Pitt Bacteremia Score Research Articles

Attributable mortality and excess length of stay associated with third-generation cephalosporin-resistant Enterobacterales bloodstream infections: a prospective cohort study in Suva, Fiji

There are scant primary clinical data on antimicrobial resistance (AMR) burden from low- and middle-income countries (LMICs). We adapted recent World Health Organization methodology to measure the effect of third-generation cephalosporin resistance (3GC-R) on mortality and excess length of hospital stay in Fiji. We conducted a prospective cohort study of inpatients with Enterobacterales bloodstream infections (BSIs) at Colonial War Memorial Hospital, Suva. We used cause-specific Cox proportional hazards models to estimate the effect of 3GC-R on the daily risk (hazard) of in-hospital mortality and being discharged alive (competing risks), and we used multistate modelling to estimate the excess length of hospital stay. From July 2020 to February 2021 we identified 162 consecutive Enterobacterales BSIs; 3GC-R was present in 66 (40.7%). Crude mortality for patients with 3GC-susceptible and 3GC-R BSIs was 16.7% (16/96) and 30.3% (20/66), respectively. 3GC-R was not associated with the in-hospital mortality hazard rate (adjusted hazard ratio [aHR] 1.13, 95% confidence interval [CI] 0.51-2.53) or being discharged alive (aHR 0.99, 95% CI 0.65-1.50), whereas Charlson comorbidity index score (aHR 1.62, 95% CI 1.36-1.93) and Pitt bacteraemia score (aHR 3.57, 95% CI 1.31-9.71) were both associated with an increased hazard rate of in-hospital mortality. 3GC-R was associated with an increased length of stay of 2.6 days (95% CI 2.5-2.8). 3GC-R was more common among hospital-associated infections, but genomics did not identify clonal transmission. Patients with Enterobacterales BSIs in Fiji had high mortality. There were high rates of 3GC-R, which was associated with increased hospital length of stay but not with in-hospital mortality.

Molecular epidemiology and outcome of carbapenem-resistant Enterobacterales in Saudi Arabia

BackgroundThe burden of carbapenem resistance is not well studied in the Middle East. We aimed to describe the molecular epidemiology and outcome of carbapenem-resistant Enterobacterales (CRE) infections from several Saudi Arabian Centers.MethodsThis is a multicenter prospective cohort study conducted over a 28-month period. Patients older than 14 years of age with a positive CRE Escherichia coli or Klebsiella pneumoniae culture and a clinically established infection were included in this study. Univariate and multivariable logistic models were constructed to assess the relationship between the outcome of 30-day all-cause mortality and possible continuous and categorical predictor variables.ResultsA total of 189 patients were included. The median patient age was 62.8 years and 54.0% were male. The most common CRE infections were nosocomial pneumonia (23.8%) and complicated urinary tract infection (23.8%) and 77 patients (40.7%) had CRE bacteremia. OXA-48 was the most prevalent gene (69.3%). While 100 patients (52.9%) had a clinical cure, 57 patients (30.2%) had died within 30 days and 23 patients (12.2%) relapsed. Univariate analysis to predict 30-day mortality revealed that the following variables are associated with mortality: older age, high Charlson comorbidity index, increased Pitt bacteremia score, nosocomial pneumonia, CRE bacteremia and diabetes mellitus. In multivariable analysis, CRE bacteremia remained as an independent predictor of 30 day all-cause mortality [AOR and 95% CI = 2.81(1.26–6.24), p = 0.01].ConclusionsThese data highlight the molecular epidemiology and outcomes of CRE infection in Saudi Arabia and will inform future studies to address preventive and management interventions.

Different clinical characteristics and impact of carbapenem-resistance on outcomes between Acinetobacter baumannii and Pseudomonas aeruginosa bacteraemia: a prospective observational study

This study aimed to evaluate the differences in clinical characteristics and impact of carbapenem resistance (CR) on outcomes between Acinetobacter baumannii (Ab) and Pseudomonas aeruginosa (Pa) bacteraemia. We prospectively identified all patients with Ab and Pa bacteraemia in 10 hospitals over 1 year. Treatment failure was defined as all-cause 30-day mortality, persistent bacteraemia, or recurrent bacteraemia within 30 days. We included 304 Ab and 241 Pa bacteraemia cases. CR was detected in 216 patients (71%) with Ab bacteraemia and 55 patients (23%) with Pa bacteraemia. Treatment failure was significantly higher in CR-Ab than in CR-Pa (60.6% vs. 34.5%, P = 0.001). In Ab, severe sepsis or septic shock and high Pitt bacteraemia score were independent risk factors for treatment failure in the inappropriate empirical antibiotics group. In Pa, hospital-acquired infection and high Pitt bacteraemia score were independent risk factors for treatment failure in both groups. CR was an independent risk factor in Ab for treatment failure in both groups, but not in Pa bacteraemia. We demonstrated significant differences in clinical characteristics and impact of CR on clinical outcomes between Ab and Pa bacteraemia, suggesting that different treatment approaches may be needed.

