Mycoplasma hominis

Mycoplasma hominis

Mycoplasma hominis

  • General information

    • the following information is not yet verified
      Family: Mycoplasmataceae

      Natural habitats
      M. hominis lives parasitically and saphrophytically with hosts.
      M. hominis plays a significant role in the microflora of men and women.

      Vector and mode of transmission.
      M. hominis infection is spread through vaginal intercourse, oral-to-genital contact, and vertically from mother to her infant in utero or by the colonization by the bacteria as the baby descends through the birth canal or by nosocomial acquisition through transplanted tissues

      Clinical significance
      M. hominis is a pathogen in humans commenly found as part of urogenital tract flora especially of women and sexually active adult males.
      This bacteria cause a variety of infections which may lead to pelvic inflammatory disease, post-abortal fever, post partum fever and extragenital infections for immunodepressed humans.
      It also can cause meningitis, pneumonia and abcesseses in newborn children.

      It can be present in bacterial vaginosis.

      Neonatal infection
      Neonates, especially if preterm, are susceptible to Mycoplasma infections organisms through vertical transmission or colonization through passing the birth canal or in utero.
      If the bacteria is present in the bloodstream it can access the central nervous system.
      If Mycoplasma hominis and ureoplasma organisms are specifically sampled and cultured, they are of etiollogic significans in neonatal lung disease, bacteremia, and meningitis.
      There are no characteristic signs and symptoms that can determine the type of pathogen present
      Clinicians can consider Mycoplasma species if signs and symptoms of infections are present and if the infant does not improve with administration of beta-lactam medications.
      Deaths have occurred in neonates with septicemia and meningitis caused by M. hominis.

      This bacteria is important due to the infections it can cause and is growing resistance to treatment, including erythromycin.

      Cell wall
      Mycoplasmas have a triple-layered membrane and lack a cell wall.

      The permanent lack of a cell wall barrier makes the Mycoplasma (class: Mollicutes) unique among prokaryotes and differentiates from bacterial L-forms for wich the cell wall is but a temporary reflection of enviromental conditions.

  • Gram stain

    • the following information is not yet verified
      Mycoplasma are smaller than conventional bacteria in cellular dimensions as well as genome size, making them the smallest free-living organism known

      Lack of cell wall also prevents the Mycoplasma from staining by the Gram reaction.

      M. hominis are a pleomorphic, gram negative bacteria with an average diameter of 0.2 to 0.3 µm.
      The pleomorphic nature of M. hominis has resultated in observations of cocci, filamentous and irregular shapes.

      Mycoplasma cells resemble those of
      - coccoid or ovoid bacteria, 0.27 x 0.73 µm and a diameter of 0.42 µm.
      - tapered rods 1-2 µm of about 0.2 - 0.3 µm

      They have no cell wall
      They lack the genes coding for a cell wall.

  • Culture characteristics

    • the following information is not yet verified

      Obligate intracellular bacteria

      BBA aeroob (Brucella Blood Agar)
      Typical mycoplasmal colonies vary from 15 to 300 µm in diameter.
      Colonies of M. hominis, often exhibit a "fried egg" appearance owing to the contrast between deeper growth in the center of the colony, with more shallow growth at the periphery.

  • Characteristics

  • References

Find related articles in Pubmed