CRE

  • Metallo-betalactamases have potent carbapenemase activity
  • inhibition to resistance by beta-lactam / ase inhibitors
  • carbapenemases can’t hydrolyze aztreonam. but same bug making carbapenemase is often also making an ESBL
  • Bugs we worry about are PsA, Acinetobacter, Enterobacteraciae. Call these Carbapenemase producing gram negative bacilli, to include serine and metallo-producing oranisms, where this has happened and made us all so nervous
  • Growing family of carbapenemases: non-metallo (serine active target, KPC). Oxa-48, and imipenem
  • Metallo (zinc at active site). VIM = class B,  New Dehli Metallo-Blase (Class B)

 

Carbapenem resistance mediated by β-lactamases, or carbapenemases, has become widespread

reports of Klebsiella pneumoniae carbapenemases, New Delhi metallo-β-lactamase-1, and recently OXA-48 (oxacillinase-48) have become more common

mechanisms:

(i) hyperproduction or derepression of Ambler class C β-lactamases (AmpC β-lactamases) or ESBLs (e.g., sulfhydryl variable (SHV), temoneira (TEM), cefotaxime (CTX-M) type β-lactamases) with loss or alteration in outer membrane porins;

(ii) augmented drug efflux;

(iii) alterations in penicillin binding proteins (PBPs);

(iv) carbapenemase production

Carbapenemases belong to three molecular classes of β-lactamases, Ambler class A, B, and D

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s