Bloodstream Infections in Hematologic Malignancy Patients With Fever and Neutropenia: Are Empirical Antibiotic Therapies in the United States Still Effective?

BackgroundRising antimicrobial resistance rates may impact the efficacy of empirical antibiotic treatment for febrile neutropenia in high-risk cancer patients. Lacking contemporary data about the epidemiology, antibiotic resistance patterns, and clinical outcomes from bloodstream infections (BSIs) in US cancer patients, it is unclear if current guidelines remain relevant.MethodsIn a cross-sectional study, 14 US cancer centers prospectively identified BSIs in high-risk febrile neutropenic (FN) patients, including those receiving chemotherapy for hematologic malignancies or hematopoietic stem cell transplantation.ResultsAmong 389 organisms causing BSI in 343 patients, there was an equal distribution of gram-negative (GN) and gram-positive (GP) bacteria, with variability across centers. Cefepime and piperacillin-tazobactam were the most commonly prescribed empirical antibiotics for FN, at 62% and 23%, respectively; a GP-directed agent was empirically included in nearly half of all FN episodes within the first 24 hours. Susceptibility to fluoroquinolones, cefepime, piperacillin-tazobactam, and carbapenems was 49%, 84%, 88%, and 96%, respectively, among GN isolates. Critical illness (CrI), defined as a new requirement for mechanical ventilation, vasopressor, or death within 30 days, occurred in 15% and did not correlate with fluoroquinolone prophylaxis, organism type, initial antibiotics, or adequacy of coverage. Only severity of illness at presentation, signified by a Pitt bacteremia score ≥2, predicted for critical illness within 30 days. Mortality was 4% by day 7 and 10% overall.ConclusionsIn accordance with US guidelines, cefepime or piperacillin-tazobactam remain effective agents or empirical treatment for high-risk cancer patients with FN who are stable at presentation, maintaining high GN pathogen susceptibility and yielding excellent outcomes.

Effectiveness of antimicrobial stewardship programmes based on rapid antibiotic susceptibility testing of haematological patients having high-risk factors for bacteraemia-related mortality: a post-hoc analysis of a randomised controlled trial

A randomised controlled trial showed that rapid phenotypic antibiotic susceptibility testing (AST) with antimicrobial stewardship programme (ASP) increases the proportion of haematological patients with bacteraemia receiving optimal targeted therapy within 72 h of blood culture collection. This post-hoc analysis aimed to evaluate the effects of rapid phenotypic AST intervention in haematological patients at high risk of a poor outcome from bacteraemia. Haematological patients with bacteraemia (n=116) were assigned randomly to a conventional AST group or a rapid AST group. The two outcome measures were the proportion of patients receiving optimal targeted therapy at 72 h post blood culture collection and the time to optimal targeted therapy; subgroup analysis was conducted based on baseline demographics (age, sex) and prognostic (Charlson comorbidity index, haematological treatment intensity, Pitt bacteraemia score, appropriateness of empirical antibiotic therapy and multidrug-resistant organism) indicators. The interaction effect between the intervention and subgroup factors was examined using regression model analysis. Age, sex, Charlson comorbidity index, haematological treatment intensity, Pitt bacteraemia score and appropriateness of empirical antibiotic therapy had no significant interaction effects on the proportion of patients receiving optimal targeted therapy (P=0.129-0.826). However, infection by a multidrug-resistant organism did have a significant interaction effect (P=0.042). Regarding time to optimal targeted therapy, there were no significant interaction effects between the intervention and subgroup factors (P=0.156-0.848). In conclusion, rapid phenotypic AST with ASP intervention may accelerate early optimal targeted antimicrobial treatment of haematological patients, even those in high-risk subgroups with bacteraemia.

Clinical Outcomes and Adverse Effects in Septic Patients with Impaired Renal Function Who Received Different Dosages of Cefoperazone-Sulbactam.

