Publications by authors named "Jean-Francois Valarcher"

As a naturally occurring bovine pathogen, bovine respiratory syncytial virus (BRSV) engages with the innate and adaptive immune responses of cattle in an evolutionarily meaningful fashion. Therefore, studying viruses in their native hosts, rather than in non-native hosts, is more likely to authentically reflect the pathogenesis of natural infection. Experimental infection of calves with BRSV provides an important tool for investigating mechanisms of pathogenesis and immunity to RSV infection, and can also be used for evaluating new strategies for the prevention and treatment of RSV infection in both cattle and man.

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Background: Lung auscultation is a common method for the routine diagnosis of calf bronchopneumonia. However, its repeatability among operators has been criticized.

Objective: Determine agreement among veterinarians for specific lung sounds after a short tutorial to standardize the definition of lung sounds.

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Orthopedic disease, presenting as lameness, is a common cause of pain in dairy cattle, often implying a prolonged course of disease, with significant economic losses and impaired animal welfare. To mitigate these negative effects, early identification of lameness and monitoring of pain levels during recovery are crucial. This study aimed to evaluate whether the Cow Pain Scale (CPS) can be used to detect pain behaviors in stationary dairy cows with mild to moderate lameness or not, and to investigate the association between certain CPS items and orthopedic disease.

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Increased evidence suggests that cattle are the primary host of Influenza D virus (IDV) and may contribute to respiratory disease in this species. The aim of this study was to detect and characterise IDV in the Swedish cattle population using archived respiratory samples. This retrospective study comprised a collection of a total 1763 samples collected between 1 January 2021 and 30 June 2024.

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Non-steroidal anti-inflammatory drugs (NSAID) are not recommended for use against pneumonia in humans, but are commonly utilised against bovine respiratory disease. This study aimed to determine if the use of NSAIDs in the early phase of bovine respiratory syncytial virus (BRSV)-infection limits pulmonary inflammation. Four to nine-week old calves were infected with BRSV by aerosol and were treated with either meloxicam intravenously on day (D)4 (n = 5, MEL), acetylsalicylat-DL-lysin intravenously on D4 and D5 (n = 5, ASA), or were left untreated as controls (n = 5, CTR).

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Foot and mouth disease (FMD) is a highly contagious viral disease affecting cloven-hoofed animals. This disease is one of the most important in animal health due to its significant socio-economic impact, especially in case of an outbreak. One important challenge associated with this disease is the ability of the FMD virus (FMDV) to persist in its hosts through still unresolved underlying mechanisms.

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The role of Influenza D virus (IDV) in bovine respiratory disease remains unclear. An in vivo experiment resulted in increased clinical signs, lesions, and pathogen replication in calves co-infected with IDV and (. ), compared to single-infected calves.

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Foot-and-mouth disease (FMD) is a highly contagious viral disease of cloven-hoofed animals that has a significant socio-economic impact. One concern associated with this disease is the ability of its etiological agent, the FMD virus (FMDV), to persist in its hosts through underlying mechanisms that remain to be elucidated. While persistence has been described in cattle and small ruminants, it is unlikely to occur in pigs.

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Article Synopsis
  • Bovine Parainfluenza Type 3 virus (BPIV-3) is a significant contributor to Bovine Respiratory Disease (BRD), first identified in 1959, and is now widespread in cattle herds globally.
  • The study sequenced and analyzed BPIV-3 strains from sick cattle in France and Sweden, discovering that the strains exist in different genotypes (A and C) and showing genetic differences from vaccine strains.
  • These findings emphasize the need for ongoing research to understand the genetic diversity between circulating field strains and vaccines, which is essential for accurate diagnostics and disease management in cattle populations.
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Article Synopsis
  • - Influenza D virus (IDV) has been linked to bovine respiratory disease and may affect humans, as indicated by the presence of IDV-specific antibodies in human blood samples.
  • - The study analyzed bulk tank milk samples from Swedish dairy farms in 2019 and 2020, finding 32% of samples positive for IDV antibodies in 2019 and 40% in 2020.
  • - The highest rates of IDV antibodies were found in the southern region of Sweden, particularly in Halland, highlighting the need for further research on IDV's impact in both cattle and humans.
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Bovine respiratory syncytial virus (BRSV) is a pathogenic pneumovirus and a major cause of acute respiratory infections in calves. Although different vaccines are available against BRSV, their efficiency remains limited, and no efficient and large-scale treatment exists. Here, we developed a new reverse genetics system for BRSV expressing the red fluorescent protein mCherry, based on a field strain isolated from a sick calf in Sweden.

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Bovine respiratory syncytial virus (BRSV) is a major cause of respiratory disease in cattle. Genomic sequencing can resolve phylogenetic relationships between virus populations, which can be used to infer transmission routes and potentially inform the design of biosecurity measures. Sequencing of short (<2000 nt) segments of the 15 000-nt BRSV genome has revealed geographic and temporal clustering of BRSV populations, but insufficient variation to distinguish viruses collected from herds infected close together in space and time.

