Chapter 1 Flashcards
What is the original beta-lactam antibiotic?
a. What is it highly active against.Name 3
b. Strains of ___ are susceptible though don’t assume
Penicillin
a. group B Strep, group A Strep and syphilis (Treponema pallidum).
b. S. pneumoniae
What are aminopenicillins?
Active against? Name 2
Amoxicillin (+ clavulanate) and ampicillin (‡ sulbactam)
They have activity against streptococcal species and Enterococcus.
What do beta-lactamase inhibitors do?
Provide coverage against some gram-negative beta-lactamase-producing organisms like H. Flu, Anaerobes( B. Fragilis) and MSSA
Which organisms are covered by amoxicillin + clavulanate- name 3
Haemophilus influenzae, selected anaerobes, MSSA
Anaerobes include Bacteroides fragilis.
What is the limitation of ampicillin/sulbactam?
Limited activity against enteric bacilli
It has not been well studied in neonates.
What are penicillinase-resistant penicillins also known as?
Semisynthetic penicillins
Examples include oxacillin and nafcillin.
What do oxacillin and nafcillin cover- name 2
What do they not cover- name 4
Beta lactamase producing MSSA and streptococci
They are not effective against MRSA, CoNS, or Enterococcus or Gram negative organisms.
What does MRSA stand for?
Methicillin-resistant Staphylococcus aureus
MRSA is resistant to many beta-lactam antibiotics.
What does CoNS stand for?
Coagulase-negative staphylococci
They are a group of staphylococci that do not produce coagulase.
What are Enterococci?
A type of bacteria that are not covered by penicillinase-resistant penicillins
Enterococci can be resistant to many antibiotics.
What is Piperacillin/tazobactam classified as?
Name 3 its active against.
Limited activity for ___
Anti pseudomonal penicillin
It has activity against Pseudomonas and many other oxidase-positive gram-negative bacilli, Enterococcus.
Due to betalactamase inhibitor Tazobactam: anaerobes and many ESBL producing enteric bacilli
Limited for MSSA
Which bacteria do first-generation cephalosporins like Cephalexin and Cefazolin have activity against. Name 2.
What do they not cover, name 3
- MSSA
- Most streptococci
They do not have activity against MRSA, CoNS, or Enterococcus.
What is a limitation of first-generation cephalosporins in terms of gram-negative coverage?
Their gram-negative coverage is limited but better than ampicillin.
No MRSA CONS or Enterococcus
Cefazolin may have reduced activity in high bacterial inoculum infections. No CNS penetration
What effect does high bacterial inoculum have on Cefazolin’s efficacy?
Reduced activity due to overproduction of beta-lactamase.
This inactivates cefazolin more than oxacillin or nafcillin.
Why is Cefazolin unlikely to be effective in treating meningitis?
Limited central nervous system penetration.
It is ineffective against meningitis caused by MSSA or susceptible gram-negative bacteria.
