Defining the Breakpoint Duration of Staphylococcus aureus Bacteremia Predictive of Poor Outcomes

Early initiation of ceftaroline-based combination therapy for methicillin-resistant Staphylococcus aureus bacteremia

PURPOSE

Monotherapy with vancomycin or daptomycin remains guideline-based care for methicillin-resistant Staphylococcus aureus bacteremia (MRSA-B) despite concerns regarding efficacy. Limited data support potential benefit of combination therapy with ceftaroline as initial therapy. We present an assessment of outcomes of patients initiated on early combination therapy for MRSA-B.

METHODS

This was a single-center, retrospective study of adult patients admitted with MRSA-B between July 1, 2017 and April 31, 2023. During this period, there was a change in institutional practice from routine administration of monotherapy to initial combination therapy for most patients with MRSA-B. Combination therapy included vancomycin or daptomycin plus ceftaroline within 72 h of index blood culture and monotherapy was vancomycin or daptomycin alone. The primary outcome was a composite of persistent bacteremia, 30-day all-cause mortality, and 30-day bacteremia recurrence. Time to microbiological cure and safety outcomes were assessed. All outcomes were assessed using propensity score-weighted logistic regression.

RESULTS

Of 213 patients included, 118 received monotherapy (115 vancomycin, 3 daptomycin) and 95 received combination therapy with ceftaroline (76 vancomycin, 19 daptomycin). The mean time from MRSA-positive molecular diagnostic blood culture result to combination therapy was 12.1 h. There was no difference between groups for the primary composite outcome (OR 1.58, 95% CI 0.60, 4.18). Time to microbiological cure was longer with combination therapy (mean difference 1.50 days, 95% CI 0.60, 2.41). Adverse event rates were similar in both groups.

CONCLUSIONS

Early initiation of ceftaroline-based combination therapy did not improve outcomes for patients with MRSA-B in comparison to monotherapy therapy.

Risk Factors for Infection-Attributable Mortality in Patients With Staphylococcus aureus Bacteremia: A Competing Risk Analysis

Background

Identifying risk factors for mortality in patients with Staphylococcus aureus bacteremia (SAB) is crucial due to its high fatality. However, data on risk factors for infection-attributable deaths considering competing risk events such as non-infection-attributable deaths remain limited. We performed a competing risk analysis to elucidate risk factors associated with 30-day infection-attributable mortality in a large cohort of patients with SAB.

Methods

This retrospective cohort study included adult patients diagnosed with SAB at a tertiary hospital from August 2008 to December 2019. Competing risk analysis was performed using Fine and Gray models to estimate subdistribution hazard ratios (sHRs) for 30-day infection-attributable death.

Results

Among 1936 patients, 444 (22.9%) died within 30 days. Of these, 338 (76.1%) were infection-attributable and 106 (23.9%) were non-infection-attributable deaths. The multivariable Fine and Gray model identified significant risk factors for 30-day infection-attributable death (sHRs with 95% confidence intervals): an increase in age by 10 years (1.14 [1.02-1.26]), presence of malignancy (1.54 [1.17-2.02]), liver cirrhosis (2.15 [1.56-2.97]), corticosteroid use (1.61 [1.19-2.17]), septic shock (3.28 [1.98-5.42]), elevated C-reactive protein (1.60 [1.19-2.14]), pneumonia (1.81 [1.21-2.72]), persistent bacteremia (1.73 [1.31-2.30]), and failure to remove the eradicable focus (2.40 [1.38-4.19]) or absence of an eradicable focus (1.49 [1.08-2.04]). Except for age and malignancy, these factors were not significantly associated with non-infection-related death.

Conclusions

Specific risk factors for infection-attributable death in patients with SAB were identified, distinct from those for nonattributable death. These findings can aid in the early identification of patients at risk for SAB-attributable mortality.

Novel Epigallocatechin Gallate (EGCG) Analogs with Improved Biochemical Properties for Targeting Extracellular and Intracellular Staphylococcus aureus

Staphylococcus aureus is a leading cause of bloodstream infection (SAB), with up to 30% mortality. Despite treatment with standard antibiotics, one in three patients develops a persistent infection, which portends a five-fold increase in the risk of death. Persistent SAB has been attributed in part to the inability of antistaphylococcal antibiotics to eradicate intracellular S. aureus surviving inside macrophages. (-)- Epigallocatechin gallate (EGCG) is a catechin found in green tea that has been widely studied for its broad biological activities, ranging from anticancer to antibacterial activity. However, EGCG is greatly limited by its poor drug-like properties in terms of stability, membrane permeability, and bioavailability. In this study, we established through a series of in vitro experiments that structural modifications of EGCG enhanced drug-like properties while maintaining or improving its antistaphylococcal activity. Our lead EGCG analogs (MCC-1 and MCC-2) showed improved biochemical properties along with increased potency against extracellular S. aureus and restored susceptibility of β-lactam agents to methicillin-resistant S. aureus (MRSA). Importantly, the lead analogs but not EGCG potentiated macrophage- and antibiotic-mediated clearance of intracellular bacteria. Overall, EGCG analogs showed promise for further development as adjunctive therapy candidates for the treatment of SAB.

Improving Turnaround Times for Routine Antimicrobial Sensitivity Testing Following European Committee on Antimicrobial Susceptibility Testing Methodology in Patients with Bacteraemia

Background/Objectives: Bacteraemia can be fatal without antibiotic intervention. Antibiotic Susceptibility Testing (AST) provides the necessary information for targeted antibiotic therapy; however, the traditional method using disc diffusion can take over two days from a positive blood culture. Inappropriate empiric therapy is associated with increased mortality and increased antibiotic resistance, highlighting the need for more rapid turnaround times for AST. By making changes to an established method, turnaround times can be reduced. Methods: Eighty-two patient positive blood culture samples were collected from January to April 2022, representing the range of common bacteria causing sepsis. This followed the normal methodology in the laboratory of inoculating agar from positive blood cultures in preparation for European Committee on Antimicrobial Susceptibility Testing (EUCAST) disc diffusion AST method. EUCAST methodology outlines that disc diffusion should be performed on isolates from an overnight culture of 16-24 h. This study looked at comparing disc diffusion results from cultures with 6 h of incubation to those with incubation times of 24 h, after organism identification by MALDI-ToF. Results from 6-h and 24-h cultures were compared by disc zone sizes and by interpreted susceptibility reading following EUCAST guidelines of sensitive, resistant, susceptible with increased exposure, or an area of technical uncertainty. Results: A total of 99.65% interpreted susceptibility readings matched across all organisms to all relevant antibiotics, with an average zone size difference of 1.08 mm between results from 6 h versus 24 h cultures. Conclusions: This method offers a non-automated way of using the traditional disc diffusion method, reducing turnaround times while still producing reliable and accurate results. This would mean validated ASTs can be set up in the same day as a blood culture flags positive rather than waiting for a longer culture. As this method is widely used within the laboratory already, it would mean that additional training is not required, as the process is the same, and only incubation time varies. This would positively impact patient outlook due to the shorter use of empiric therapy, and benefit antimicrobial stewardship (AMS).

Effect of a bundle intervention on adherence to quality-of-care indicators and on clinical outcomes in patients with Staphylococcus aureus bacteraemia hospitalized in non-referral community hospitals

BACKGROUND

Although a significant number of cases of Staphylococcus aureus bacteraemia (SAB) are managed at non-referral community hospitals, the impact of a bundle-of-care intervention in this setting has not yet been explored.

METHODS

We performed a quasi-experimental before-after study with the implementation of a bundle of care for the management of SAB at five non-referral community hospitals and a tertiary care university hospital. Structured recommendations for the five indicators selected to assess quality of care were provided to investigators before the implementation of the bundle and monthly thereafter. Primary endpoints were adherence to the bundle intervention and treatment failure, defined as death or relapse at 90 days of follow-up.

RESULTS

One hundred and seventy patients were included in the pre-intervention period and 103 in the intervention period. Patient characteristics were similar in both periods. Multivariate analysis controlling for potential confounders showed that performance of echocardiography was the only factor associated with improved adherence to the bundle in the intervention period (adjusted OR 2.13; 95% CI 1.13-4.02). Adherence to the bundle, performance of follow-up blood cultures, and adequate duration of antibiotic therapy for complicated SAB presented non-significant improvements. The intervention was not associated with a lower rate of 90 day treatment failure (OR 1.11; 95% CI 0.70-1.77).

CONCLUSIONS

A bundle-of-care intervention for the management of SAB at non-referral community hospitals increased adherence to quality indicators, but did not significantly reduce rates of 90 day mortality or relapse.

Clinical outcome of combination of vancomycin and ceftaroline versus vancomycin monotherapy for treatment of methicillin resistant Staphylococcus aureus bloodstream infection

BACKGROUND

The role of combination therapies for serious methicillin-resistant Staphylococcus aureus (MRSA) infections is widely debated.

METHODS

This retrospective cohort study included adults with MRSA bacteraemia treated between January 1, 2013, to December 31, 2022. Patients receiving combination therapy with vancomycin and ceftaroline were matched in a 2:1 ratio with those on vancomycin monotherapy based on bacteraemia source and illness severity. The primary outcome was frequency of bacteraemia recurrence. Secondary outcomes were all cause 30/90-day mortality, recurrence or mortality at 30/90 days and in hospital length of stay.

RESULTS

Of 57 patients included, 37 (65%) were in the combination group. The overall intensive care unit admission rate was 63.2% (36/57) and the Pitt Bacteraemia Score was 1 [0-4] at the time of diagnosis. The most common source of infection was endovascular/endocarditis (n = 36, 63.2%). Demographic and clinical characteristics were similar between the monotherapy and combination group of patients, except for higher body mass index (32.5 [25.5-36.4] vs. 24.4 [20.9-29], p = 0.004) and a greater immunosuppression prevalence (3 (15%) vs. 0 (0%), p = 0.039) in monotherapy group. There was no significant difference in bacteraemia recurrence (3 (15%) vs. 4 (10.8%), p = 0.7) or all-cause 30-day mortality (3 (15%) vs. 4 (10.8%), p = 0.7) between the two groups.

