C-reactive protein predicts persistent bacteremia caused by community-acquired methicillin-resistant Staphylococcus aureus strain

There is limited data on persistent bacteremia (PB) caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Here, we aimed to investigate the clinical and microbiological characteristics of PB caused by the major CA-MRSA strain in Korea (ST72-SCCmecIV). All adult patients with S. aureus bacteremia were prospectively investigated from August 2008 to December 2018. Patients with ST72 MRSA bacteremia were included in the study. Patients were stratified into the PB group (defined as positive blood cultures for ≥ 3 days) and short bacteremia (SB) group. A total of 291 patients were included, comprising 115 (39.5%) with PB and 176 (60.5%) with SB. Although the 30-day mortality did not differ between PB and SB, recurrent bacteremia within 12 weeks was significantly more common in PB (8.7% vs 1.7%; P = 0.01). Multivariate analysis showed risk factors of PB were liver cirrhosis (adjusted odds ratio [aOR], 3.27; 95% confidence interval [CI], 1.50–7.12), infective endocarditis (aOR, 7.13; 95% CI, 1.37–37.12), bone and joint infections (aOR, 3.76; 95% CI, 1.62–8.77), C-reactive protein ≥ 10 mg/dL (aOR, 2.20; 95% CI, 1.22–3.95), metastatic infection (aOR, 7.35; 95% CI, 3.53–15.29), and agr dysfunction (aOR, 2.47; 95% CI, 1.05–5.81). PB occurred in approximately 40% of bacteremia caused by ST72 MRSA with a significantly higher recurrence rate. Patients with risk factors of PB, including liver cirrhosis, high initial CRP, infective endocarditis, or bone and joint infections, might require early aggressive treatment.