Outbreak of Western Equine Encephalitis Virus Infection Associated with Neurological Disease in Horses Following a Nearly 40-Year Intermission Period in Argentina.

Western equine encephalitis virus (WEEV) is a mosquito-borne arbovirus (genus , family ) that has re-emerged in South America in late 2023, causing severe disease in both horses and humans after a nearly 40-year intermission period. We here describe the virological, serological, pathological, and molecular features of WEEV infection in horses during the 2023-2024 outbreak in Argentina. WEEV-infected horses developed neurological signs with mild to severe encephalitis associated with minimal to abundant WEEV-infected cells, as demonstrated by WEEV-specific in situ hybridization.

A novel reconstruction model for thoracic spinal cord injury in swine.

Spinal cord (SC) reconstruction (process to reestablish the severed neural continuity at the injury site) may provide better recovery from blunt SC injury (SCI). A miniature swine model of blunt SC compression was used to test the hypothesis that reconstruction of the SC with sural nerve in combination with surgical decompression and stabilization improves functional, macro- and microstructural recovery compared to decompression and stabilization alone. Following blunt T9-T11 SC compression injury, five adult Yucatan gilts randomly received laminectomy and polyethylene glycol (as fusogen) with (n = 3) or without (n = 2) sural nerve graft SC reconstruction.

H5N1 clade 2.3.4.4b dynamics in experimentally infected calves and cows.

In March 2024, highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.

Acute myeloid leukemia-M1 in a horse with neurologic signs and necrotizing enterocolitis.

An 18-y-old American Saddlebred mare was admitted with fever and acute onset of neurologic signs including grade 3 of 5 ataxia, difficulty in prehension, and dull mentation. Because of financial restraints, desired testing could not be performed; the horse's condition declined despite supportive treatment, and euthanasia was elected. Postmortem examination revealed petechiae and ecchymoses in the meninges and neuroparenchyma of the encephalon.

Fatal gastric amebiasis in a Linnaeus's two-toed sloth associated with infection.

Here we describe a case of fatal amebic gastritis associated with infection in an 11-mo-old Linnaeus's two-toed sloth (). The sloth had a history of weight loss and intermittent diarrhea for 18 d, and subsequently died despite empirical treatment. Postmortem findings included emaciation, gastric dilation with fluid content, and fibrinonecrotic gastritis with intralesional amebic trophozoites and cysts in the glandular region of the fundus.

Macrophage Colony Stimulating Factor (M-CSF) and Interleukin-34 (IL-34) Expression in Canine Osteosarcoma in the Context of the Tumour Immune Microenvironment.

Canine osteosarcoma (OSA) is a malignancy that has been shown to modulate the host immune system. Macrophage colony-stimulating factor (M-CSF; CSF1) and interleukin-34 (IL-34; IL34) are both ligands of colony stimulating factor 1 receptor (CSF-1R), and may play a role in the pathogenesis of a variety of human cancers, including OSA. This study aimed to, (1) assess M-CSF and IL-34 expression in canine OSA cell lines and tissue samples, and (2) determine any correlations between M-CSF and IL-34 expression and immune cell infiltrates within canine OSA tissues.

Outcome of H5N1 clade 2.3.4.4b virus infection in calves and lactating cows.

In March 2024, highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.

Little Brown Bats (Myotis lucifugus) Are Resistant to SARS-CoV-2 Infection.

It has been proposed that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus that spread through human populations as a pandemic originated in Asian bats. There is concern that infected humans could transmit the virus to native North American bats; therefore, the susceptibility of several North American bat species to the pandemic virus has been experimentally assessed. Big brown bats (Eptesicus fuscus) were shown to be resistant to infection by SARS-CoV-2, whereas Mexican free-tailed bats (Tadarida brasiliensis) became infected and orally excreted moderate amounts of virus for up to 18 d postinoculation.