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Human and bovine respiratory syncytial virus (HRSV and BRSV) are closely genetically related and cause respiratory disease in their respective host. Whereas HRSV vaccines are still under development, a multitude of BRSV vaccines are used to reduce clinical signs. To enable the design of vaccination protocols to entirely stop virus circulation, we aimed to investigate the duration, character and efficacy of the immune responses induced by natural infections.

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Article Synopsis
  • Bovine respiratory disease (BRD) is a significant illness affecting young cattle, caused by various pathogens interacting with environmental and host factors.
  • This study explored the effects of simultaneous infection with influenza D virus (IDV) and Mycoplasma bovis, finding that coinfection led to more severe respiratory disease and lung damage than infections with either pathogen alone.
  • The research revealed increased immune responses in the lungs of coinfected calves, particularly elevated levels of the gamma interferon gene, indicating a stronger immune reaction to the dual infection.
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Background: The vector-borne human viral zoonosis tick-borne encephalitis (TBE) is of growing concern in Sweden. The area where TBE is considered endemic has expanded, with an increasing geographical distribution of Ixodes ricinus as the tick vector and a rising number of reported TBE cases in humans. Efforts to map TBE risk areas have been carried out by sentinel monitoring, mainly based on individual sampling and analysis of wild and domestic animals, as well as ticks, for tick-borne encephalitis virus (TBEV).

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The induction of long-lasting clinical and virological protection is needed for a successful vaccination program against the bovine respiratory syncytial virus (BRSV). In this study, calves with BRSV-specific maternally derived antibodies were vaccinated once, either with (i) a BRSV pre-fusion protein (PreF) and Montanide ISA61 VG (ISA61, = 6), (ii) BRSV lacking the SH gene (ΔSHrBRSV, = 6), (iii) a commercial vaccine (CV, = 6), or were injected with ISA61 alone ( = 6). All calves were challenged with BRSV 92 days later and were euthanized 13 days post-infection.

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Influenza D virus (IDV) is considered a new agent involved in bovine respiratory disease (BRD). Based on seroprevalence studies or isolation from clinical samples, this virus has been detected on several continents and in several animal species, including cattle, pigs, camel, horses, and goats. We used an indirect in-house ELISA to detect anti-IDV antibodies in 165 serum samples from bulls on 116 farms in the province of La Pampa, Argentina.

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Achieving safe and protective vaccination against respiratory syncytial virus (RSV) in infants and in calves has proven a challenging task. The design of recombinant antigens with a conformation close to their native form in virus particles is a major breakthrough. We compared two subunit vaccines, the bovine RSV (BRSV) pre-fusion F (preF) alone or with nanorings formed by the RSV nucleoprotein (preF+N).

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Lipopolysaccharide (LPS) expressed on the surface of Gram-negative bacteria activates pro-inflammatory pathways, dys-regulates the function of endometrial cells and is a key player in the mechanisms involved in endometritis. This study aimed to investigate the effects of LPS on bovine endometrial epithelial cells (bEEC) from whole transcriptome with a special focus on genes involved in embryo-maternal interactions. Following in vitro culture, bEEC from three cows were exposed to 0, 2, and 8 μg/mL LPS for 24h.

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Foot-and-mouth disease virus (FMDV) causes a highly contagious vesicular disease in livestock, with serious consequences for international trade. The virus persists in the nasopharynx of cattle and this slows down the process to obtain an FMDV-free status after an outbreak. To study biological mechanisms, or to identify molecules that can be targeted to diagnose or interfere with persistence, we developed a model of persistent FMDV infection in bovine dorsal soft palate (DSP).

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The recently discovered influenza D virus (IDV) of the family has been detected in swine and ruminants with a worldwide distribution. Cattle are considered to be the primary host and reservoir, and previous studies suggested a tropism of IDV for the upper respiratory tract and a putative role in the bovine respiratory disease complex. This study aimed to characterize the pathogenicity of IDV in naive calves as well as the ability of this virus to transmit by air.

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Foot-and-mouth disease (FMD) is the most devastating disease of cloven-hoofed livestock, with a crippling economic burden in endemic areas and immense costs associated with outbreaks in free countries. Foot-and-mouth disease virus (FMDV), a picornavirus, will spread rapidly in naïve populations, reaching morbidity rates of up to 100% in cattle. Even after recovery, over 50% of cattle remain subclinically infected and infectious virus can be recovered from the nasopharynx.

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Concerns are growing over the impact of livestock farming on environment and public health. The livestock industry is faced with the double constraint of limiting its use of natural resources and antimicrobials while ensuring its economic sustainability. In this context, reliable methods are needed to evaluate the effect of the prevention of endemic animal diseases on the productivity of livestock production systems.

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Article Synopsis
  • An outbreak of pseudocowpox virus (PCPV) affected a dairy herd of about 80 cows, with 90% of them displaying skin lesions primarily on the vulva and vaginal mucosa.
  • Histological examinations revealed a viral infection, confirmed by electron microscopy showing parapoxvirus particles and deep sequencing identifying the PCPV strain VR 634.
  • The study ruled out other causes for the symptoms, such as bovine herpesvirus 1, and suggested that a rolling cow brush might have facilitated the virus's transmission.
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