Streptococcus

• Streptococcus pyogenes, also known as Group A streptococcus, is the causative agent of acute tonsilitis, pyogenic tissue inflammations, and phlegmon.
• Erythrogenous toxin, produced by Streptococcus pyogenes, causes scarlatina, scarlatiniform tonsilitis, and erysipelas.
• Streptococcus pyogenes can be infected by a bacteriophage, becoming a meat-eating bug and causing Necrotizing fasciitis.
• Sequels of Streptococcus pyogenes infection include acute glomerulonephritis and rheumatic fever.
• Streptococcus agalactiae, also known as Group B streptococcus, infects lower parts of the body, including the urogenital tract, with a risk of newborn infection.
• Streptococcus agalactiae is the causative agent of neonatal meningitis and sepsis.
• Streptococcus pneumoniae, also known as pneumococcus, is a diplococcus that does not form chains, but couples, and its shape is not perfectly spherical, but lancet shaped.
• Streptococcus pneumoniae causes pneumonia, sinusitis, otitis media, and even sepsis and meningitis.
• Penicillin is used in the form of G-penicillin for parenteral use and V-penicillin for oral use.
• Vancomycin is a 100% effective antibiotic and is used as a reserve.
• Cultivation on BA grey to colorless colonies, usually small, larger colonies indicate Streptococcus agalactiae.
• Amikacin is a selective medium for streptococci and enterococci, they are resistant to aminoglycosides.
• Streptococci do not grow on BA with 10 % NaCl, nor on Slanetz-Bartley or Bile aesculin medium.
• Diffusion disk test is performed by measuring the zones and comparing with the reference zones.
• Hemolysis classifies streptococci into haemolytical, viridating and others.
• Catalase is + in staphylo, - in strepto.
• Amoxicillin, ampicillin, and others are used as alternatives to penicillin.
• Streptococcus pneumoniae is present in the healthy people's pharynx.
• Doxycyklin, co-trimoxazol, ampicilin and others might be used as alternatives to macrolides.
• Optochin test is used to distinguish Pneumococcus from oral streptococci, it is also a test of solubility in powder bile.
• The worse pathogen, pyogenic streptococcus, is more susceptible than milder pathogens.
• Antigen analysis helps in hemolytic streptococci.
• Macrolides are used in PNC-allergic persons only.
• Lancefield system is an antigen analysis, mainly for non- A, non- B S. Theoretically all streptococci are involved, but many viridans streptococci have no antigen in this system.
• Biochemical differentiation of individual species is possible especially in viridating streptococci.
• Enterococci are positive in PYR-test while the streptococci grow on SB and BE media.
• Microscopy identifies G+ cocci as streptococci.
• Gram stain shows all bacteria, that do not belong among G+ cocci.
• Biochemical tests for streptococci show both catalase and oxidase.
• Pneumococcus is susceptible to optochin (ATB), oral streptococci are resistant.
• Sometimes test of solubility in powder bile is used.
• Streptococcus pneumoniae has optional vaccinations.
• Viridans streptococci, alpha streptococci, and oral streptococci are all names that describe streptococci viridating on blood agar.
• Viridans streptococci, alpha streptococci, and oral streptococci are part of normal oral and pharyngeal flora.
• Latex agglutination is used for detailed diagnostics of non-A-non-B streptococci, with the agglutination of streptococci with the antibody helped by latex particles.
• The values of dilution in ASO are in a table, with titre over cca 250 indicating a risk of antibody response.
• Pyogenes is a type of hemolytic streptococci, and the PYR test is used to identify it.
• A reagent is added, and another minute of waiting follows.
• Anti-Streptolysin O (ASO) is used to detect a normal antibody response or an autoimmunity over-response with risk of development of glomerulonephritis/rheumatic fever.
• The Bacitracin test is similar to the Optochin test, using another antibiotic.