Pigs are highly susceptible to but do not transmit mink-derived highly pathogenic avian influenza virus H5N1 clade 2.3.4.4b.

Rapid evolution of highly pathogenic avian influenza viruses (HPAIVs) is driven by antigenic drift but also by reassortment, which might result in robust replication in and transmission to mammals. Recently, spillover of clade 2.3.

Modulation of Equid Herpesvirus-1 Replication Dynamics Using CRISPR/Cas9-Assisted Genome Editing.

(1) Background: equid alphaherpesvirus-1 (EHV-1) is a highly contagious viral pathogen prevalent in most horse populations worldwide. Genome-editing technologies such as CRISPR/Cas9 have become powerful tools for precise RNA-guided genome modifications; (2) Methods: we designed single guide RNAs (sgRNA) to target three essential (ORF30, ORF31, and ORF7) and one non-essential (ORF74) EHV-1 genes and determine their effect on viral replication dynamics ; (3) Results: we demonstrated that sgRNAs targeting essential lytic genes reduced EHV-1 replication, whereas those targeting ORF74 had a negligible effect. The sgRNAs targeting ORF30 showed the strongest effect on the suppression of EHV-1 replication, with a reduction in viral genomic copy numbers and infectious progeny virus output.

Development and validation of multiplex one-step qPCR/RT-qPCR assays for simultaneous detection of SARS-CoV-2 and pathogens associated with feline respiratory disease complex.

Feline respiratory disease complex (FRDC) is caused by a wide range of viral and bacterial pathogens. Both Influenza A virus (IAV) and Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) also induce respiratory diseases in cats. Two one-step multiplex qPCR/RT-qPCR assays were developed and validated: FRA_1 (Feline respiratory assay 1) for the detection of four viral targets and FRA_2 for the detection of three bacteria associated with FRDC.

Coding-complete genome sequences of two strains of canine pneumovirus derived from dogs with upper respiratory disease in the United States.

Canine pneumovirus was detected by RT-qPCR in 2022 from nasal swabs collected from two dogs with upper respiratory disease in a shelter in Louisiana, United States. The genomes from the designated strains CPnV USA/LA/2022/124423 and USA/LA/2022/123696 were sequenced and show the closest similarity to the pneumonia virus of mice J3666.

Th2 and Th17-associated immunopathology following SARS-CoV-2 breakthrough infection in Spike-vaccinated ACE2-humanized mice.

Vaccines have demonstrated remarkable effectiveness in protecting against COVID-19; however, concerns regarding vaccine-associated enhanced respiratory diseases (VAERD) following breakthrough infections have emerged. Spike protein subunit vaccines for SARS-CoV-2 induce VAERD in hamsters, where aluminum adjuvants promote a Th2-biased immune response, leading to increased type 2 pulmonary inflammation in animals with breakthrough infections. To gain a deeper understanding of the potential risks and the underlying mechanisms of VAERD, we immunized ACE2-humanized mice with SARS-CoV-2 Spike protein adjuvanted with aluminum and CpG-ODN.

Equine Rotavirus A under the One Health Lens: Potential Impacts on Public Health.

Group A rotaviruses are a well-known cause of viral gastroenteritis in infants and children, as well as in many mammalian species and birds, affecting them at a young age. This group of viruses has a double-stranded, segmented RNA genome with high genetic diversity linked to point mutations, recombination, and, importantly, reassortment. While initial molecular investigations undertaken in the 1900s suggested host range restriction among group A rotaviruses based on the fact that different gene segments were distributed among different animal species, recent molecular surveillance and genome constellation genotyping studies conducted by the Rotavirus Classification Working Group (RCWG) have shown that animal rotaviruses serve as a source of diversification of human rotavirus A, highlighting their zoonotic potential.

ACE2 and TMPRSS2 distribution in the respiratory tract of different animal species and its correlation with SARS-CoV-2 tissue tropism.

