What is the best course of treatment for a patient with cervical cancer and a gluteal abscess with a culture positive for Morganella morganii?

Treatment of Cervical Cancer with Gluteal Abscess and Morganella morganii Infection

Immediate Management Approach

This patient requires urgent surgical drainage of the gluteal abscess combined with targeted antibiotic therapy based on susceptibility testing, while simultaneously addressing the underlying cervical cancer and any associated immunocompromise.

The presence of Morganella morganii in a gluteal abscess in a cervical cancer patient represents a serious opportunistic infection requiring aggressive intervention. The combination of malignancy and abscess formation creates significant morbidity and mortality risk, particularly given that M. morganii infections carry a 15% mortality rate even with treatment, and up to 41% in-hospital mortality when causing bacteremia 1, 2.

Surgical Management - First Priority

Immediate surgical drainage is essential and takes precedence over antibiotic therapy alone 3:

• Perform incision and drainage of the gluteal abscess urgently
• Use multiple counter-incisions for large abscesses rather than single long incisions to prevent step-off deformity 3
• Send abscess fluid for culture and susceptibility testing, including extended cultures for acid-fast bacilli and fungi if initial cultures are negative 4
• Consider repeat debridement if clinical response is inadequate 3

Source control through drainage is critical because M. morganii is commonly part of polymicrobial infections (58% of cases) and can cause devastating outcomes without adequate surgical management 5.

Antibiotic Selection Based on Susceptibility

The optimal antibiotic regimen depends on susceptibility testing, but empiric therapy should begin immediately after cultures are obtained 6, 7:

First-Line Empiric Options (pending susceptibilities):

• Carbapenems (meropenem 1g IV every 8 hours or imipenem): Most commonly used and effective for M. morganii bacteremia with good outcomes 1, 2
• Ciprofloxacin 400mg IV every 12 hours: FDA-approved for skin and soft tissue infections caused by M. morganii and was the most frequently used single agent in case series 6, 5

Definitive Therapy Based on Susceptibilities:

• Gentamicin-based combination: Gentamicin was the most frequently used antibiotic with successful outcomes in systematic review of M. morganii invasive infections 2
• Recommended combination: Gentamicin plus third-generation cephalosporin (ceftazidime) after testing for AmpC β-lactamase production 2
• Alternative susceptible agents: Amikacin, imipenem, or ceftazidime based on susceptibility patterns 1, 2

Critical Resistance Considerations:

M. morganii frequently demonstrates resistance to ciprofloxacin, trimethoprim/sulfamethoxazole, gentamicin, amoxicillin, nitrofurantoin, and colistin 1. The organism has high potential to develop multidrug resistance, making susceptibility-guided therapy essential 2.

Duration of Antibiotic Therapy

• Minimum 2-4 weeks of IV antibiotics for deep soft tissue abscess with adequate source control 2, 5
• Continue until clinical resolution (defervescence, normalization of inflammatory markers, wound healing)
• Consider transition to oral therapy only after clinical improvement and if susceptibilities allow 5

Special Considerations for Cervical Cancer Patients

The underlying cervical cancer significantly increases infection risk and mortality 4:

• Assess degree of immunocompromise from cancer and any chemotherapy/radiation
• Patients with compromised immune systems require individualized follow-up and more aggressive management 4
• Monitor for polymicrobial infection - 58% of M. morganii infections involve multiple organisms 5
• Consider broader coverage if polymicrobial infection suspected until cultures finalize 5

High-Risk Features Requiring Intensive Monitoring

Mortality risk is substantially elevated in specific scenarios 1, 8:

• ICU admission (54% of M. morganii bacteremia cases required ICU care) 1
• Age >65 years increases mortality risk 1
• Presence of bacteremia - check blood cultures even with localized abscess 1, 8
• Co-infection with other organisms (particularly Klebsiella pneumoniae) 1
• Debilitated patients have 8% mortality even with localized infections 5

Warning Signs of Severe Disease:

• Massive hemolysis and metabolic acidosis can occur with M. morganii sepsis and is rapidly fatal 8
• Monitor hemoglobin, lactate dehydrogenase, and acid-base status closely 8
• Any signs of sepsis require immediate escalation of care 8

Common Pitfalls to Avoid

• Never use monotherapy with macrolides or single agents - promotes resistance development 3
• Do not delay surgical drainage - antibiotics alone have poor outcomes for abscesses 3, 2
• Do not assume susceptibility - M. morganii has unpredictable resistance patterns requiring testing 1, 2
• Do not overlook polymicrobial infection - obtain adequate cultures and consider anaerobic coverage 5
• Do not use ciprofloxacin empirically - high resistance rates documented 1

Monitoring Parameters

• Daily assessment of abscess drainage and wound healing
• Serial inflammatory markers (CRP, WBC) to assess treatment response 4
• Renal function monitoring with aminoglycosides 2
• Blood cultures if fever persists or patient deteriorates 1, 8
• Repeat imaging if clinical improvement not evident within 48-72 hours 4

Concurrent Cervical Cancer Management

Coordinate with oncology regarding timing of cancer treatment:

• Defer chemotherapy/radiation until infection controlled if possible
• Early-stage cervical cancer may require surgery (hysterectomy) or chemotherapy after infection resolution 4
• Address any underlying causes of immunocompromise that may have predisposed to infection 4

6, 7, 1, 2, 5, 8, 3, 4