From Olaf Swarbrick
Arundel, West Sussex
The item on antibiotics and hospital epidemics mistakenly states that animals
are injected with the antibiotic avoparcin (This Week, 27 July, p 7). This is a
food-grade antibiotic which is insoluble and so cannot be absorbed by the gut.
It is thus incorporated into feed and enhances protein absorption and
utilisation.
In hospitals, human patients receive large doses of antibiotics, a procedure
which actively selects for resistance by leaving behind resistant survivors. It
is thus no accident that resistant bacteria appear within hospitals, especially
in situations where rapid control of pathogenic bacteria is an urgent clinical
necessity.
By contrast, low-level administration in animal feed does not kill bacteria
and therefore has limited effects on the development of resistance. Bacterial
resistance is a fact of life with which all doctors and their patients will have
to live. It is too simplistic to blame the development of resistance on any one
particular source or method of use.
Advertisement
Wolfgang Witte, the German microbiologist on whose work the article was
based, has performed previous studies which suggest very strongly that
resistance can move from the farm to the human population. Witte found that in
East Germany, between 1982 and 1987, resistance to the antibiotic
streptothricine spread from bacteria in farm animals to bacteria in the general
population. Streptothricine has only ever been used on farms, which were
therefore the only possible source of the resistant bacteria in
people—Ed