CONCLUSION

The results of this study are limited by a retrospective observational design; however, combination of vancomycin and ceftaroline for MRSA bacteraemia was not associated with lower bacteraemia recurrence or mortality compared to vancomycin monotherapy.

Impact of rapid blood culture identification PCR panel on optimal antibiotic use in methicillin-susceptible Staphylococcus aureus bacteremia

Rapid identification of methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia may optimize antibiotic use and clinical outcomes. The study objective was to assess the impact of the BioFire® blood culture identification (BCID) polymerase chain reaction (PCR) panel on antibiotic use and clinical outcomes in patients with MSSA bacteremia. This was a retrospective chart review of adult inpatients with MSSA bacteremia during the pre-PCR (June 2018-December 2019) and post-PCR (June 2020-December 2021) implementation periods. The primary endpoint was the difference between the pre-PCR and post-PCR groups in time to optimal MSSA antibiotic therapy (oxacillin or cefazolin). Secondary endpoints included duration of anti-MRSA antibiotic use, in-hospital mortality, hospital and ICU lengths of stay, duration of bacteremia, and 30-day MSSA-related and all-cause readmissions. Two hundred patients were included in the study (100 per group). Median time to optimal therapy was reduced by 19.9 hours in the post-PCR group (49 vs 29.1 hours, respectively, P < 0.001). PCR implementation was associated with significant reductions in the initiation of empiric anti-MRSA antibiotic therapy (98% vs 84%, P = 0.001), duration of empiric anti-MRSA antibiotic use (44.2 vs 20.9 hours, P < 0.001), and duration of bacteremia (68.6 vs 47.3 hours, P = 0.015). No significant differences in length of stay, in-hospital mortality, or 30-day MSSA-related or all-cause readmissions were observed. In patients with MSSA bacteremia, BCID PCR panel implementation decreased time to optimal MSSA antibiotic therapy, duration of bacteremia, and duration of empiric anti-MRSA antibiotic therapy.

IMPORTANCE

In this retrospective study of 200 patients with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, the implementation of the BioFire® blood culture identification polymerase chain reaction (PCR) panel was associated with a decreased time to optimal MSSA antibiotic therapy and shorter durations of empiric anti-MRSA antibiotic therapy and bacteremia. The findings demonstrate the significant role of rapid PCR testing and routine stewardship review in optimizing antimicrobial therapy and management of MSSA bacteremia.

Early Oral Antibiotic Switch in Staphylococcus aureus Bacteraemia: The Staphylococcus aureus Network Adaptive Platform (SNAP) Trial Early Oral Switch Protocol

BACKGROUND

Staphylococcus aureus bloodstream infection (bacteremia) is traditionally treated with at least 2 weeks of intravenous (IV) antibiotics in adults, 3-7 days in children, and often longer for those with complicated disease. The current practice of treating S. aureus bacteremia (SAB) with prolonged IV antibiotics (rather than oral antibiotics) is based on historical observational research and expert opinion. Prolonged IV antibiotic therapy has significant disadvantages for patients and healthcare systems, and there is growing interest in whether a switch to oral antibiotics following an initial period of IV therapy is a safe alternative for clinically stable patients.

PROTOCOL

The early oral switch (EOS) domain of the S. aureus Network Adaptive Platform (SNAP) trial will assess early switch to oral antibiotics compared with continued IV treatment in clinically stable patients with SAB. The primary endpoint is 90-day all-cause mortality. Hospitalised SAB patients are assessed at platform day 7 ±2 (uncomplicated SAB) and day 14 ±2 (complicated SAB) to determine their eligibility for randomization to EOS (intervention) or continued IV treatment (current standard of care).

DISCUSSION

Recruitment is occurring in the EOS domain of the SNAP trial. As of August 2023, 21% of all SNAP participants had been randomized to the EOS domain, a total of 264 participants across 77 centers, with an aim to recruit at least 1000 participants. We describe challenges and facilitators to enrolment in this domain to aid those planning similar trials.

Risk factors for mortality and complications in peripheral venous catheter-associated Staphylococcus aureus bacteraemia: a large multicentre cohort study

BACKGROUND

Peripheral venous catheter-associated Staphylococcus aureus bacteraemia (PVC-SAB) is a potentially life-threatening nosocomial infection.

AIM

This cohort study aims to identify the risk factors associated with its mortality and complications.

METHODS

Retrospective analysis of a prospective cohort study conducted at two tertiary-care hospitals in Spain. Adult patients admitted between January 2011 and July 2019 which developed PVC-SAB during their hospital stay were included. Primary outcome was all-cause 30- and 90-day mortality. Secondary outcomes were sepsis or septic shock at the onset of bacteraemia, metastatic infection and length of hospital stay. Univariate and multivariate analyses were performed.

FINDINGS

A total of 256 PVC-SAB were diagnosed in 243 patients between 2011 and 2019. Thirty-day and 90-day all-cause mortality were 18.3% and 24.2%, respectively. Lack of susceptible antibiotic administration the day after blood culture collection (odds ratio: 4.14; 95% confidence interval: 1.55-11.03; P = 0.005), sepsis and complicated bacteraemia were identified as independent risk factors for 30- and 90-day mortality; meticillin-resistant S. aureus bacteraemia was identified as an independent risk factor only for 30-day mortality and functional dependence only for 90-day mortality. Persistent bacteraemia and sepsis were associated with septic metastases, which significantly increased hospital stay, and endocarditis. A greater proportion of patients experiencing septic shock were subsequently institutionalized compared to those without.

CONCLUSION

PVC-SAB remains linked to high mortality rates. Prompt administration of appropriate antibiotics is crucial for lowering mortality. A comprehensive diagnostic approach is essential, especially in patients with persistent bacteraemia and implanted cardiovascular devices, to rule out metastatic complications and endocarditis.

Estimating bacterial load in S. aureus and E. coli bacteremia using bacterial growth graph from the continuous monitoring blood culture system

BACKGROUND

We examined whether the time to positivity (TTP) and growth and detection plot graph (GDPG) created by the automated blood culture system can be used to determine the bacterial load in bacteremic patients and its potential association correlation with disease severity.

METHODS

Known bacterial inocula were injected into the blood culture bottles. The GDPGs for the specific inocula were downloaded and plotted. A cohort of 30 consecutive clinical cultures positive for S. aureus and E. coli was identified. Bacterial load was determined by comparing the GDPG with the "standard" curves. Variables associated with disease severity were compared across 3 bacterial load categories (< 100, 100-1000, > 1000 CFU/mL).

RESULTS

S. aureus growth was sensitive to the blood volume obtained whereas E. coli growth was less so. A 12-hour delay in sample transfer to the microbiology laboratory resulted in a decrease in TTP by 2-3 h. Mean TTP was 15 and 10 h for S. aureus and E. coli, respectively, which correlates with > 1000 CFU/mL and 500-1000 CFU/ml. For S. aureus, patients with a bacterial load > 100 CFU/mL had a higher mortality rate, (OR for death = 9.7, 95% CI 1.6-59, p = 0.01). Bacterial load > 1000 CFU/mL had an odds ratio of 6.4 (95% CI1.2-35, p = 0.03) to predict an endovascular source. For E. coli bacteremia, we did not find any correlations with disease severity.

CONCLUSION

GDPG retrieved from the automated blood culture system can be used to estimate bacterial load. S.aureus bacterial load, but not E.coli, was associated with clinical outcome.

Impact of [18F] FDG PET/CT on outcomes in patients with Staphylococcus aureus bacteremia: A retrospective single-center experience

OBJECTIVE

Staphylococcus aureus bacteremia (SAB) is a leading cause of community and hospital-acquired bacteremia with significant morbidity and mortality. Effective management depends on accurate diagnosis, source control and assessment of metastatic infections. [18F] FDG PET/CT has been shown to reduce mortality in high-risk SAB patients. This study aims to evaluate the impact of [18F] FDG PET/CT on outcomes in patients with SAB.

METHODS

Single-center, retrospective, real-life setting study including all consecutive SAB cases from 2017 to 2019. Medical records were analyzed to collect information.

RESULTS

Out of the 315 included patients, 132 underwent [18F] FDG PET/CT. In those patients, a clear focus of infection was more frequently identified, leading to better adapted treatments and extended hospital stays. Overall mortality rates at 30 days, 90 days and one year were 25.1 %, 36.8 % and 44.8 % respectively. Mortality was significantly lower in the [18F] FDG PET/CT group (p < 0.0001) and persisted (p < 0.05) after adjusting for imbalances between groups regarding oncologic patients and deaths within 7 days. The difference in mortality remained significant irrespective of prolonged bacteremia but was not significant with regard to hospital-acquired SAB. Supplementary analysis using the Cox proportional hazards model confirmed that [18F] FDG PET/CT was significantly associated with reduced mortality (p < 0.05).

CONCLUSION

In this real-life cohort, patients with SAB having undergone [18F] FDG PET/CT experienced lower mortality rates, highlighting the additional value of [18F] FDG PET/CT in SAB management. Further research is needed to identify the subpopulations that would benefit most from the integration of [18F] FDG PET/CT in their work-up.

Comparative in vitro efficacy of antibiotics against the intracellular reservoir of Staphylococcus aureus

Staphylococcus aureus (SA) is a leading cause of bloodstream infection. The liver represents the sentinel immune organ for clearance of bloodstream pathogens and eradication of intracellular SA from liver-resident macrophages (Kupffer cells, KCs) eliminates the likely pathogenic reservoir that contributes to persistent bacteraemia.