A wide range of animal species show variable susceptibility to SARS-CoV-2; however, host factors associated with varied susceptibility remain to be defined. Here, we examined whether susceptibility to SARS-CoV-2 and virus tropism in different animal species are dependent on the expression and distribution of the virus receptor angiotensin-converting enzyme 2 () and the host cell factor transmembrane serine protease 2 (). We cataloged the upper and lower respiratory tract of multiple animal species and humans in a tissue-specific manner and quantitatively evaluated the distribution and abundance of and mRNA .

Experimental co-infection of calves with SARS-CoV-2 Delta and Omicron variants of concern.

Since emerging in late 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has repeatedly crossed the species barrier with natural infections reported in various domestic and wild animal species. The emergence and global spread of SARS-CoV-2 variants of concern (VOCs) has expanded the range of susceptible host species. Previous experimental infection studies in cattle using Wuhan-like SARS-CoV-2 isolates suggested that cattle were not likely amplifying hosts for SARS-CoV-2.

Th2 and Th17-Associated Immunopathology Following SARS-CoV-2 Breakthrough Infection in Spike-Vaccinated ACE2-humanized Mice.

Vaccines have demonstrated remarkable effectiveness in protecting against COVID-19; however, concerns regarding vaccine-associated enhanced respiratory diseases (VAERD) following breakthrough infections have emerged. Spike protein subunit vaccines for SARS-CoV-2 induce VAERD in hamsters, where aluminum adjuvants promote a Th2-biased immune response, leading to increased type 2 pulmonary inflammation in animals with breakthrough infections. To gain a deeper understanding of the potential risks and the underlying mechanisms of VAERD, we immunized ACE2-humanized mice with SARS-CoV-2 Spike protein adjuvanted with aluminum and CpG-ODN.

Multiplex One-Step RT-qPCR Assays for Simultaneous Detection of SARS-CoV-2 and Other Enteric Viruses of Dogs and Cats.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was transmitted from humans to dogs and cats (reverse zoonosis) during the COVID-19 pandemic. SARS-CoV-2 has been detected in fecal samples of infected dogs and cats, indicating potential fecal-oral transmission, environmental contamination, and zoonotic transmission (i.e.

Development and Validation of a Panel of One-Step Four-Plex qPCR/RT-qPCR Assays for Simultaneous Detection of SARS-CoV-2 and Other Pathogens Associated with Canine Infectious Respiratory Disease Complex.

Canine infectious respiratory disease complex (CIRDC) is the primary cause of respiratory disease in the canine population and is caused by a wide array of viruses and bacterial pathogens with coinfections being common. Since its recognition in late 2019, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has been reported to cause respiratory disease in dogs. Therefore, the rapid detection and differentiation of SARS-CoV-2 from other common viral and bacterial agents is critical from a public health standpoint.

Quadruplex Real-Time TaqMan RT-qPCR Assay for Differentiation of Equine Group A and B Rotaviruses and Identification of Group A G3 and G14 Genotypes.

Equine rotavirus A (ERVA) is the leading cause of diarrhea in foals, with G3P[12] and G14P[12] genotypes being the most prevalent. Recently, equine G3-like RVA was recognized as an emerging infection in children, and a group B equine rotavirus (ERVB) was identified as an emergent cause of foal diarrhea in the US. Thus, there is a need to adapt molecular diagnostic tools for improved detection and surveillance to identify emerging strains, understand their molecular epidemiology, and inform future vaccine development.

Systemic -like coccidiosis in a clutch of hatchling red-eared slider turtles ().

like organisms (CLOs) form a clade of at least 11 genotypes of related coccidia that can cause epizootic mortality in marine turtles. The biology, transmission, host species range, and host cell tropism of these organisms are still largely unknown. The goal of this study was to characterize the host cell tropism, pathologic and ultrastructural features, and phylogeny associated with the first report of a mortality event due to CLO in the freshwater red-eared slider turtle ().