title: Intramammary immunization with ultraviolet-killed Escherichia coli shows partial protection against late gestation intramammary challenge with a homologous strain.
abstract: The objective of this study was to evaluate the efficacy of intramammary immunization with UV-killed Escherichia coli ECC-Z on prevention of intramammary colonization after a challenge with a dose of the homologous E. coli ECC-Z live bacteria. A total of 10 cows were included in a study to evaluate the efficacy of intramammary immunization. All 10 cows received an intramammary immunization of 100 cfu of UV-killed E. coli ECC-Z bacteria into one hind quarter at the time of dry off. Approximately 2wk before the anticipated calving date, both hind quarters of all cows were challenged with 100 cfu of live E. coli ECC-Z bacteria. Five of the cows were vaccinated parenterally with a commercial J5 bacterin, and 5 cows served as controls with no parenteral vaccination. The cows were then followed over time and infection risk, clinical scores, somatic cell count, and milk production were observed over time. The results of these 10 cows showed partial protection of intramammary immunization on the outcome of a subsequent homologous intramammary challenge. Immunization resulted in a lower probability of infection, a lower bacteria count, lower somatic cell counts and milk conductivity, a lower clinical mastitis score, and increased milk production compared with unimmunized control quarters. Once the analysis was corrected for immunization, parenteral J5 vaccination had no significant effect on any of the measured parameters. These results provide the first evidence that intramammary immunization may improve the outcome of an intramammary E. coli infection in late gestation and onset of mastitis immediately following parturition. Unlike systemic vaccination, which generally does not reduce the intramammary infection risk, the intramammary immunization did show a 5-times reduced odds of an established intramammary infection after challenge. Cytokine profiles indicated a local return of proinflammatory response after challenge as the data showed a more pronounced increase in in IFN-γ with a subsequent negative feedback due to a spike in the level of IL-10 in immunized quarters relative to nonimmunized quarters. Although these results are preliminary and obtained on only 10 cows, the results provide insight into the biological benefits of triggering mucosal immunity in the mammary gland.
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853. Electronic address: bjp62@cornell.edu.
authors.forename: B
authors.initials: B
authors.lastname: Pomeroy
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
authors.forename: A
authors.initials: A
authors.lastname: Gurjar
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
authors.forename: A
authors.initials: A
authors.lastname: Sipka
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
authors.forename: S
authors.initials: S
authors.lastname: Klaessig
authors.affiliation: Zoetis Animal Health, Kalamazoo, MI 49007.
authors.forename: S
authors.initials: S
authors.lastname: Salmon
authors.affiliation: Zoetis Animal Health, Kalamazoo, MI 49007.
authors.forename: R
authors.initials: R
authors.lastname: Quesnell
authors.affiliation: Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853; GD Animal Health, Arnsbergstraat 7, 7411 EZ Deventer, the Netherlands; Department of Animal Sciences, Wageningen University, 6708 PB Wageningen, the Netherlands.
authors.forename: Y H
authors.initials: YH
authors.lastname: Schukken
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000907:Antibodies, Bacterial / Q000097:blood; D002417:Cattle; D002452:Cell Count / Q000662:veterinary; D004926:Escherichia coli / Q000276:immunology; D004927:Escherichia coli Infections / Q000517:prevention & control / Q000662:veterinary*; D022361:Escherichia coli Vaccines / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D007371:Interferon-gamma / Q000097:blood; D016753:Interleukin-10 / Q000097:blood; D008321:Mammary Glands, Animal / Q000276:immunology / Q000382:microbiology; D008414:Mastitis, Bovine / Q000382:microbiology / Q000517:prevention & control*; D014611:Vaccination / Q000662:veterinary*
chemical_list: D000907:Antibodies, Bacterial; D022361:Escherichia coli Vaccines; D016753:Interleukin-10; D007371:Interferon-gamma
keywords: Escherichia coli; late gestation; mastitis; vaccination