Final answer:
Necrotizing fasciitis is a severe infection that can be caused by various bacteria, including S. pyogenes and S. aureus. Empiric antibiotic therapy is typically initiated, but its effectiveness may be limited due to bacterial toxins and antibiotic resistance.
Step-by-step explanation:
Necrotizing fasciitis is a severe infection of the fascia, a connective tissue layer between the skin and muscles. The causative agents of necrotizing fasciitis can include Streptococcus pyogenes, Klebsiella, Clostridium, Escherichia coli, Staphylococcus aureus, and Aeromonas hydrophila. When necrotizing fasciitis is diagnosed, empiric antibiotic therapy is usually initiated to help minimize the risk of complications like sepsis. However, the effectiveness of intravenous antibiotics may be limited due to genetically encoded bacterial toxins and the presence of antibiotic-resistant strains of bacteria, such as methicillin-resistant S. aureus (MRSA).