From the Guidelines
For a patient with 50,000-100,000 CFU/mL of coagulase-negative Staphylococcus (CoNS) in a blood culture, the most appropriate management is to remove the catheter and treat with antibiotics for 5-7 days if the catheter is removed, or for 10-14 days with antibiotic lock therapy if the catheter is retained 1. This approach is based on the most recent and highest quality evidence available, which prioritizes the management of catheter-related bloodstream infections (CRBSI) due to CoNS. The diagnosis of CRBSI due to CoNS should be based on multiple positive blood cultures, including one drawn from a peripheral vein, and the presence of symptoms such as fever or inflammation at the catheter exit site 1. Some studies suggest that CoNS infections may resolve with removal of the catheter without antibiotic therapy, but many experts recommend treating these infections with antibiotics to prevent complications such as sepsis or endocarditis 1. The choice of antibiotic therapy should be based on susceptibility testing, but common options include vancomycin, daptomycin, or other agents effective against CoNS 1. It is essential to correlate laboratory findings with clinical presentation before initiating treatment for CoNS in blood cultures, as CoNS are common skin flora and can contaminate blood samples during collection. In general, the management of CRBSI due to CoNS should prioritize the removal of the catheter, appropriate antibiotic therapy, and close monitoring for signs of complications or treatment failure.
Key considerations in the management of CRBSI due to CoNS include:
- Removal of the catheter as soon as possible to prevent further infection and complications
- Initiation of antibiotic therapy based on susceptibility testing and clinical presentation
- Use of antibiotic lock therapy for retained catheters to prevent recurrence of infection
- Close monitoring for signs of complications, such as sepsis or endocarditis, and adjustment of treatment as needed
- Correlation of laboratory findings with clinical presentation to ensure appropriate management and prevent unnecessary treatment.
Overall, the management of CRBSI due to CoNS requires a comprehensive approach that prioritizes catheter removal, appropriate antibiotic therapy, and close monitoring for complications, with the goal of reducing morbidity, mortality, and improving quality of life for affected patients.
From the Research
Coagulase-Negative Staphylococci
- Coagulase-negative staphylococci (CoNS) are a heterogeneous group of Gram-positive cocci that are widespread commensals among mammals 2
- They can cause infections in normal host tissue and are opportunists that display adherence to medical device materials to produce a protective biofilm 2
- CoNS have historically been more resistant to antimicrobials, including beta-lactam antibiotics, than Staphylococcus aureus 2
Antibiotic Resistance
- CoNS have emerged as important nosocomial pathogens with high resistance rates to multiple antimicrobial agents 3
- The prevalence of strains non-susceptible to teicoplanin has increased, and potentially vancomycin-resistant subpopulations have been selected from teicoplanin-non-susceptible strains 3
- Newer antimicrobial agents, such as daptomycin, linezolid, and tigecycline, have excellent antistaphylococcal activity and may be effective against CoNS infections 4, 2
Clinical Significance
- CoNS are among the most frequently recovered bacteria in routine clinical care, and their incidence has steadily increased over the past decades 5
- They play a prominent role in infections in preterm neonates, patients with implanted medical devices, immunodeficient patients, and those with other relevant comorbidities 5
- The main diagnostic hurdle is to correctly identify cases in which CoNS are causative agents rather than contaminants, and true infections often necessitate the use of second-line antimicrobial drugs 5
Species Distribution
- The distribution of CoNS species can vary, with Staphylococcus epidermidis and Staphylococcus saprophyticus being the most common species isolated from urine specimens 6
- Other species, such as Staphylococcus haemolyticus, Staphylococcus warneri, and Staphylococcus schleiferi, can also be isolated from clinical specimens 6, 4