Streptococci

Key points

• Streptococci are gram-positive cocci. They may be divided into alpha and beta haemolytic types Alpha haemolytic streptococci (partial haemolysis) The most important alpha haemolytic Streptococcus is Streptococcus pneumoniae…
• most important organism is Streptococcus pyogenes
• responsible for erysipelas, impetigo, cellulitis, type 2 necrotizing fasciitis and pharyngitis/tonsillitis
• immunological reactions can cause rheumatic fever or post-streptococcal glomerulonephritis
• erythrogenic toxins cause scarlet fever Group B