The high prevalence of methicillin-resistant Staphylococcus aureus (MRSA) coupled with an increase in vancomycin use have induced vancomycin tolerance in MRSA, adversely affecting the outcome of MRSA bacteraemia. This study aimed to identify predictors of persistent MRSA bacteraemia (PMRSAB) in patients treated with vancomycin. A retrospective, case-control study was performed at a university hospital in Korea from January 2006 to February 2009. Subjects included 96 patients who had MRSA bacteraemia and received vancomycin under therapeutic drug monitoring. We compared the clinical characteristics, management and outcomes of cases with PMRSAB (≥7 days, n = 31) with controls with non-PMRSAB (≤3 days, n = 32). Vancomycin MICs were determined by the Vitek 2 system. Of 96 patients with MRSA bacteraemia, MRSA isolates from 21 patients (21.9%) showed a vancomycin MIC of 2 mg/L. Independent predictors of PMRSAB were: retention of implicated medical devices [odds ratio (OR), 10.35; 95% confidence interval (CI), 1.03–104.55]; MRSA infection of at least two sites (OR, 10.24; 95% CI, 1.72–61.01); and vancomycin MIC of 2 mg/L (OR, 6.34; 95% CI, 1.21–33.09). The frequency of side effects and mean trough serum vancomycin concentrations were not significantly different between the two groups. Sixteen patients with PMRSAB subsequently received teicoplanin ± arbekacin, linezolid or quinupristin/dalfopristin, due to vancomycin failure or intolerance. To minimize the risk of PMRSAB, early removal of implicated devices and evaluation for metastatic infections should be encouraged. Alternative antibiotic therapy is warranted for infections due to isolates with elevated vancomycin MICs, as well as for the high rates of side effects.

To evaluate the effects of transfusions in patients with severe sepsis and septic shock on mortality. Propensity-matched analysis of a prospective observational database (April 2005 to February 2009). Twenty-two medical and surgical intensive care units in 12 teaching hospitals in Korea. One thousand fifty-four patients with community-acquired severe sepsis and septic shock. None. Of the 1,054 patients, 407 (38.6%) received a blood transfusion. The mean pretransfusion hemoglobin level was 7.7 ± 1.2 g/dL. Transfused patients had higher 28-day and in-hospital mortality rates (32.7% vs. 17.3%; p < .001, 41.3% vs. 20.3%; p < .001, respectively) and a longer duration of hospital stay (21 [interquartile range, 10-35] vs. 13 [interquartile range, 8-24] days; p < .001), but were more severely ill at admission (lower systolic blood pressure, higher Acute Physiology and Chronic Health Evaluation II score, and Sequential Organ Failure Assessment score at admission). In 152 pairs matched according to the propensity score depending on patient transfusion status, transfused patients had a lower risk of 7-day (9.2% vs. 27.0%; p < .001), 28-day (24.3% vs. 38.8%; p = .007), and in-hospital mortality rates (31.6% vs. 42.8%; p = .044). After adjusting for blood transfusion as a time-dependent variable in multivariable analysis, blood transfusion was independently associated with lower risk of 7-day (hazard ratio 0.42, 95% confidence interval 0.19-0.50, p = .026), 28-day (hazard ratio 0.43, 95% confidence interval 0.29-0.62, p < .001), and in-hospital mortality (hazard ratio 0.51, 95% confidence interval 0.39-0.69, p < .001). In this observational study of patients with community-acquired severe sepsis and septic shock, red blood cell transfusions were associated with lower risk of mortality.

Yoon YK, et al. Infect Chemother. 2021 Sep;53(3):617-659. https://doi.org/10.3947/ic.2021.0098

The time to positivity (TTP) of blood cultures is associated with the microbial load in the blood and prognosis in patients with bloodstream infections caused by various bacterial species. However, relevant information about the TTP for Candida species in candidaemia is limited. We investigated the clinical impact of the TTP on mortality in patients with candidaemia. All consecutive patients ≥18 years of age with candidaemia between January 2006 and July 2012 were included. The demographics, clinical and microbiological characteristics, antifungal treatment and outcomes of the patients were collected retrospectively. A total of 152 patients were identified. The overall mortality rate at 6 weeks was 53%. The median TTP for Candida isolates was 27 h (IQR 19–37 h). A TTP of ≤24 h was significantly related to a higher mortality rate (P = 0.021). In a multivariate Cox regression analysis, the Charlson comorbidity index value [adjusted hazard ratio (HR) 1.15, 95% CI 1.02–1.29, P = 0.018], sequential organ failure assessment score (adjusted HR 1.23, 95% CI 1.13–1.34, P < 0.001), TTP ≤24 h (adjusted HR 2.74, 95% CI 1.51–4.97, P = 0.001), timing of appropriate antifungal therapy >72 h (adjusted HR 2.38, 95% CI 1.26–4.51, P = 0.008) and persistent candidaemia (adjusted HR 2.50, 95% CI 1.33–4.72, P = 0.005) were independently associated with the 6 week mortality rate. A short TTP (≤24 h) for Candida species was independently associated with increased mortality in patients with candidaemia. Additional studies on the relevance of the TTP to clinical outcome in patients with candidaemia are needed.

Kim JY, et al. Infect Chemother. 2023 Jan;55:e1. https://doi.org/10.3947/ic.2022.0145

Yoon YK, et al. Infect Chemother. 2017 Dec;49(4):326-352. https://doi.org/10.3947/ic.2017.49.4.326