This study aimed to compare clinical outcomes and adverse effects in septic patients with impaired renal function who received different dosages of cefoperazone–sulbactam (CFP–SUL 1 g/1 g or 2 g/2 g every 12 h). The retrospective study was conducted using the Chang Gung Research Database to include adult patients who had renal insufficiency presented with septicemia caused by Gram-negative organisms and had received CFP–SUL for more than 1 week. A total of 265 patients (44 in the CFP–SUL 1 g/1 g group and 221 in the CFP–SUL 2 g/2 g group) were eligible to be included in this study. After 1:3 propensity score matching, 41 and 123 patients in the CFP–SUL 1 g/1 g and CFP–SUL 2 g/2 g groups, respectively, were included for analyses. There were no significant between-group differences in all-cause mortality rates and adverse effects, including prolonged prothrombin time. A logistic regression model showed that the Pitt bacteremia score was related to all-cause mortality rate and prolonged prothrombin time was associated with renal replacement therapy. The adverse effects of CFP–SUL did not increase in septic patients with impaired renal function receiving CFP–SUL 2 g/2 g Q12H. However, this study may be underpowered to reveal a difference in all-cause mortality.

Influence of daptomycin dose and fosfomycin susceptibility on outcome of vancomycin-resistant Enterococcus faecium bloodstream infections treated with daptomycin and fosfomycin combination.

Synergistic combinations of daptomycin and β-lactam antibiotics are currently recommended for treatment of VRE bloodstream infection (BSI). The efficacy of these combinations is jeopardized by VRE inherently resistant to β-lactam antibiotics. The combination of daptomycin and fosfomycin is recommended as an alternative therapy for VRE BSI; however, clinical data to support use of this combination are lacking. We conducted a prospective observational multicentre study of patients treated with a combination of daptomycin and fosfomycin for VRE BSI during 2016-20. The primary outcome was 28 day mortality. Multivariable logistic regression was performed for outcome analysis. The study included 106 patients from 1112 VRE BSI episodes. The overall 28 day mortality was 40.6%. The median (IQR) daptomycin dose was 10.18 mg/kg (9.43-10.70). The fosfomycin dose was 16 g/day (8-22.5). Ninety-six isolates were available for MIC testing. The fosfomycin MIC was 32 mg/L in 6 (6.3%), 64 mg/L in 68 (70.8%) and ≥128 mg/L in 22 (22.9%) isolates. Independent of Charlson comorbidity index and Pitt bacteraemia score, fosfomycin MIC ≥128 mg/L [adjusted OR (aOR) = 3.05; 95% CI = 1.01-9.19; P = 0.047] and daptomycin dose (aOR = 0.64; 95% CI = 0.43-0.97; P = 0.04) predicted mortality. Higher daptomycin dose and susceptibility to fosfomycin were independently associated with lower mortality in patients with VRE BSI. Our results suggest that higher doses of daptomycin are indicated for VRE BSI, whether or not it is used in combination with fosfomycin. The combination was less effective for patients with fosfomycin-resistant isolates.

Frequency and Clinical Features of Candida Bloodstream Infection Originating in the Urinary Tract.

The urinary tract is considered an uncommon source of Candida bloodstream infection (CBSI). We aimed to determine the source of CBSI in hospitalized patients, and to compare clinical and microbiological features of CBSI originating in the urinary tract (U-CBSI) and non-urinary CBSI (NU-CBSI). Of 134 patients with CBSI, 28 (20.8%) met criteria for U-CBSI, 34 (25.3%) had vascular catheter-related CBSI and 21 (15.6%) had a gastrointestinal origin. Compared to NU-CBSI patients, patients with U-CBSI were older with higher rates of dementia. Bladder catheterization for urinary retention and insertion of ureteral stents or nephrostomies were risk factors for U-CBSI. Fifty percent of U-CBSI cases occurred within 48 h of hospital admission, versus 16.9% of NU-CBSI (p < 0.0001). The mortality rate was lowest for CBSI originating in the urinary tract and highest for CBSI of undetermined origin. CBSI of undetermined origin remained associated with higher mortality in a Cox regression model that included age, Candida species, Pitt bacteremia score and neutropenia as explanatory variables. U-CBSI may be increasing in frequency, reflecting extensive use of bladder catheters and urologic procedures in elderly debilitated patients. Distinct clinical features are relevant to the diagnosis, treatment and prevention of U-CBSI.

