Mycoplasmas are different from other bacteria because they do not have cell walls. Many antibiotics, such as penicillin, kill bacteria by weakening cell walls. Because mycoplasmas do not have cell walls, many antibiotics cannot effectively treat them.
Mycoplasma pneumoniae is a common cause of community-acquired pneumonia Community-Acquired Pneumonia Community-acquired pneumonia is lung infection that develops in people who are not patients in a hospital, usually in people with normal (competent) immune systems, or in those who are immunocompromised... read more in all age groups. Outbreaks have occurred in schools, camps, and military camps.
Mycoplasma genitalium can cause sexually transmitted infections Overview of Sexually Transmitted Infections (STIs) Sexually transmitted infection (STI) refers to an infection that is passed through blood, semen, vaginal fluids, or other body fluids during oral, anal, or genital sex with an infected partner... read more 
of the urethra (urethritis Urethritis Urethritis is infection of the urethra, the tube that carries urine from the bladder out of the body. Bacteria, including those that are sexually transmitted, are the most common cause of urethritis... read more ) and sometimes, in women, pelvic inflammatory disease Pelvic Inflammatory Disease (PID) Pelvic inflammatory disease is an infection of the upper female reproductive organs (the cervix, uterus, fallopian tubes, and ovaries). Pelvic inflammatory disease is often caused by a sexually... read more 
.
Symptoms of Mycoplasmas
Symptoms of pneumonia due to M. pneumoniae are typically mild, including low-grade fever, tiredness, sore throat, and cough. This infection is sometimes called "walking" pneumonia, which is a nonmedical term for mild pneumonia that does not require bedrest or hospitalization. Some people even feel well enough to go to work and participate in other daily activities. However, M. pneumoniae sometimes causes a more serious pneumonia that requires hospitalization.
Many people with urinary and genital infection with mycoplasma, especially women, have no symptoms. When symptoms are present, they are similar to those of urinary and genital infection with chlamydia and vary by sex and location of infection:
Women may have an abnormal vaginal discharge or a burning sensation while urinating.
Men may notice a burning sensation while urinating and sometimes a discharge from the penis.
Diagnosis of Mycoplasmas
Nucleic acid amplification tests or detection of antibodies
Doctors can sometimes identify mycoplasmas by doing nucleic acid amplification tests (NAATs) on respiratory secretions or on vaginal or urethral swabs. NAATs are used to look for an organism's unique genetic material, its DNA or RNA (which are nucleic acids). NAATs use a process that increases the amount of the bacteria's DNA or RNA so that it can be more easily identified.
Sometimes doctors diagnose Mycoplasma pneumoniae by doing blood tests to detect antibodies to it.
Treatment of Mycoplasmas
Antibiotics
Mycoplasmal infections are treated with antibiotics such as azithromycin, doxycycline, or, sometimes, levofloxacin or moxifloxacin.
Prevention of Mycoplasmas
As with other respiratory infections, prevention includes covering the mouth when coughing or sneezing and washing hands often with soap and water.
Safe sex practices Prevention Chlamydial infections include sexually transmitted infections of the urethra, cervix, and rectum that are caused by the bacteria Chlamydia trachomatis. These bacteria can also infect... read more 
are recommended to decrease risk of sexually transmitted infections. (See also Prevention of STIs Prevention Sexually transmitted infection (STI) refers to an infection that is passed through blood, semen, vaginal fluids, or other body fluids during oral, anal, or genital sex with an infected partner... read more .)
More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
Centers for Disease Control and Prevention (CDC): Mycoplasma genitalium: A resource providing information about Mycoplasma genitalium
CDC: Mycoplasma pneumoniae Infections: A resource providing information such as causes, risk factors, and prevention
