In the last century, nothing has made a bigger impact
on human health than antimicrobial chemotherapy.
After 20 years of clinical use, antibiotics have
increased the average human life expectancy by ten
years while in comparison, curing cancer would only
extend life expectancy by two years.
What went wrong with
1. Treating trivial infections / viral Infections with
antibiotics has become routine affair.
2. Many use antibiotics without knowing the basic
principles of antibiotic therapy.
3. Many medical practitioners are under pressure
for short term solutions.
4. Commercial interests of Pharmaceutical industry.
Antibiotics are misused in hospitals
“It has been recognized for several decades
that up to 50% of antimicrobial use is
Antibiotic are misused in a variety
1. Given when they are not needed
2. Continued when they are no longer necessary
3. Given at the wrong dose
4. Broad spectrum agents are used to treat very
5. The wrong antibiotic is given to treat an
Nowadays, about 70 percent of the bacteria
that cause infections in hospitals are resistant
to at least one of the drugs most commonly
used for treatment.
Wound infections, gonorrhea, tuberculosis,
pneumonia, septicemia and childhood ear
infections are just a few of the diseases
that have become hard to treat with
One part of the problem is that bacteria and other
microbes that cause infections are remarkably
resilient and have developed several ways to
resist antibiotics and other antimicrobial drugs.
Another part of the problem is due to increasing
use, and misuse, of existing antibiotics in human
and veterinary medicine and in agriculture.
Any use of antibiotics can increase selective pressure in a population of bacteria to
allow the resistant bacteria to thrive and the susceptible bacteria to die off.
As resistance towards antibiotics becomes more
common, a greater need for alternative treatments
arises. However, despite a push for new antibiotic
therapies there has been a continued decline in the
number of newly approved drugs. Antibiotic
resistance therefore poses a significant problem.
While the rate of development of antimicrobial resistance has
been accelerating, the pace of development of new
antimicrobial agents has slowed considerably during the past
several decades. Only two classes of new antibacterials have
come to market over the last 30 years. The period from 1983
to 2007 saw a 75 percent decrease in systemic antibacterials
approved by the FDA, reflecting a decline in the antibiotic
New antibacterial agents approved by the FDA and EMA
Most alarming of all are the diseases caused
by multidrug-resistant microbes, which are
virtually non-treatable and thereby create a
03/08/2014 17 Kasr Al-Ainy Medical School in Cairo
It is important to have a clear understanding of the terms used for wound infection.
Since 1985 the most commonly used terms have included wound contamination,
wound colonisation, wound infection and, more recently, critical colonisation. These
terms can be defined as:
Classic signs Additional signs
• Increase in exudate or pus
• Delayed healing
• Bridging of skin across a wound
• Dark/discoloured granulation tissue
• Increased friability (tissue which bleeds easily)
• Painful/altered sensation to the wound
• Altered odour
• Wound breakdown
• Pocketing at the base of the wound
• Increased watery/serous exudate rather than
Signs and symptoms of wound infection
All wounds contain a variety of microorganisms,
however it is only when wound infection is suspected
from clinical signs that further investigation is required.
HOW TO TAKE A
A representative area of the wound should be
sampled. If the wound is large, it may not be
feasible to cover the entire surface, but at least
1cm² should be sampled and material from both the
wound bed and wound margin should be collected.
If pus is present, the clinician should ensure that a
sample is sent to the laboratory.
Immediately following collection, the swab should
be returned to its container (placed into the
transport medium) and accurately labelled.
Returning the swab to its container
Interpreting microbiology results
Conversely, where a microbiology result of ‘no
growth’ or ‘no significant growth’ is returned, the
result should be interpreted with care and should
not be automatically interpreted as meaning that no
infection is present, particularly if the patient has
clinical signs and symptoms that suggest otherwise.
In this situation such a result should be regarded as
a false negative (Kingsley, 2003).
Interpreting microbiology results
Diagnosing wound infection is essentially a clinical
skill and microbiological investigations should only be
used to aid diagnosis, rather than the other way round
Not all laboratories look for pus cells when examining
wound swabs. Micro- organisms reported from wound
cultures are not necessarily indicative of SSI and if pus
cells are not indicated as present in the wound culture
report there must also be at least two clinical symptoms
of infection and a clinicians diagnosis.
Why is an antibiotic policy necessary?
An antibiotic policy will:
1. improve patient care by promoting the best practice in
antibiotic prophylaxis and therapy,
2. make better use of resources by using cheaper drugs
3. retard the emergence and spread of multiple antibiotic-
4. improve education of junior doctors by providing
guidelines for appropriate therapy
5. eliminate the use of unnecessary or ineffective antibiotics
and restrict the use of expensive or unnecessarily
What is the Ideal Antibacterial?
1-Selective target – target unique
2- Bactericidal – kills
3- Narrow spectrum – does not kill normal flora
4- High therapeutic index – ratio of toxic level to
5- Few adverse reactions – toxicity, allergy
6- Various routes of administration – IV, IM, oral
8- Good absorption
9-Good distribution to site of infection
10- Emergence of resistance is slow
1. Efficacy in treating the infection
2. Severity of the patient’s illness
3. Physician’s previous experience with and
knowledge about the drug
4. Side effects
5. Cost to patient
6. Ease of use
7. Risk of contributing to the problem of
Factors Influencing Physicians’ Choice of Drug
1. Consider whether or not the patient actually requires an antibiotic.
2. Avoid treating colonised patients who are not actually infected.
3. In general do not change antibiotic therapy if the clinical condition is
4. If there is no clinical response within 72 hours, the clinical diagnosis, the
choice of antibiotic and/or the possibility of a secondary infection
should be reconsidered.
5. Consider the use of pharmacy ‘stop' policy after 5 days.
6. For surgical prophylaxis start the antibiotic with the induction of
anaesthesia and continue for a maximum of 24 hours only.
7. Give the antibiotic for the minimum length of time that is effective.
1. Antibiotics should only be prescribed for proven or clinically
suspected bacterial infection unless recommended for prophylaxis.
2. Choice of antibiotic should be guided by clinical signs and
symptoms, history and recent laboratory results.
3. Many antibiotics require dosage adjustment in renal impairment.
4. When treating blind (empirical therapy), and as a general rule, use
the narrowest spectrum drug that will cover the most likely
pathogens. Where microbiological data, e.g. MRSA status, culture
results and sensitivities are available, or become available after
treatment is started, these should be taken into account. Always
check (using electronic results system) if results of previous
microbiology (inpatient or outpatient/GP) should influence
empirical therapy, e.g. previous infection with MRSA, ESBL
producing organism, or C difficile.
5. If clinically safe it is recommended to take samples for cultures
before initiating antimicrobial treatment.