OBJECTIVES

We assessed antimicrobial activity at phagolysosome-mimicking pH, intracellular penetration, and SA eradication within KCs in vitro for clinically prescribed antistaphylococcal agents alone or in combination: vancomycin, daptomycin, ceftaroline, ceftobiprole, oritavancin, oxacillin, cefazolin; rifampin and fosfomycin.

METHODS

pH-adjusted broth microdilution assays, intracellular bioaccumulation assays, and intracellular killing assays against clinical bloodstream isolates were performed using a murine KC line with study agents.

RESULTS

Rifampin and β-lactams exhibited enhanced activity [2- to 16-fold minimum inhibitory concentrations (MIC) decrease] at phagolysosomal pH while vancomycin, oritavancin, daptomycin and fosfomycin demonstrated reduced activity (2- to 32-fold MIC increase in order of least to greatest potency reduction). All agents evaluated had poor to modest intracellular to extracellular concentration ratios (0.024-7.8), with exceptions of rifampin and oritavancin (intracellular to extracellular ratios of 17.4 and 78.2, respectively). Finally, we showed that the first-line treatment for SA bacteraemia (SAB), vancomycin, performed worse than all other tested antibiotics in eradicating intracellular SA at human Cmax concentration (0.20 log cfu decrease), while oritavancin performed better than all other agents alone (2.05 versus 1.06-1.36 log cfu decrease).

CONCLUSIONS

Our findings raise concerns about the efficacy of commonly prescribed antibiotics against intracellular SA reservoirs and emphasize the need to consider targeting pathogen eradication from the liver to achieve early control of SAB.

Vascular catheter-related infections: an endemic disease in healthcare institutions. An opinion paper of the Spanish Society of Cardiovascular Infections (SEICAV)

Catheter-related infections (CRI) are a serious healthcare problem due to their potential to cause serious complications, including bacteraemia or infective endocarditis, and to increase patient morbidity and mortality. In addition, these in fections significantly prolong hospital stay and cost. Preventing CRI is crucial and is considered a criterion for quality and safety in healthcare. For these reasons, the Spanish Society of Cardiovascular Infections (SEICAV) has considered it pertinent to review this topic, with experts in different areas including clinical microbiologists, infectious disease specialists, surgeons and nurses. The data were presented at a session held at the Ramón Areces Foundation, which was organised in the form of specific questions grouped into three round tables. The first panel analysed the scale of the problem including epidemiological, clinical and diagnostic aspects; the second panel addressed advances in the treatment of CRI; and the third panel reviewed developments in the prevention of CRI. The recorded session is available on the Areces Foundation website and we believe it maybe of interest not only to health professionals, but also to any non-expert citizen interested in the subject.

Host-induced cell wall remodeling impairs opsonophagocytosis of Staphylococcus aureus by neutrophils

The bacterial pathogen Staphylococcus aureus responds to the host environment by increasing the thickness of its cell wall. However, the impact of cell wall thickening on susceptibility to host defenses is unclear. Using bacteria incubated in human serum, we show that host-induced increases in cell wall thickness led to a reduction in the exposure of bound antibody and complement and a corresponding reduction in phagocytosis and killing by neutrophils. The exposure of opsonins bound to protein antigens or lipoteichoic acid (LTA) was most significantly reduced, while opsonization by IgG against wall teichoic acid or peptidoglycan was largely unaffected. Partial digestion of accumulated cell wall using the enzyme lysostaphin restored opsonin exposure and promoted phagocytosis and killing. Concordantly, the antibiotic fosfomycin inhibited cell wall remodeling and maintained the full susceptibility of S. aureus to opsonophagocytic killing by neutrophils. These findings reveal that host-induced changes to the S. aureus cell wall reduce the ability of the immune system to detect and kill this pathogen through reduced exposure of protein- and LTA-bound opsonins.

IMPORTANCE

Understanding how bacteria adapt to the host environment is critical in determining fundamental mechanisms of immune evasion, pathogenesis, and the identification of targets for new therapeutic approaches. Previous work demonstrated that Staphylococcus aureus remodels its cell envelope in response to host factors and we hypothesized that this may affect recognition by antibodies and thus killing by immune cells. As expected, incubation of S. aureus in human serum resulted in rapid binding of antibodies. However, as bacteria adapted to the serum, the increase in cell wall thickness resulted in a significant reduction in exposure of bound antibodies. This reduced antibody exposure, in turn, led to reduced killing by human neutrophils. Importantly, while antibodies bound to some cell surface structures became obscured, this was not the case for those bound to wall teichoic acid, which may have important implications for vaccine design.

Risk factors for vancomycin treatment failure in heterogeneous vancomycin-intermediate Staphylococcus aureus bacteremia

The incidence of heterogeneous vancomycin-intermediate Staphylococcus aureus (hVISA) infection is increasing and is associated with vancomycin treatment failures. However, studies investigating the risk factors for treatment failure in hVISA infection are limited. Patients with hVISA bacteremia treated with vancomycin over 7 days between August 2008 and June 2020 were enrolled in this study. Clinical and microbiological characteristics were compared between vancomycin treatment failure and success groups to identify the risk factors for vancomycin treatment failure. Among the 180 patients with hVISA bacteremia, 102 patients treated with vancomycin over 7 days were included. Vancomycin treatment failed in 80 (78%) patients. Patients in the vancomycin treatment failure group were older (P < 0.001) and more frequently had solid cancer (P = 0.04) than those in the vancomycin treatment success group. Solid organ transplantation (SOT) was more frequent (P < 0.001) in the vancomycin treatment success group. The Charlson comorbidity index (P = 0.01) and Acute Physiology and Chronic Health Evaluation II scores (P < 0.001) were higher in the vancomycin treatment failure group. In multivariate analysis, independent risk factors for vancomycin treatment failure were old age and severity of bacteremia. SOT and vancomycin minimal inhibitory concentration (MIC) ≤ 1.0 mg/L using the broth microdilution (BMD) method were associated with successful vancomycin treatment. Old age and infection severity were independent risk factors for vancomycin treatment failure. Vancomycin MIC using the BMD method is an important risk factor for vancomycin treatment failure, and its use should be considered in hVISA bacteremia.IMPORTANCEIn this study, we assessed the clinical and microbiological characteristics of heterogeneous vancomycin-intermediated Staphylococcus aureus (hVISA) bacteremia and identified risk factors for vancomycin treatment failure. We found that advanced age and severity of infection were independent risk factors for vancomycin treatment failure. On the other hand, solid organ transplantation and a low vancomycin minimal inhibitory concentration were associated with successful vancomycin treatment. This study highlights the importance of vancomycin minimal inhibitory concentration in hVISA bacteremia.

Adherence to and clinical utility of "quality indicators" for Staphylococcus aureus bacteremia: a retrospective, multicenter study

BACKGROUND

We aimed to improve the prognosis, treatment, and management of Staphylococcus aureus bacteremia (SAB) by evaluating the association between adherence to quality indicators (QIs) and clinical outcomes in patients with their clinical outcomes.

METHODS

We retrospectively collected clinical and microbiological data on hospitalized patients with SAB from 14 hospitals (three with >  600, two with 401-600, five with 201-400, and four with ≤ 200 beds) in Japan from January to December 2022. The SAB management quality was evaluated using the SAB-QI score (ranging from 0 to 13 points), which consists of 13 QIs (grouped into five categories) based on previous literature.

RESULTS

Of the 4,448 positive blood culture episodes, 289 patients with SAB (6.5%) were enrolled. The SAB-QI scores ranged from 3 to 13, with a median score of 9 points. The SAB-QI score was highest in middle-sized hospitals with 401-600 beds. Adherence to each of the four QI categories (blood culture, echocardiography, source control, and antibiotic treatment) was significantly higher in survived cases than in fatal cases. Kaplan-Meier curves with log-rank tests demonstrated that higher adherence to SAB-QIs indicated a better prognosis. Logistic regression analysis revealed that age, methicillin resistance, multiple comorbidities (≥ 2), and low SAB-QI score were significantly associated with 30-day mortality in patients with SAB.

CONCLUSIONS

Our study highlights that greater adherence to the SAB-QIs correlates with improved patient outcomes. Management of patients with SAB should follow these recommended indicators to maintain the quality of care, especially for patients with poor prognosticators.

Epidemiology and clinical relevance of persistent bacteraemia in patients with Gram-negative bloodstream infection: a retrospective cohort study

OBJECTIVES

The risk factors and outcomes associated with persistent bacteraemia in Gram-negative bloodstream infection (GN-BSI) are not well described. We conducted a follow-on analysis of a retrospective population-wide cohort to characterize persistent bacteraemia in patients with GN-BSI.

METHODS

We included all hospitalized patients >18 years old with GN-BSI between April 2017 and December 2021 in Ontario who received follow-up blood culture (FUBC) 2-5 days after the index positive blood culture. Persistent bacteraemia was defined as having a positive FUBC with the same Gram-negative organism as the index blood culture. We identified variables independently associated with persistent bacteraemia in a multivariable logistic regression model. We evaluated whether persistent bacteraemia was associated with increased odds of 30- and 90-day all-cause mortality using multivariable logistic regression models adjusted for potential confounders.

RESULTS

In this study, 8807 patients were included; 600 (6.8%) had persistent bacteraemia. Having a permanent catheter, antimicrobial resistance, nosocomial infection, ICU admission, respiratory or skin and soft tissue source of infection, and infection by a non-fermenter or non-Enterobacterales/anaerobic organism were associated with increased odds of having persistent bacteraemia. The 30-day mortality was 17.2% versus 9.6% in those with and without persistent bacteraemia (aOR 1.65, 95% CI 1.29-2.11), while 90-day mortality was 25.5% versus 16.9%, respectively (aOR 1.53, 95% CI 1.24-1.89). Prevalence and odds of developing persistent bacteraemia varied widely depending on causative organism.

