Sites of pathology for species of GPAC.

Species of major importance are underlined, ? denotes uncertain pathology.


Parvimonas micra

  • General information

    • the following information is not yet verified
      Family: Peptoniphilaceae

      synonym: Peptostreptococcus micros

      Natural habitats
      P. micros is part of the normal flora of the gingival crevice and the gastrointestinal tract; there are conflicting reports on its status in the normal vaginal flora.
      It is increasingly recognized as an important oral pathogen.

      Clinical significance
      P. micros was little studied until recently, but its importance in a range of oral infections is now recognized.
      Its strong proteolytic activity may be significant in the development of mixed extraoral anaerobic abscesses.

      In contrast to P. magnus, it was always recovered with other anaerobes but only half the strains were isolated with facultative organisms.

  • Gram stain

    • the following information is not yet verified
      Gram positive cocci,

      0.3 to 0.7 mm,

      usually arranged in pairs and chains,

      but they can occur in clumps when they have been cultured on solid media

  • Culture characteristics

    • the following information is not yet verified

      Obligate anaerobic


      Slow growing, highly characteristic colonies, 1 mm after incubation for 5 days: they are typically white (but sometimes grey), glistening, and domed and are often surrounded by a distinctive yellow-brown halo of discolored agar up to 2 mm wide.

      2 morphotypes
      ►a rough morphotype, dry, white, hemolytic colonies with crinkled edges
      (from the gingival plaque of patients with periodontitis)
      ►a smooth morphotype

      Broth culture
      Rough type readily changes to a smooth-like variant in broth culture.

      When haloes are present, the colony morphology of P. micros is distinctive enough to make a presumptive identification.

  • Characteristics

  • References

Find related articles in Pubmed