Fig. 4: Immunohistochemical staining for influenza A following primary inoculation and virus detection in milk.
From: Dairy cows develop protective immunity against reinfection with bovine H5N1 influenza virus
a, Cow #6 was euthanized at 4 days post inoculation. Representative IHC staining (dark brown colour) for influenza A in the teat cistern and mammary alveoli. Cytoplasmic staining for influenza A indicated by black arrows. Sloughed cells in the mammary alveoli of the left hindquarter showing positive staining. Images were captured at ×200 magnification, insets are digital magnifications of the boxed area. b,d, Virus detection in milk by RT–qPCR. Each sample was tested in duplicate, with the mean Ct value converted to TCID50 equivalent per ml (represented by each data point) by interpolating from a standard curve generated by downtitrating bovine H5N1 virus in milk. c,e, Infectious virus titres in milk. Each data point represents the TCID50 value calculated using the Spearman and Karber algorithm. Cow schematic generated using BioRender.com.