Comparison of quick Pitt to quick sofa and sofa scores for scoring of severity for patients with urinary tract infection

Quick Pitt (qPitt), which includes temperature, systolic blood pressure, respiratory rate, cardiac arrest, and mental status, is a new prognostic score derived from the Pitt Bacteremia score. The aim of our study is to compare qPitt with quick SOFA (qSOFA) and SOFA for scoring of severity in patients with urinary tract infection (UTI). Prospective observational study of patients diagnosed with UTI. Area under the ROC curve, sensibility, and specificity to predict 30-day mortality were calculated for qPitt, qSOFA and SOFA and compared. 382 UTI cases were analyzed. Thirty-day mortality (18.8% vs. 5.9%, p < 0.001) and longer hospital stay (6 [1–11] vs. 4 [1–7] days, p < 0.001) were associated with qPitt ≥ 2. However, qPitt had a worse performance to predict 30-day mortality compared to qSOFA and SOFA (AUROC 0.692 vs. 0.832 and 0.806, respectively, p = 0.010 and p = 0.041). The sensitivity of qPitt was lower than the sensitivity of qSOFA and SOFA (70.45 vs. 84.09 for both qSOFA and SOFA, p < 0.001), with a specificity lower than qSOFA and similar to SOFA (60.36 vs. 82.25 and 63.61, p < 0.001 and p = 0.742, respectively). Quick Pitt had moderate prognostic accuracy and performed worse than qSOFA and SOFA scores for predicting mortality in patients with UTI.

Quantitative Evaluation of the Economic Impact of Antimicrobial Resistance on the Treatment of Community-Acquired Acute Pyelonephritis in Korea.

BackgroundThe proportion of antimicrobial-resistant Enterobacteriales as a causative pathogen of community-acquired acute pyelonephritis (APN) has been increasing. The aim of this study was to quantitatively evaluate the impact of antimicrobial resistance on medical costs and length of hospital stay for the treatment of APN.Materials and MethodsA single-center retrospective cohort study was conducted between January 2018 and December 2019. All hospitalized patients aged ≥19 years who were diagnosed with community-acquired APN were recruited, and those diagnosed with Enterobacteriales as a causative pathogen were included. Log-linear regression analysis was performed to determine the risk factors for medical costs and length of hospital stay.ResultsA total of 241 patients participated in this study. Of these, 75 (31.1%) and 87 (36.1%) had extended-spectrum beta-lactamase (ESBL)-producing pathogens and ciprofloxacin-resistant pathogens as the causative pathogen, respectively. Based on the log-linear regression model, ESBL-producing Enterobacteriales is a causative pathogen that is, on average, 27.0%, or United States Dollar (USD) 1,211 (P = 0.026) more expensive than non-ESBL-producing Enterobacteriales. A patient who is a year older would incur USD 23 (P = 0.040) more, those having any structural problems in the urinary tract would incur USD 1,231 (P = 0.015) more, and those with a unit increase in the Pitt bacteremia score would incur USD 767 (P <0.001) more, with all other variables constant. Having a case in which ESBL-producing Enterobacteriales is a causative pathogen would explain staying 22.0% longer or 2 more days (P = 0.050) in the hospital than non-ESBL-producing Enterobacteriales. A patient who is 10 years older would, on average, would have to stay for half a day longer (P = 0.045). Any structural problems in the urinary tract explain a longer stay (2.4 days longer; P = 0.032), and moving from 0 to 5 on the Pitt bacteremia score would explain four more days (P = 0.038) in the hospital.ConclusionPatients with community-acquired APN with ESBL-producing Enterobacteriale as the causative pathogen would incur, on average, 27.0% higher medical costs and 22.0% longer hospitalization days than patients detected with non-ESBL-producing pathogens.

Evaluation of step-down oral antibiotic therapy for uncomplicated streptococcal bloodstream infections on clinical outcomes.

