Transcript Bacterial Resistance to Antibiotics

Bacterial Resistance
to Antibiotics
Antibiotics
Natural substances that attack metabolic
pathways in bacteria (not in the host)
– Immobilize or destroy bacteria
Review: What do we know about
antibiotics and viruses?
– ex. penicillin
Produced by mold (pencillium notatum) prevents
bacteria from building a normal cell wall
Since 1940’s “Age of Antibiotics” – more than
2500 naturally occurring antibiotics identified
Over past 50 years, many disease-causing
bacteria slowly developed ‘resistance’
How does ‘resistance’ happen?
Variation
Variation cont’d…
Bacterial populations have variation
When first exposed to antibiotic…weak
strains of bacteria are killed
– Other members with slight variation in genetic
material survive
– These individuals reproduce and pass on
genes
Why is this a problem?
Some bacteria can resist up to 7 separate
antibiotics
Drug resistant strains claim lives everyday
– Over-use / over-prescription is a major
problem today
Which antibiotics should be used to
combat this bacterial infection?
Remember…
Always use all doses, do not save unused
antibiotics for later infections
Antibiotics destroy helpful bacteria as well
– Prolonged use can have side-effects