Pseudomonas aeruginosa: Difference between revisions

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Pseudomonas aeruginosa
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===Microbiology===
 
===Microbiology===
   
*Oxidase-positive]], [[Has fermentation::non-fermenting]] [[Stain::Gram [[Oxidase::negative]] [[Cellular shape::bacillus]]
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*Oxidase [[Oxidase::positive]], non-fermenting [[Stain::Gram-negative]] [[Cellular shape::bacillus]]
   
 
===Mechanisms of Resistance===
 
===Mechanisms of Resistance===

Revision as of 20:49, 14 September 2020

Background

Microbiology

  • Oxidase positive, non-fermenting Gram-negative bacillus

Mechanisms of Resistance

  • Broad intrinsic and acquired antibiotic resistance
  • 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
  • β-lactamases
    • Derepressed AmpC β-lactamase: resistance to penicillins and cephalosporins (except ceftolozane)
    • Acquired carbapenemases such as NDM-1: resistance to essentially all β-lactam antibiotics
  • 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

References

  1. ^  D. M. Livermore. Multiple Mechanisms of Antimicrobial Resistance in Pseudomonas aeruginosa: Our Worst Nightmare?. Clinical Infectious Diseases. 2002;34(5):634-640. doi:10.1086/338782.