Background:Despite the severity and frequency of streptococcal bloodstream infections (BSIs), the effectiveness of oral definitive therapy remains unknown. The objective of this study was to evaluate the clinical outcomes of step-down oral antibiotics for the treatment of uncomplicated streptococcal BSIs.Methods:In this retrospective cohort study, adult patients admitted with uncomplicated streptococcal BSI between June 2015 and June 2017 were included. Patients were excluded if they received <48 h of antibiotic therapy; therapy was started >48 h after first positive culture; had complicated infections of endocarditis, bone and joint infections, or central nervous system infections; Pitt bacteremia score (PBS) ⩾ 4; or failed to respond to effective therapy necessitating continued intravenous (IV) therapy. Patients were grouped by receipt of step-down oral antibiotic therapy (PO group) versus continued IV therapy (IV group). Outcomes included hospital length of stay (LOS), 30-day recurrence of BSI, 30-day readmission, 30-day all-cause mortality, and catheter-related or drug-related adverse events (AEs).Results:Of 244 patients included, 40% received step-down oral therapy (n = 98). Overall, the most common source of BSI was pneumonia (22%), followed by skin and soft tissue infections (SSTI) (18%). Severity of illness measured by intensive care unit (ICU) admission and PBS was similar. The IV group had significantly longer LOS [median 10 (interquartile range [IQR] = 5–21) versus 5 (4–6) days, p < 0.01] compared with the PO group. BSI recurrence, readmission, all-cause mortality within 30 days, and AEs were similar between the groups (p = ns).Conclusion:In uncomplicated streptococcal BSI, patients treated with step-down oral antibiotic therapy had significantly shorter LOS compared with continued IV therapy without compromise of clinical outcomes.

Re-evaluation of cefepime or piperacillin-tazobactam to decrease use of carbapenems in extended-spectrum beta-lactamase-producing Enterobacterales bloodstream infections (REDUCE-BSI).

To re-examine the use of noncarbapenems (NCBPs), specifically piperacillin-tazobactam (PTZ) and cefepime (FEP), for extended-spectrum beta-lactamase-producing Enterobacterales bloodstream infections (ESBL-E BSIs). Retrospective cohort study. Tertiary-care, academic medical center. The study included patients hospitalized between May 2016 and May 2019 with a positive blood culture for ESBL-E. Patients were excluded if they received treatment with antibiotics other than meropenem, ertapenem, PTZ, or FEP. Patients were also excluded if they were aged <18 years, received antibiotics for <24 hours, were treated for polymicrobial BSI, or received concomitant antibiotic therapy for a separate gram-negative infection. We compared CBPs with FEP or PTZ for the treatment of ESBL-E BSI. The primary outcome was in-hospital mortality. Secondary outcomes included clinical cure, microbiologic cure, infection recurrence, and resistance development. Data from 114 patients were collected and analyzed; 74 (65%) patients received carbapenem (CBP) therapy and 40 (35%) patients received a NCBP (30 received FEP and 10 received PTZ). The overall in-hospital mortality was 6% (N = 7), with a higher death rate in the CBP arm than in the N-CBP arm, (8% vs 3%; P = .42). No difference in mortality was detected between subgroups with Pitt bacteremia score ≥4, those requiring ICU admission, those whose infections were cause by a nongenitourinary source or causative organism (ie, 76 had Escherichia coli and 38 had Klebsiella spp). We detected no differences in secondary outcomes between the groups. Compared to CBPs, FEP and PTZ did not result in greater mortality or decreased clinical efficacy for the treatment of ESBL-E BSI caused by susceptible organisms.

Association of capsular polysaccharide locus 2 with prognosis of Acinetobacter baumannii bacteraemia

ABSTRACT Acinetobacter baumannii causes healthcare-associated infections worldwide. Capsular polysaccharide (CPS) is shown an important virulence factor of A. baumannii both in vitro and in vivo. Capsule locus 2 (KL2) for CPS is the most common KL type and is associated with carbapenem resistance. It is unclear whether KL2 is related to the clinical outcome of invasive A. baumannii infection. Here we had followed patients with A. baumannii bacteraemia prospectively between 2009 and 2014. One-third of the unduplicated blood isolates were randomly selected each year for microbiological and clinical studies. The KL2 gene cluster was identified using polymerase chain reaction. A total of 148 patients were enrolled randomly. Eighteen isolates (12.2%) carried KL2, and 130 isolates (87.8%) didn’t. Compared with non-KL2 isolates, KL2 isolates had significantly higher resistance to imipenem, sulbactam, and tigecycline. Compared with the non-KL group, in the KL2 group, the hospital stay before development of bacteraemia was longer (P < 0.001), a higher percentage had pneumonia (P = 0.004), and the white blood cell count was lower (P = 0.03). Infection with KL2 A. baumannii predicted mortality (adjusted hazard ratio [aHR], 2.03; 95% confidence interval [CI], 1.09–3.78; P = 0.03), independently of the Pitt bacteraemia score (aHR, 1.34; 95% CI, 1.23–1.46; P < 0.001) and leucopenia (aHR, 2.16; 95% CI, 1.30–3.57; P = 0.003). Thrombocytopenia contributed to the effect of KL2 on mortality in bacteraemia (Sobel test P = 0.01). Large-scale studies are warranted to confirm these findings and the underlying mechanisms deserve further investigation.

