadian provinces (British Columbia, Ontario, Nova Scotia, and Québec) with the objective of better understanding the grapevine virome composition. In total, 310 composite grapevine samples representing nine Vitis vinifera red; five V. vinifera white; seven American–French red; and five white hybrid cultivars were analyzed. dsRNA, enriched using two different methods, was used as the starting material and source of viral nucleic acids in HTS. The virome status on the distribution and incidence in different regions and grapevine cultivars is addressed. Results from this study revealed the presence of 20 viruses and 3 viroids in the samples tested. Twelve viruses, which are in the regulated viruses list under grapevine certification, were identified in this survey. The major viruses detected in this survey and their incidence rates are GRSPaV (26% to 100%), GLRaV-2 (1% to 18%), GLRaV-3 (15% to 63%), GRVFV (0% to 52%), GRGV (0% to 52%), GPGV (3.3% to 77%), GFkV (1.5% to 31.6%), and GRBV (0% to 19.4%). This survey is the first comprehensive virome study using viral dsRNA and a metagenomics approach on grapevine samples from the British Columbia, Ontario, Nova Scotia, and Quebec provinces in Canada. Results from this survey highlight the grapevine virome distribution across four major grapevine-growing regions and their cultivars. The outcome of this survey underlines the need for strengthening current management options to mitigate the impact of virus spread, and the implementation of a domestic grapevine clean plant program to improve the sanitary status of the grapevine ecosystem.