Elizabethkingia Infections Differential Diagnoses

Updated: Feb 03, 2017
  • Author: Meenal Malviya, MBBS, MD; Chief Editor: Michael Stuart Bronze, MD  more...
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Diagnostic Considerations

E meningoseptica may show colistin-resistant and vancomycin-sensitive growth, which is paradoxic for a gram-negative bacterium. It resembles Burkholderia cepacia, which is also a nonfermenter and does not grow well on MacConkey agar. These two can be differentiated using the indole test or the Pyr test, both of which should be clearly negative for B cepacia and positive for E meningoseptica.

Automated bacterial identification system results should be observed with caution, especially when a patient with gram-negative bacteremia does not improve with broad-spectrum antibiotic therapy, because several bacteria, including Aeromonas salmonicida [6] and Sphingobacterium species, may be confused with this bacterium, especially the atypical ones. However, unlike many other Aeromonas species such as Aeromonas hydrophilia and Aeromonas punctata, A salmonicida is indole-negative, which can help in distinguishing it in doubtful cases. [11, 12]