Pseudomonas Aeruginosa

last authored: Feb 2010, David LaPierre
last reviewed:

 

Introduction

Pseudomonas is a uniquitous organism that only transiently colonizes health people. Serious opportunistic infections can occur during broad-spectrum antibiotic administration or in people with compromised immune systems

 

Pseudomonas is a common nosocomial agent, responsible for approximately 10% of hospital-acquired infections.

 

 

 

The Case of...

a simple case introducing clincial presentation and calling for a differential diagnosis to get students thinking.

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Epidemiology

Ubiquitous; found in soil, decaying matter, vegetation, water. They are often seen in rivers, lakes, swimming pools, and tap water.

Present in moist reservoirs in hospitals - mops, sinks, equiment, even disinfection solutions

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Classification and Characteristics

Pseudomonas is a gram negative rod.

It is rich in genetic material, with almost as much as yeasts. This codes for a number of enzymes that allow for metabolism of various substrates.

Antimicrobial resistance is common and stems from its porins and the effective pump systems.

Many pseudomonads can grow at 4 C, and given their capacity to digest proteins and lipids, they are often responsible for spoiled food.

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Transmission and Infection

 

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Clinical Manifesations

Pseudomonas can transiently colonize the respiratory and gastrointestinal tracts.

Primarily opportunistic due to hosts' ability to prevent colonization and invasion. In compromised states, Pseudomonas can cause:

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Diagnosis

Frequent environmental contamination of samples leads to many false positives.

Isolation of pseudomonads in healthy people is of little concern.

Detection in hospitalized patients is more worrisome, but not much needs to be done unless there is clinical evidence of disease.

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Treatment

Pseudomonas can be difficult to treat. It shows high rates of resistance to many antibiotics, including ceftriaxone and TMP/SMX. Options to consider, given local rates of resistance, include ciprofloaxacin (though guard against overuse), ceftazedime, pipercillin, gentamycin, tobramycin, and imipenem.

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Resources and References

 

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