Antibiotic Medications

Question 1

What is an Antibiotic

Answer 1

are soluble compounds that are produced and released by microorganisms and that inhibit the group or kill other microorganisms
- does include synthetically or semi-synthetically produced antimicrobial agents

Question 2

What is Bacteria?

Answer 2

-are single celled organisms
-among the first life forms to appear on Earth
- present in most habitats
-symbiotic and parasitic relationships with plants and animals

Question 3

categories for classifying bacteria

Answer 3

1. aerobic vs. anaerobic
2. shape (rod, spheres, or spirals)
3. cell wall components (gram negative or gram positive)

Question 4

What are Cell Walls made of?

Answer 4

peptidoglycan - polysaccharide chains

Question 5

Gram positive bacteria

Answer 5

possess a thick cell wall with many layers of peptidoglycan

Question 6

Gram negative bacteria

Answer 6

have a relatively thin cell wall with few layers of peptidoglycan surrounded by a second lipid membrane containing lipopolysaccharides and lipoproteins
- most bacteria have gram-negative cell wall

Question 7

normal flora

Answer 7

we are covered in thousands of microbial species, particularly in the skin mouth, large intestine and genital area
- normal flora can only cause trouble if immune systems are weakened or if they gain access to normally sterile part of the body (i.e., bowel perforation)

Question 8

Pathogenic Bacteria

Answer 8

-pathogens do not require that the host be immunocompromised or injured
- have developed highly specialized mechanisms for crossing cellular and biochemical barriers and for eliciting specific responses from host organism that contribute to the survival and multiplication of the pathogen

Question 9

Diseases caused by Pathogenic Bacteria

Answer 9

-food borne illnesses
-STD
-skin infections
-highly infectious diseases (cholera, whooping cough,TB)

Question 10

spectrum of activity

Answer 10

can be narrow or broad spectrum depending on the number of differential bacterial species against which they exhibit useful activity

Question 11

bacterial sensitivity

Answer 11

sensitivity is measured by assessing the ability of bacteria strain to replicate following antibiotic exposure

• bacteriocidal antibiotic leads to permanent loss of replicative ability
  -bacteriostatic antibiotic leads to temporary loss of growth and replication that returns following the removal of antibiotics

Question 12

therapeutic index

Answer 12

ratio of minimum concentration likely to produce an adverse effect to the minimum concentration needed to produce a desired effect

Question 13

ability to penetrate

Answer 13

delivery of antibiotic to site of infection is most challenge of antibiotic delivery

Question 14

Classes of Antibiotics

Answer 14

• cell wall inhibitors
• folic acid
• DNA synthesis
• Protein synthesis inhibitors

Question 15

Antibiotic Specificity

Answer 15

Why don’t antibiotic inhibit protein synthesis in human cells as well?
- selectivity is provided by the differences in protein synthesis enzymes between humans and microorganisms and the rapid growth of bacteria
-e.g., mammalian cells cannot synthesize folic acid from PABA (must get it from diet)

Question 16

Bacterial Resistance

Answer 16

resistance is the ability of the microbe to resist the effects of antibiotics
1. drug inactivation or modification
2. alteration of binding site
3. alteration of metabolic pathways
4. reduced drug accumulation

Question 17

Gastrointestinal Distress

Answer 17

• antibiotic therapy alters the bacterial environment of the body
• loss of normal intestinal flora produces diarrhea or GI discomfort with a number of antibiotics
  -probiotics may be used as adjunctive therapy to minimize GI effects