bluuebunny/crossref_metadata_2025_split huggingface dataset:
1023. A Controlled-Release Prescription Oral Opioid Can Prolong S. aureus Survival in Injection Drug Preparation Equipment and Potentially Increase Bacteremia Risk
Authors: Kasper Katherine , Manoharan Iswarya , Glockler-Lauf Dresden , Ball Laura , Hallam Brian , Koivu Sharon , McCormick John , Silverman Michael 
Published: November 2018

Abstract

Background
S. aureus is the most common pathogen associated with injection drug use-associated endocarditis (IDUaIE). Our center has a high incidence of IDUaIE and the opiate of choice in our population is hydromorphone-controlled release (HCR), a prescribed oral opiate widely used in Canada and Europe. The complex technique for preparation for injection provides multiple opportunities for contamination of the solution and the controlled-release preparation contains several excipients (carbohydrates, protein, and iron), which could enhance Staphylococcal survival. A large amount of drug remains in the injection drug preparation equipment (IDPE) after each use and therefore, used IDPE is saved by people who inject drugs (PWID) for subsequent reuse by adding more water and then injecting the solution intravenously.

Methods
Used IDPE was collected from active PWID, rinsed with sterile water, aspirated into a syringe in a technique which mimicked reuse of equipment by PWID, and then plated on Mannitol salt agar (MSA). Bacterial isolates from local bacteremic PWID were used to test the survival of S. aureus (MRSA and MSSA) and S. pyogenes on unused IDPE with HCR or hydromorphone immediate release (HIR). The solutions were aspirated using techniques similar to that of local PWID and then plated on MSA and Blood agar.

Results
A total of 109 used IDPE samples were collected between March 2017 and March 2018. S. aureus was detected in 15/94 (16%) IDPE samples that had been used for injection of HMC (seven MRSA, seven MSSA, and two borderline resistant [one sample contained both MRSA and MSSA]), but 0/15 (0%) samples used for hydromorphone immediate release (HIR). HCR, but not HM, was associated with greater survival of MSSA and MRSA (but not S. pyogenes) in solutions of the drug when compared with sterile water vehicle control (Figure 1). There was a 2-log reduction in the number of viable S. aureus when IDPE containing HCR solutions spiked with MRSA or MSSA were heated with a cigarette lighter until bubbling (&lt;10 seconds).

Conclusion
IDPE that has been used in the preparation of HCR is frequently contaminated with S. aureus; and in vitro HCR, but not HM, prolongs the survival of MRSA and MSSA. Heating IDPE may be an effective harm-reduction strategy to reduce bacterial complications of injection of HCR.

Disclosures
All authors: No reported disclosures.
1027. Outpatient Parenteral Antimicrobial Therapy (OPAT) in Injection Drug Users (IDUs): Is It Safe?
Authors: Rizvi Hira , Baratz Nathalie , Hadid Hind , Bardossy Ana C , Herc Erica , Misikir Helina , Chen Anne , Markowitz Norman , Zervos Marcus J 
Published: November 2018

Abstract

Background
OPAT is widely implemented in the United States. However, there are concerns surrounding discharge of IDU with a peripherally inserted central catheter (PICC). The objective of this study was to evaluate the characteristics and treatment outcomes of IDUs discharged on OPAT.

Methods
This is a retrospective observational study conducted on patients discharged from an Infectious Diseases unit at a quaternary academic healthcare center in Detroit. Charts of all IDUs discharged on OPAT between 2011 and 2017 were reviewed. Current or former IDU were discharged on OPAT if they met the following criteria: self-reported history of IDU, stable living conditions, controlled psychiatric illness (if present), and willingness to sign a discharge agreement to refrain from using the PICC as a route for illicit drugs. Patients were categorized based on clinic follow-up vs. no clinic follow-up. Outcomes evaluated were: cured (completed treatment and symptom free for 1 month after completion), improved (symptoms were improved but there was no confirmation of treatment completion); and relapsed (readmitted within 30 days for the same infection or sequela). Outcomes of patients with no clinic follow-up were based on chart review of subsequent emergency department visits or admissions.

Results
Patient characteristics are shown in Table 1. Of the 61 patients evaluated, 33 (54.1%) attended clinic follow-up and 28 (45.9%) did not. Outcomes based on clinic follow-up are shown in Table 2. Of the 18 patients who were cured, 16 attended clinic follow-up vs. two who did not.