CONCLUSIONS

Persistent bacteraemia is uncommon in GN-BSI but is associated with poorer outcomes. A validated risk stratification tool may be useful to identify patients with persistent bacteraemia.

Impact of a Bundle of Interventions on Quality-of-Care Indicators for Staphylococcus aureus Bacteraemia: A Single-Centre, Quasi-Experimental, Before-After Study

Staphylococcus aureus bacteraemia (SAB) is a life-threatening bloodstream infection. Improved adherence to quality-of-care indicators (QCIs) can significantly enhance patient outcomes. This quasi-experimental study evaluated the impact of a bundle of interventions on QCI adherence in adult patients with SAB. Additionally, a molecular rapid diagnostic test (mRDT) for S. aureus and methicillin resistance was introduced during weekdays. We compared pre-intervention (January-December 2022) and post-intervention (May 2023-April 2024) data on QCI adherence and time to appropriate treatment. A total of 56 and 40 SAB episodes were included in the pre- and post-intervention periods, respectively. Full QCI adherence significantly increased from 28.6% to 67.5% in the post-intervention period (p < 0.001). The mRDT diagnosed SAB in eight cases (26.6%), but the time to achieve appropriate target therapy did not improve in the post-intervention period (54 h (IQR 30-74) vs. 72 h (IQR 51-83), p = 0.131). The thirty-day mortality rate was comparable between the two periods (17.9% vs. 12.5%, p = 0.476). This study demonstrates that a bundle of interventions can substantially improve adherence to SAB management QCIs.

Clinical and microbiological characteristics of persistent Staphylococcus aureus bacteremia, risk factors for mortality, and the role of CD4+ T cells

This study evaluated the determinants of mortality and the T cell immune response in patients with persistent Staphylococcus aureus bacteremia (SAB). This was a prospective cohort study and patients with confirmed SAB were enrolled from 2008 to 2020. We compared clinical, microbiological, and genotypic features between surviving and deceased patients with persistent SAB. The concentrations of cytokines and the proportions of IFN-γ secreting CD4+ T cells were measured serially during the bacteremia period. Of the 1760 patients, 242 had persistent bacteremia (PB), and 49 PB patients died within 30 days. In the multivariate analysis, the APACHE II score and female sex were independently associated with 30 days mortality. The level of IL-10 was significantly increased in the plasma of patients with a high Pitt bacteremia score and those who died within 12 weeks from the index day. The proportion of IFN-γ-secreting CD4+ T cells were the highest just before the positive-to-negative conversion of blood cultures in patients with a low Pitt bacteremia score and those who survived for 12 weeks. The level of IL-10 is correlated with clinical outcomes in PB patients. IFN-γ secreting CD4+ T cells might play a pivotal role in SAB PB.

Clinical characteristics and outcomes of persistent bacteremia in patients with head and neck cancer in a tertiary care hospital

Introduction

Compared to other cancers, research on bloodstream infection in head and neck cancer is scarce, lacking comparative studies on persistent versus transient bacteremia outcomes.

Methods

This retrospective survey examined patients with head and neck cancer undergoing blood culture at our center from June 2009 to May 2023. Blood culture-positive cases suspected of infection were divided into persistent bacteremia and transient bacteremia groups. We investigated their clinical, epidemiological, and microbiological features, including risk factors for persistent bacteremia and mortality. The primary outcome was 90-day mortality.

Results

In this 97-patient cohort, 14 (14%) cases were assigned to the persistent bacteremia group. Catheter-related bloodstream infections were the leading cause of infection in both groups, consistently contributing to a high proportion of overall bloodstream infections. The mortality rate was generally higher in the persistent bacteremia group than in the transient bacteremia group (odds ratio [OR], 2.6; 95% confidence interval [CI], 0.6-11.1), particularly in the non-clearance subgroup (OR, 9; 95% CI, 0.5-155.2). Pyogenic spondylitis was a key risk factor for persistent bacteremia, while hypoalbuminemia increased mortality.

Conclusion

In patients with bacteremia and head and neck cancer, persistent bacteremia was associated with higher mortality than was transient bacteremia. Adittionally, bacteremia clearance in persistent bacteremia is thus crucial for prognostic improvement.

A Retrospective Cohort Study Comparing Dual Therapy With Ceftaroline With Vancomycin or Daptomycin Monotherapy for High-Grade or Persistent MRSA Bacteremia

Background: Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is a serious clinical infection associated with a high risk of mortality. Dual therapy is often used in patients with persistent bacteremia. Objective: This study aimed to compare the outcomes of vancomycin or daptomycin monotherapy with those of dual therapy with ceftaroline in high-grade or persistent MRSA bacteremia. Methods: We conducted a retrospective cohort study at a university teaching hospital between January 2014 and June 2021, involving adults initially treated with vancomycin or daptomycin. Patients were categorized into monotherapy and dual therapy groups. The primary outcome was 30-day mortality. Secondary outcomes included microbiological relapse and antibiotic-related adverse events. Results: In a group of 155 patients, 30-day mortality rates were similar between the monotherapy (23.4%) and dual therapy (22.6%) groups, with comparable microbiological relapse rates (6.5%). In inverse probability of treatment weighting analysis, we found no significant association between dual therapy and mortality (adjusted risk ratio [ARR] 1.38, 95% CI 0.64-2.41, P = 0.38) or microbiological relapse (ARR 0.95, 95% CI 0.31-2.73, P = 0.93). Dual therapy was associated with a lower risk of antibiotic-related adverse events (ARR 0.45, 95% CI 0.21-0.89, P = 0.02). Infectious diseases (ID) consultation was associated with a reduced mortality risk (ARR 0.27, 95% CI 0.07-0.95, P = 0.04). Conclusions: Dual therapy with ceftaroline did not reduce mortality risk compared with monotherapy in patients with MRSA bacteremia. However, patients with ID consultations showed a 73% reduction in mortality rates. Large-scale, prospective, and randomized controlled trials are needed to provide conclusive evidence regarding the potential benefits of dual therapy with ceftaroline for MRSA bacteremia.

Ceftaroline in CNS and ocular infections: a case series

Background

There are limited data describing outcomes of patients treated with ceftaroline for infections with CNS or ocular involvement.

Objectives

To describe outcomes of patients treated with ceftaroline for methicillin-resistant staphylococcal infections involving the CNS or eye.

Patients and methods

This was a retrospective review of 10 patients at an academic medical centre who received ceftaroline for CNS or ocular infections.

Results

All patients were treated with ceftaroline as part of a combination for salvage therapy. Four patients died, whereas six patients experienced clinical cure. Only one experienced microbiological recurrence.

Conclusions

These preliminary data suggest that ceftaroline may be an option for salvage therapy of severe staphylococcal infections when used in combination.

Impact of the implementation of the Intelligent Antimicrobial System (iAMS) on clinical outcomes among patients with bacteraemia caused by methicillin-resistant Staphylococcus aureus

OBJECTIVES

This study aimed to investigate the clinical impact of the Intelligent Antimicrobial System (iAMS) on patients with bacteraemia due to methicillin-resistant (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA).

METHODS

A total of 1008 patients with suspected SA infection were enrolled before and after the implementation of iAMS. Among them, 252 with bacteraemia caused by SA, including 118 in the iAMS and 134 in the non-iAMS groups, were evaluated.

RESULTS

The iAMS group exhibited a 5.2% (from 55.2% to 50.0%; P = 0.96) increase in the 1-year survival rate. For patients with MRSA and MSSA compared to the non-iAMS group, the 1-year survival rate increased by 17.6% (from 70.9% to 53.3%; P = 0.41) and 7.0% (from 52.3% to 45.3%; P = 0.57), respectively, both surpassing the rate of the non-iAMS group. The iAMS intervention resulted in a higher long-term survival rate (from 70.9% to 52.3%; P = 0.984) for MRSA patients than for MSSA patients. MRSA patients experienced a reduced length of hospital stay (from 23.3% to 35.6%; P = 0.038), and the 45-day discharge rate increased by 20.4% (P = 0.064). Furthermore, the intervention resulted in a significant 97.3% relative decrease in near miss medication incidents reported by pharmacists (P = 0.013).

CONCLUSIONS

Implementation of iAMS platform improved long-term survival rates, discharge rates, hospitalization days, and medical cost (although no significant differences were observed) among patients with MRSA bacteraemia. Additionally, it demonstrated significant benefits in ensuring drug safety.

Daptomycin Plus Oxacillin for Persistent Methicillin-Susceptible Staphylococcus aureus Bacteremia

BACKGROUND

The preferred antibiotic salvage regimen for persistent methicillin-susceptible Staphylococcus aureus bacteremia (MSSAB) is unclear. Ertapenem with cefazolin or an antistaphylococcal penicillin has been primarily described, but identifying alternative carbapenem-sparing options may support antibiotic stewardship efforts and decrease the risk of antibiotic-associated Clostridioides difficile infection.

OBJECTIVE

We sought to evaluate the effectiveness and safety of daptomycin plus oxacillin (D/O) for persistent MSSAB.

METHODS

This was a single-center, retrospective cohort of patients with persistent MSSAB who received D/O between January 1, 2014, and January 1, 2023. Adult patients were included if they had blood cultures positive for MSSA ≥72 hours and received D/O combination for ≥48 hours. Patients were excluded if they were pregnant, incarcerated, or received another antibiotic considered to have excellent activity against MSSA. The primary outcome was time to MSSA bacteremia clearance post-daptomycin initiation. Secondary outcomes included microbiological cure, hospital length of stay, 90-day all-cause mortality, MSSA bacteremia-related mortality, 90-day readmission for MSSAB, and incidence of antibiotic-associated adverse effects. Time to MSSAB clearance post-D/O initiation was plotted using Kaplan-Meier estimation.

RESULTS

Seven unique patient encounters were identified including 4 with endocarditis. Despite a median MSSA bacteremia duration of 7.8 days, median clearance was 2 days post-daptomycin initiation. All achieved microbiological cure, and no adverse effects were reported. Ninety-day all-cause mortality, MSSAB-related mortality, and 90-day readmission for MSSAB occurred in 28.6%, 14.3%, and 14.3% of patients, respectively.

