Does Vancomycin cover Klebsiella?

Vancomycin Does Not Cover Klebsiella

Vancomycin does not provide coverage against Klebsiella species or other gram-negative bacteria. 1 Vancomycin is a glycopeptide antibiotic with activity limited to gram-positive organisms, making it ineffective against Klebsiella, which is a gram-negative bacterium.

Spectrum of Activity of Vancomycin

• Vancomycin is active against gram-positive organisms only, including staphylococci (including MRSA), streptococci, enterococci, and certain gram-positive bacilli 2, 3
• Vancomycin works by inhibiting the second stage of cell wall synthesis in susceptible bacteria, which is not effective against the cell wall structure of gram-negative organisms like Klebsiella 3
• Klebsiella species, being gram-negative bacteria, have an outer membrane that prevents vancomycin from reaching its site of action 1

Appropriate Antibiotics for Klebsiella Coverage

• For Klebsiella species, appropriate antibiotic choices include:

  • Cephalosporins (particularly cefepime for non-ESBL producing strains) 1
  • Carbapenems (imipenem, meropenem) which are effective against ESBL-producing Klebsiella 1
  • Piperacillin-tazobactam as part of broad-spectrum coverage 1
  • Aminoglycosides (though not recommended as monotherapy) 1

• For carbapenemase-producing Klebsiella (KPC), options are more limited:

  • Colistin or tigecycline may be required for treatment 1
  • These strains are resistant to all β-lactam antibiotics 1

Clinical Implications

• When treating suspected Klebsiella infections, appropriate empiric therapy should include antibiotics with gram-negative coverage 1
• Vancomycin should only be added to a regimen when there are specific indications for gram-positive coverage, such as:
  • Hemodynamic instability or severe sepsis 1
  • Suspected catheter-related infections 1
  • Positive blood cultures for gram-positive bacteria 1
  • Known colonization with resistant gram-positive organisms 1

Common Pitfalls to Avoid

• Adding vancomycin unnecessarily to treatment regimens can lead to:

  • Development of drug resistance in Enterococcus species and S. aureus 1
  • Potential nephrotoxicity and other adverse effects 4
  • No improvement in outcomes for infections caused by gram-negative organisms like Klebsiella 1

• For empiric coverage of suspected gram-negative infections, appropriate monotherapy options include:

  • Cefepime 1
  • Carbapenems (imipenem-cilastatin or meropenem) 1
  • Piperacillin-tazobactam 1

Special Considerations

• In cases of mixed infections where both gram-positive and gram-negative coverage is needed, vancomycin would need to be combined with appropriate gram-negative agents 1
• Recent research has explored novel formulations combining vancomycin with other agents to enhance activity against resistant gram-negative bacteria, but these are experimental and not standard of care 5
• Oral vancomycin treatment can disrupt intestinal microbiota and potentially increase susceptibility to colonization by Klebsiella pneumoniae 6