The increase in antibiotic resistance parallels the increase in
antibiotic use in humans. And antibiotic resistance is spreading fast!
There are two reasons for it: a) the increase in infection transmission
and b) inappropriate antibiotic use.
If a bacterial pathogen is able to develop resistance to an
antibiotic, the substance becomes useless in the treatment of an
infectious disease caused by that pathogen. That means we always have
to develop new antibiotics not only against ‘old’ diseases but also
against new bacterial diseases which we did not know several decades
ago, like Legionnaire’s disease, gastric ulcers, Lyme disease and skin
eating Streptococci.
ANTIBIOTICS are substances mostly produced by micro organisms that
kill or inhibit other micro organisms. They are soil products and a
by-product of secondary cellular metabolism.
The very first antibiotic, penicillin, discovered 1929 by Alexander
Fleming inhibited the growth of staphylococci by a mould called Penicillium.
Marketed in 1946, penicillin was used against infections caused by
staphylococci and streptococci and was extremely successful against
strep throat, pneumonia, septicaemia, skin and wound infections,
scarlet fever and toxic shock syndrome. It had the ability to kill the
bacterial pathogens without harming the host.
The first drug-resistance to penicillin in some strains of these
bacteria was observed immediately after the introduction of the drug.
Nowadays the resistance to penicillin happens in 80% of all strains of Staphylococcus aureus.
In the late 40s and 50s streptomycin, chloramphenicol and
tetracycline was discovered and it was the age of antibiotic
chemotherapy. These antibiotics were successful against many bacterial
pathogens and even some intracellular parasites.
Some bacteria always showed an inherent (natural) resistance to
certain antibiotics, others which previously were sensitive to
antibiotics can develop a resistance. This mostly happens through
HORIZONTAL EVOLUTION: the acquisition of genes for resistance from
another organism. This happens in nature through conjugation,
transduction and transformation.
More people are contracting infections. Sinusitis among adults and
ear infections among children is on the rise. Why? Doctors prescribed
always antibiotics to treat these infections, although most of the
times the illness is viral and antibiotics do NOT work against a virus.
Of course some people clearly need to be treated with antibiotics
but the majority of experts are concerned about the inappropriate use
of these powerful drugs.
Other factors of resistance: increased use of day-care facilities,
immunosuppressant drugs during chemotherapy and organ transplants,
breakdown in public health measures (closing down of hospitals,
reduction in prevention programmes, ready-meals in hospitals) and
antibiotic use in livestock.
Another very important factor in drug resistance is that patients
often stop taking the drug too soon, because symptoms improve. This is
the most typical way to create drug resistance. If the infection
returns a few weeks later, a different drug must be used for treatment.
We have now reached the dangerous point where bacteria show
increased resistance against Vancomycin, the last drug which works
against hospital-acquired staph infections (first reported in 1987).