CONCLUSIONS AND RELEVANCE

D/O was an effective, well-tolerated salvage regimen in this cohort and may represent a carbapenem-sparing option for persistent MSSAB.

Early Initiation of Ceftaroline-Based Combination Therapy for Methicillin-resistant Staphylococcus aureus Bacteremia

Purpose

Monotherapy with vancomycin or daptomycin remains guideline-based care for methicillin-resistant Staphylococcus aureus bacteremia (MRSA-B) despite concerns regarding efficacy. Limited data support potential benefit of combination therapy with ceftaroline as initial therapy. We present an assessment of outcomes of patients initiated on early combination therapy for MRSA-B.

Methods

This was a single-center, retrospective study of adult patients admitted with MRSA-B between July 1, 2017 and April 31, 2023. During this period, there was a change in institutional practice from routine administration of monotherapy to initial combination therapy for most patients with MRSA-B. Combination therapy included vancomycin or daptomycin plus ceftaroline within 72 hours of index blood culture and monotherapy was vancomycin or daptomycin alone. The primary outcome was a composite of persistent bacteremia, 30-day all-cause mortality, and 30-day bacteremia recurrence. Time to microbiological cure and safety outcomes were assessed. All outcomes were assessed using propensity score-weighted logistic regression.

Results

Of 213 patients included, 118 received monotherapy (115 vancomycin, 3 daptomycin) and 95 received combination therapy with ceftaroline (76 vancomycin, 19 daptomycin). The mean time from MRSA-positive molecular diagnostic blood culture result to combination therapy was 12.1 hours. There was no difference between groups for the primary composite outcome (OR 1.58, 95% CI 0.60, 4.18). Time to microbiological cure was longer with combination therapy (mean difference 1.50 days, 95% CI 0.60, 2.41). Adverse event rates were similar in both groups.

Conclusions

Early initiation of ceftaroline-based combination therapy did not improve outcomes for patients with MRSA-B in comparison to monotherapy therapy.

The anti-infective and immunologic effect of babassu (Attalea speciosa, Mart. ex Spreng) reduces mortality induced by MRSA-Staphylococcus aureus

ETHNOPHARMACOLOGICAL RELEVANCE

Babassu mesocarp, derived from the Attalea speciosa fruits, is used in folk medicine for infections, inflammatory diseases, and skin wounds.

AIM OF THE STUDY

To investigate the antimicrobial and immunological effect of babassu mesocarp aqueous extract (BAE) in Swiss mice lethally infected with methicillin-resistant Staphylococcus aureus (MRSA).

MATERIALS AND METHODS

The animals (n = 14/group) received an overload of MRSA (3.0 × 108 CFU/mL, via intraperitoneal) and were treated 6 h later with the BAE (125 and 250 mg/kg, subcutaneously). Two experiments were performed with four groups each (Control, ATB, BAE125 and BAE 250). The first was to determine the survival (n = 7 animals/group). The second is to evaluate 24h after infection the number of Colony Forming Units (CFU) and cells in the blood, peritoneum and bronchoalveolar fluid. Cytometric Bead Assay - CBA quantified the cytokines and flow cytometry to determine the cellular distribution in the mesenteric lymph node.

RESULTS

Treatment with BAE improved the survival (60%) in all groups, reduced the number of colony-forming units in the peritoneum and blood, the number of peritoneal and bronchoalveolar cells, and the levels of pro-inflammatory IL-6, TNF-α, and IL-17 cytokines. Additionally, BAE increased: IL-10 and INF-γ levels, nitric oxide release, CD4+ T helper cells, CD14+/IaIe + activated macrophages and Ly6G + neutrophils in the mesenteric lymph node.

CONCLUSIONS

BAE can be used as a complementary treatment during infections due to its antimicrobial and immunomodulatory effect and the ability to protect animals from death after MRSA lethal infection.

Safety and effectiveness of fifth generation cephalosporins for the treatment of methicillin-resistant staphylococcus aureus bloodstream infections: a narrative review exploring past, present, and future

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) is a major issue in healthcare, since it is often associated with endocarditis or deep site foci. Relevant morbidity and mortality associated with MRSA-BSIs forced the development of new antibiotic strategies; in particular, this review will focus the attention on fifth-generation cephalosporins (ceftaroline/ceftobiprole), that are the only ß-lactams active against MRSA.

AREAS COVERED

The review discusses the available randomized controlled trials and real-world observational studies conducted on safety and effectiveness of ceftaroline/ceftobiprole for the treatment of MRSA-BSIs. Finally, a proposal of MRSA-BSI treatment flowchart, based on fifth-generation cephalosporins, is described.

EXPERT OPINION

The use of anti-MRSA cephalosporins is an acceptable choice either in monotherapy or combination therapy for the treatment of MRSA-BSIs due to their relevant effectiveness and safety. Particularly, their use may be advisable in combination therapy in case of severe infections (including endocarditis or persistent bacteriemia) or in monotherapy in subjects at higher risk of drugs-induced toxicity with older regimens. On the contrary, caution should be taken in case of suspected/ascertained central nervous system infections due to inconsistent data regarding penetration of these drugs in cerebrospinal fluid and brain tissues.

Contemporary Management of Staphylococcus aureus Bacteremia-Controversies in Clinical Practice

Staphylococcus aureus bacteremia (SAB) carries a high risk for excess morbidity and mortality. Despite its prevalence, significant practice variation continues to permeate clinical management of this syndrome. Since the publication of the 2011 Infectious Diseases Society of America (IDSA) guidelines on management of methicillin-resistant Staphylococcus aureus infections, the field of SAB has evolved with the emergence of newer diagnostic strategies and therapeutic options. In this review, we seek to provide a comprehensive overview of the evaluation and management of SAB, with special focus on areas where the highest level of evidence is lacking to inform best practices.

Risk Factors and Outcomes of Hematogenous Vertebral Osteomyelitis in Patients With Staphylococcus aureus Bacteremia

BACKGROUND

Hematogenous vertebral osteomyelitis (HVOM) is an incompletely understood complication of Staphylococcus aureus bacteremia (SAB).

METHODS

Eligible SAB patients with and without HVOM were prospectively enrolled from 1995 through 2019 at Duke University Health System. HVOM was diagnosed either radiographically or microbiologically. Multivariable logistic regression analysis was performed to identify clinical and microbial factors associated with HVOM risk. All bloodstream S. aureus isolates were genotyped using spa typing.

RESULTS

Of 3165 cases of SAB, 127 (4.0%) developed HVOM. Patients who experienced HVOM were more likely to have community-acquired SAB (30.7% vs 16.7%, P < .001), have a longer time to diagnosis of SAB (median, 5 days; interquartile range [IQR], 2-10.5 vs median, 2 days; IQR, 0-4; P < .001), and to exhibit persistent bacteremia (48.8% vs 20.6%, P < .001). A significant number of HVOM patients developed infective endocarditis (26% vs 15.2%, P = .002). Overall, 26.2% (n = 33) of SAB patients with HVOM underwent surgical intervention. Methicillin resistance (46.6% vs 41.7%, P = .318) and bacterial genotype were not associated with the development of HVOM. At the 12-month follow-up, 22% of patients with HVOM had died. Of the surviving patients, 20.4% remained on antibiotic therapy, and 29.6% had recurrence of either HVOM or SAB.

CONCLUSIONS

Among patients with SAB, HVOM risk was associated with clinical factors and not bacterial genotype. Despite being a rare complication of SAB, patients with HVOM had high all-cause mortality rates and healthcare resource requirements up to 1 year after their HVOM diagnosis. Close clinical monitoring is indicated in this vulnerable population.

Therapeutic Options for Adult Patients With Persistent Methicillin-Susceptible Staphylococcus aureus Bacteremia: A Narrative Review

OBJECTIVE

To compare the efficacy of antimicrobial therapies used in the management of persistent methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia.

DATA SOURCES

A literature search using the PubMed database (inception to December 2022) was conducted using the search terms "Staphylococcus aureus bacteremia," "methicillin-susceptible Staphylococcus aureus bacteremia," "persistent methicillin-susceptible Staphylococcus aureus bacteremia," and "refractory methicillin-susceptible Staphylococcus aureus bacteremia ." In addition, therapeutic agents which could be used as treatment for MSSA including "nafcillin," "oxacillin," "cefazolin," "ceftaroline," "gentamicin," "rifampin," and "daptomycin" were also combined with the aforementioned search terms to capture data using these agents.

STUDY SELECTION/DATA EXTRACTION

Clinical data were limited to those published in the English language. Articles and abstracts were considered for inclusion in addition to ongoing trials identified through ClinicalTrials.gov.

DATA SYNTHESIS

A total of 78 articles were reviewed including 17 in vitro or animal model studies and 39 studies including patient data. The remaining 22 articles included guidelines, review articles, and editorials. Recent data evaluating use of dual β-lactam regimens for persistent MSSA bacteremia were limited to 8 case reports or case series.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

At present, there is little guidance on how to best manage patients with persistent MSSA bacteremia. This narrative review collates the available data to assist clinicians in selecting the best possible antimicrobial regimen when facing this clinical conundrum.

CONCLUSIONS

Modification of antimicrobial therapy, in conjunction with source control and infectious diseases consultation, may all be necessary to sterilize blood cultures in patients with persistent MSSA bacteremia.

