RANK: Genus

TAXONOMY: cellular organisms -> Bacteria -> Proteobacteria -> Gammaproteobacteria -> Enterobacteriales -> Enterobacteriaceae -> Plesiomonas


Rod-shaped, straight cells, 0.8–1.0 × 3.0 µm (Janda, 1998). Endospores not produced. Gram negative. Motile. Growth on common basal agars with most strains growing on mineral media containing ammonium salts and glucose as sole nitrogen and carbon sources (Schubert, 1984). Chemoorganotrophic with both a respiratory- and fermentative-type metabolism. Facultatively anaerobic. Acid from the catabolism of d-glucose, without gas. Anaerogenic fermentation of a limited number of carbohydrates including m-inositol. Oxidase and catalase positive. Lysine- and ornithine-decarboxylase and arginine dihydrolase positive. NaCl supplementation not required for growth. Most strains susceptible to 10 μg and 150 μg of the vibriostatic agent O/129 (2,4-diamino-6,7-diisopropylpteridine). Few extracellular enzymes elaborated (Schubert, 1984). Starch not hydrolyzed. 16S rDNA and 16S rRNA analysis indicate plesiomonads belong to the Gammaproteobacteria, with maximum homology to members of the Enterobacteriaceae (Martinez-Murcia et al., 1992a; Ruimy et al., 1994). Unique genus-specific signature oligonucleotides have not been identified.The mol% G + C of the DNA is: 51 (Sebald and Véron, 1963).Type species: Plesiomonas shigelloides

This genus contains microbial species that can reside in the human gastrointestinal tract. [PMC 4262072]

Gut associated
Dysbiosis associated
Substrates/ Growth Factors
  • Iron supplements [parent]
  • Acetoin [parent]

  • Metabolic Endproducts
  • 2,3-Butanediol [parent]

  • Growth Inhibited by
  • Pomegranate ellagitannins [parent]

  • Growth Enhanced By
  • Aspartame [parent]