Elizabethkingia

MICROBIOLOGY

• Elizabethkingia meningoseptica, non-fermenting mildly curved Gram-negative bacillus--the primary organism described as a human pathogen in this class.
  
  • Previously known as Chryseobacterium meningosepticum, and before this, Flavobacterium meningosepticum.
    • Isolated in 1959 by Elizabeth O. King, an American bacteriologist.
  • Hardy organisms found in water and soil are ubiquitous in hospital environments.
  • Positive findings for catalase, oxidase and indole. Growth is better at 40°C.
    • It may be confused with Burkholderia cepacia, Aeromonas salmonicida or Sphingobacterium spp.
    • E. meningoseptica is colistin-resistant but vancomycin-susceptible, unusual for a Gram-negative organism.
  • Multi-drug resistance is the norm, including carbapenems:
    
    • Class A extended-spectrum β-lactamases and Metallo-β-lactamases, BlaB (subclass B1) and GOB (subclass B3) are described.
      
• E. miricola: usually multi-drug resistant.
• E. anophelis: typically identified through MALDI-TOF. Contaminated water is a typical source of outbreaks.
  • Outbreak (2015-2016) in Wisconsin and Michigan.
  • Appears to be less drug-resistant than E. meningoseptica.
• Three other species were proposed as additions: E. bruuniana, E. ursingii, and E. occulta.