The Epidemiological, Clinical, and Microbiological Features of Patients with Burkholderia pseudomallei Bacteraemia-Implications for Clinical Management

Patients with melioidosis are commonly bacteraemic. However, the epidemiological characteristics, the microbiological findings, and the clinical associations of Burkholderia pseudomallei bacteraemia are incompletely defined. All cases of culture-confirmed melioidosis at Cairns Hospital in tropical Australia between January 1998 and June 2023 were reviewed. The presence of bacteraemia was determined and correlated with patient characteristics and outcomes; 332/477 (70%) individuals in the cohort were bacteraemic. In multivariable analysis, immunosuppression (odds ratio (OR) (95% confidence interval (CI)): (2.76 (1.21-6.27), p = 0.02), a wet season presentation (2.27 (1.44-3.59), p < 0.0001) and male sex (1.69 (1.08-2.63), p = 0.02), increased the likelihood of bacteraemia. Patients with a skin or soft tissue infection (0.32 (0.19-0.57), p < 0.0001) or without predisposing factors for melioidosis (0.53 (0.30-0.93), p = 0.03) were less likely to be bacteraemic. Bacteraemia was associated with intensive care unit admission (OR (95%CI): 4.27 (2.35-7.76), p < 0.0001), and death (2.12 (1.04-4.33), p = 0.04). The median (interquartile range) time to blood culture positivity was 31 (26-39) hours. Patients with positive blood cultures within 24 h were more likely to die than patients whose blood culture flagged positive after this time (OR (95%CI): 11.05 (3.96-30.83), p < 0.0001). Bacteraemia portends a worse outcome in patients with melioidosis. Its presence or absence might be used to help predict outcomes in cases of melioidosis and to inform optimal clinical management.

Global Differences in the Management of Staphylococcus aureus Bacteremia: No International Standard of Care

BACKGROUND

Despite being the leading cause of mortality from bloodstream infections worldwide, little is known about regional variation in treatment practices for Staphylococcus aureus bacteremia (SAB). The aim of this study was to identify global variation in management, diagnostics, and definitions of SAB.

METHODS

During a 20-day period in 2022, physicians throughout the world were surveyed on SAB treatment practices. The survey was distributed through listservs, e-mails, and social media.

RESULTS

In total, 2031 physicians from 71 different countries on 6 continents (North America [701, 35%], Europe [573, 28%], Asia [409, 20%], Oceania [182, 9%], South America [124, 6%], and Africa [42, 2%]) completed the survey. Management-based responses differed significantly by continent for preferred treatment of methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) bacteremia, use of adjunctive rifampin for prosthetic material infection, and use of oral antibiotics (P < .01 for all comparisons). The 18F-FDG PET/CT scans were most commonly used in Europe (94%) and least frequently used in Africa (13%) and North America (51%; P < .01). Although most respondents defined persistent SAB as 3-4 days of positive blood cultures, responses ranged from 2 days in 31% of European respondents to 7 days in 38% of Asian respondents (P < .01).

CONCLUSIONS

Large practice variations for SAB exist throughout the world, reflecting the paucity of high-quality data and the absence of an international standard of care for the management of SAB.

High Incidence of Metastatic Infections in Panton-Valentine Leucocidin-Negative, Community-Acquired Methicillin-Resistant Staphylococcus aureus Bacteremia: An 11-Year Retrospective Study in Japan

Panton-Valentine leucocidin (PVL)-negative community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) was originally disseminated in Japan and has since replaced healthcare-associated MRSA (HA-MRSA). However, the clinical characteristics of CA-MRSA bacteremia (CA-MRSAB) compared with those of HA-MRSA bacteremia (HA-MRSAB) are unknown. We aim to clarify differences and investigate associations between the clinical manifestations and virulence genes associated with plasma-biofilm formation in PVL-negative CA-MRSA. From 2011 to 2021, when CA-MRSA dramatically replaced HA-MRSA, 79 MRSA strains were collected from blood cultures and analyzed via SCCmec typing and targeted virulence gene (lukSF-PV, cna, and fnbB) detection. The incidence of metastatic infection was significantly higher in CA-MRSAB than in HA-MRSAB. PVL genes were all negative, although cna and fnbB were positive in 55.6% (20/36) and 50% (18/36) of CA-MRSA strains and 3.7% (1/27) and 7.4% (2/27) of HA-MRSA strains, respectively. cna and fnbB carriage were not associated with the development of metastatic infections in MRSAB; however, the bacteremia duration was significantly longer in CA-MRSAB harboring cna. CA-MRSAB may be more likely to cause metastatic infections than HA-MRSAB. Since CA-MRSA is dominant in Japan, suspected metastatic infection foci should be identified by computed tomography, magnetic resonance imaging, and echocardiography when treating MRSAB.

Cloxacillin plus fosfomycin versus cloxacillin alone for methicillin-susceptible Staphylococcus aureus bacteremia: a randomized trial

Treatment failure occurs in about 25% of patients with methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia. We assessed whether cloxacillin plus fosfomycin achieves better treatment success than cloxacillin alone in hospitalized adults with MSSA bacteremia. We conducted a multicenter, open-label, phase III-IV superiority randomized clinical trial. We randomly assigned patients (1:1) to receive 2 g of intravenous cloxacillin alone every 4 h or with 3 g of intravenous fosfomycin every 6 h for the initial 7 days. The primary endpoint was treatment success at day 7, a composite endpoint with the following criteria: patient alive, stable or with improved quick Sequential Organ Failure Assessment score, afebrile and with negative blood cultures for MSSA, adjudicated by an independent committee blinded to treatment allocation. We randomized 215 patients, of whom 105 received cloxacillin plus fosfomycin and 110 received cloxacillin alone. We analyzed the primary endpoint with the intention-to-treat approach in 214 patients who received at least 1 day of treatment. Treatment success at day 7 after randomization was achieved in 83 (79.8%) of 104 patients receiving combination treatment versus 82 (74.5%) of 110 patients receiving monotherapy (risk difference 5.3%; 95% confidence interval (CI), -5.95-16.48). Secondary endpoints, including mortality and adverse events, were similar in the two groups except for persistent bacteremia at day 3, which was less common in the combination arm. In a prespecified interim analysis, the independent committee recommended stopping recruitment for futility prior to meeting the planned randomization of 366 patients. Cloxacillin plus fosfomycin did not achieve better treatment success at day 7 of therapy than cloxacillin alone in MSSA bacteremia. Further trials should consider the intrinsic heterogeneity of the infection by using a more personalized approach. ClinicalTrials.gov registration: NCT03959345 .

Factors for mortality in patients with persistent Staphylococcus aureus bacteremia: The importance of treatment response rather than bacteremia duration

BACKGROUND

The criteria for antibiotic failure in persistent Staphylococcus aureus bacteremia (SAB) are unclear, but treatment response and bacteremia duration are commonly used indicators of antibiotic failure. We evaluated the effects of treatment response and bacteremia duration on mortality in persistent SAB.

METHODS

We retrospectively identified patients with persistent SAB in four university-affiliated hospitals between 2017 and 2021. Bacteremia duration was calculated from the first day of active antibiotic therapy, and persistent SAB was defined as bacteremia lasting for 2 or more days. Defervescence and Pitt bacteremia score (PBS) were used to evaluate treatment response at treatment day 4. The primary outcome was 30-day in-hospital mortality. Time-dependent multivariable Cox regression analysis and subgroup analysis according to methicillin resistance were performed.

RESULTS

A total of 221 patients was included in the study, and the 30-day in-hospital mortality was 28.5%. There was no significant difference in bacteremia duration between survived and deceased patients. Independent factors for mortality included age, Charlson comorbidity index, initial PBS, pneumonia, and removal of the eradicable focus. PBS at treatment day 4 ≥ 3 was the strongest risk factor (adjusted hazard ratio [HR] = 4.260), but defervescence was not. Bacteremia duration was not an independent factor except for 13 days or more of methicillin-resistant SAB (adjusted HR = 1.064).

CONCLUSIONS

In patients with persistent SAB, PBS at treatment day 4 was associated with 30-day in-hospital mortality rather than defervescence and bacteremia duration. The results of this study could help determine early intensified treatment strategies in persistent SAB patients.

Efficacy and safety of vancomycin for the treatment of Staphylococcus aureus bacteraemia: a systematic review and meta-analysis

OBJECTIVES

To evaluate the safety and efficacy of vancomycin with the other anti-Gram-positive bacteria antibiotics in the treatment of Staphylococcus aureus bacteraemia.

METHODS

We searched the PubMed, MEDLINE, Embase and Cochrane Library databases until August 2022 for studies that compared vancomycin with other antibiotic regimens for treating Staphylococcus aureus bacteraemia. Clinical and microbiological responses, adverse events, relapse rate and mortality were considered.

RESULTS

Fifteen randomized controlled trials and nine retrospective studies were included. The efficacy and safety data of vancomycin differed from those of the comparators group. After subgroup analysis, the differences came mainly from the trials compared with daptomycin. Compared to daptomycin, vancomycin showed a lower microbiological cure rate (OR = 0.58, 95% CI = 0.41∼0.82, I2 = 0%, P = 0.002) and clinical cure rate (OR = 0.53, 95% CI = 0.42∼0.68, I2 = 3%, P < 0.00001), as well as more adverse events (OR = 3.21, 95% CI = 1.43∼7.19, I2 = 59%, P = 0.005).

CONCLUSION

The efficacy of vancomycin in treating Staphylococcus aureus bacteraemia is still excellent but slightly inferior in adverse events. However, this does not affect its use as a first-line drug. Daptomycin is expected to be a better antimicrobial drug.

Risk of Cardiac Implantable Electronic Device Infection in Patients with Bloodstream Infection: Microbiologic Effect in the Era of Positron Emission Tomography-Computed Tomography

PURPOSE OF REVIEW

Bloodstream infection (BSI) in patients with cardiac implantable electronic devices (CIEDs) is common and can prompt challenges in defining optimal management. We provide a contemporary narrative review of this topic and propose a pathogen-dependent clinical approach to patient management.