Conclusion
This study demonstrates that some IDUs can be discharged safely on OPAT. Patients with clinic follow-up had improved outcomes compared with those who did not. Further studies are needed to look at other predictors of outcome in this patient population.

Disclosures
All authors: No reported disclosures.
1030. Risk Predictive Model for Candida Endocarditis in Patients with Candidemia: A 12-year Experience in a Single Tertiary Care Hospital
Authors: Foong Kap Sum , Kronen Ryan , Salazar Ana S , Hsueh Kevin , Lin Charlotte , Powderly William , Spec Andrej 
Published: November 2018

Abstract

Background
Candida endocarditis (CE) is a rare but an invasive infection associated with a high mortality rate. The current understanding of this infection is poorly defined from case reports, case series and small cohorts. This study aimed to assess the risk factors for CE in patients with candida bloodstream infections (CBSI).

Methods
We conducted a retrospective analysis of all hospitalized patients diagnosed with CBSI at a large tertiary care hospital between 2002 and 2015. Data included demographics, comorbidities, laboratory parameters, and outcomes. Univariate and multivariable logistic regression analyses were used to build the predictive model.

Results
Of 1,873 cases of CBSI, 47 patients were identified to have CE. The most commonly isolated species were C. albicans (59.6%) followed by C. parapsilosis (16.2%). On univariate analysis, preexisting valvular disease (7.95, 95% CI [3.16, 20.02]) was associated with a higher risk of CE (P &lt; 0.05). Factors such as isolation of C. glabrata (0.17, 95% CI [0.04, 0.68]), hematologic malignancy (0.09, 95% CI [0.01, 0.68]), and total parenteral nutrition (TPN) (0.40, 95% CI [0.17, 0.95]) were all associated with a lower risk of CE. In multivariable modeling, the factors of valvular disease (5.05, 95% CI [1.77, 14.43]), isolation of C. glabrata (0.19, 95% CI [0.05, 0.80]), hematologic malignancy (0.09, 95% CI [0.01, 0.66]), and total parenteral feeding (0.43, 95% CI [0.17, 1.09]) remained significant. The final model had a C-statistic of 0.82. The crude 90-day mortality for CE was 48.9%, similar to the overall CBSI mortality of 42.1%.

Conclusion
In a population of patients with CBSI, previous valvular disease was the only factor associated with a greater risk of development of CE. Use of TPN, hematologic malignancy, and isolation of C. glabrata were protective factors. A predictive model may reduce the need for expensive and sometimes invasive diagnostic imaging such as trans-esophageal echocardiography, as a subset of patients may be at low enough risk for CE not to warrant them.

Disclosures
All authors: No reported disclosures.
1031. Nationwide Temporal Trends of Candidemia Incidence Over 18 Years Within the Veteran Health Administration System
Authors: Suzuki Hiroyuki , Perencevich Eli , Diekema Daniel , Livorsi Daniel , Schweizer Marin , Nair Rajeshwari , Ohl Michael , Richardson Kelly , Beck Brice , Alexander Bruce , Goto Michihiko 
Published: November 2018

Abstract

Background
Bloodstream infection due to Candida spp. is common and associated with significant mortality and morbidity. Previous population-based studies in 2000s and early 2010s have suggested that the incidence of candidemia might be increasing, presumably due to widespread use of central lines and broad-spectrum antibiotics. However, recent trends of candidemia incidence have not been not well described.

Methods
We conducted a retrospective cohort study of all veterans cared for in the Veterans Health Administration (VHA) system from January 2000 to December 2017 to determine the incidence of candidemia. All patients who had positive blood cultures were identified using data available in the electronic medical record data warehouse, and the number of unique patients for each month was calculated. Patient-days was used as a denominator, and the incidence rate was expressed as the number of unique patients with candidemia per patient-days for each month. Temporal trends were analyzed by joinpoint regression models to identify statistically significant changes in trend.

Results
Over the study period, 31,370 positive blood cultures for Candida spp. from 15,763 unique patients were identified. The mean monthly incidence rate was 22.5 per 100,000 patient-days (IQR: 15.6–28.4). Incidence rates were increasing in the early 2000s and relatively stable in the mid-2000s, followed by a sustained decline (figure). Joinpoint regression analysis revealed there were two statistically significant changes in slope, one in September 2003 (95% CI: 2/2002–1/2005) and another in 6/2007 (95% CI: 4/2006–3/2009).