Prediction of Mortality in Patients with Sepsis Due to Gram-negative Bacteremia: Pitt Bacteremia Score, qSOFA, SIRS

Prediction of Mortality in Patients with Sepsis Due to Gram-negative Bacteremia: Pitt Bacteremia Score, qSOFA, SIRS

Prediction of mortality in Staphylococcus aureus bloodstream infection using quick Pitt bacteremia score

ObjectivesThe quick Pitt bacteremia score (qPitt) predicts mortality in patients with serious infections due to gram-negative bacteria. This retrospective cohort study examines utility of qPitt to predict mortality in patients with Staphylococcus aureus bloodstream infection (SAB). MethodsMultivariate logistic regression was used to examine risk factors for 28-day mortality in hospitalized adults with SAB at four Prisma Health hospitals in South Carolina, USA from January 2015 to December 2017. Area under receiver operating characteristic curve (AUROC) was used to examine model discrimination. ResultsAmong 692 patients with SAB, 305 (44%) had methicillin-resistant S. aureus (MRSA), and 129 (19%) died within 28 days. After adjustment for age, comorbidities, and MRSA, each component of the qPitt was associated with 28-day mortality. There was a 3-fold increase in the risk of 28-day mortality for each one-point increase in qPitt. Predicted 28-day mortality was 3%, 9%, 22%, 45%, and 70% for qPitt of 0, 1, 2, 3, and ≥4, respectively. AUROC of the qPitt in predicting 28-day, 14-day, and in-hospital mortality were 0.80, 0.81, and 0.80, respectively. ConclusionsThe qPitt predicts mortality with good discrimination in SAB. These results support using qPitt as a measure of acute severity of illness in future studies.

193. Evaluation of Severity Scores in Patients with Methicillin-Susceptible Staphylococcus aureus Bloodstream Infections

Abstract Background Staphylococcus aureus bloodstream infections (BSIs) are associated with increased morbidity, mortality, and healthcare costs. Severity of illness scores help stratify critically ill patients and assist providers in making decisions. The quick Pitt (qPitt) score is a reliable predictor of mortality in patients with Gram-negative BSIs (AUROC 0.85); however, limited data exist for using the qPitt in methicillin-susceptible S. aureus (MSSA) BSIs. Methods This retrospective cohort evaluated patients with MSSA BSIs. The primary outcome was the discrimination of the qPitt in predicting hospital mortality compared to the Pitt bacteremia score (PBS). Secondary outcomes were clinical failure and the predictive discrimination of the qPitt score in comparison to other severity scoring modalities. Categorical data were analyzed using chi-square test or Fisher’s exact test. Continuous data were analyzed using Student’s t-test or Mann-Whitney U. Predictive discrimination was determined by the area under receiver operating characteristic curve. Results One hundred patients were included with the mean age of 52 years (p=0.84) and a BMI of 30 kg/m2. Males were predominant (70%). Mortality occurred in 13 patients who had more ICU admissions (92% vs. 37%; p&amp;lt; 0.01) and longer ICU LOS (10 vs. 5 days; p=0.03) despite similar baseline comorbidities. Time to definitive therapy was longer in the mortality group than non-mortality group (28 vs. 23 hours; p=0.79) though antimicrobial use did not differ. As outlined in Figure 1, the mortality group had higher severity of illness scores. The qPitt had a ROC of 0.83, indicating high discrimination. Overall, qPitt was found to be similarly predictive than PBS, equally as predictive as qSOFA, and more predictive than SIRS and APACHE II (Figure 1). Clinical failure occurred in 23% of patients; 54% of the mortality group experienced persistent BSI vs. 11% in the non-mortality group (p&amp;lt; 0.01), and 3% of the non-mortality group had recurrent infection (p=1.00). Conclusion Compared to previous studies on Gram-negative BSIs, the qPitt performed similarly in MSSA BSIs. The qPitt can be considered for use in predicting mortality for patients with MSSA BSIs; however, further studies are needed to confirm these results. Disclosures All Authors: No reported disclosures

