bluuebunny/crossref_metadata_2025 huggingface dataset:
1058. Prognostic Biomarkers for Persistent Bacteremia and Mortality in Complicated S. aureus Bloodstream Infection
Authors: Cao Yi , Guimaraes Alessander , Hong Kyu , Mayba Oleg , Peck Melicent , Gutierrez Johnny , Ruffin Felicia , Carrasco-Triguero Montserrat , Dinoso Jason , Clemenzi-Allen A Asa , Koss Catherine , Maskarinec Stacey A , Chambers Henry F , Fowler Jr. Vance G , Baruch Amos , Rosenberger Carrie
Published: November 2018

Background

Staphylococcus aureus is a leading cause of bacteremia, yet there remains a significant knowledge gap in the identification of relevant biomarkers that predict clinical outcomes in patients with S. aureus bacteremia. Heterogeneity in the host response to invasive S. aureus infection suggests that specific biomarker signatures could be utilized to differentiate patients prone to severe disease, thereby facilitating earlier implementation of more aggressive therapies. To further elucidate the inflammatory correlates of poor clinical outcomes in patients with S. aureus bacteremia, we evaluated the association between a panel of blood proteins at initial presentation of bacteremia and disease severity outcomes.

Methods

We conducted an observational study (n = 32) to evaluate the prognostic value of circulating protein biomarkers for mortality and persistent bacteremia in patients with S. aureus bloodstream infections. A case–control study of 124 patients with complicated confirmed S. aureus bloodstream infections was used to validate our findings in the observational study.

Results

We identified 13 candidate proteins that were correlated with mortality and persistent bacteremia by multiple comparisons. Further statistical modeling identified IL-8 and CCL2 as the strongest individual predictors of mortality, with the combination of these biomarkers having the best power to classify fatal outcome. Baseline IL-17A levels were elevated in patients with persistent bacteremia, endovascular and metastatic tissue infections.

Conclusion

The results demonstrate the potential utility of selected biomarkers to distinguish patients with the highest risk for treatment failure and bacteremia-related complications, providing a valuable tool for clinicians in the management of S. aureus bacteremia. Additionally, these biomarkers could identify patients with the greatest potential to benefit from novel therapies in clinical trials.

Disclosures

All authors: No reported disclosures.
1062. Daptomycin/Ceftaroline in Combination vs. Vancomycin for the Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia
Authors: Fox Matthew , Zeqollari Klarida , Lee Grant , Pontiggia Laura , Byrne Dana , Adams Jessica , King Madeline , Rose Lucia
Published: November 2018

Background

Vancomycin has historically been the mainstay of therapy for MRSA bacteremia, but severe infections due to vancomycin-intermediate Staphylococcus aureus have emerged. In vitro studies have shown that the combination of a β-lactam antibiotic, such as ceftaroline with daptomycin, was synergistic against MRSA. The purpose of this study was to compare outcomes in patients who received daptomycin and ceftaroline in combination vs. vancomycin for the treatment of MRSA bacteremia.

Methods

This was a retrospective exploratory cohort study approved by the institutional review board at Cooper University Hospital. Patients were included if they received daptomycin/ceftaroline (cases) or vancomycin (controls) for the treatment of MRSA bacteremia between November 2010 and March 2017. Cases were matched 1:1 with controls based on source of MRSA bacteremia, age within 10 years, and renal function. The primary endpoint was clinical cure, defined as the improvement of signs and symptoms of bacteremia. Secondary endpoints included microbiologic cure, time to sterilization of blood cultures, duration of hospital stay, overall mortality, and MRSA-related mortality.

Results

Forty-one cases were included. There was no statistical difference between the two groups in microbiologic cure, time to sterilization of blood cultures, overall mortality, or MRSA-related mortality. There were no significant differences between patients in each group including in those with ICU admissions and who required vasopressors. Cases were significantly more likely to have hardware compared with the control group (43.9% vs. 12.2%; P = 0.0014). Clinical cure was achieved in 27 patients (65.9%) in the case group and 26 patients (63.4%) in the control group (P = 0.8173). Patients in the case group had a statistically longer mean hospital duration (29 days vs. 21 days, respectively, P = 0.0206) and more secondary complications such as bone infection (P = 0.0076).