Conclusion
In the VHA system, there were significant changes in temporal trends of candidemia incidence rates over 18 years, including a substantial increase in the early 2000s followed by a sustained decline in later years. The incidence rates during 2016–2017 were nearly one-third of their peak in the mid-2000s. Possible explanations for the sustained decline include prevention efforts for healthcare-associated infections, such as central-line associated bloodstream infections. Further study is needed to investigate etiologies of these changes in temporal trends to identify potential effective prevention for candidemia.

Disclosures
M. Ohl, Gilead Sciences, Inc.: Grant Investigator, Research grant
1032. A Case Series of Clostridium septicum Aortitis
Authors: Lehman Bethany , Miller Ryan , Keller George , Richter Sandra S , Rehm Susan J 
Published: November 2018

Abstract

Background
Clostridium septicum is an anaerobic, motile, spore forming, toxin-producing Gram-positive bacillus (GPB) that has been associated with colon and hematologic malignancies. Despite the low incidence of infection, it is a virulent organism leading to rapidly progressive gas gangrene. Only 51 cases of C. septicum related aortic aneurysms have been reported. 100% mortality is reported in patients without surgical intervention vs. 79% undergoing surgery. The primary aim of this study was to determine the incidence and clinical outcomes of patients treated at our institution with C. septicum aortitis.

Methods
In this IRB-approved retrospective case series, we reviewed our microbiology laboratory’s blood and tissue cultures from January 2005 to 2018 to identify cases of C. septicum infection. All patients &gt;18 years of age who had positive cultures were reviewed to provide radiographic or histopathologic correlation.

Results
Among 50 patients with C. septicum in blood and tissue cultures, seven patients were identified with aortitis. Underlying malignancy was found in four cases and included colon cancer (three cases) and prostate cancer (one case). The most common location for infection was the infrarenal aorta (four cases). Previous vascular surgery had been performed in three cases. Five of the seven patients underwent surgical repair with pathology revealing GPB in three patients and acute inflammation in the other two patients. C. septicum grew in tissue cultures from these patients. Four of the seven patients (all of whom underwent surgery) had positive blood cultures. The two patients that did not undergo surgery died which is consistent with the 100% mortality described in the literature. All patients were treated with β-lactam therapy. The median duration among the five who completed treatment was 7.5 weeks. Among the five patients who underwent surgery, two are alive (one at 1 year and another at 5 months postoperatively), two died within the first year after surgery, and one patient was lost to follow-up.

Conclusion
A small percentage of patients with C. septicum aortitis survived over 1 year. Earlier recognition and emergent surgery with appropriate antimicrobial therapy are needed to improve the outcome of patients diagnosed with this rare infection.

Disclosures
S. S. Richter, bioMerieux: Grant Investigator, Research grant. BD Diagnostics: Grant Investigator, Research grant. Roche: Grant Investigator, Research grant. Hologic: Grant Investigator, Research grant. Diasorin: Grant Investigator, Research grant. Accelerate: Grant Investigator, Research grant. Biofire: Grant Investigator, Research grant.
1034. “Four-Leaf Clover Sign” as a Rapid Identification of Coagulase-Negative Staphylococci Species by Gram Stain of Blood Culture
Authors: Matsuo Takahiro , Hayashi Kuniyoshi , Mori Nobuyoshi 
Published: November 2018

Abstract

Background
Gram-positive coccus (GPC) in cluster bacteremia is associated with high mortality and morbidity. Although laboratory technologists note morphological characteristics such as the size and number of cells help distinguish S. aureus and Coagulase-negative staphylococci (CoNS), there are few studies that explored the optimal findings to distinguish between them by Gram stain. Here, we analyze some findings in Gram stain contributing to identify S. aureus or CNS.

Methods
This study was conducted at St. Luke`s International Hospital from November 2016 and September 2017. Broths for which a Gram stain showed GPC cluster were included in our study. Two infectious diseases fellows examined direct Gram stains of blood culture within 24 hours of positivity. We defined the sign as follows: four-leaf clover (FLC) sign if four GPCs gather like four-leaf clover (Figure 1) and three-dimensional (3D) sign if GPCs resemble big grapes. They counted the number of fields that have FLC and 3D signs out of 10 fields per each slide. We performed logistic regression analysis to assess whether these signs are the contributable factors to identify SA or CNS. The predictive ability of these signs was evaluated on the basis of the sensitivity (Sen), specificity (Spe), positive predictive value (PPV), and negative predictive value (NPV) for CoNS with receiver operating curve (ROC) analysis.

