View source for Pseudomonas aeruginosa

==Background==
===Microbiology===

*Oxidase [[Oxidase::positive]], non-fermenting [[Stain::Gram-negative]] [[Cellular shape::bacillus]]

===Mechanisms of Resistance===

*Broad intrinsic and acquired antibiotic resistance[[CiteRef::livermore2002mu]]
*Membrane impermeability
**Decreased or absent OprD porin: resistance to [[carbapenems]] ([[imipenem]] and [[meropenem]])
**Membrane changes: resistance to polymixins ([[colistin]])
**Reduced aminoglycoside transport: resistance to [[aminoglycosides]]
*Efflux pumps
**MexAB-OprM: resistance to [[fluoroquinolones]] and all [[β-lactams]] except [[imipenem]]
**MexCD-OprJ: resistance to [[fluoroquinolones]] and most [[β-lactams]] ([[cefoperazone]], [[cefpirome]], [[cefepime]], [[meropenem]]) but not [[imipenem]]
**MexEF-OprN: resistance to [[fluoroquinolones]] and all [[β-lactams]]
**MexXY-OprM: resistance to [[fluoroquinolones]], [[tetracyclines]] including [[tigecycline]], most [[β-lactams]] (but not [[imipenem]] or [[ceftazidime]]), and [[aminoglycosides]]
*β-lactamases
**Derepressed AmpC β-lactamase: resistance to [[penicillins]] and [[cephalosporins]] (except [[ceftolozane]])
**Acquired [[carbapenemases]] such as NDM-1: resistance to essentially all [[β-lactams]]
*Aminoglycoside-modifying enzymes: resistance to [[aminoglycosides]]
*Target site mutations
**Topoisomerase II (gyrA) or IV (parC) point mutations: resistance to [[fluoroquinolones]]

===Epidemiology===

*Loves moist and wet environments
*Causes healthcare-associated infections
**UTI, SSI, bacteremia, HAP, VAP
**Especially common in cystic fibrosis

==Treatment==

*Refer to [[antipseudomonal antibiotics]] for specific treatment options
*Double coverage (ß-lactam + non-ß-lactam) in cases of severe infection in order to ensure activity against the infection

{{DISPLAYTITLE:''Pseudomonas aeruginosa''}}
[[Category:Gram-negative bacilli]]