General information

• the following information is not yet verified
  Taxonomy
  Family: Enterobacteriaceae genus: S. marcescens
  2 subsp.- S. marcescens ssp marcescens
  - S. marcescens ssp sakuensis
  S. odorifera
  S. liquefaciens group
  - S. liquefaciens
  - S. grimesii
  
  S. plymuthica and S. rubidiaea (red pigment, rarely from clinical material)
  
  Not pathogenic
  S. entomophila, S. ficaria, S. fonticola, S. proteamaculans, S. quinivorans, S.ureilytica
  
  Natural habitats
  They are widely distributed in nature. Isolated from water, soil, foods.
  
  Clinical significance
  Serratia ssp are notorious health care-associated pathogens and colonizers
  
  Transmission is predomiately from person to person, but medical apparatuses, intravenous fluid, and other solutions are often implicated as well.
  
  In children, the gastrointestinal tract is a common source of infections.
  
  Pigment
  Production in S. marcescens appears to be a marker that the strain is environmental in origin and of low virulence.

Gram stain

• the following information is not yet verified
  Gram negative straight coccoid rods
  
  0.5-0.8 x 0.9-2.0 μm,
  
  some strains are capsulated
  
  

Culture characteristics

• the following information is not yet verified
  

  Facultative anaerobic
  
  Colonies are 1-3 mm, circular, shiny, opaque, creamwhite and smooth with an entire margin.
  Some strains have a capsule
  
  Pigment production is variable and not all strains produce it, pink (pyrimine), red (prodigiosine).
  
  McConkey growth, non lactose fermenter
  
  Smell
  Serratia can spread a fish-like urine air.
  
  BBAØ growth

Characteristics

• Gram-negative
• bacilli
• growth both-aerobic-and-anaerobic
• catalase-positive
• oxidase-negative
• indole-negative
• urease-negative
• TSI no production of H2S
• vancomycin-resistant
• colistine-resistant
• motility peritrichous flagella

References