Mycoplasma Infections

Mycoplasmas are the smallest free-living microbes known. They are also very small compared to other bacteria. They may exist as part of the normal organisms found in the throat, upper respiratory tract, and genitourinary tract.


Mycoplasma is a bacterium that can infect different parts of your body.  The body part affected (your lungs, skin, or urinary tract) depends on which type of mycoplasma bacteria is causing the infection.  There are about 200 types of mycoplasma bacteria, but most of them are harmless.  The ones of concern are:

  • Mycoplasma pneumoniae
  • Mycoplasma genitalium
  • Mycoplasma hominis

All mycoplasma infections have one thing in common, unlike other bacteria, mycoplasma doesn’t have cell walls.  This is important, because many antibiotics kill bacteria by weakening cell walls.  Since mycoplasma bacteria don’t have them, some antibiotics, won’t work against them.

Testing for a mycoplasma infection

Mycoplasma testing is used to determine whether someone currently has or recently had a mycoplasma infection.

Mycoplasma testing includes a group of tests that either measure antibodies in the blood produced in response to a mycoplasma infection or detect the microbe directly through culturing or by detecting its genetic material (DNA) in a body sample.

Mycoplasma pneumoniae causes lung infections.  Mostly it is a mild infection.  Mycoplasma pneumoniae testing may be ordered when someone has severe respiratory symptoms that are not due to a typical bacterial infection, such as pneumococcal pneumonia.

Mycoplasma testing of genital samples isn’t often done, because mycoplasmas are frequently part of the normal organisms of the genital tract.  However, a test for Mycoplasma genitalium may sometimes be ordered when a sexually active male has inflammation of the prostate (prostatitis) or inflammation of the urethra that is not due to gonorrhoea or chlamydia (non-gonococcal urethritis).  In woman tests for Mycoplasma genitalium and Mycoplasma hominis may sometimes be ordered when a female is suspected of having a genital mycoplasma infection, after tests for gonorrhoea and chlamydia come back negative.

Mycoplasma hominis may be linked to pelvic inflammatory disease, an infection of female reproductive organs.  It can also lead to problems in pregnant women, such as, ectopic pregnancy (the embryo grows outside the uterus), early delivery or miscarriage.  Mycoplasma hominis can cause fever and infection in newborns, as the organism is transferred to the baby in the birth channel.

Among women, Mycoplasma genitalium has been associated with cervicitis, PID, preterm delivery, spontaneous abortion and infertility.  Urogenital Mycoplasma genitalium infection is associated with HIV among both men and women.