Microbiology - Bottom Up

Question 1

Define a antimicrobial agent

Answer 1

Substance with inhibitory properties against microorganisms, with minimal effects of mammalian cells.

Question 2

Define antibiotic

Answer 2

Substance that stops growth or kills bacteria.
Can be produced by other microorganisms or made synthetically

Question 3

Define empirical therapy

Answer 3

A non selective antimicrobial therapy used when waiting for microbial identification would be inappropriate

Question 4

Define Directed therapy

Answer 4

Therapy that targets a specific pathogen

Question 5

Define resistance (in context of a microorganism)

Answer 5

Ability of microorganism to avoid the effects of an antimicrobial agent

Question 6

Define susceptibility

Answer 6

Level of venerability of a microorganism to an antimicrobial

Question 7

What are the main sites of action of antibiotics

Answer 7

Cell wall
Cell membrane
Protein synthesis
DNA synthesis
RNA synthesis

Question 8

What class of antibiotics block cell wall synthesis

Answer 8

Beta-lactams
Glycopeptides

Question 9

Name some beta-lactams

Answer 9

Penicillin
Cephalosporins
Monobactams
Carbapenems

Question 10

Beta-Lactams mechanism of action

Answer 10

Inhibits transpeptidase enzymes
Weakens cell walls
Ruptures cells

Question 11

Types of penicillins and examples of each

Answer 11

Narrow spectrum - benzylpenicillin or phenoxymethylpenicillin
Moderate spectrum - amoxicillin
Extended-spectrum - ticarcillin

Question 12

What bacteria are benzylpenicillin and phenoxymethlypenicillin active against?

Answer 12

Streptococci

Question 13

What is ticarcillin effective against

Answer 13

Streptococci and many coliforms E.g E. coli

Question 14

What is piperscillin used to treat?

Answer 14

Pseudomonas aeruginosa
(Causes hospital acquired pneumonia)

Question 15

Examples of Cephalosporins

Answer 15

Cefuroxime
Ceftazidime
Cefotexime

Question 16

What are carbapenems used to treat?

Answer 16

Severe multi-bacterial antibiotic resistant infections
- Live sepsis
- peritonitis

Question 17

Examples of carbapenems

Answer 17

Imipenem
Meropenem
Ertapenem

Question 18

What are glycopeptides effective against

Answer 18

Gram positive bacteria

Question 19

Give examples of glycopeptide antibiotics

Answer 19

Vancomycin
Teicoplanin

Question 20

What are the adverse side effects of vancomycin?

Answer 20

Nephrotoxicity and ototoxicity (ear).
A rapid transfusion can also cause an erythematous rash.

Question 21

What situations might glycopeptides be appropriate to prescribe?

Answer 21

Cellulitis or wound infections where patient is beta-lactam allergic or the pathogen is resistant.

Question 22

What type of antibiotic prevents protein synthesis?

Answer 22

Aminoglycosides

Question 23

What is the action of aminiglycosides

Answer 23

Block 30s ribosomes

Question 24

What is Beta-lactamase

Answer 24

A form of antibiotic resistance, it destroys beta-lactams

Question 25

What produces penicillinase?

Answer 25

Staphylococci

Question 26

Penicillinase does not inactivate which penicillin?

Answer 26

Flucloxacillin

Question 27

What inactivates aminoglycosides?

Answer 27

Gram negative bacteria

Question 28

What is metronidazole effective against?

Answer 28

Aerobic bacteria

Question 29

Vancomycin can be used to combat?

Answer 29

Gram positive bacteria

Question 30

give examples of Aminoglycosides

Answer 30

Amikacin Gentamicin Netilmicin Streptomycin Tobramycin

Question 31

What side effects may occur with Aminoglycosides?

Answer 31

Hypersensitivity, Ototoxicity, and Nephrotoxicity

Question 32

What is Ototoxicity?

Answer 32

Damage to the ear - can effect balance or hearing

Question 33

What is the action of Tetracyclines

Answer 33

Inhibition of protein synthesis (30s ribosome inhibition)

Question 34

Name 2 Tetracyclines

Answer 34

Tetracycline and Doxycycline

Question 35

Who should not be prescribed tetracyclines and why?

Answer 35

Children - effects bone and tooth development Maybe people with IBS due to gastrointestinal intolerance

Question 36

What disease can be treated with tetracyclines?

Answer 36

**Chlamydia trachomatis** (mycoplasma spp, rickettsia spp, coxiella burnetiid)

Question 37

What are Macrolides?

Answer 37

Antimicrobial protein synthesis inhibitors (50s ribosome inhibition)

Question 38

give examples of macrolides

Answer 38

Clarithromycin, Azithromycin, Erythromycin

Question 39

Streptococcal and staphylococcal soft tissue infections should be treated with what type of antimicrobial?

Answer 39

Macrolides

Question 40

What pneumonia causing microbe should be treated with Macrolides (Erythromycin)

Answer 40

Mycoplasma pneumoniae

Question 41

What type of bacteria are Clindamycin effective against

Answer 41

Anaerobic bacteria

Question 42

To which classification of antibiotic does Clindamycin belong

Answer 42

Lincosamides

Question 43

Potential side effect of Clindamycin

Answer 43

Pseudomembranous colitis - C Dif proliferation in large bowl

Question 44

Clindamycin is used to treat what infections?

Answer 44

Cellulitis and osteomyelitis

Question 45

What classes of antibiotic are protein synthesis inhibitors?

Answer 45

Macrolides, Tetracyclines, Aminoglycosides, Lincosamides, and Chloramphenicol