No, vancomycin does NOT cover Enterobacter
Vancomycin is ineffective against Enterobacter species and should not be used for wound infections growing this organism. Enterobacter is a gram-negative bacterium, and vancomycin's spectrum of activity is limited exclusively to gram-positive organisms 1.
Vancomycin's Spectrum of Activity
According to the FDA label, vancomycin is indicated specifically for:
- Methicillin-resistant staphylococci (MRSA)
- Enterococcal infections (in combination with aminoglycosides)
- Streptococcal infections
- Other gram-positive organisms 1
The drug label explicitly states vancomycin is effective for "serious or severe infections caused by susceptible strains of methicillin-resistant (β-lactam-resistant) staphylococci" and various gram-positive pathogens, with no mention of gram-negative coverage 1.
Appropriate Treatment for Enterobacter Wound Infections
For wound infections with Enterobacter (a gram-negative rod), you need antibiotics with gram-negative coverage. Based on the 2022 multidrug-resistant organism guidelines 2, appropriate options include:
For complicated skin/soft tissue infections with gram-negative organisms:
- Ceftazidime/avibactam 2.5 g IV q8h
- Imipenem/cilastatin/relebactam 1.25 g IV q6h
- Meropenem/vaborbactam 4 g IV q8h
- Aminoglycosides (gentamicin 5-7 mg/kg/day IV or amikacin 15 mg/kg/day IV)
- Fluoroquinolones (if susceptible)
The 2014 IDSA skin and soft tissue infection guidelines 3 recommend combination therapy with clindamycin or metronidazole plus an aminoglycoside or fluoroquinolone for polymicrobial infections involving gram-negative organisms.
Critical Clinical Pitfall
The most dangerous error would be continuing vancomycin monotherapy after culture results show Enterobacter growth. This provides zero antimicrobial activity against the pathogen while allowing the infection to progress. Once culture data identifies Enterobacter, immediately switch to appropriate gram-negative coverage based on susceptibility testing. If the patient is clinically unstable, consider empiric broad-spectrum coverage (such as a carbapenem or anti-pseudomonal beta-lactam) until susceptibilities return.
Vancomycin may still have a role if there is concern for concurrent gram-positive infection (such as MRSA), but it must be combined with appropriate gram-negative coverage—never used alone for Enterobacter.