OUTPATIENT MANAGEMENT OF CARBAPENEM-RESISTANT Escherichia coli DIABETIC FOOT INFECTION WITH ORAL MINOCYCLINE: A CASE REPORT FROM KING HUSSEIN MEDICAL CENTER

Background: Diabetic foot infections (DFIs) are a significant clinical problem especially in patients with long-standing diabetes and multiple comorbidities. Carbapenem-resistant Escherichia coli (CREC) has emerged as a concerning pathogen in diabetic foot infections (DFIs) that historically have necessitated hospitalization for intravenous (IV) therapy with agents like colistin, tigecycline, or combination regimens. Hospitalization is associated with the risk of nosocomial infection, venous access problems, functional decline, and high healthcare costs, particularly in elderly patients with multiple comorbidities. In this context, oral agents with good bioavailability and activity against Gram-negative pathogens such as minocycline are still underinvestigated. We report a case of a novel approach to management of CREC diabetic foot osteomyelitis in a high-risk elderly patient with oral minocycline as an alternative to injectable colistin.
Case Presentation: We present a 63-year-old man with a 15-year history of type 2 diabetes mellitus (T2DM), hypertension, chronic kidney disease (CKD) stage 3, peripheral vascular disease (PVD), and prior myocardial infarction (age-adjusted Charlson Comorbidity Index [CCI] of 8) who presented with a non-healing right foot plantar ulcer. Clinical examination revealed a 4.5 × 3.0 cm ulcer extending to bone (probe-to-bone positive), with surrounding erythema and purulent drainage. There were no systemic signs of sepsis. Deep tissue cultures obtained during surgical debridement grew carbapenem-resistant E. coli (non-susceptible to meropenem, ertapenem, ceftriaxone, ciprofloxacin, and trimethoprim-sulfamethoxazole) that was susceptible to minocycline (MIC ≤4 µg/mL). Given the patient's clinical stability, adequate perfusion (ankle-brachial index [ABI] = 0.98), successful source control, and preference to avoid hospitalization, he was initiated on outpatient oral minocycline 100 mg twice daily for 6 weeks, combined with total contact casting (TCC) for offloading and weekly multidisciplinary wound care.
Outcomes: The person took minocycline by mouth for 6 weeks and had no bad effects from it. The wound was checked several times and it healed slowly but surely and by week 10 the epithelium was fully covered. The level of inflammatory markers went back to normal (CRP went from 48 mg/L to 6 mg/L). The renal function stayed the same (creatinine 1.4–1.5 mg/dL). No one had to go to the hospital during the treatment. There were no signs of recurrence at the 3-month follow-up.
Conclusions: This case highlights that selected patients with CREC diabetic foot infections can be successfully managed in the outpatient setting with oral minocycline as an alternative to injectable colistin. This method might cut healthcare expenses, prevent the use of intravenous antibiotics in hospitals on patients and avoid nephrotoxicity related to colistin in fragile patients. More research is needed to define the best ways to manage it.