Bloodstream Infection and Endocarditis Caused by Staphylococcus aureus in Patients with Cancer: A Multicenter Cohort Study

Retrospective study to investigate appropriate duration of antibiotic treatment for uncomplicated Staphylococcus aureus bacteremia in patients with immunodeficiency

BACKGROUND

Since the appropriate antibiotic duration for uncomplicated Staphylococcus aureus (S. aureus) bacteremia (u-SAB) in an immunocompromised state is still unclear, physicians are likely to extend antibiotic therapy from 2 weeks to 4-6 weeks. To examine the appropriate duration of antibiotic therapy for u-SAB, we performed this study.

PATIENTS AND METHODS

We reviewed all patients with u-SAB at our institute seen between January 2020 and August 2023. A total of 51 patients were enrolled, and they were divided into the following two groups by antibiotic duration: longer duration group ≥28 days after blood culture negativity, and shorter duration group. Then, the patients were matched by a propensity score using the covariates of age, sex, qSOFA, and CCI. The primary outcome was to identify the prognosis by duration of antibiotic treatment.

RESULTS

After propensity score matching, all-cause 30-day mortality was 0 % in both groups. Hence, there was no significant difference in all-cause 90 days mortality (19.0% vs 9.5%, p = 0.33) or recurrence (9.5%% vs 0%, p = 0.22). Before propensity-score matching, we found that a serum level of CRP 2.0 mg/dL and greater after intravenous antibiotic treatment was one of the poor prognostic factors. The cut-off value of serum CRP level was 2.0 mg/dL with a sensitivity of 82.1% and a specificity of 75.0%.

CONCLUSION

We suggested that 4-6 weeks of antibiotic treatment for immunodeficient u-SAB patients was unnecessary. Moreover, the serum level of CRP after completion of IV antibiotic treatment could be a prognostic marker for u-SAB.

Update on Staphylococcus aureus bacteraemia

PURPOSE OF REVIEW

To review recently published evidence relevant to Staphylococcus aureus bacteremia (SAB).

RECENT FINDINGS

Staphylococcus aureus is the most common pathogen causing co-infections and superinfections in patients with COVID-19. Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia ratios have sharply risen during the pandemic. SAB mortality is 18% at 1 month and 27% at 3 months but has gradually decreased over the last 30 years. Recurrences and reinfections are common (9%). Standardised items to define complicated SAB, and a new cut-off defining persisting bacteremia after 2 days with positive blood cultures have been proposed. Multiple antibiotic combinations have been trialled including vancomycin or daptomycin with β-lactams, fosfomycin, or clindamycin, without significant results. In the recently published guidelines, vancomycin remains the first line of treatment for MRSA bacteremia. For the management of methicillin-susceptible Staphylococcus aureus , cefazolin less frequently causes acute kidney injury than flucloxacillin, and when susceptibility is demonstrated, de-escalation to penicillin G is suggested.

SUMMARY

Our review confirms that Staphylococcus aureus represents a special aetiology among all causes of bloodstream infections. Pending results of platform and larger trials, its distinct epidemiology and determinants mandate careful integration of clinical variables and best available evidence to optimize patient outcomes.

Exebacase: A Novel Approach to the Treatment of Staphylococcal Infections

Lysins are bacteriophage-derived enzymes that degrade essential components of bacteria. Exebacase (Lysin CF-301) is an attractive antimicrobial agent because it demonstrates rapid bacteriolytic activity against staphylococcal species, including Staphylococcus aureus, has a low resistance profile, eradicates biofilms, and acts synergistically with other antibiotics. Combinations including exebacase and standard of care antibiotics represent an alternative to antibiotic monotherapies currently used to treat invasive staphylococcal infections. This manuscript reviews what is known about exebacase and explores how this novel agent may be used in the future to treat human bacterial pathogens.