There are almost 200 varieties of Mycoplasma. These unique bacteria lack a cell wall and cause a variety of infections and conditions. Some researchers call mycoplasma the “crabgrass” of bacterial cultures because they are like weeds in the garden: persistent, difficult to get rid of, and frequently hard to detect.
Mycoplasma Pneumoniae
One of the most common types of Mycoplasma that affects humans is Mycoplasma pneumoniae. It primarily attacks the moist mucosal areas of the respiratory tract and causes walking pneumonia. This bacterium is commonly transmitted from person to person. Transmission from animals to humans is rare.
Transmission
Mycoplasma transmission depends on the type. For example, Mycoplasma pneumoniae spread through droplet transmission from coughing or sneezing and attach to the respiratory tract using a special organelle. While it does occur, experts do not understand exactly how this bacteria transmits to non-respiratory tissues. Other Mycoplasmas affect the mucosal tissue of the urogenital tract and are spread through direct contact.
Manifestations
Mycoplasma pneumoniae infections most often affect children between five and 14 and present in different ways depending on where in the respiratory tract they develop. The person may have a headache, fever, or cough with a sore throat. Lung sounds are often a tell-tale sign. Rhonchi or a rattling sound indicates that the infection affects the upper airway, and crackles in the lower lungs indicate that pneumonia has developed. Recovery from this condition can take up to six weeks.
Mycoplasma Genitalium
Mycoplasma genitalium is another common Mycoplasm; it causes sexually transmitted diseases such as urethritis in men and endometritis, cervicitis, and pelvic inflammatory disease in women. This Mycoplasm may also contribute to preterm births and ectopic pregnancies. Medical professionals do not completely understand the mechanisms the bacteria use to cause these reactions.
Ureaplasma
Ureaplasmas are an interesting type of Mycoplasm that require urea, found in the urine, to survive. This bacteria is spread primarily through sexual contact. Women may be asymptomatic carriers of this Mycoplasm, though it has been associated with multiple pregnancy complications, including infections of the amniotic fluid, spontaneous abortion, and low birth weight in infants.
Common Mycoplasmas
Other types of Mycoplasma also inhabit the body, most commonly in the oropharynx — the back of the throat between the soft palate and the uvula. Though they are not beneficial, these Mycoplasmas are generally not harmful, either, except in immunosuppressed individuals. In this case, the Mycoplasmas can be opportunistic and cause infection.
How Mycoplasmas Cause Damage
Mycoplasmas cause damage to the host cell by preventing cilia from clearing debris and invaders from the mucosa. Mycoplasma then causes direct damage to the cell by producing hydrogen peroxide radicals. Next, it enters the cell to replicate, triggering an immune response that releases cytokines, which lead to inflammation.
Diagnosis
Mycoplasma infections are usually diagnosed clinically. Bacterial cultures are useful for confirmation, but they are time-consuming and generally do not guide initial treatment. For example, Mycoplasma genitalium can take as long as eight weeks to grow in a culture. To diagnose Mycoplasma pneumonia, doctors often use serum antibody tests to measure the body’s response to the infection, rather than the infection itself.
Imaging
In the case of Mycoplasma pneumonia, x-rays can often help doctors make a diagnosis instead of waiting on a culture. That said, the results are variable. A chest x-ray may show diffuse infiltrates, consolidation, nodules, or masses. In most cases, these affect only one lung but can affect both in about 20 percent of cases. The lower lobes of the lungs are most commonly involved.
Treatment
Mycoplasma pneumonia is resistant to many antibiotics because it does not have a cell wall. Furthermore, some effective antibiotics must be limited in their dose when given to children, as they can cause toxicity. With the right antibiotic, though, a course of treatment is only five days. Other Mycoplasmas also require hefty antibiotics, and treatment varies depending on the illness. In the case of a genitourinary tract infection, sexual partners should also receive treatment, even if they are asymptomatic.