What is the treatment plan for a 66-year-old female with Diabetes Mellitus type 2 (DM2) diagnosed with a Morganii (Proteus morganii) infection?

Treatment Plan for Morganella morganii Infection in a 66-Year-Old Female with DM2

For a 66-year-old female with diabetes mellitus type 2 and Morganella morganii infection, treatment should include gentamicin in combination with a third-generation cephalosporin, with appropriate dose adjustments for renal function. 1

Initial Assessment and Classification

• Classify the infection severity (mild, moderate, or severe) based on the presence of inflammatory signs and systemic manifestations to guide appropriate antibiotic selection 2
• Obtain proper wound cultures before starting antibiotics to guide definitive therapy 3
• Evaluate for possible osteomyelitis through imaging studies (X-ray or MRI) if deep infection is suspected 4
• Assess vascular status of the affected area, as ischemia may limit antibiotic delivery 4

Antibiotic Therapy

First-line Treatment Options

• For mild to moderate infections: Start with ceftazidime plus gentamicin 1
• For severe infections: Consider imipenem-cilastatin or piperacillin-tazobactam 2
• M. morganii is ubiquitously resistant to first-generation cephalosporins and ampicillin-clavulanate; avoid these agents 5
• Recent studies show high susceptibility to carbapenems (98.2%) and piperacillin-tazobactam (98.2%), making these excellent choices for severe infections 5

Antibiotic Considerations

• Test M. morganii isolates for production of AmpC β-lactamases which may affect third-generation cephalosporin efficacy 1
• Adjust antibiotic dosing based on the patient's renal function, which may be compromised due to age and diabetes 3
• Consider ciprofloxacin as an alternative (90% susceptibility rate), especially for step-down oral therapy 5
• If the patient has recently received antibiotics or has a history of resistant organisms, consider broader initial coverage 3

Duration of Therapy

• For mild to moderate soft tissue infections: 1-2 weeks of antibiotic therapy 3
• For severe soft tissue infections: 2-4 weeks depending on clinical response 4
• For confirmed osteomyelitis: At least 4-6 weeks of appropriate antibiotic therapy 4

Comprehensive Management

• Implement appropriate wound care including proper cleansing and debridement of necrotic tissue 3
• Ensure off-loading of pressure on the affected area to promote healing 3
• Monitor glycemic control closely, as hyperglycemia impairs immune function and wound healing 2
• Consider surgical consultation for deep abscess drainage or debridement of necrotic tissue if present 4

Monitoring Response

• Assess clinical signs of inflammation daily and monitor inflammatory markers (ESR, CRP) to evaluate treatment response 4
• If infection does not respond to initial therapy, consider:
  • Antibiotic resistance or inadequate spectrum of coverage 2
  • Undiagnosed osteomyelitis 4
  • Inadequate surgical debridement 4
  • Severe ischemia limiting antibiotic delivery 4

Special Considerations for Diabetic Patients

• M. morganii infections in diabetic patients are associated with higher mortality rates, with recent studies showing 41% in-hospital mortality 6
• Diabetes is a significant risk factor for M. morganii infections, particularly in elderly patients 5, 6
• Consider the possibility of polymicrobial infection, especially in diabetic foot ulcers 7
• Prompt diagnosis and treatment are imperative to reduce overall morbidity and mortality 7

Common Pitfalls to Avoid

• Failing to identify osteomyelitis, which requires longer treatment duration 4
• Inadequate surgical debridement of necrotic tissue 4
• Overlooking polymicrobial infections that may require broader antibiotic coverage 4
• Underestimating the severity of M. morganii infections, which have high mortality rates especially in diabetic patients 6