As estimated by the Centers for Disease Control and Prevention (CDC), there are two million cases of Mycoplasma pneumoniae infections in the United States every year, of which 100,000 require hospitalization. Mycoplasma pneumoniae is considered to be the most common cause of pneumonia in young adults and in children over the age of five years.
What Are Mycoplasma?
Mycoplasma are a type of bacteria. There are 14 species, but only four species are medically important. M. pneumoniae causes a type of pneumonia, M. genitalium can cause a urinary infection, while M. hominis can cause a fever in women after they give birth (called a postpartum fever). Ureaplasma urealyticum is in the mycoplasma family, and also causes a urinary infection as well as an infection in the prostate gland. According to Warren Levinson, M.D., Ph.D., Professor of Microbiology at the University of California in "Review of Medical Microbiology and Immunology," unlike most bacteria, mycoplasma do not have a cell wall. So, antibiotics that are designed to kill bacteria by preventing them from making cell walls will not kill mycoplasma. It is also the only type of bacteria that has cholesterol in its membrane.
How Do Mycoplasma Cause Disease?
M. pneumoniae is passed from one person to another through respiratory droplets. This is why there are outbreaks in crowded facilities, such as college dorms and military bases. George Brooks, M.D., Professor of Laboratory Medicine and Microbiology and Immunology at the University of California, states that this bacteria has a special structure, or a tip, that it uses to attach and adhere to the cells in your lungs. This tip is made out of protein. The cells that line the surface of your lungs have cilia, or hair-like structures. The cilia move in a coordinated fashion to push foreign substances out of your respiratory tract. Dr. Levinson explains in "Review of Medical Microbiology and Immunology" that after mycoplasma attach with their tip, the cilia stop moving. The mycoplasma then make hydrogen peroxide, enzymes and superoxide radicals. These substances damage your respiratory lining and the infection continues.
The Pneumonia of M. Pneumoniae
Pneumonia is the inflammation of your lungs. M. pneumoniae causes what is referred to as an atypical pneumonia. It is called atypical because it is different from the pneumonia caused by Streptococcus pneumoniae. It is also considered to be atypical because it cannot grow on regular lab nutrition. M. pneumoniae is the most common cause of an atypical pneumonia. With the nickname of "walking pneumonia," the symptoms start gradually. At first, you may just have a cough or your ears may hurt. You may also have a sore throat. But the symptoms will then progress to include headache, muscle aches and fever.
References
- Centers for Disease Control and Prevention: Mycoplasma pneumoniae
- "Jawetz, Melnick, & Adelberg's Medical Microbiology"; George Brooks, M.D., Karen Carroll, M.D., Janet Butel, Ph.D., Stephen Morse, Ph.D.; 2007
- "Review of Medical Microbiology and Immunology," Warren Levinson, M.D., Ph.D.; 2008
