Streptococci colonize the mucous membranes of healthy people and are considered harmless there. However, they are also responsible for a number of sometimes serious infections and diseases.
What are streptococci?
Streptococci are bacteria that have a ball-like appearance. Their shape is circumscribed by the term “cocci” derived from ancient Greek. Streptococci have a large number of subspecies, such as Streptococcus pneumoniae or Streptococcus salivarius. In healthy people, they are found in the throat and mouth as well as in the intestines and vagina of women and do not normally cause any problems there. However, as soon as the immune system is weakened, streptococci can sometimes cause serious illnesses. These include middle ear infections, pneumonia, meningitis, appendicitis as well as strep throat and scarlet fever. Streptococci are further responsible for the occurrence of blood poisoning and urinary tract infections.
Significance and function
Streptococci settle on the mucous membranes in healthy people. They are limited in number there by normal immune defenses such that no disease can occur. However, they can be detected by laboratory tests. Streptococcus mutans was isolated in the mouth as early as 1924. This strain of bacterium is considered to be the trigger of caries and is also responsible for bacterial plaque. If the immune system is weakened, an increase in the number of bacteria will increase the risk of caries accordingly. The same applies to Streptococcus pyogenes, which can be detected in the throat of one in five people without causing symptoms of a sore throat. The number of germs present is far too small for an outbreak of disease. It is therefore important to take it easy during an acute illness, because untreated infections or too early exposure can lead to serious secondary diseases of the heart muscle as well as the heart valves and kidneys. Rheumatic fever also occurs after an infection with streptococci. In most cases, the bacteria respond well to treatment with antibiotics. However, it can also happen that resistance has already developed. This risk is particularly present in patients who have had to be treated repeatedly with antibiotics. For this reason, too, it is important to always take these drugs exactly as prescribed and to consult the doctor again if there is no improvement. He or she can then determine the exact pathogen within the strep family, if necessary, to find an effective medication.
Diseases
Streptococci are a common cause of urinary tract infections. These primarily include bladder infections, but they can also rapidly affect the kidneys, where they can trigger renal pelvic inflammation. If the typical pain during urination does not improve and if there is also pain on one side in the kidney area, a doctor must be consulted quickly. Middle ear infections are initially a result of colds spreading to the ear canal. They are characterized by severe ear pain and often fever. In this case, too, a doctor must be consulted to prevent further aggravation of the inflammation. This may subsequently lead to perforation of the eardrum. Bacterial pneumonia also progresses with fever and chills, as well as an agonizing cough. Decreased oxygen saturation can be seen in the patient’s bluish lips. Especially during exertion, the area under the fingernails may also be bluish in color. The best known are probably the sore throat (angina) and also scarlet fever. Both diseases start with fever and sore throat. In scarlet fever, a typical red rash appears in the groin after a few days and spreads over the whole body. In this case, treatment with antibiotics is advisable, especially because of possible late effects such as rheumatic fever and kidney damage. Meningitis can also develop from an untreated infection in the nose or throat. Immediate treatment is needed for headaches with fever and stiffness in the neck. Blood poisoning (sepsis) can also develop after injuries and surgeries due to an infection with streptococci. This is a life-threatening inflammatory reaction requiring immediate treatment.
