Spectrum of Activity

Question 1

Natural Penicillins: Aqueous Penicillin G, benzathine penicillin G, procaine penicillin G, penicillin VK

Answer 1

Gram (+) bacteria:
- Group streptococcus (A,B,C,F,G)
- Viridans streptococci
- Some streptococcus pneumoniae
- Most Enterococcus spp.
- Very little activity against Staph.
- Bacillus spp.
- Corynebacterium

Gram (-) COCCI:
- Neisseria
- Non-B-lactamase neisseria gonorrhoeae
- Pasteurella

Gram (+) anaerobes:
- Peptococcus and Peptosteptococcus

Other:
- Trepnema pallidum

Question 2

Penicillinase-Resistant Penicillins (AKA Antistaphylococcal Penicillins)

Answer 2

Gram (+):
- Group and viridans streptococci
- MSSA–> NOT ACTIVE MRSA

Gram (-): NO ACTIVITY

Anaerobes: limited to no activity

Question 3

Aminopenicillins (Ampicillin and Amoxicillin)

Answer 3

Gram (+):
- ineffective against Staphylococcus aureus
- Better activity than natural penicillins against Enterococcus
- Excellent against Listeria monocytogenes

Gram (-): better than natural
- Salmonella and Shigella
- H. influenza
- E. coli
- Proteus

Anaerobes: activity similar to Pen G

DOC for infections due to Listeria and Enterococcus

Question 4

Carboxypenicillins (Ticarcillin)

Answer 4

Gram (+): generally weak activity
- Less active against Streptococcus
- Not active against Enterococcus or staphylococcus

Gram (-): enhanced activity
- Salmonella and Shigella
- H. influenza
- E. coli
- Proteus
- Morganella
- Enterobacter
- Providencia
- Pseudomonas aeruginosa (SHEPMEPP)

NOT ACTIVE AGAINST KLEBSIELLA OR SERRATIA

Question 5

Ureidopenicillins (Pipericillin)

Answer 5

Gram (+):
- Good activity against Group and viridans streptococci
- Some activity against Enterococcus
- No activity against staphylococcus

Gram (-): improved activity
- Enterobacterales
- Serratia and some Klebsiella
- Pseudomonas aeruginosa (pipericillin is the most active penicillin)

Anaerobes:
- Similar to Pen G against Clostridium and Peptostreptococcus
- Some activity against Bacteroides

Question 6

First generation cephalosporins (cefazolin, cephalexin

Answer 6

Gram (+) aerobes:
- Group strep
- Viridans strep
- PSSP
- MSSA

Gram (-) aerobes (PEK)
- Proteus
- E. coli
- Klebsiella

Question 7

Second generation cephalosporins (Cefuroxime, cefprozil, cefoxitin)

Answer 7

Gram (+) aerobes:
- Group strep
- Viridans strep
- PSSP
- MSSA

Gram (-): (HENPEK)
- H. influenza
- Enterobacter
- Neisseria
- Proteus
- E.coli
- Klebsiella pneumoniae

Anaerobes:
- Bacteroides fragilis
- Bacteroides fragilis group

Question 8

Third generation cephalorsporins (ceftriaxone, ceftazidime, cefpodoxime)

Answer 8

Gram (+) aerobes: LESS THAN 1ST AND 2ND
- PRSP

Gram (-) aerobes: (HENPECKSSS)
- H. influenza
- Enterobacter
- Neiserria
- Proteus
- E. coli
- Citrobacter
- Klebsiella
- Salmonella
- Shigella
- Serratia

Question 9

Fourth generation cephalosporins (cefepime)

Answer 9

Gram (+) aerobes: similar to ceftriaxone

Gram (-) aerobes: similar to ceftazidime
- Pseudomonas aeruginosa
- B-lactamase producing Enterobacter

Question 10

Anti-MRSA cephalosporin (ceftaroline)

Answer 10

Gram (+): similar to ceftriaxone, but also activity against MRSA

Gram (-): similar to ceftriaxone (does not cover pseudomonas)

Question 11

Cefiderocol

Answer 11

Gram (+): no clinically relevant activity

Gram (-): similar to cefipime; also includes many ESBLs, AmpCs (both Enterobacterales and resistant Pseudomonas eruginosa) and CREs KPCs, NDMs, VIM, OXA-48

Question 12

Ceftolozane-tazobactam

Answer 12

Gram (+):
- Streptococcus

Gram (-): similar to cefepime also includes some ESBLs and AmpCs (resistant Pseudomonas aeruginosa)

Question 13

Ceftazidime-Avibactam

Answer 13

Gram (+):
- Streptococcus

Gram (-): similar to cefepime; also includes ESBLs, some AmpCs (both enterobacterales and resistant Pseudomonas aerugonosa) and KPCs/OXAs

Question 14

Carbapenems (imip and dori the best)

Answer 14

Gram (+) aerobes:
- Group strep
- Viridans strep
- PSSP
- Enterococcus faecalis
- MSSA