Briefing on GM animal feeds

Friends of the Earth have updated their briefing on GM animal feeds: http://www.foe.co.uk/resource/briefings/gm_animal_feeds.pdf

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GM cows for GM drugs

Mastitis is a nasty disease of the mammary gland to which cows in industrial agriculture are particularly prone.

Mastitis is said to cost the U.S. dairy industry approximately $2 billion annually - and the problem is made considerably worse by Monsanto's genetically engineered cattle drug, aimed at boosting milk production, rBGH (also knowwn as BST and commercially 'Prosilac'). For this reason Monsanto's GM drug is banned in Europe not only on human health grounds but on animal welfare grounds as well. The GM cattle drug is also banned on animal welfare grounds in Canada.

But never fear, a U.S. Agricultural Research Service (ARS)-led team are developing transgenic dairy cows that are enginneered to have a built-in defense against mastitis. This, of course, means it will be easier to give these cows a GM hormone to give more milk...

Below are several items relating to this exciting technological breakthrough, including comment from the geneticist Prof Joe Cummins who thinks kids who drink the resulting milk may suffer injury or death from allergy.

But, hey, when you're talking 2 billion a year and increased profits for Monsanto...
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Prof Joe Cummins:

Recently there has been publicity on USDA's introduction of cows with synthetic genes. Essentially the synthetic genes are made up an antibacterial gene from Staphylococcus (lyphostatin) joined to a gene from a Streptococcus bacteria phage specifying endolysin that dissolves bacteria. The genes are altered in DNA sequence and truncated. The synthetic gene is used to modify cows so they produce milk that kills bacteria. One problem discussed was allergy of the milk protein. It was pointed out that the cows bearing the synthetic gene were unlikely to be allergic to the toxin because it is a part of their genome thus recognized as self. They failed to mention that kids drink the allergenic milk and do not recognize it as self. Efforts were made to alter the DNA sequences specify sugar additions to the protein to avoid human allergy (allergy sites on proteins are often have signals for sugar added to the protein) but that approach was only partly effective.

The problem I see is that USDA regulates the things that they own patents for the cows with synthetic genes which are likely to cause a lot of injury to people if they are rushed to commerce. However, USDA's synthetic genes may solve one of Monsanto's greatest problems with its growth hormone, that is the good news, the bad news is that kids who drink the milk may suffer injury or death from allergy.

Transgenic Research
Publisher: Springer Netherlands
ISSN: 0962-8819 (Paper) 1573-9368
DOI: 10.1007/s11248-005-0670-8
Issue: Volume 14, Number 5
Date: October 2005
Pages: 563 - 567
Perspective
Engineering Disease Resistant Cattle
David M. Donovan1, David E. Kerr2 and Robert J. Wall1

Abstract: Mastitis is a disease of the mammary gland caused by pathogens that find their way into the lumen of the gland through the teat canal. Mammary gland infections cost the US dairy industry approximately $2 billion dollars annually and have a similar impact in Europe. In the absence of effective treatments or breeding strategies to enhance mastitis resistance, we have created transgenic dairy cows that express lysostaphin in their mammary epithelium and secrete the antimicrobial peptide into milk. Staphylococcus aureus, a major mastitis pathogen, is exquisitely sensitive to lysostaphin. The transgenic cattle resist S. aureus mammary gland challenges, and their milk kills the bacteria, in a dose dependent manner. This first step in protecting cattle against mastitis will be followed by introduction of other genes to deal with potential resistance issues and other mastitis causing organisms. Care will be taken to avoid altering milk’s nutritional and manufacturing properties. Multi-cistronic constructs may be required to achieve our goals as will other strategies possibly involving RNAi and gene targeting technology. This work demonstrates the possibility of using transgenic technology to address disease problems in agriculturally important species.

Applied and Environmental Microbiology, April 2006, p. 2988-2996, Vol 72, No. 4

doi:10.1128/AEM.72.4.2988-2996.2006

Peptidoglycan Hydrolase Fusions Maintain Their Parental Specificities David M. Donovan,1* Shengli Dong,2 Wes Garrett,1 Geneviève M. Rousseau,3 Sylvain Moineau,3 and David G. Pritchard2

The increased incidence of bacterial antibiotic resistance has led to a renewed search for novel antimicrobials. Avoiding the use of broad-range antimicrobials through the use of specific peptidoglycan hydrolases (endolysins) might reduce the incidence of antibiotic-resistant pathogens worldwide. Staphylococcus aureus and Streptococcus agalactiae are human pathogens and also cause mastitis in dairy cattle. The ultimate goal of this work is to create transgenic cattle that are resistant to mastitis through the expression of an antimicrobial protein(s) in their milk. Toward this end, two novel antimicrobials were produced. The (i) full-length and (ii) 182-amino-acid, C-terminally truncated S. agalactiae bacteriophage B30 endolysins were fused to the mature lysostaphin protein of Staphylococcus simulans. Both fusions display lytic specificity for streptococcal pathogens and S. aureus. The full lytic ability of the truncated B30 protein also suggests that the SH3b domain at the C terminus is dispensable. The fusions are active in a milk-like environment. They are also active against some lactic acid bacteria used to make cheese and yogurt, but their lytic activity is destroyed by pasteurization (63°C for 30 min). Immunohistochemical studies indicated that the fusion proteins can be expressed in cultured mammalian cells with no obvious deleterious effects on the cells, making it a strong candidate for use in future transgenic mice and cattle. Since the fusion peptidoglycan hydrolase also kills multiple human pathogens, it also may prove useful as a highly selective, multipathogen-targeting antimicrobial agent that could potentially reduce the use of broad-range antibiotics in fighting clinical infections.