Plesiomonas shigelloides


  • Gram negative bacteria
  • Found in aquatic environments
  • Opportunistic pathogens of fish, reptiles and rarely mammals


  • Straight rods
  • Catalase and oxidase positive
  • Facultative anaerobes
  • Motile
  • Grow on non-enriched media; NaCl supplementation required for Vibrio species
  • Found in freash water and oral cavity and skin of fish and reptiles
  • Tropical and subtropical regions
  • Septicaemia in fish, reptiles
  • Diarrhoea in harbour seals
  • Diarrhoea and neonatal meningitis in humans


  • Isolation and identification from lesions
  • Widespread in environments


  • Antibiotics including Cephalosporins against Aeromonas and P. shigelloides and Gentamicin against Vibrio species