Pseudomonas aeruginosa: Difference between revisions

Revision as of 14:05, 15 August 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
- 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, most β-lactams (but not imipenem), 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-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

^ 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.

@@ Line 1: / Line 1: @@
-== Background ==
+==Background==
-=== Microbiology ===
+===Microbiology===
-* [[Oxidase test::Oxidase-positive]], [[Has fermentation::non-fermenting]] [[Stain::Gram-negative]] [[Cellular shape::bacillus]]
+*[[Oxidase test::Oxidase-positive]], [[Has fermentation::non-fermenting]] [[Stain::Gram-negative]] [[Cellular shape::bacillus]]
-=== Mechanisms of Resistance ===
-* Broad intrinsic and acquired antibiotic resistance
-* Membrane impermeability
-* MexAB-OprM efflux pump
-* Acquired mutations
-* Inducible AmpC β-lactamase
-* Plasmid sharing
+===Mechanisms of Resistance===
-=== Epidemiology ===
-* Loves moist and wet environments
-* Causes healthcare-associated infections
-** UTI, SSI, bacteremia, HAP, VAP
-** Especially common in cystic fibrosis
+*Broad intrinsic and acquired antibiotic resistance
-== Treatment ==
+*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, most β-lactams (but not [[imipenem]]), 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-lactam antibiotics
+*Aminoglycoside-modifying enzymes: resistance to [[aminoglycosides]]
+*Target site mutations
+**Topoisomerase II (gyrA) or IV (parC) point mutations: resistance to fluoroquinolones
+===Epidemiology===
-* 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
+*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''}}