187. Vancomycin Plus Ceftaroline Salvage Therapy for Persistent Methicillin-Resistant Staphylococcus aureus Bacteremia

BackgroundThe preferred antibiotic salvage regimen for persistent methicillin-resistant Staphylococcus aureus bacteremia (pMRSAB) is unclear. Vancomycin plus ceftaroline (V/C) has demonstrated potent in vitro synergistic activity against MRSA; however, clinical data is limited. Thus, we sought to evaluate V/C salvage therapy for pMRSAB.MethodsThis was a single-center, retrospective cohort study of patients with MRSAB who received V/C salvage therapy between 1/1/2016-3/10/2021. Adult patients were included if blood cultures (BC) were positive for MRSA for ≥ 72 hours, received anti-MRSA monotherapy initially, and subsequently received V/C ≥ 24 hours. Patients were excluded if they received other anti-MRSA antibiotics within 72 hours of V/C initiation. The primary outcome was time to BC clearance following V/C initiation. Secondary outcomes included 90-day all-cause mortality, microbiological cure, 90-day MRSAB recurrence, and length of stay (LOS). Microbiological cure was defined as BC clearance.ResultsOf 178 patients identified, 20 were evaluated after inclusion and exclusion criteria were applied. Mean (SD) age and Pitt Bacteremia score were 38.5 (14.5) years and 4.2 (3.1), respectively. Most patients were male (70%), intravenous drug users (65%), and admitted to the intensive care unit (65%). The most common source was intravenous drug use (55%) and the majority had infective endocarditis (70%). All patients received infectious disease consultation and median (IQR) vancomycin AUC:MIC was 527 (454, 611). Source control, if possible, was obtained in most patients (55%). Median (IQR) time to bloodstream clearance from first positive BC and from when ceftaroline was initiated was 9.7 (8.4, 10.2) and 2.4 (1.5, 3.1) days, respectively. 90-day all-cause mortality, microbiological cure, and 90-day MRSAB recurrence occurred in 35%, 95%, and 5% of patients, respectively. Median (IQR) LOS was 25 (14.5, 32.0) days.ConclusionTo our knowledge, this is the largest cohort to evaluate V/C for pMRSAB. Patients were medically complex; however, median time to MRSAB clearance following ceftaroline initiation was < 2.5 days and microbiological cure was obtained in nearly all patients. V/C may represent a potential salvage regimen for pMRSAB.Disclosures Wesley D. Kufel, PharmD, Melinta (Research Grant or Support)Merck (Research Grant or Support)Theratechnologies, Inc. (Advisor or Review Panel member) Jeffrey Steele, Pharm.D., Paratek Pharmaceuticals (Advisor or Review Panel member)

191. Oral Antibiotic Step-Down Therapy for Non-Staphylococcal Gram-Positive Bloodstream Infections

BackgroundBloodstream infections are traditionally treated with intravenous (IV) antimicrobial therapy, which may increase length of stay and healthcare costs. The purpose of this study is to evaluate if oral antibiotic step-down therapy for non-staphylococcal gram-positive bloodstream infections (GP-BSIs) is non-inferior to IV antibiotics.MethodsThis single-center, retrospective cohort study included patients with a non-Staphylococcus aureus, non-Staphylococcus lugdunensis GP-BSI from January 2017 to December 2019. Patients were excluded if they fit any of the following criteria: organism identified as contaminant, polymicrobial BSI, recurrent BSI within the past 90 days, or receipt of an effective antibiotic for a duration longer than what is indicated for BSI treatment. Patients were categorized into those who received an IV antibiotic for the total duration of therapy and those who received an oral step-down antibiotic for at least one-third of the treatment course. The primary composite outcome was the incidence of 90-day clinical failure consisting of 90-day all-cause mortality, change in therapy due to inadequate clinical response, and 90-day BSI recurrence. The secondary outcomes included the individual components of the primary composite outcome, line-related complications, and hospital length of stay. Bivariate analysis was conducted to assess for predictors of 90-day clinical failure.ResultsA total of 308 patients were included (oral group, n=94; IV group, n=214). Pitt Bacteremia Scores were low overall, but higher in the IV group (0 vs 1, p=0.045). The oral group had a higher proportion of GP-BSI caused by streptococcal species (76% vs 61%, p< 0.001). The oral group had a lower incidence of 90-day clinical failure and was found to be noninferior to the IV group (9% vs 14%; mean difference -5%, 90% CI -12.7 to 2.6). The IV group had a longer hospital length of stay (4 vs 6 days, p< 0.001), however there were no other significant differences in secondary outcomes. Bivariate analysis found no significant predictors of 90-day clinical failure.ConclusionOral antibiotic step-down therapy was found to be non-inferior to IV antibiotic therapy, and thus may be an alternative option for the treatment of non-staphylococcal GP-BSIs.Disclosures All Authors: No reported disclosures

