View source for Multidrug-resistant organisms (MDRO)

MDRO pathogens that are frequently implicated in severe healthcare-associated infections (HAIs) and have important infection control implications are the following:

* Gram-positive: methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE);
* Gram-negative: Pseudomonas aeruginosa, Acinetobacter baumanni and Enterobacteriaceae that are resistant to at least one agent in three or more antimicrobial categories (see table) and organisms such as Stenotrophomonas maltophilia and Burkholderia cepacia, that are intrinsically resistant to the broadest-spectrum antimicrobial agents.

Table: Antimicrobial categories used to define MDR gram-negative bacteria.
{| class="wikitable" 
|- style="font-style:italic; font-weight:bold;"
! style="vertical-align:bottom;" | Enterobacteriaceae
! style="vertical-align:bottom;" | Pseudomonas aeruginosa
! style="vertical-align:bottom;" | Acinetobacter spp
! style="font-style:normal; font-weight:normal;" | 
! style="font-style:normal; font-weight:normal;" | 
|-
| style="vertical-align:bottom;" | Aminoglycosides
| style="vertical-align:bottom;" | Aminoglycosides
| style="vertical-align:bottom;" | Aminoglycosides
| 
| 
|-
| style="vertical-align:bottom;" | Cephalosporins
| style="vertical-align:bottom;" | Antipseudomonal cephalosporins   (ceftazidime, cefepime)
| style="vertical-align:bottom;" | Antipseudomonal carbapenems   (Imipenem, Meropenem, Doripenem)
| 
| 
|-
| style="vertical-align:bottom;" | Carbapenems   (Ertapenem, Imipenem, Meropenem, Doripenem)
| style="vertical-align:bottom;" | Antipseudomonal carbapenems   (Imipenem, Meropenem, Doripenem)
| style="vertical-align:bottom;" | Antipseudomonal fluoroquinolones   (ciprofloxacin, levofloxacin)
| 
| 
|-
| style="vertical-align:bottom;" | Antipseudomonal   penicillins + beta-lactamase inhibitors
| style="vertical-align:bottom;" | Antipseudomonal fluoroquinolones   (ciprofloxacin, levofloxacin)
| style="vertical-align:bottom;" | Antipseudomonal penicillins +   beta-lactamase inhibitors
| 
| 
|-
| style="vertical-align:bottom;" | Fluoroquinolones
| style="vertical-align:bottom;" | Antipseudomonal penicillins +   beta-lactamase inhibitors (piperacillin/tazobactam, ticarcillin-clavulanic   acid)
| style="vertical-align:bottom;" | Extended spectrum cephalosporins   (cefotaxime, ceftriaxone, ceftazidime, cefepime)
| 
| 
|-
| style="vertical-align:bottom;" | Folate   pathway inhibitors
| style="vertical-align:bottom;" | Monobactams
| style="vertical-align:bottom;" | Folate pathway inhibitors
| 
| 
|-
| style="vertical-align:bottom;" | Glycylcyclines
| style="vertical-align:bottom;" | Phosphonic acids
| style="vertical-align:bottom;" | Penicillins + beta-lactamase   inhibitors (ampicillin/sulbactam)
| 
| 
|-
| style="vertical-align:bottom;" | Monobactams
| style="vertical-align:bottom;" | Polymyxins
| style="vertical-align:bottom;" | Polymyxins
| 
| 
|-
| style="vertical-align:bottom;" | Penicillins
| style="vertical-align:bottom;" | 
| style="vertical-align:bottom;" | Tetracyclines
| 
| 
|-
| style="vertical-align:bottom;" | Phenicols
| style="vertical-align:bottom;" | 
| style="vertical-align:bottom;" | 
| 
| 
|-
| style="vertical-align:bottom;" | Phosphonic   acids
| style="vertical-align:bottom;" | 
| style="vertical-align:bottom;" | 
| 
| 
|-
| style="vertical-align:bottom;" | Polymyxins
| style="vertical-align:bottom;" | 
| style="vertical-align:bottom;" | 
| 
| 
|-
| style="vertical-align:bottom;" | Tetracyclines
| style="vertical-align:bottom;" | 
| style="vertical-align:bottom;" | 
| 
| 
|}

=References=
* Magiorakos AP, Srinivasan A, Carey RB, Carmeli Y, Falagas ME, Giske CG, et al. Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: An international expert proposal for interim standard definitions for acquired resistance. Clin Microbiol Infect. 2012; 18:268-81.
[[Category:Main pathogens and resistance]]