streptokokkeryhmät

Streptokokkeryhmät, often referred to as streptococci, are a genus of Gram-positive, spherical bacteria. They are known for their tendency to form chains or pairs, a characteristic that gives them their name, derived from the Greek word "streptos" meaning twisted. These bacteria are ubiquitous in nature and are commonly found in the oral cavity, gastrointestinal tract, and on the skin of humans and animals. While many streptococci are harmless commensals, some species are significant human pathogens, causing a wide range of infections.

Streptococci are often classified into groups based on specific carbohydrate antigens in their cell walls, known as Lancefield groups. The most medically significant groups include Group A Streptococcus (GAS), primarily Streptococcus pyogenes, which is responsible for strep throat, scarlet fever, and skin infections like impetigo. Group B Streptococcus (GBS), or Streptococcus agalactiae, can cause serious infections in newborns, such as pneumonia, meningitis, and sepsis, as well as infections in pregnant women. Other important groups include Group D Streptococcus, which can be associated with urinary tract infections and endocarditis, and Viridans streptococci, typically found in the mouth and sometimes implicated in subacute bacterial endocarditis. Diagnosis of streptococcal infections usually involves culturing samples from infected sites, and antibiotic treatment is the primary therapeutic approach. Prevention strategies often focus on good hygiene practices.