The bacteria Gram - aerobes strict or “easy” Pseudomonades of culture very often form a group of bacteria oxydase +.

They at present are classified better thanks to many genetic studies ADN-ADN or ARNr-DNA what led to the invention of new kinds and families. It is however quite delicate to define a family of Pseudomonades ( Pseudomonadaceae ): the situation remains extremely confused considering the great diversity of the group and of the later studies will doubtless allow to differentiate several families. The kind Pseudomonas (and some bacteria close), which represents the bacilli negative Gram aerobic strict most frequently met in the laboratories of bacteriology, underwent, following these rehandlings, a bursting which led to the invention of new kinds (even of new families), on genetic criteria.

The Pseudomonas close and bacteria are defined by 7 criteria, like are the Entérobactérie S (with the same limits in the definition of these criteria):

• Nondemanding Bacilli with negative Gram

• (of easy culture)
• Oxydase +
• Réductase Nitrate + in general
• Aerobic strict (can push only in the presence of dioxygene)
• Oxydatifs or Inert with respect to the Glucose (=" bacilli not fermentants")
• Very generally mobile by a polar Ciliature

One can also attach to them other characteristics useful to their identification:

• they often have inclusions of polyhydroxybutyrate being able to give a striped coloring to Gram.
• certain species produce a mucous extracellular substance of not very clear nature (polyosidic): the slime.
• some produce also fluorescent pigments (Pyocyanine, pyoverdine).
• the antigens O make it possible to differentiate a certain number of sérovars from ((Pseudomonas aeruginosa]] , the agent more met in the infections nosocomiales (infections contracted at the hospital).

See too

• bacterial Wall
• Pseudomonadaceae
• Pseudomonas