title: Genetically enhanced cows resist intramammary Staphylococcus aureus infection.
abstract: Mastitis, the most consequential disease in dairy cattle, costs the US dairy industry billions of dollars annually. To test the feasibility of protecting animals through genetic engineering, transgenic cows secreting lysostaphin at concentrations ranging from 0.9 to 14 micrograms/ml [corrected] in their milk were produced. In vitro assays demonstrated the milk's ability to kill Staphylococcus aureus. Intramammary infusions of S. aureus were administered to three transgenic and ten nontransgenic cows. Increases in milk somatic cells, elevated body temperatures and induced acute phase proteins, each indicative of infection, were observed in all of the nontransgenic cows but in none of the transgenic animals. Protection against S. aureus mastitis appears to be achievable with as little as 3 micrograms/ml [corrected] of lysostaphin in milk. Our results indicate that genetic engineering can provide a viable tool for enhancing resistance to disease and improve the well-being of livestock.
authors.affiliation: Biotechnology and Germplasm Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA. bobwall@anri.barc.usda.gov
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Wall
authors.forename: Anne M
authors.initials: AM
authors.lastname: Powell
authors.forename: Max J
authors.initials: MJ
authors.lastname: Paape
authors.forename: David E
authors.initials: DE
authors.lastname: Kerr
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Bannerman
authors.forename: Vernon G
authors.initials: VG
authors.lastname: Pursel
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Wells
authors.forename: Neil
authors.initials: N
authors.lastname: Talbot
authors.forename: Harold W
authors.initials: HW
authors.lastname: Hawk
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002417:Cattle; D003612:Dairying; D005240:Feasibility Studies; D005260:Female; D005818:Genetic Engineering / Q000379:methods; D007113:Immunity, Innate / Q000235:genetics; D007774:Lactation; D008248:Lysostaphin / Q000008:administration & dosage / Q000032:analysis / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000382:microbiology*; D008414:Mastitis, Bovine / Q000382:microbiology / Q000517:prevention & control*; D008892:Milk / Q000737:chemistry / Q000382:microbiology; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000378:metabolism; D013203:Staphylococcal Infections / Q000517:prevention & control* / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000201:enzymology
chemical_list: D011994:Recombinant Proteins; D008248:Lysostaphin