Megaspheara species

Megasphaera bacteria are highly associated with bacterial vaginosis (type 1 and type 2), and in one study using PCR testing, were found in higher concentrations (up to five times more) in those with BV than those without. This unculturable bacteria can only be found using DNA/RNA testing techniques. Megasphaera are, however, lactic-acid producing bacteria, so may be considered part of a healthy environment by lowering the local pH.

Some Megasphaera species may be unique to the vaginal environment, and be an indicator, not necessarily a cause, of vaginal flora imbalances or infections.



  • Marconi, Camila; Donders, Gilbert G; Parada, Cristina M G L; Giraldo, Paulo C da Silva, Marcia Guimarães.Do Atopobium vaginae, Megasphaera sp. and Leptotrichia sp. change the local innate immune response and sialidase activity in bacterial vaginosis?  Sexually Transmitted Infections; London Vol. 89, Iss. 2, (Mar 2013): 167.
  • Zozaya-Hinchliffe M, Martin DH, Ferris MJ. Prevalence and Abundance of Uncultivated Megasphaera-Like Bacteria in the Human Vaginal EnvironmentApplied and Environmental Microbiology. 2008;74(5):1656-1659. doi:10.1128/AEM.02127-07.