What is the treatment for coagulase-negative (CoNS) staph infections?

From the Guidelines

The treatment for coagulase-negative staphylococcal (CoNS) infections typically involves antibiotics, with vancomycin being the first-line therapy for most serious infections, as recommended by the most recent guidelines 1.

Treatment Approach

The approach to treating CoNS infections depends on the severity and location of the infection. For uncomplicated catheter-related bloodstream infections (CRBSI), treatment with antibiotics for 5–7 days if the catheter is removed and for 10–14 days, in combination with antibiotic lock therapy, if the catheter is retained is recommended 1.

Antibiotic Selection

Vancomycin is usually administered at 15-20 mg/kg IV every 8-12 hours, with dose adjustments based on renal function and drug levels. Alternative options include daptomycin (6-10 mg/kg IV daily), linezolid (600 mg IV/oral twice daily), or teicoplanin (400 mg IV every 12 hours for 3 doses, then 400 mg daily) 1.

Treatment Duration

Treatment duration generally ranges from 7-14 days for uncomplicated infections to 4-6 weeks for more severe cases like endocarditis or osteomyelitis. For device-related infections, removal of the infected foreign body (such as catheters or implants) is often necessary alongside antibiotic therapy for complete resolution 1.

Considerations

Antibiotic selection should ultimately be guided by susceptibility testing, as CoNS frequently exhibit methicillin resistance and variable susceptibility to other antibiotics. The effectiveness of treatment stems from targeting the bacterial cell wall (vancomycin, teicoplanin) or protein synthesis (linezolid), while considering the biofilm-forming capability of CoNS that can complicate eradication, particularly in device-associated infections 1. Some key points to consider in the treatment of CoNS infections include:

• The importance of removing infected devices or foreign bodies to prevent recurrence and promote healing
• The need for susceptibility testing to guide antibiotic selection
• The potential for biofilm formation and its impact on treatment efficacy
• The variation in treatment duration based on the severity and location of the infection
• The role of combination therapy in certain cases, such as endocarditis or osteomyelitis 1.

From the Research

Treatment Options for Coagulase-Negative Staph Infections

• The treatment of coagulase-negative staph (CoNS) infections often involves the use of antibiotics, with vancomycin being a commonly used option 2, 3, 4, 5.
• However, the emergence of vancomycin-resistant CoNS strains has become a concern, and alternative antibiotics such as daptomycin, linezolid, and teicoplanin are being considered 2, 5, 6.
• Daptomycin has shown high efficacy against CoNS strains, with no resistance observed in some studies 5.
• Linezolid has also been effective, but the massive and continuous use of this antibiotic has led to the emergence of resistance 5.
• Teicoplanin-non-susceptible CoNS strains with inducible resistance to vancomycin have also been reported, highlighting the need for vigilant surveillance of nosocomial isolates of CoNS 6.

Antibiotic Susceptibility Patterns

• CoNS strains have shown varying levels of resistance to different antibiotics, including:
  • High resistance to penicillin G, oxacillin, and erythromycin 6.
  • Medium resistance to tetracycline, clindamycin, ciprofloxacin, trimethoprim/sulfamethoxazole, and chloramphenicol 6.
  • Low resistance to rifampicin, ceftizoxime, and gentamicin 6.
• The susceptibility patterns of CoNS strains to vancomycin and other antibiotics can vary depending on the species and strain, highlighting the need for antibiotic susceptibility testing to guide treatment decisions 2, 3, 5.

Clinical Implications

• The clinical impact of vancomycin MICs on outcomes in patients with CoNS bloodstream infections has been studied, with no significant difference in mortality observed between patients with vancomycin MICs <2 µg/mL and those with MICs ≥2 µg/mL 3.
• However, CoNS strains with vancomycin MICs ≥2 µg/mL were more likely to be oxacillin resistant, highlighting the need for careful consideration of antibiotic treatment options 3.