Antibiotic
Apocalypse? Antibiotic Resistance: Occurrence and Challenges
By
Kate Viscardi
November’s PubSci was timely, coming as it did in
World Antibiotic Awareness Week. Dr Michael Byford, who is a Biochemist
lecturing at London South Bank University, outlined the dangers that arise from
the development of resistance to antibiotics and discussed a different approach
taken in the Soviet Union.
Bacteria are all around us and generally do us no
harm; indeed we have symbiotic relationships with some, inside and outside our
bodies. However, when the wrong bacteria get in the wrong place they can, and
do, kill. Until the discovery of penicillin, infections in wounds were very bad
news indeed and made surgery a risky business, while tuberculosis patients were
isolated in remote sanatoria for long periods.
Today we take antibiotics for granted – too much for
granted. Bacteria reproduce simply by splitting in half, so one bacterium can
become a million in just a few hours. The more “copies” there are, the more
chance there is of one of them having a mutation: and that mutation could be
something that enables that bacterium to survive the attack by the antibiotic
that is killing its neighbours. The mutated bacterium then divides and passes
on its newly-acquired resistance to its offspring. The chances of resistant
bacteria developing are increased when a course of antibiotics is not completed
– antibiotics take time to kill all the bacteria, if the course of treatment stops
too soon there will be bacteria still around that have been weakened but not
killed, and they will develop their defences. And if antibiotics are used when
there is no infection it results in bacteria in balance in the body being
exposed needlessly to the pressure to evolve resistance.
It takes time and costs money to identify the exact
strain of bacteria that is causing an infection, so most antibiotics used are
broad-spectrum – effective against a variety of bacterial strains. In fact,
most antibiotics are only profitable for pharmaceutical companies if they are
broad-spectrum because they can then be used for more conditions, so for more
patients, so more sales volume. It is not, however, in the pharmaceutical
companies’ interests for bacteria to develop resistance to their products.
Developing new antibiotics is an expensive business and the speed at which
resistance is now spreading makes it a risky undertaking.
Most antibiotics have at the base of their development
some kind of fungus, natural or synthetic. Another approach, however, is the
use of bacteriophages (phages). These are a specific kind of virus that attack
bacterial cells. Their disadvantage is that they are very specific to
individual strains of bacteria so banks of phages are needed in preparedness
for different infections. It is said there are still buildings full of phages
near Moscow and these could yet prove valuable.
Many of the audience were clearly very knowledgeable,
able to follow the technical details, and the questions at the end revealed
deep concern about the problem of antibiotic resistance when it affects gravely
ill patients.
Will this prove to be the end of the Antibiotic Age,
with the subsequent return of fear of disease and lengthy treatment regimens? The speaker was hugely pleased when “measures
to address antibiotic resistance” was chosen by public vote as the winner of
the Latitude Prize 2014, but it would help now if people would trust expert
knowledge. A cold is caused by a virus, not a bacterium, so there is no point
in taking antibiotics, yet people express dissatisfaction with doctors who
don’t prescribe them.
Pubsci is held on the third Wednesday of every month,
upstairs at: The Old King’s Head, King's Head Yard, 45-49 Borough High Street,
London SE1 1NA
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