What is the treatment for a tracheostomy site infection caused by Morganella morganii and Klebsiella pneumoniae?

Treatment for Tracheostomy Site Infection with Morganella morganii and Klebsiella pneumoniae

For tracheostomy site infection caused by Morganella morganii and Klebsiella pneumoniae, the recommended treatment is piperacillin-tazobactam or an antipneumococcal, antipseudomonal β-lactam (such as cefepime, imipenem, or meropenem) with or without an aminoglycoside. 1, 2

Antimicrobial Selection

First-line Options:

• Piperacillin-tazobactam: FDA-approved for skin and skin structure infections caused by Morganella morganii and Klebsiella pneumoniae 2
• Carbapenems (imipenem or meropenem): Effective against both organisms, especially in cases with suspected ESBL-producing Klebsiella 1
• Cefepime: Appropriate for both pathogens when ESBL production is not suspected 1

Alternative Options (based on susceptibility):

• Aminoglycosides: Amikacin or gentamicin may be effective based on susceptibility testing 3, 4
• Fluoroquinolones: Ciprofloxacin or levofloxacin can be considered if susceptible, but should be avoided if there's high local resistance 5, 6

Treatment Algorithm

1. Initial empiric therapy:

   • Start with piperacillin-tazobactam or a carbapenem
   • Consider adding an aminoglycoside if severe infection or sepsis is present

2. Adjust therapy based on culture and susceptibility results:

   • De-escalate to narrower spectrum antibiotics when possible
   • For ESBL-producing Klebsiella: maintain carbapenem therapy
   • For AmpC-producing Morganella: avoid third-generation cephalosporins

3. Duration of therapy:

   • 7-10 days for uncomplicated infections
   • 10-14 days for more severe infections

Local Wound Care

In addition to systemic antibiotics, proper tracheostomy care is essential:

• Use aseptic technique when changing the tracheostomy tube 7
• Replace with a tube that has undergone sterilization or high-level disinfection 7
• Use sterile saline for cleaning the site
• Consider more frequent tracheostomy tube changes during active infection

Special Considerations

For Multidrug-Resistant Organisms:

• Morganella morganii can develop resistance through AmpC β-lactamase production 4
• Klebsiella pneumoniae may produce ESBLs or carbapenemases 1
• If carbapenem-resistant Klebsiella is present, consider ceftazidime-avibactam 1

Biofilm Considerations:

• Both organisms can form biofilms on tracheostomy tubes 3
• Consider tracheostomy tube replacement to eliminate biofilm reservoir
• Amikacin and gentamicin have shown better activity against biofilm-producing organisms in tracheostomy tubes 3

Monitoring and Follow-up

• Assess clinical response within 48-72 hours
• Monitor for signs of respiratory distress or mucus plugging 7
• Follow-up cultures may be needed if clinical improvement is not observed
• Be vigilant for complications such as bleeding or tracheal stenosis 7

Common Pitfalls to Avoid

1. Inadequate source control: Failure to replace the tracheostomy tube can lead to persistent infection due to biofilm formation
2. Inappropriate antibiotic selection: Morganella is intrinsically resistant to ampicillin and many first-generation cephalosporins
3. Monotherapy for polymicrobial infections: These infections often require combination therapy initially
4. Prolonged broad-spectrum therapy: De-escalate based on culture results to prevent further resistance

Tracheostomy site infections with these organisms require prompt and appropriate antimicrobial therapy along with meticulous local care to prevent complications and ensure optimal outcomes.