Antibiotics Flashcards
Describe Bacteriostatic antibiotics ?
- they prevent the bacteria from growing further
- do not necessarily kill the organism
Describe Bacteriocidal antibiotics ?
- they kill the bacterium
Why are gram positive bacteria more susceptible to antibiotics than gram negative?
- gram negative have an extra layer (the outer membrane) which protects these organisms
What are some example of natural resistance in bacteria ?
- lack of transporter
- lack of target
- outer membrane
What are some examples of acquired resistance in bacteria?
- Vertical gene transfer
- Horizontal gene transfer
Define Transduction
occurs when bacteria-specific viruses transfer DNA between 2 closely related bacteria
Define Transformation
Process where parts of the DNA are taken up by the bacteria from the external environment
Define Conjugation
occurs when there is direct cell-cell contact between 2 bacteria and transfer small pieces of DNA called plasmids.
Describe the general structure of penicillins
- Acyl side chain
- Beta-Lactam Ring
- Thiazolidine Ring
Describe the main resistance mechanism to B-lactam antibiotics
- the Beta-Lactam ring is vulnerable and can be hydrolysed by B-lactamase enzymes
How have scientists tried to make B-Lactam antibiotics resistant to B-lactamase enzymes?
- they’ve modified their structure
- causing them to be labelled as synthetic
- they alter the R groups to provide protection to the B-Lactam Ring
