Picture 7
This picture shows Streptococcus pyogenes stained with Gram stain.
Streptococcus pyogenes
Morphology: colonies are white and shiny, Gram positive cocci arranged in chains or pairs, beta-hemolytic, catalase negative
Route of transmission: fomites
Investigations: Gram stain and culture, Anti-Streptolysin O titers
Diseases:
Pharyngitis (may cause post infectious acute rheumatic fever and glomerulonephritis)
Impetigo
Cellulitis and necrotizing fasciitis
Treatment:
Penicillin V for minor infections
IV Benzylpenicillin G for major infections
IM Benzathine penicillin G for prophylaxis of rheumatic fever
Surgical debridement in necrotizing fasciitis