Mesocricetus auratus

Female golden hamsters (Mesocricetus auratus) with an average weight of 100 g were obtained from Charles River Laboratories (Wilmington, MA, USA). Following a 48-h quarantine and 5-day acclimation period, animals were randomly assigned to groups and individually marked with ear tags. All work with animals was performed in the Biosafety Level 3 area of the AAALAC-accredited Laboratory Animal Research Center at Utah State University (USU). Hamsters were cared for under an animal use protocol approved by the Institutional Animal Care and Use Committee Laboratory Animals (IACUC) at USU.

Five-to-six-week old female Syrian golden hamsters (Mesocricetus auratus) (Charles River) were challenged via the intranasal (i.n.) route with 10-fold serial dilutions (10¹ to 10⁵ TCID₅₀) of NiV-M (n = 3), rgNiV-M (n = 5 or 6), and rgNiV-B (n = 5 or 6) in a volume of 100 μl, with 50 μl delivered to each nare using a pipette. Post-challenge, animals were weighed daily and observed to assess any clinical signs of disease. Clinical signs were scored as follows: weight loss 0–9% (0), 10–14% (1), 15–20% (4), >20% (10); hunched posture (2); ruffled coat (2); aggression to handlers (2); reduced movement (2); laboured breathing (2); disorientation (2); wobbling gait (4); unresponsive (10); hind-limb paralysis (10); dyspnea (10); seizure (10); hemorrhaging (10). Euthanasia was carried out at a score of 10. The median (50%) lethal dose (LD₅₀) was calculated by the Reed and Muench method⁷⁴ . Terminal blood samples were obtained from hamsters at 3 days post-infection by cardiac bleed under deep isoflurane anesthesia just prior to euthanasia. Necropsies were performed and tissues were harvested for downstream assays, as described below.

Female Golden Syrian hamsters (Mesocricetus auratus; Charles River Laboratories, Germany) (70 to 90 g) were used for immunization and challenge studies. The hamsters were randomly distributed within groups and housed 3 per 800-cm² cage (Serlab); they were housed individually with isocaps after C. difficile challenge.

All animal experimentation was performed under the guidance of veterinarians and trained animal technicians within the Emory University Division of Animal Resources (DAR). Animal experiments were performed with prior approval from the Emory University Institutional Animal Care and Use Committee (IACUC) under protocol PROTO201700396. Male and female Syrian golden hamsters (Mesocricetus auratus; 6–8 weeks old) were purchased from Charles River Laboratories and housed in sterile, individual cages in an animal biosafety level 2 facility. Animals considered moribund based on defined endpoints were euthanized in accordance with the Panel on Euthanasia of the American Veterinary Medical Association. The University is in compliance with state and federal Animal Welfare Acts, the standards and policies of the Public Health Service, including documents entitled "Guide for the Care and Use of Laboratory Animals" National Academy Press, 2011, "Public Health Service Policy on Humane Care and Use of Laboratory Animals" September 1986, and Public Law 89–544 with subsequent amendments. Emory University is registered with the United States Department of Agriculture (57-R-003) and has filed an Assurance of Compliance statement with the Office of Laboratory Animal Welfare of the National Institutes of Health (A3180-01).