Burkholderia pseudomallei: Difference between revisions

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Burkholderia pseudomallei
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= ''Burkholderia pseudomallei'' (melioidosis) =
= ''Burkholderia pseudomallei'' (melioidosis) =


== Microbiology ==
= Microbiology =


* Oxidase positive, indole-negative Gram-negative rod with "'''safety pin'''" appearance
* Oxidase positive, indole-negative Gram-negative rod with "'''safety pin'''" appearance
* Non-hemolytic
* Non-hemolytic


== Epidemiology ==
= Epidemiology =


* Humans and animals
* Humans and animals
Line 23: Line 23:
** Thalassemia
** Thalassemia


== Clinical Presentation ==
= Clinical Presentation =


* Incubation period 9 days (range 1 to 21 days)
* Incubation period 9 days (range 1 to 21 days)
Line 35: Line 35:
* About 20% of clinical cases with develop septic shock
* About 20% of clinical cases with develop septic shock


== Diagnosis ==
= Diagnosis =


* Culture
<ul>
** Blood, throat, and urine cultures from all patients with suspected melioidosis
<li><p>Culture</p>
** Grows on blood agar, MacConkey, etc. (i.e. ''not'' a fastidious organism)
<ul>
** Can use selective colistin or polymyxin B
<li>Blood, throat, and urine cultures from all patients with suspected melioidosis</li>
<li>Grows on blood agar, MacConkey, etc. (i.e. ''not'' a fastidious organism)
** On sheep blood agar, grows as small, smooth, cream-coloured colony with metallic sheen
** May develop a dry and '''wrinkled''' appearance after 1 to 2 days of incubation</ul>
<ul>
* MALDI-ToF is ''not'' reliable for identifying it
<li>Can use selective colistin or polymyxin B</li></ul>
* Other methods
</li>
** PCR
<li>On sheep blood agar, grows as small, smooth, cream-coloured colony with metallic sheen
** Immunofluorescence and latex agglutination
<ul>
** Serology (acute/convalescent)
<li>May develop a dry and '''wrinkled''' appearance after 1 to 2 days of incubation</li></ul>
</li></ul>
</li>
<li><p>MALDI-ToF is ''not'' reliable for identifying it</p></li>
<li><p>Other methods</p>
<ul>
<li>PCR</li>
<li>Immunofluorescence and latex agglutination</li>
<li>Serology (acute/convalescent)</li></ul>


== Management ==
= Management =


* Intrinsic resistance to many antibiotics, especially using efflux pumps
<ul>
* Ceftazidime
<li>Intrinsic resistance to many antibiotics, especially using efflux pumps</li>
* Amoxicillin-clavulanic acid
<li>Ceftazidime</li>
* TMP-SMX
<li>Amoxicillin-clavulanic acid</li>
<li>TMP-SMX</li></ul>


== Biosafety ==
= Biosafety =


* Lab workers can have aerosol exposure
<ul>
* May need prophylaxis in high-risk patients
<li>Lab workers can have aerosol exposure</li>
** Septra or doxy or amox/clav</ul>
<li>May need prophylaxis in high-risk patients
* Monitor with serology at baseline, weeks 1 2 4 and 6 post-exposure
<ul>
** Needs to be sent to CDC via NML</ul>
<li>Septra or doxy or amox/clav</li></ul>

</li>
{{DISPLAYTITLE:''Burkholderia pseudomallei''}}
<li>Monitor with serology at baseline, weeks 1 2 4 and 6 post-exposure
[[Category:Gram-negative bacilli]]
<ul>
<li>Needs to be sent to CDC via NML</li></ul>
</li></ul>
</li></ul>

Revision as of 01:29, 15 August 2019

Burkholderia pseudomallei (melioidosis)

Microbiology

  • Oxidase positive, indole-negative Gram-negative rod with "safety pin" appearance
  • Non-hemolytic

Epidemiology

  • Humans and animals
  • Important cause of death in SE Asia and northern Australia
    • Up to 80% seroprevalence in Thailand, mostly asymptomatic
    • Sporadic cases elsewhere
  • May have latent disease with reactivation much later
  • Acquired by percutaneous inoculation, inhalation (esp. lab workers), and ingestion
  • Risk factors for clinical disease
    • Diabetes
    • Heavy alcohol use
    • Chronic lung disease
    • Chronic kidney disease
    • Treatment with glucocorticoids
    • Cancer
    • Thalassemia

Clinical Presentation

  • Incubation period 9 days (range 1 to 21 days)
  • Presentations can vary from asymptomatic, skin ulcers, abscesses, latent infection, chronic pneumonia (similar to TB), or fulminant shock
    • Pneumonia (50%)
    • GU infection (15%)
    • Skin (15%)
    • Primary bacteremia (10%)
    • Septic arthritis/OM (3-5%)
    • Neuro (3-5%)
  • About 20% of clinical cases with develop septic shock

Diagnosis

  • Culture
    • Blood, throat, and urine cultures from all patients with suspected melioidosis
    • Grows on blood agar, MacConkey, etc. (i.e. not a fastidious organism)
    • Can use selective colistin or polymyxin B
    • On sheep blood agar, grows as small, smooth, cream-coloured colony with metallic sheen
    • May develop a dry and wrinkled appearance after 1 to 2 days of incubation
  • MALDI-ToF is not reliable for identifying it
  • Other methods
    • PCR
    • Immunofluorescence and latex agglutination
    • Serology (acute/convalescent)
  • Management

    • Intrinsic resistance to many antibiotics, especially using efflux pumps
    • Ceftazidime
    • Amoxicillin-clavulanic acid
    • TMP-SMX

    Biosafety

    • Lab workers can have aerosol exposure
    • May need prophylaxis in high-risk patients
      • Septra or doxy or amox/clav
  • Monitor with serology at baseline, weeks 1 2 4 and 6 post-exposure
    • Needs to be sent to CDC via NML
  • References

    1. ^  Bart J. Currie, Linda Ward, Allen C. Cheng. David Joseph Diemert. The Epidemiology and Clinical Spectrum of Melioidosis: 540 Cases from the 20 Year Darwin Prospective Study. PLoS Neglected Tropical Diseases. 2010;4(11):e900. doi:10.1371/journal.pntd.0000900.