Microbiology and Infectious Diseases

Question 1

Inhibit bacterial growth by inhibiting protein synthesis

Answer 1

Bacteristatic

Question 2

Kill bacteria

Answer 2

Bactericidal

Question 3

Minimum Inhibitory Concentration

Answer 3

Minimum concentration of antibiotic at which visible growth is inhibited

Question 4

Give a syndergistic example of 2 types of antibiotics used to treat streptococcal endocarditis

Answer 4

Aminoglycoside and beta lactam

Question 5

Which types of antibiotics target the bacterial cell wall?

Answer 5

Beta lactams and glycopeptides

Question 6

What is the name of the major constituent of bacterial cell walls and name the 2 glucose derivatives that it is made up of

Answer 6

Peptidoglycan
N-acetyl muramic acid (NAM)
N-acetyl glycosamine (NAG)

Question 7

Describe the beta lactam ring

Answer 7

C-C-C-N in a ring structure. Structural analogue of D-alanyl D-alanine

Question 8

How do beta lactams work?

Answer 8

Interfere with the function of the ‘penicillin binding proteins’ (transpeptidase enzymes) involved in the peptidoglycan cross linking

Question 9

Name 4 types of beta lactams

Answer 9

Penicillins, cephalosporins, carbapenems,monobactams

Question 10

Amoxicillin is an example of what type of antibiotic?

Answer 10

Penicillin- beta lactam

Question 11

cefuroxime is an example of what type of antibiotic?

Answer 11

cephalosporin-beta lactam

Question 12

meropenem is an example of what type of antibiotic?

Answer 12

carbapenem

Question 13

azteronam is an example of what type of antibiotic?

Answer 13

monobactam

Question 14

Give an example of a glycopeptide

Answer 14

Vancomycin

Question 15

How do glycopeptides work?

Answer 15

Bind directly to terminal D-alanyl-D-alanine on NAM to prevent binding of transpeptidases and thus peptidoglycan cross linking

Question 16

Glycopeptides work on what sort of bacteria?

Answer 16

Gram +ve- unable to penetrate outer membrane on gram -ves

Question 17

Name the different antibiotics that act as protein synthesis inhibitors

Answer 17

Aminoglycosides
Macrolides, Lincosamides, streptogramins (MLS)
Tetracyclines
Oxazolidinones
(others e.g. mupirocin, fusidic acid)

Question 18

Name an example of an aminoglycoside

Answer 18

Gentamycin

Question 19

How do aminoglycosides work?

Answer 19

Bind to 30s ribosomal subunit

Question 20

Name an example of a macrolide

Answer 20

Erythromycin

Question 21

How do MLS antibiotics work?

Answer 21

Bind to 50S ribosomal subunit

Question 22

Name an example of a tetracycline

Answer 22

doxytetracycline

Question 23

How do tetracyclines work?

Answer 23

Bind to 30S ribosomal subunit, and interfere with binding of tRNA to rRNA

Question 24

Name an example of an oxazolidinone

Answer 24

Linezolid

Question 25

How do oxazolidinones work?

Answer 25

Bind to 50S ribosomal subunit and inhibits assembly of initiation complex.

Question 26

Name the types of DNA Synthesis inhibitors

Answer 26

Trimethoprim and Sulfonamides | Quinolones and Fluoroquinolones

Question 27

How do trimethoprim and sulfonamides work?

Answer 27

Inhibit folate synthesis- folic acid is a purine synthesis precursor.

Question 28

What is the target enzyme in DNA synthesis that trimethoprim targets?

Answer 28

Dihdydrofolate reductase

Question 29

What is the target enzyme in DNA synthesis that sulfonamides target?

Answer 29

Dihydropteroate synthetase

Question 30

Give an example of a trimethoprim/sulfonamide antibiotic

Answer 30

Co-trimoxazole (trimethoprim/sulfomethoxazole)

Question 31

How do quinolones and fluoroquinolones act?

Answer 31

Inhibit enzymes involved in remodelling of DNA during DNA replication

Question 32

Give an example of a quinolone/fluoroquinolone

Answer 32

Ciprofloxacin

Question 33

What categories of antibiotics act as RNA synthesis inhibitors?

Answer 33

Rifampicin

Question 34

How does rifampicin work?

Answer 34

RNA polymerase inhibitor- prevents synthesis of RNA

Question 35

What adverse effects are common with aminoglycosides?

Answer 35

reversible renal impairment and ototoxicity -toxic to ear

Question 36

What adverse effects commonly occur with beta lactams?

Answer 36

Allergic reactions and rashes

Question 37

What adverse effects commonly occur with linezolid

Answer 37

Bone marrow depression

Question 38

Safe to use which beta lactams in patients with non-severe penicillin allergy?

Answer 38

Cephalosporins and carbapenems

Question 39

Safe to use which beta lactam in patients with severe penicillin allergy?

Answer 39

Aztrenam (unicycle)

Question 40

What is the name of the hypervirulent strain of C.Diff?

Answer 40

027

Question 41

C.Diff may be precipitated by any antibiotic, but which 4 most commonly?

Answer 41

Co-amoxiclal cephalosporin, ciproflaxin, clindamycin

Question 42

Clindamycin belongs to what group of antibiotics?

Answer 42

Lincosamide

Question 43

3 strategies of antibiotic use- in order of specificity

Answer 43

Empiric, targeted, susceptibility guided

Question 44

What antibiotic is used to treat staph A

Answer 44

Flucloxacillin

Question 45

What antibiotic is used to treat steptococcus pyogenes

Answer 45

Benzylpenicillin

Question 46

What class of antibiotic is used to treat gram -ve bacilli

Answer 46

Cephalosporins

Question 47

What type of antibiotic is used to treat anaerobes?

Answer 47

Metronidazole

Question 48

What antibiotic is used to treat gram +ves?

Answer 48

Vancomycin

Question 49

What antibiotic is used as a last option to treat multi-resistant gram negatives?

Answer 49

Colistin

Question 50

What antibiotics are used to treat CSF infections?

Answer 50

beta lactams

Question 51

What antibiotics are used to treat urine infections?

Answer 51

Trimethoprim and beta lactams