When strep make you sick

Streptococci are bacteria in the normal bacterial flora in humans. But they also play a role as pathogens - an overview

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Streptococci cause many infections, often purulent

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Streptococci are spherical bacteria that typically arrange themselves in chains or pairs. They are part of the skin and mucous membrane flora and colonize the intestines, mouth and throat and the vagina. Some streptococci can make you sick.

The genus of streptococci includes different species. They can be classified based on their ability to dissolve red blood cells (hemolysis). In the laboratory, samples of the pathogen are applied to nutrient plates (blood agar) containing blood and they are cultivated. If the streptococci partially break down the blood pigment (hemoglobin) in the red blood cells, this is known as alpha hemolysis. Since greenish products are formed during this breakdown, these bacterial strains are also called greening streptococci. For example, they are often found in the oral cavity. Beta hemolysis means that the streptococci completely break down the red blood pigment. There is no hemolysis with gamma hemolysis.

Another classification differentiates streptococci according to certain cell wall components into groups A – Q (Lancefield classification).The most medically significant streptococci include group A beta-hemolytic streptococci.

What diseases cause strep?

Group A streptococci (Streptococcus pyogenes) are often responsible for acute infections in the upper respiratory tract, for example inflammation of the middle ear, sinuses, throat or tonsils (streptococcal angina). The childhood disease scarlet fever is also caused by A streptococci, as well as skin and soft tissue infections such as erysipelas.

Group B streptococci (Streptococcus agalactiae) play a role as pathogens, especially in people with weakened immune systems and newborns. They become a risk during pregnancy, because there is a risk that the baby will be infected during the birth from the mother and, in the worst case, develop meningitis or neonatal sepsis. Antibiotic administration during childbirth can largely prevent transmission. A smear test can be used to determine whether B streptococci settle in the vagina or anus. Gynecologists recommend this preventive examination for B streptococci for all pregnant women between the 35th and 37th week of pregnancy. However, the health insurance companies do not always cover the costs. The doctor can provide information about this.

Enterococci are bacteria that used to be counted among the group D streptococci, but are now considered a separate genus of bacteria. Enterococci are typical inhabitants of the intestines and rarely cause diseases in healthy people. But they can be found, for example, as a causative agent of bladder infections.

Streptococcus pneumoniae bacteria are also called pneumococci. They colonize the nasopharynx and can cause various forms of pneumonia and other sometimes serious infections. Infants, small children and the elderly and people with weakened immune systems are particularly at risk. This also includes tumor patients and patients who have had their spleen removed. There is a vaccination against pneumococci. The Standing Vaccination Commission (STIKO) recommends it as a standard vaccination for children and for all people over 60 years of age.

Streptococci can also be involved in many other infections, for example blood poisoning (sepsis).

Secondary diseases of streptococci

A few weeks after infection with A streptococci, secondary diseases can occur. These are not caused by the bacteria, but by antibodies that were formed by the immune system against the bacteria and that are similar to the body's own structures in muscles, connective tissue or the kidneys. These antibodies mistakenly attack your own body. So it is an autoimmune disease. This includes acute rheumatic fever with possible damage to the heart valves (endocarditis) and the heart muscle (myocarditis). If the kidney is attacked, it is called glomerulonephritis.

How is strep infection diagnosed?

Infectious diseases caused by streptococci are diagnosed based on symptoms (such as scarlet fever rash) and how the disease has progressed. In addition, the pathogen can be detected directly in the laboratory, for example from a swab of the throat or a wound. If you have a sore throat (pharyngitis), a quick test for streptococci can be useful to decide whether antibiotics are necessary.

Treatment with antibiotics

Streptococcal infections can usually be treated well with antibiotics. Which antibiotic is most suitable depends on the clinical picture. Because of the risk of streptococcal secondary diseases, it is important to take antibiotics as prescribed by your doctor and not to discontinue therapy prematurely.

Important NOTE:
This article is for general guidance only and is not intended to be used for self-diagnosis or self-treatment. He can not substitute a visit at the doctor. Unfortunately, our experts cannot answer individual questions.


Robert Koch Institute: Advice on Streptocococcus pyogenes infections. Online: www.rki.de (accessed on January 22, 2019)

Federal Center for Health Education (BzgA): www.Impfen-info.de (accessed on January 22, 2019)

Common guideline of the professional association of gynecologists eV (BVF), Federal Association "The Premature Child" eV (BVDfK), German Society for Gynecology and Obstetrics (DGGG), German Society for Hygiene and Microbiology (DGHM), German Society for Pediatric Infectious Diseases (DGPI) , German Society for Perinatal Medicine (DGPM) and Society for Neonatology and Pediatric Intensive Care Medicine eV (GNPI): Prophylaxis of neonatal sepsis - early form - by streptococci of group B. Guideline 3/2016. Online: www.awmf.org/uploads/tx_szleitlinien/024-020l_S2k_Prophylaxe_Neugeborenensepsis_Streptokokken_2016-04.pdf (accessed on January 22, 2019)

Pschyrembel Clinical Dictionary. De Gruyter, Berlin 2017

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