A 60-year-old diabetic man has a painless diabetic foot ulcer (Wagner Grade 3) with deep space infection and osteomyelitis of the 2nd metatarsal head on MRI. Initial empirical antibiotic therapy should cover which organism as the predominant pathogen?
- A Polymicrobial infection including gram-negative rods and anaerobes ✓
- B Staphylococcus aureus only
- C Pseudomonas aeruginosa only
- D Streptococcus pyogenes only
Correct answer: A. Polymicrobial infection including gram-negative rods and anaerobes
Explanation
Diabetic foot infections, especially deep space and chronic osteomyelitis cases, are typically polymicrobial. Gram-positive cocci (Staphylococcus aureus, MRSA, streptococci) dominate early infections, but chronic and deep infections also harbour gram-negative bacilli (Pseudomonas, Proteus, Enterobacter) and obligate anaerobes (Bacteroides, Peptostreptococcus), reflecting the ischemic, necrotic, and neuropathic tissue environment. Empirical broad-spectrum antibiotics covering this polymicrobial flora are required until cultures guide definitive therapy.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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