RECENT FINDINGS

BSI due to staphylococci, viridans group streptococci, and enterococci is associated with an increased risk of underlying CIED infection, while the risk of CIED infection due to other organisms is poorly defined. There is growing evidence that positron emission tomography-computed tomography may be helpful in some patients with BSI and underlying CIED. Twenty studies were included to examine the impact of microbiologic findings on the risk of CIED infection among patients with BSI. Diagnosis of CIED infection in patients with BSI without pocket findings is often difficult, necessitating the use of novel diagnostic tools to help guide the clinician in subsequent patient management.

Contemporary pharmacologic treatments of MRSA for hospitalized adults: rationale for vancomycin versus non-vancomycin therapies as first line agents

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) remains an important pathogen in the hospital setting and causes significant morbidity and mortality each year. Since the initial discovery over 60 years ago, vancomycin has remained a first-line treatment for many different types of MRSA infections. However, significant concerns related to target attainment and nephrotoxicity have spurred efforts to develop more effective agents in the last two decades.

AREAS COVERED

Newer anti-MRSA antibiotics that have been approved since 2000 include linezolid, daptomycin, and ceftaroline. As clinical evidence has accumulated, these newer agents have become more frequently used, and some are now recommended as co-first-line options (along with vancomycin) in clinical practice guidelines. For this review, a scoping review of the literature was conducted to support our findings and recommendations.

EXPERT OPINION

Vancomycin remains an important standard of care for MRSA infections but is limited with respect to nephrotoxicity and rapid target attainment. Newer agents such as linezolid, daptomycin, and ceftaroline have specific indications for treating different types of MRSA infections; however, newer agents also have unique attributes which require consideration during therapy.

Machine Learning with Alpha Toxin Phenotype to Predict Clinical Outcome in Patients with Staphylococcus aureus Bloodstream Infection

Staphylococcus aureus bloodstream (SAB) infection remains a leading cause of sepsis-related mortality. Yet, current treatment does not account for variable virulence traits that mediate host dysregulated immune response, such as SA α-toxin (Hla)-mediated thrombocytopenia. Here, we applied machine learning (ML) to bacterial growth images combined with platelet count data to predict patient outcomes. We profiled Hla phenotypes of SA isolates collected from patients with bacteremia by taking smartphone images of beta-hemolytic growth on sheep blood agar (SBA). Electronic medical records were reviewed to extract relevant laboratory and clinical data. A convolutional neural network was applied to process the plate image data for input along with day 1 patient platelet count to generate ML-based models that predict thrombocytopenia on day 4 and mortality. A total of 229 patients infected with SA strains exhibiting varying zone sizes of beta-hemolysis on SBA were included. A total of 539 images of bacterial growth on SBA were generated as inputs for model development. One-third of patients developed thrombocytopenia at onset, with an overall mortality rate of 18.8%. The models developed from the ML algorithm showed strong performance (AUC 0.92) for predicting thrombocytopenia on day 4 of infection and modest performance (AUC 0.711) for mortality. Our findings support further development and validation of a proof-of-concept ML application in digital microbiology, with a measure of bacterial virulence factor production that carries prognostic significance and can help guide treatment selection.

Methicillin-resistant Staphylococcus aureus bacteremia with elevated vancomycin minimum inhibitory concentrations

This case-control study of 25 cases with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia with vancomycin minimum inhibitory concentration (MIC) ≥ 2 µg/mL and 391 controls (MIC < 2 µg/mL) characterized the clinical characteristics, treatments, and outcomes associated with elevated vancomycin MIC. Elevated vancomycin MIC was associated with baseline hemodialysis, prior MRSA colonization, and metastatic infection.

Predictors of mortality of Staphylococcus aureus bacteremia among patients hospitalized in a Swiss University Hospital and the role of early source control; a retrospective cohort study

S. aureus bacteremia is associated with high mortality. The aim was to identify predictors of mortality among patients with S. aureus bacteremia and evaluate the role of early source control. This retrospective study was conducted at the Lausanne University Hospital, Switzerland. All episodes of S. aureus bacteremia among adult patients from 2015 to 2021 were included. During the study period, 839 episodes of S. aureus bacteremia were included, of which 7.9% were due to methicillin-resistant isolates. Bacteremias were related to bone or joint infections (268; 31.9%), followed by bacteremia of unknown origin (158; 18.8%), proven endocarditis (118; 14.1%) and lower-respiratory tract infections (79; 9.4%). Overall 28-day mortality was 14.5%. Cox multivariate regression model showed that Charlson comorbidity index > 5 (P < 0.001), nosocomial bacteremia (P 0.019), time to blood culture positivity ≤ 13 h (P 0.004), persistent bacteremia for ≥ 48 h (P 0.004), sepsis (P < 0.001), bacteremia of unknown origin (P 0.036) and lower respiratory tract infection (P < 0.001) were associated with 28-day mortality, while infectious diseases consultation within 48 h from infection onset (P < 0.001) was associated with better survival. Source control was warranted in 575 episodes and performed in 345 episodes (60.0%) within 48 h from infection onset. Results from a second multivariate analysis confirmed that early source control (P < 0.001) was associated with better survival. Mortality among patients with S. aureus bacteremia was high and early source control was a key determinant of outcome. Infectious diseases consultation within 48 h played an important role in reducing mortality.

Outcomes of Daptomycin Plus Ceftaroline Versus Alternative Therapy for Persistent Methicillin-resistant Staphylococcus aureus (MRSA) Bacteraemia

OBJECTIVES

This study aimed to evaluate both efficacy and safety of combination therapy with daptomycin plus ceftaroline (DAP/CPT) versus alternative therapy in the treatment of persistent methicillin-resistant Staphylococcus aureus bacteraemia (MRSAB).

METHODS

This retrospective, single-centre study investigated adult patients who underwent a change in antibiotic therapy for persistent MRSAB. Daptomycin plus ceftaroline was compared with alternative therapy after initial treatment with vancomycin or DAP monotherapy was modified. The primary outcome was in-hospital mortality, and several secondary efficacy and safety outcomes were evaluated.

RESULTS

A total of 68 patients with persistent MRSAB had initial therapy switched to DAP/CPT (n = 43) or alternative therapy (n = 25). In-hospital mortality was similar with DAP/CPT versus alternative therapy (16.3% vs. 16%; P = 1.0). On average, the total duration of bacteraemia was numerically 1 day less in patients switched to DAP/CPT (11.4 days vs. 12.5 days; P = 0.5). Daptomycin plus ceftaroline was de-escalated in 81% of patients after receiving combination therapy for an average of 12.5 days. Secondary outcomes, including rates of adverse events and emergence of antimicrobial resistance, were similar between the two groups.

CONCLUSIONS

Switching to DAP/CPT after approximately 1 week of persistent MRSA bacteraemia may result in similar clinical outcomes when compared with alternative therapy. Rates of adverse events and emergence of antimicrobial resistance were low without a statistically significant difference observed between DAP/CPT and alternative therapy. These findings, as well as the impact of earlier switch or prolonged treatment with the combination, require further investigation.

Persistent Methicillin-Resistant Staphylococcus aureus Bacteremia: Host, Pathogen, and Treatment

Methicillin-resistant Staphylococcus aureus (MRSA) is a devastating pathogen responsible for a variety of life-threatening infections. A distinctive characteristic of this pathogen is its ability to persist in the bloodstream for several days despite seemingly appropriate antibiotics. Persistent MRSA bacteremia is common and is associated with poor clinical outcomes. The etiology of persistent MRSA bacteremia is a result of the complex interplay between the host, the pathogen, and the antibiotic used to treat the infection. In this review, we explore the factors related to each component of the host-pathogen interaction and discuss the clinical relevance of each element. Next, we discuss the treatment options and diagnostic approaches for the management of persistent MRSA bacteremia.

Persistent bacteremia predicts poor outcomes among neutropenic patients with carbapenem-resistant gram-negative bloodstream infections receiving appropriate therapy

PURPOSE

Identifying persistent bacteremia early in patients with neutropenia may improve outcome. This study evaluated the role of follow-up blood cultures (FUBC) positivity in predicting outcomes among patients with neutropenia and carbapenem-resistant gram-negative bloodstream infections (CRGNBSI).

METHODS

This retrospective cohort study conducted between December 2017 and April 2022 included patients more than 15 years old with neutropenia and CRGNBSI, who survived for ≥ 48 h, receiving appropriate antibiotic therapy and had FUBCs. Patients with polymicrobial bacteremia within 30 days were excluded. The primary outcome was 30 day mortality. Persistent bacteremia, septic shock, recovery from neutropenia, prolonged or profound neutropenia, requirement of intensive care and dialysis, and initiation of appropriate empirical therapy were also studied.

RESULTS

In our study cohort of 155 patients, the 30 day mortality rate was 47.7%. Persistent bacteremia was common in our patient cohort (43.8%). Carbapenem resistant isolates identified in the study were K.pneumoniae (80%), E.coli (12.26%), P.aeruginosa (5.16%), A.baumanii (1.94%) and E.cloacae (0.65%). The median time for sending a FUBC was 2 days (IQR, 1-3 days). Patients with persistent bacteremia had higher mortality than those without (56.76% versus 32.1%; p < 0.001). Appropriate initial empirical therapy was given to 70.9%. Recovery from neutropenia occurred in 57.4% while 25.8% had prolonged or profound neutropenia. Sixty-nine percent (107/155) had septic shock and needed intensive care; 12.2% of patients required dialysis. Non-recovery from neutropenia (aHR, 4.28; 95% CI 2.53-7.23), presence of septic shock (aHR, 4.42; 95%CI 1.47-13.28), requirement of intensive care (aHR,3.12;95%CI 1.23-7.93), and persistent bacteremia (aHR,1.74; 95%CI 1.05-2.89) significantly predicted poor outcomes in multivariable analysis.

CONCLUSION

FUBC showing persistent bacteremia predicted poor outcomes among neutropenic patients with carbapenem-resistant gram-negative bloodstream infections (CRGNBSI) and should be routinely reported.

