The Genetics Controversy - Agri-culture: Reconnecting People, Land and Nature - page 137

effect, then this would be significant only for this particular gene and
its product. Equally, though, the absence of effect does not mean that
all genetically modified organisms are safe. Other potential problems
might arise in potatoes with modified biochemical pathways that could
inadvertently lead to increased levels of glycoalkaloids. It is also important
to distinguish between the consumption of food products that potentially
contain genetically modified DNA, and food products that are identical
to those from conventional crops, such as refined sugar, which contains
no DNA. 19
Antibiotic resistance marker genes
The first-generation genetically modified organisms have used antibiotic
or herbicide marker genes for easy cellular selection. In theory, antibiotic-
resistant marker genes from a genetically modified organism could be
incorporated into bacteria in the guts of humans and livestock, rendering
them resistant to the antibiotic. Although this has not yet been demon-
strated empirically, antibiotic resistance is still a major cause for concern.
Antibiotics and other antimicrobials are used in agriculture for therapeutic
treatment of clinical diseases (20 per cent) and prophylactic use and
growth promotion (80 per cent of total). Concern is growing that the
overuse of antibiotics may render some human drugs ineffective and/or
make some strains of bacteria untreatable. The World Health Organiz-
ation has documented direct evidence that antimicrobial use in farm
livestock has resulted in the emergence of resistant Salmonella, Campylobacter,
E.coli types, and vancomycin-resistant Enterococci that are linked to the
overuse of antibiotics both in hospitals and on farms. 20 Alternatives to
antibiotic markers now exist, and many believe antibiotics should not be
used in commercial genetically modified organisms. 21 The Royal Society
has said: 'It is no longer acceptable to have antibiotic resistance genes present in a new
genetically modified crop.' 22 Nonetheless, it is still not clear whether antibiotic
marker genes add significantly to the risk of resistance that is emerging
from exposure to antibiotics used elsewhere in the food chain.
The Contrasting Concerns of
Different Stakeholders
The pace of change in developing genetic modification has provoked many
debates, some specifically about the benefits and risks of genetically
modified technologies. Others, though, are about important indirect