[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[SANET-MG] transgenic cattle with antibiotic genes



The article below provides a technique that may be welcomed by the
producer of bovine growth hormone. One feature typical of growth hormone
treatment of cattle  is increased pus in the milk stemming from
mastitis. However, the constant production of the antibiotic is likely
to act as a generator for lysostaphin resistant bacteria. The transgenic
cows could turn into "typhoid Mary" bossys , spreading resistant
bacteria  that spread their plasmids to human as well as bovine
pathogens.There are numerous publications on lysostaphin resistant
bacteria , many of which are spread with multiple resistance
plasmids.The authors of the article below do not deal with antibiotic
resistance and how to deal with it. Do you put down transgenic herds
that show signs of  mastitis? Would a gene therapy strategy using
somatic transformation using germ therapy vectors be better than
transgenic animals? Te regulators of transgenic animals may be too
unreliable to be trusted with such issues.

Nature Biotechnology  23, 445 - 451 (2005)
Published online: 3 April 2005; | doi:10.1038/nbt1078
Genetically enhanced cows resist intramammary Staphylococcus aureus
infection
Robert J Wall1, Anne M Powell1, Max J Paape2, David E Kerr3, Douglas D
Bannerman2, Vernon G Pursel1, Kevin D Wells4, Neil Talbot1 & Harold W Hawk1
1 Biotechnology and Germplasm Laboratory, Agricultural Research Service,
United States Department of Agriculture, Beltsville, Maryland 20705, USA.

2 Bovine Functional Genomics Laboratory, Agricultural Research Service,
United States Department of Agriculture, Beltsville, Maryland 20705, USA.

3 Department of Animal Sciences, University of Vermont, Burlington,
Vermont 05405, USA.

4 Current address: Revivicor Inc., 1700 Kraft Drive, Suite 2400
Blacksburg, Virginia 24060, USA.

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 mg/ml 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 mg/ml 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.

********************************************************
To unsubscribe from SANET-MG:
1- Visit http://lists.sare.org/archives/sanet-mg.html to unsubscribe or;
2- Send a message to <listserv@sare.org> from the address subscribed to the list. Type "unsubscribe sanet-mg" in the body of the message.

Visit the SANET-MG archives at: http://lists.sare.org/archives/sanet-mg.html
For more information on grants and other resources available through the SARE program, please visit http://www.sare.org.