Transcript Antibiotic Pressure and Resistance in Bacteria

Antibiotic Resistance in Bacteria
Antibiotic Resistant Bacteria
Are:
• Bacteria that mutate and are able to resist the
antibiotics that are meant to kill them.
• This is a normal process speeded up by the
overuse and misuse of antibiotics.Bacteria
that mutate and are able to resist the
aBacteriatha mutate and are able to resist the
antibiotics that are meant to kill them.
ntibioti that are meant to kill them.
What is Antibiotic Misuse?
• Taking antibiotics when they are not needed:
– for viral infections
• When needed, taking antibiotics incorrectly:
– Stopping the medicine when you feel better - not
finishing the prescription
– Saving antibiotics for a future illness
– Sharing or using someone else’s medicine
Why is Antibiotic Misuse a
Problem?
• Antibiotics become less effective and may not
work the next time you use them.
• Improper use of antibiotics leads to more
antibiotic resistant bacteria.
• Antibiotic resistant bacteria can be spread
throughout the community and from person
to person.
Antibiotics promote resistance
If a patient forgets to take the doses regularly,
• Then resistant strains get a chance to build up
• The antibiotics also kill bacteria which are
non-pathogens e.g normal flora.
• Killing of normal flora reduces the competition
for the resistant pathogens which will
prolifirate quickly.
•
Antibiotic Resistance in Bacteria
How does it happen ?
• Bacteria can become resistant as a result of
genetic mutations; these can be transferred
between bacteria.
• Under selective pressure of antibiotic
exposure, these strains then proliferate.
Mechanisms of Bacterial Resistance : how DO
they do it ??
Mechanisms
• Several mechanisms have evolved in bacteria
which confer them with antibiotic resistance.
These mechanisms can either:
1- chemically modify the antibiotic, render it
inactive.
2- Physical removal from the cell,
3-Or modify target site so that it is not
recognized by the antibiotic.
4-Prevention of penetration of drug
Antibiotic Selection for Resistant
Bacteria
Antibiotic Resistance in Bacteria
Why is it important?
• Antibiotic resistance has developed in almost all
classes of bacteria of pathogenic potential.
• Resistance in organisms of low virulence can emerge
as important pathogens.
• The development of resistant bacteria has driven
pharmaceutical research to develop more potent,
broad-spectrum antibiotics.