1239. Ceftaroline versus Vancomycin as First-Line Therapy for MRSA Bacteremia

BackgroundBeta-lactams have demonstrated superior outcomes over vancomycin in MSSA bacteremia. Despite this, studies of the anti-MRSA beta-lactam ceftaroline in MRSA bacteremia (MRSAB) are largely limited in size or focus on combination or salvage regimens. This study sought to further examine ceftaroline as first-line therapy for MRSAB.MethodsThis was a retrospective matched cohort study at the San Diego VA Medical Center between November 2010 and June 2020. Patients had to have received at least 72 hours of ceftaroline or vancomycin for MRSAB and less than 72 hours of prior MRSA therapy. Adjunct MRSA therapy was allowed only if routinely indicated for the infection (e.g. rifampin for prosthesis). Patients in the vancomycin group were matched 1:1 to patients in the ceftaroline group by age (+/- 10 years) and Pitt bacteremia score (+/- 1 point). The primary outcome was duration of bacteremia after initiation of MRSA therapy, including time on prior MRSA therapy.ResultsFifteen patients were included in each group, with a median age of 65 years and Pitt bacteremia score of 0. Patients in the ceftaroline group were more likely to have CKD; to have been on a different MRSA agent prior to initiation of the study drug, with a median of 1 day of prior treatment; and to have been on adjunctive rifampin or clindamycin. Though not significant, more patients in the ceftaroline group also had endovascular sources, uncontrolled sources, and longer durations of therapy. The median duration of bacteremia after initiation of MRSA therapy did not significantly differ between ceftaroline and vancomycin (4 vs. 3 days, p = 0.806). In addition, 30-day all-cause mortality, in-hospital mortality, 90-day readmission or treatment failure, inpatient length of stay, total duration of bacteremia, and rate of adverse events did not significantly differ between groups.ConclusionThis study suggests ceftaroline may be an appropriate first-line agent for the treatment of MRSA bacteremia with similar outcomes between groups despite the ceftaroline group likely experiencing more difficult-to-treat infections. However, it was not powered to detect differences between groups, and its retrospective nature has the potential to introduce bias. Prospective comparative studies are needed to corroborate these findings.Disclosures All Authors: No reported disclosures

49. Impact of a Rapid Genotypic Platform for Gram-negative Bloodstream Infections, Paired with an Antimicrobial Stewardship Intervention, on Time to Optimal Antimicrobial Therapy

BackgroundGram-negative bacteremia is associated with significant morbidity and mortality. Development of an algorithm for antimicrobial selection, using institution-specific antibiogram data and rapid diagnostics (RDT), achieves timely and appropriate antimicrobial therapy. The objective of this study is to assess the impact of a pharmacy-driven antimicrobial stewardship initiative in conjunction with ePlex® BCID on time to optimal antimicrobial therapy for patients with gram-negative bloodstream infections. MethodsThis retrospective, observational, single-center study included adult patients with a documented gram-negative bloodstream infection in whom the ePlex® BCID was employed. A pharmacist-driven antimicrobial stewardship intervention was initiated on December 1, 2020; pre-intervention (December 2019 – March 2020) was compared to the post-intervention (December 2020 – February 2020) period. The following organisms were included: Citrobacter spp., Escherichia coli, Klebsiella aerogenes/pneumoniae/oxytoca, Proteus spp, Enterobacter spp., Pseudomonas aeruginosa, and Acinetobacter baumannii. Polymicrobial bloodstream infections or those who had an ePlex® panel performed prior to admission were excluded. The following clinical outcomes were assessed: time to optimal antimicrobial therapy, length of stay (LOS), and inpatient-30-day mortality.ResultsOne hundred and sixty-three met criteria for inclusion; 98 patients in the pre-intervention group and 65 patients in the post-intervention group. The mean Pitt Bacteremia Score was 1 in both groups (p=0.741). The most common organism identified by ePlex® BCID was E. coli (65.3% vs 70.8%; p=0.676). Eight E. Coli isolates were CTX-M positive; no other gene targets were detected. The most common suspected source of bacteremia was genitourinary (72.5% vs 72.3%; p=1.0). Time to optimal therapy was reduced by 29 hours [37 (31 – 55) vs. 8 (4 – 28); p=0.048). Length of stay and mortality was similar between groups. ConclusionImplementation of a rapid blood culture identification panel along with an antimicrobial stewardship intervention significantly reduced time to optimal therapy. Further studies are warranted to confirm these results. Disclosures All Authors: No reported disclosures