Results
In total, 106 blood cultures in which a direct Gram stain showed GPC in cluster were examined. Cultures revealed 46 (43%) were SA and 66 (57%) were CoNS. A multivariate logistic analysis showed that FLC sign was statistically significant variable of CoNS with odds ratio (OR) 1.20 (95% CI 1.09–1.35, P &lt; 0.05). In aerobic bottles, Sen, Spe, PPV, and NPV were 0.67, 0.91, 0.92, and 0.65, respectively (Table 1) and area under the curve (AUC) was 0.79 (95% CI 0.67–0.91) (Figure 2). Cut-off fields were 6.5 out of 20.

Conclusion
This is the first study to show FLC sign could be a rapid and useful finding of Gram stain to identify CoNS rather than SA in aerobic bottles. In the presence of FLC sign, clinicians should highly suspect of CoNS with PPV of 92% before the final identification.

Disclosures
All authors: No reported disclosures.
1035. Differentiation Between True Infection and Contamination of Coagulase-Negative Staphylococci by Developing a Prediction Rule
Authors: Fujino Takahisa , Matsuo Takahiro , Rahman Mahbubur , Mori Nobuyoshi 
Published: November 2018

Abstract

Background
Coagulase-negative staphylococci (CoNS) are one of the most common contaminant microorganisms isolated from blood cultures (BCs).

Methods
We conducted a retrospective cohort study at St Luke’s International Hospital from 2004 to 2017. We collected a total of 1,192 BCs due to CoNS. Of 1,192 BCs, 143 patients with polymicrobial infection and 112 patients who were &lt;18 years old were excluded. We defined the true infection (TI) on the following criteria; (1) patients with persistent bacteremia due to CoNS, (2) BCs that were positive more than two sets, (3) patients with foreign body implanted 28 days before taking BCs. Chi-square test, Fisher’s exact test and Student’s t-test were used in univariate analysis and logistic regression analysis was used in multivariable analysis.

Results
Of 927 patients’ BCs data, 201 patients were defined as TI, and 726 patients were defined as contamination. BCs collection location (general ward), inpatient, malignant tumor, steroids or chemotherapy use 90 days before collection, presence of central venous catheter (CVC), mortality in 90 days after collection, time to positivity (TTP: 24–48 hours, and &lt;24 hours) differed significantly between these two groups. Based on multivariable analysis, TTP: 24–48 hours (adjusted odds ratio [OR] 1.93, P = 0.019, 95% confidential interval [CI] 1.11–3.36), and &lt;24 hours: (OR 4.83, P &lt; 0.001, 95% CI 2.68–8.68), BCs collection location: general ward (OR 2.21, P &lt; 0.001, 95% CI 1.58–3.10), and presence of CVC (OR 1.91, P &lt; 0.001, 95% CI 1.37–2.66) were identified as independent risk factors of TI. Based on the estimates of OR, we assigned a score to each factors (Table 1). Area under the curve was 0.702 (95% CI 0.662–0.741) (Figure 1). ROC analysis showed that, if a patient’s score is 0 point, TI can be excluded with sensitivity: 98%. On the other hands, if a patient’s score is 7 points or more, TI can be diagnosed with specificity: 87%.

Conclusion
Time to positivity, location of blood collection, and the presence of CVC were associated with TI. The prediction rule developed in this study can be useful for clinicians for making decision whether to use antibiotics or not.

Disclosures
All authors: No reported disclosures.
1037. Effect of Oral Step-Down Therapy on Readmission Rates in Escherichia coli Bacteremia
Authors: Sessa Julia , Conn Kelly M , Avery Lisa 
Published: November 2018

Abstract

Background
Escherichia coli is the most common cause of community-acquired bloodstream infections. Fluoroquinolones (FQ) and trimethoprim/sulfamethoxazole (TS) are preferred for oral step-down therapy due to high bioavailability. Antimicrobial stewardship programs commonly restrict FQ use, promoting consideration of non-FQ agents for treatment of sensitive organisms. We hypothesized that oral β-lactams would be non-inferior to FQ and TS with a primary outcome of 30-day all-cause readmission.

