Ch. 14 - Antibiotics

What did Ehrlich discover? What did he name this antibiotic?

• Magic bullet; compound 606

By magic bullet, what was Ehrlich refer to?

• Selective toxicity: harm pathogen, not the host

What did Dorothy Hodgkin make regarding antiobiotics?

• Made 1st semi synthetic penicillin

What is semisynthetic?

• Chemically altered natural antimicrobial

What are the traits of Actinomycetes?

• Gram +, High G + C

What do most antibiotics come from? Examples?

• Actinomycetes; over half of all antibiotics come from these

e.g. soil microbes, streptomyces

What do broad spectrum antibiotics apply to?

• Applies to multiple pathogens

What do narrow spectrum antibiotics apply to?

• Applies to a specific or niche pathogen

What is the best option for antimicrobial stewardship?

• Best option; to reduce antimicrobial resistance of pathogens

not exposing more bacteria to antibiotics; giving them a chance to mutate

What can the use of too many broad spectrum antibiotics lead to? What is the definition?

• Superinfection: secondary infection in patient with pre-existing infection

How can C. albicans become a superinfection?

• Overgrow when lactobacilli has been inhibited by antibiotic; ending up with overgrowth of Gardnerella

What is dosage?

• Amount and intervals of medication

What are the main factors that influence medication administration?

• Body mass

• Dysphagia

• Absorption

• How drug is metabolized and eliminated

• Half life

What is a half life in relation to medication?

• How long for half the medication to be gone from blood plasma

What is dose dependent?

• More effective with high dose; short time

What is time dependent?

• More effective with low level for long time

What are the 3 routes of administration?

1. Oral

2. Intramuscular

3. Intravenous

What occurs in a synergistic reaction?

• Two or more substances interact to produce a greater effect

What occurs in a antagonistic reaction?

• Two or more substances interact and lessen the effect of one of them

What is an example of an antagonistic reaction?

• Birth control pills less effective while on certain antiobiotics

What occurs in selective toxicity?

• Targeting structures that microbes have, that we do NOT

What bacteria structures do antibiotics target?

1. Cell wall

2. Plasma membrane

3. RIbosomes

4. Nucleic Acid

5. Metabolic Pathways