Prognostic significance of early platelet dynamics in Staphylococcus aureus bacteremia

BACKGROUND

Platelets are recognized as key immune effectors, but they are targets of bacterial virulence factors. In the present study, we aimed to examine the relationship between early platelet dynamics and the outcome of Staphylococcus aureus bacteremia (SAB).

METHOD

Electronic medical records of adult patients hospitalized for SAB between July 2012 and November 2020 were retrospectively reviewed for relevant demographic, laboratory, and clinical data. The outcome endpoints were mortality and microbial persistence.

RESULTS

Among the 811 patients evaluated, 29% experienced thrombocytopenia on Day 1. Platelet count nadir occurred on Days 2-3 following SAB onset, and Day 4 was a determining point of platelet count trajectory and mortality. Mortality risk was 6% or less for those with normal platelet count by Day 4 regardless of whether they experienced thrombocytopenia on Day 1, but the risk increased to 16-21% for those who experienced thrombocytopenia on Day 4 regardless of whether they had normal platelet count on Day 1 or sustained thrombocytopenia. The duration of bacteremia was prolonged by one day (median 3 d vs. 2 d) for those with sustained thrombocytopenia compared to those without.

CONCLUSION

Early platelet dynamics during SAB have prognostic significance and represent an early window for potential platelet-directed therapeutic interventions to improve outcome.

Inappropriate empirical antibiotic therapy was an independent risk factor of pediatric persistent S. aureus bloodstream infection

Persistent S. aureus bloodstream infection (PSBSI) increased the incidence of metastatic infection and mortality. We aimed to clarify its risk factors and correlation with metastatic infection and septic shock in children. This retrospective and observational study enrolled children with S. aureus bloodstream infection who admitted to Children's Hospital of Chongqing Medical University between January 2016 and December 2021. The logistic regression model was used for multivariable analyses to determine independent factors associated with PSBSI and clarify the effect of persistent S. aureus bloodstream infection and other factors on metastatic infection and septic shock. One hundred and twenty-seven children were included in this study retrospectively. There were thirty-two cases in the persistent S. aureus bloodstream infection group and ninety-five children in the non-persistent infection group. Multivariate logistic regression analysis indicated that inappropriate empirical antibiotic therapy (OR, 7.26; 95%CI, 2.48-21.30; P<0.01) was an independent risk factor of persistent S. aureus bloodstream infection. Persistent S. aureus bloodstream infection (OR, 6.40; 95%CI, 2.08-19.70; P<0.01) and community-acquired S. aureus bloodstream infection (OR, 4.75; 95%CI, 1.34-16.89; P=0.02) were independent predictors of metastatic infection. Pittsburgh bacteremia scores ≥ 2 (OR, 28.81; 95%CI, 5.26-157.99; P<0.01), hypoalbuminemia (OR, 13.34; 95%CI, 2.43-73.28; P<0.01) and persistent S. aureus bloodstream infection (OR, 5.48; 95%CI, 1.13-26.54; P=0.04) were independent risk factors of septic shock.

CONCLUSION

Inappropriate empirical antibiotic therapy was an independent risk factor of pediatric persistent S. aureus bloodstream infection. Pediatric persistent S. aureus bloodstream infection was associated with metastatic infection and septic shock.

WHAT IS KNOWN

• Pathogenic features such as Methicillin-resistant S. aureus and sources of infection such as central venous catheter related infection were risk factors of PSBSI in adults. • PSBSI increased the incidence of metastatic infection and mortality in adults.

WHAT IS NEW

• Inappropriate empirical antibiotic therapy was an independent risk factor of pediatric persistent S. aureus bloodstream infection. • Pediatric persistent S. aureus bloodstream infection was associated with metastatic infection and septic shock.

Clinical and Epidemiological Characteristics of Persistent Bacteremia: A Decadal Observational Study

Background: Bloodstream infections (BSIs), including persistent bacteremia (PB), are a leading source of morbidity and mortality globally. PB has a higher mortality rate than non- PB, but the clinical aspects of PB in terms of the causative pathogens and the presence of clearance of PB are not well elucidated. Therefore, this study aimed to describe the clinical and epidemiological characteristics of PB in a real-world clinical setting. Methods: We performed a retrospective observational survey of patients who underwent blood culture between January 2012 and December 2021 at Tohoku University Hospital. Cases of PB were divided into three groups depending on the causative pathogen: gram-positive cocci (GPC), gram-negative rods (GNRs), and Candida spp. For each group, we examined the clinical and epidemiological characteristics of PB, including differences in clinical features depending on the clearance of PB. The main outcome variable was mortality, assessed as early (30-day), late (30-90 day), and 90-day mortality. Results: Overall, we identified 31,591 cases of single bacteremia; in 6709 (21.2%) cases, the first blood culture was positive, and in 3124 (46.6%) cases, a follow-up blood culture (FUBC) was performed. Of the cases with FUBCs, 414 (13.2%) were confirmed to be PB. The proportion of PB cases caused by Candida spp. was significantly higher (29.6%, 67/226 episodes) than that for GPC (11.1%, 220/1974 episodes, p < 0.001) and GNRs (12.1%, 100/824 episodes, p < 0.001). The Candida spp. group also had the highest late (30-90 day) and 90-day mortality rates. In all three pathogen groups, the subgroup without the clearance of PB tended to have a higher mortality rate than the subgroup with clearance. Conclusions: Patients with PB due to Candida spp. have a higher late (30-90 day) and 90-day mortality rate than patients with PB due to GPC or GNRs. In patients with PB, FUBCs and confirming the clearance of PB are useful to improve the survival rate.

Redefining Staphylococcus aureus bacteremia: A structured approach guiding diagnostic and therapeutic management

The current duration of therapy in patients with Staphylococcus aureus bacteremia (SAB) is based on differentiating complicated from uncomplicated disease. While this approach allows clinicians and investigators to group SAB patients into broadly similar clinical categories, it fails to account for the intrinsic heterogeneity of SAB. This is due in part to the fact that risk factors for metastatic infection and confirmed metastatic infection are considered as equivalent in most scoring systems. In this viewpoint, we propose a two-step system of categorizing patients with SAB. Initially, patients with SAB would be categorized as 'high risk' or 'low risk' for metastatic infection based upon an initial set of diagnostic procedures. In the second step, patients identified as 'high-risk' would undergo additional diagnostic evaluation. The results of this stepwise diagnostic evaluation would define a 'final clinical diagnosis' to inform an individualized final treatment plan.

Evaluation of clinical response to empirical antimicrobial therapy on day 7 and mortality in the intensive care unit: sub-analysis of the DIANA study Japanese data

It is not clear whether evaluating the clinical response to antibiotic use at day 7 among critically ill patients accurately predicts outcomes. We aimed to evaluate the relationship between clinical response to the initial empiric therapy on day 7 and mortality.

Methods

The determinants of antimicrobial use and de-escalation in critical care (DIANA) study was an international, multicenter, observational study on antibiotic use in the intensive care unit (ICU). ICU patients ages over 18 years in whom an empiric antimicrobial regimen in Japan was initiated were included. We compared patients who were evaluated as cured or improved ("effective") 7 days after starting antibiotic treatment with patients who were evaluated as deteriorated ("failure").

Results

Overall, 217 (83%) patients were in the effective group, and 45 (17%) were in the failure group. Both the infection-related mortality rate in the ICU and the in-hospital infection-related mortality rate in the effective group were lower than those in the failure group (0% versus 24.4%; P < 0.01 and 0.5% versus 28.9%; P < 0.01, respectively).

Conclusion

Assessment of efficacy of empiric antimicrobial treatment on day 7 may predict a favorable outcome among patients suffering from infection in the ICU.

Vancomycin plus ceftaroline for persistent methicillin-resistant Staphylococcus aureus bacteremia

STUDY OBJECTIVE

The preferred antibiotic salvage regimen for persistent methicillin-resistant Staphylococcus aureus bacteremia (MRSAB) is unclear. We sought to evaluate the effectiveness and safety of vancomycin plus ceftaroline for persistent MRSAB. The primary outcome was time to MRSAB clearance post-ceftaroline initiation. Secondary outcomes included microbiological cure, hospital length of stay, 90-day readmission for MRSAB, 90-day all-cause mortality, MRSAB-related mortality, and incidence of antibiotic-associated adverse effects.

DESIGN

Single-center, retrospective cohort study between January 1, 2016, and December 31, 2021.

SETTING

State University of New York Upstate University Hospital, a 748-bed tertiary care, academic medical center in Syracuse, NY.

PATIENTS

Adult patients were included if they had blood cultures positive for MRSA ≥72 h, received vancomycin monotherapy initially, and received vancomycin plus ceftaroline for ≥24 h. Patients were excluded if they received other anti-MRSA antibiotics, were pregnant, or were incarcerated. Of the 178 patients identified, 30 unique patients were evaluated.

MEASUREMENTS AND MAIN RESULTS

Patients were medically complex with a median Pitt bacteremia score of 3, 63.3% (19/30) were admitted to the intensive care unit, and 66.7% (20/30) had infective endocarditis. Vancomycin-associated acute kidney injury was observed in 10% (3/30) of patients, which resulted in dose adjustments. No patients experienced ceftaroline-associated neutropenia or Clostridioides difficile infection, but 6.7% (2/30) developed a rash attributed to ceftaroline. Median time to MRSAB clearance post-ceftaroline initiation was 2.6 days. Microbiologic cure occurred in nearly all patients 96.7% (29/30). Median hospital length of stay was 19.5 days, and 6.7% (2/30) of patients had 90-day readmission for MRSAB. 90-day all-cause mortality and MRSAB-related mortality occurred in 26.7% (8/30) and 13.3% (4/30) of patients, respectively.

CONCLUSIONS

Vancomycin plus ceftaroline may represent an effective and well-tolerated salvage regimen option for persistent MRSAB.