Methods
This was a retrospective non-inferiority study that reviewed electronic health records for patients with E. coli bacteremia from January 1, 2016 to December 31, 2017. Exclusion criteria included hospital acquired infections, death during hospitalization and concomitant infections. Patient demographics, Pitt Bacteremia Score, Charleston Comorbidity Index, antibiotic regimen (IV/PO), and readmission were collected. Patients were divided into two groups, oral FQ/TS verses β-lactams. A pretrial noninferiority margin for the primary outcome was set at 3%. Secondary outcomes included 30-day infection and E. coli readmission. Significant risk factors for readmission were entered into a multiple logistic regression model in a forward stepwise approach using SPSS.

Results
Demographics were similar between groups, 57 patients received FQ/TS and 151 received β-lactams. The 30-day-all cause readmission rate was 15.8% and 29.1%, respectively (absolute risk difference 13.3%, CI: 1–25).β-lactams were found to be inferior to FQ/TS for 30-day all-cause readmission. readmission occurred in 5.3% of patients in the FQ/TS group verses 14.6% of patients in the β-lactam group (P = 0.07). E.coli accounted for 100% of the infection-related readmissions in the FQ/ST group and 70% in the β-lactam group. Patients who received a β-lactam antibiotic were more likely to be readmitted then those patients treated with FQ/TS (odds ratio: 2.25, CI: 0.95–5.30, P = 0.06).

Conclusion
Step-down therapy to oral β-lactams resulted in higher rates of 30-day all-cause and infection-related readmissions in patients with E. coli bacteremia.

Disclosures
All authors: No reported disclosures.
1044. Aztreonam (AZT) vs. Cephalosporin (CEP) Therapy for the Treatment of Gram-Negative Bacteremia
Authors: Shah Sunish , Krevolin Kyle , Bias Tiffany 
Published: November 2018

Abstract

Background
The IDSA recommends use of AZT in patients with a confirmed beta-lactam allergy for nosocomial Gram-negative infections. Despite this recommendation, there is limited data to suggest AZT is inferior to cephalosporins (CEP) for the treatment of Gram-negative infections. This study aims to evaluate clinical outcomes in bacteremic patients treated with either AZT or CEP therapy.

Methods
A single-center, retrospective chart review of adult patients with positive blood cultures for Escherichia coli, Klebsiella pneumoniae or Pseudomonas aeruginosa was conducted to compare clinical outcomes between those who received ≥ 48 hours of AZT or CEP therapy (cefepime or ceftriaxone). The following clinical outcomes were assessed: clinical cure, in-hospital mortality, post-infection length of stay (LOS), post-infection intensive care unit LOS, microbiologic cure and leukocytosis resolution.

Results
One-hundred and twenty-nine patients met criteria for evaluation: 41 received AZT and 88 received CEP therapy. At baseline, patients who received AZT were more likely to have renal dysfunction (34.1% vs. 18.2%, P = 0.046), receive synergistic antimicrobials (61% vs. 28.4%, P &lt; 0.001) and had a longer pre-infection LOS (1 day [0–2] vs. 0 [0–1], P = 0.032) compared with those who received CEP. Although in-hospital mortality rates were similar between both groups (2.4% vs. 3.4%, P = 1.000), there was a statistically significant difference in clinical cure rates (70.7% vs. 90.9%, P = 0.003), post-infection length of stay (7 days [5–10] vs. 5 [4–8], P = 0.007), and time to clinical cure (2.8 days (1.6–5.8) vs. 2.0 (1.2–2.9), P = 0.018) in the AZT and CEP groups respectively. In a multivariate logistic regression model, patients who received AZT were significantly less likely to achieve clinical cure (OR=0.187, 95% CI (0.058–0.597). In a pre-determined subgroup analysis, clinical cure rates varied in E. coli (72% vs. 94.4%, P = 0.009), K. pneumoniae (70% vs. 90.5%, P = 0.296) and P. aeruginosa (66.7% vs. 76.9%, P = 1.000) in the AZT and CEP group respectively.

Conclusion
Patients who receive aztreonam for Gram-negative bacteremia may be more likely to experience clinical failure. Larger, prospective studies are warranted to confirm these findings.

Disclosures
All authors: No reported disclosures.