History of present illness

1
History of present illness

• 48 yr old WM with ESRD secondary to FSGS on
  peritoneal dialysis.
• Admitted 5/13/03 with hemothorax
• Underwent right thoracotomy and decortication
  5/23/03, extubated 6/3/03. Treated with
  cefuroxime for ? VAP
• On Abx (cipro, pip-tazo) for positive peritoneal
  culture from 5/28/03

2
Hospital course

• Tracheal aspirate obtain at time of extubation
  growing pseudomonas
• CXR showing improving bilateral airspace
  opacities
• ID consult requested for management of tracheal
  and peritoneal cultures

3
PERITONEAL FLUID ANALYSIS
4
Vitals and physical exam

• On physical exam, peritoneal dialysis catheter in
  place, exit site clean
• Bibasilar crackles and coarse breath sounds
• Rest of exam normal
• WBC 17.4, segs 93

5
(No Transcript)
6
Recommendations

• Recommended to reculture peritoneal fluid
• Consider removal and replacement of dialysis
  catheter in view of possible catheter
  colonization
• Patient transferred out to renal service

7
Hospital course

• Reconsulted one week later, patient with sepsis
  syndrome
• Repeat peritoneal fluid analysis 6/12/03

8
Peritoneal culture
9
Prototheca Wickerhamii
10
Introduction

• Prototheca species are algae that lack
  chlorophyll, but are closely related to the green
  algae chlorella
• Prototheca is ubiquitous in nature and has been
  isolated from a wide variety of sources including
  sewage, soil, and many water sources, including
  both fresh and salt water.

11
Introduction

• They are heterotrophic, requiring external
  sources of carbon, nitrogen, and thiamine, which
  they obtain from detritus and the waste products
  of other organisms
• There remains some controversy over the taxonomic
  classification as Prototheca shares some
  important features with both alae and fungi

12
Introduction

• Prototheca can transiently colonize the
  alimentary canal of both animals and humans
  without causing disease
• In humans, protothecosis is almost always caused
  by P. wickerhamii.
• Most of the reported cases have been in adults
  and can be divided into three major categories of
  disease

13
Clinical presentations

• Simple cutaneous infections represent over half
  of the cases and present as discrete, indurated
  and painless papules, plaques, or ulcers.
  Systemic disease does not typically follow

14
Pyoderma-like lesion
Infiltrating papules
15
Clinical presentations

• Olecranon bursitis make up about a third of the
  cases and can occur following surgical procedures
  or after non-penetrating trauma such as falls or
  motor vehicle accidents where the site of trauma
  later becomes contaminated.

16
Clinical presentations

• Opportunistic infections that occur in patients
  with cancer, on steroids or other
  immunosuppressive therapy
• peritonitis
• meningitis
• algaemia
• catheter related algaemia
• cholangitis

17
Clinical presentations

• Prototheca is very sensitive to amphotericin B,
  apparently due to the ergosterol that makes up 4
  of its membrane.
• For patients who cannot tolerate amphotericin,
  ketoconazole or fluconazole have been used

18
V. Krcméry Jr, International Journal of
Antimicrobial Agents, Vol. 15, Issue 3 July
2000, Pages 235-237

• Systemic chlorellosis, an emerging infection in
  humans caused by algae
• One hundred and eight cases of human
  protothecosis occuring over 25 years reviewed
• The most common species isolated was Prototheca
  wickerhamii

19
V. Krcméry Jr, International Journal of
Antimicrobial Agents, Vol. 15, Issue 3 July
2000, Pages 235-237

• Most cases have been successfully treated by
  excising the lesion or with antifungals
• Most strains are sensitive to 5-fluorocytosine,
  amphotericin B and the azoles but resistance does
  occur

20
V. Krcméry Jr, International Journal of
Antimicrobial Agents, Vol. 15, Issue 3 July
2000, Pages 235-237

• Data on antimicrobial susceptibility were
  available from eight reports and 21 cases
• In all 21 patients, organisms were susceptible to
  amphotericin B and most of them were resistant to
  5-flucytosine, fluconazole (FCZ) and itraconazole
  (ITZ).

21
(No Transcript)
22
Calcofluor stain
Cornmeal agar morphology
23
Sabouraud culture
24
These endospores give Prototheca its
characteristic "cart wheel" appearance of a round
structure with internal septations
25
Theca are Gram negative and the endospores Gram
positive
26
lactol-phenol cotton blue preparation