From the Research
No, gram-negative bacilli are not covered by zoster (which is actually a virus, not an antibiotic) or vancomycin. Vancomycin is an antibiotic that primarily targets gram-positive bacteria such as Staphylococcus aureus (including MRSA), Streptococcus species, and Enterococcus 1. It works by inhibiting cell wall synthesis in gram-positive organisms but is ineffective against gram-negative bacilli because these bacteria have an outer membrane that prevents vancomycin from reaching its target site.
Key Points to Consider
- Vancomycin's mechanism of action and its limitations against gram-negative bacteria are crucial in understanding its ineffectiveness against these pathogens 1.
- The rising resistance of gram-negative bacilli to various antibiotics, including carbapenems, cephalosporins, and fluoroquinolones, complicates the treatment of infections caused by these bacteria 2, 3.
- For gram-negative coverage, other antibiotics such as cephalosporins (ceftriaxone, cefepime), fluoroquinolones (ciprofloxacin, levofloxacin), aminoglycosides (gentamicin, tobramycin), carbapenems (meropenem, imipenem), or piperacillin-tazobactam would be more appropriate choices.
- When treating infections that might involve both gram-positive and gram-negative organisms, combination therapy or broad-spectrum antibiotics are typically used rather than vancomycin alone.
Clinical Implications
- Clinicians must be aware of the local resistance patterns and adjust their antibiotic choices accordingly to ensure effective treatment and minimize the risk of promoting further resistance 2, 3.
- The use of vancomycin should be judicious and reserved for infections caused by gram-positive bacteria, especially in cases where resistance to other antibiotics is a concern 4, 5.