What is the treatment for Kocuria kristinae (a type of bacteria) isolated from an aerobic bottle blood culture?

Treatment of Kocuria kristinae Bacteremia

Kocuria kristinae isolated from blood culture should be treated as a true pathogen when found in immunocompromised patients, those with indwelling catheters, or when isolated from multiple blood culture sets, with vancomycin as the preferred initial therapy. 1, 2

Initial Assessment: Contamination vs. True Infection

Determine clinical significance before initiating treatment:

• True bacteremia is likely when K. kristinae grows in multiple blood culture sets from separate venipuncture sites, or when isolated from both blood and catheter tip simultaneously 3, 2
• Contamination is more likely when only a single blood culture set is positive, particularly if the patient has other recognized infections and lacks clinical signs of sepsis 2
• High-risk patients include premature infants, immunocompromised hosts (malignancy, chemotherapy), and those with long-term central venous catheters 4, 2, 5

Recommended Antibiotic Therapy

First-line treatment:

• Vancomycin is the most effective agent with highest susceptibility rates and should be used as initial parenteral therapy 1
• Combination therapy with vancomycin plus another susceptible antibiotic is recommended for initial treatment 1
• Alternative agents with high susceptibility include linezolid, rifampicin, teicoplanin, tigecycline, cefotaxime, ampicillin/sulbactam, minocycline, and meropenem 1

Treatment duration:

• 14-16 days of parenteral therapy has been successful in documented cases 4
• Adjust based on clinical response and source control measures 4

Source Control Considerations

Catheter management is critical:

• Remove or replace central venous catheters when K. kristinae is isolated from catheter-drawn blood cultures, especially if catheter-related bloodstream infection is suspected 4, 2
• Ethanol lock therapy (5 days) can be considered as adjunctive treatment for catheter salvage in select cases 4
• Culture the catheter tip if removed to confirm catheter-related infection 2

Important Caveats

Resistance patterns are concerning:

• Universal resistance to penicillin and oxacillin has been documented in recent isolates 5
• Do not use penicillin or oxacillin as empiric therapy 5
• Obtain susceptibility testing for all isolates to guide definitive therapy, as resistance patterns are evolving 5

Clinical pitfalls to avoid:

• Do not dismiss as contaminant in immunocompromised patients or those with indwelling catheters, even if only one culture is positive 2, 5
• Repeat blood cultures from separate peripheral venipuncture sites (at least 2 sets of 20-30 mL each) if contamination is suspected but clinical sepsis is present 6, 3
• Misidentification risk: K. kristinae resembles coagulase-negative staphylococci and requires proper identification systems (VITEK 2 or equivalent) 5, 7

Monitoring and Follow-up

Treatment is almost universally effective:

• Mortality is rare with appropriate antibiotic therapy, with only one death reported in systematic review 1
• Repeat blood cultures after 48-72 hours of therapy to document clearance 4
• Monitor clinical response including resolution of fever and improvement in inflammatory markers 4