Antimicrobial Spectrum

Question 1

Which bacteria have LESS resistance and thus easier to kill? (HiPEEL)

Answer 1

H. influenza
P. mirabalis
E. coli
Enterococcus faecalis
Listeria

Question 2

Which bacteria have MORE resistance and thus harder to kill? (SPACE)

Answer 2

S. aureus (MRSA)
Serratia sp.
P. aeruginosa
Protease, morganella, providencia spp.
Acinetobacter/indole positive.
Citrobater spp
Enterobacter faciam

Question 3

Which antibiotic classes cover Staphylococcus aureus (MSSA)?

Answer 3

Penicillinase-resistant penicillins (e.g., nafcillin, oxacillin), first-generation cephalosporins (e.g., cefazolin), clindamycin, vancomycin

Question 4

Which antibiotics cover MRSA?

Answer 4

Vancomycin, daptomycin, linezolid, ceftaroline, trimethoprim-sulfamethoxazole (TMP-SMX), doxycycline.

Question 5

What is the drug of choice for Streptococcus pyogenes (Group A strep)?

Answer 5

Penicillin or amoxicillin.

Question 6

Which antibiotic classes cover Enterococcus species?

Answer 6

Ampicillin, vancomycin, daptomycin, linezolid. For VRE (Vancomycin-resistant Enterococcus), use daptomycin or linezolid.

Question 7

What are the gram positive bacteria?

Answer 7

Streptococcus (S. pneumo, Group B strep); S. aureas/Staph/Saprophyticus; Enterococcus; Listeria mono.

Question 8

What are the gram negative bacteria?

Answer 8

PEK (proteus mirabalis, e. coli, klebsiela), H. influenza, M. cat, N. meningitidis

Question 9

Which are the atypical bacteria? MCL

Answer 9

Mycoplasma pneumoniae
Chlamydia pneumoniae
Legionella sp.

Question 10

What are anaerobes?

Answer 10

Oral anaerobes - peptostreptococcus; B. fragilis; C. diff

Question 11

Which antibiotics cover Pseudomonas aeruginosa?

Answer 11

Piperacillin-tazobactam, ceftazidime, cefepime, carbapenems (except ertapenem), ciprofloxacin, levofloxacin, aminoglycosides (e.g., gentamicin, tobramycin), polymyxins

Question 12

What is the antibiotic class of choice for E. coli in urinary tract infections?

Answer 12

Nitrofurantoin, fosfomycin, trimethoprim-sulfamethoxazole (TMP-SMX), fluoroquinolones.

Question 13

Which antibiotics cover Haemophilus influenzae?

Answer 13

Amoxicillin-clavulanate, third-generation cephalosporins (e.g., ceftriaxone, cefotaxime), azithromycin.

Question 14

Which antibiotic classes are effective against anaerobes like Bacteroides fragilis?

Answer 14

Metronidazole, carbapenems, beta-lactam/beta-lactamase inhibitor combinations (e.g., piperacillin-tazobactam, amoxicillin-clavulanate).

Question 15

What is the drug of choice for Clostridioides difficile infections?

Answer 15

Oral vancomycin or fidaxomicin.

Question 16

Which antibiotics cover atypical bacteria like Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella?

Answer 16

Macrolides (e.g., azithromycin), fluoroquinolones (e.g., levofloxacin), tetracyclines (e.g., doxycycline).

Question 17

Which antibiotic is used for Rickettsia infections (e.g., Rocky Mountain spotted fever)

Answer 17

Doxycycline.

Question 18

Which antibiotic classes have broad-spectrum coverage against both Gram-positive and Gram-negative bacteria?

Answer 18

Carbapenems, beta-lactam/beta-lactamase inhibitor combinations (e.g., piperacillin-tazobactam, amoxicillin-clavulanate), fluoroquinolones.

Question 19

Which antibiotic is used as an empiric therapy for sepsis due to its broad-spectrum activity?

Answer 19

Piperacillin-tazobactam or a carbapenem (e.g., meropenem).

Question 20

Which bacteria are commonly associated with beta-lactamase production?

Answer 20

Gram-negative bacteria such as E. coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa.

Question 21

How does vancomycin resistance develop in Enterococcus (VRE)?

Answer 21

Modification of the D-Ala-D-Ala target site in the bacterial cell wall to D-Ala-D-Lac, reducing vancomycin binding.

Question 22

Which antibiotics are contraindicated in pregnancy?

Answer 22

Tetracyclines (e.g., doxycycline), fluoroquinolones, aminoglycosides, nitrofurantoin (late pregnancy only)

Question 23

Which antibiotic is safe for use in pregnant women with a urinary tract infection?

Answer 23

Nitrofurantoin (except in late pregnancy) or amoxicillin.

Question 24

What is the antibiotic of choice for surgical prophylaxis?

Answer 24

cefazolin

Question 25

Which antibiotic is used for Pneumocystis jirovecii pneumonia (PJP) prophylaxis in immunocompromised patients?

Answer 25

SMX-TMP

Question 26

Which antibiotics cover both MRSA and Pseudomonas?

Answer 26

None. These pathogens require different drugs: MRSA (e.g., vancomycin) and Pseudomonas (e.g., piperacillin-tazobactam).

Question 27

Which antibiotics require therapeutic drug monitoring?

Answer 27

Vancomycin, aminoglycosides (e.g., gentamicin, tobramycin).