Conclusion

Time to sterilization of blood cultures and overall mortality were similar in both groups. Patients in the combination group had longer hospital stays compared with vancomycin monotherapy. Daptomycin/ceftaroline combination therapy is an option for complicated MRSA bacteremia. Larger studies should be conducted to further evaluate this combination.

Disclosures

All authors: No reported disclosures.
1067. Comparative Effectiveness of Nafcillin or Oxacillin, Cefazolin, and Piperacillin/Tazobactam in Methicillin-Sensitive Staphylococcus aureus Bacteremia
Authors: Beganovic Maya , Cusumano Jaclyn , Lopes Vrishali , LaPlante Kerry , Caffrey Aisling
Published: November 2018

Background

β-Lactam antibiotics are recommended as first line for treatment of methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia. The objective of this study was to compare effectiveness among β-lactam therapies in MSSA bacteremia patients that were exclusively treated with one antibiotic.

Methods

This was a retrospective cohort study of patients hospitalized at Veterans Affairs (VA) medical centers with MSSA bacteremia from January 1, 2002 to October 1, 2015. Patients were included if they were treated exclusively with nafcillin, oxacillin, cefazolin, or piperacillin/tazobactam (i.e., monotherapy with no changes in therapy). The primary outcome was 30-day mortality, and secondary outcomes were time to discharge, inpatient mortality, 30-day readmission, and 30-day S. aureus reinfection. Hazard ratios (HRs) and 95% confidence intervals (CI) were calculated using unadjusted, quintile adjusted, and propensity-score (PS) matched (nearest neighbor, 0.05 caliper) Cox proportional hazards regression.

Results

A total of 326 patients were included in the final analysis. When comparing nafcillin (n = 75)/oxacillin (n = 30) with cefazolin (n = 108), 30-day mortality was similar between groups (PS matched n = 40, HR 4.0, 95% CI 0.45–35.79), as were rates of the other outcomes assessed. When combining nafcillin/oxacillin with cefazolin, and comparing to piperacillin/tazobactam (n = 113), 30-day mortality was significantly lower in the nafcillin/oxacillin/cefazolin group (PS matched n = 66, HR 0.29, 95% CI 0.09–0.87). Inpatient mortality and 30-day mortality were significantly lower with nafcillin/oxacillin/cefazolin in PS-adjusted analyses (HR 0.29, 95% CI 0.11–0.73 and HR 0.23, 95% CI 0.10–0.50, respectively).

Conclusion

In hospitalized patients with MSSA bacteremia, no difference in mortality was observed between nafcillin/oxacillin and cefazolin in patients that were exclusively treated with these monotherapies. However, higher mortality was observed with piperacillin/tazobactam as compared with nafcillin/oxacillin/cefazolin, suggesting that it may not be as effective as other monotherapies for MSSA bacteremia.

Disclosures

K. LaPlante, Merck: Grant Investigator, Research grant. Pfizer Pharmaceuticals: Grant Investigator, Research grant. Allergan: Scientific Advisor, Honorarium. Ocean Spray Cranberries, Inc.: Grant Investigator and Scientific Advisor, Honorarium and Research grant. Achaogen, Inc.: Scientific Advisor, Honorarium. Zavante Therapeutics, Inc.: Scientific Advisor, Honorarium. A. Caffrey, Merck: Grant Investigator, Research grant. The Medicine’s Company: Grant Investigator, Research grant. Pfizer: Grant Investigator, Research grant.
1072. Streamlining to Oral β-Lactam vs. Fluoroquinolone as Definitive Therapy for Enterobacteriaceae Bacteremia
Authors: Fong Karen , Dubrovskaya Yanina , Siegfried Justin , Papadopoulos John , Pham Vinh , Jen Shin-Pung (Polly)
Published: November 2018

Background

Oral treatment strategies for Enterobacteriaceae bacteremia (EB) are controversial, with both β-lactams (BL) and fluoroquinolones (FQ) used in clinical practice. FQ may be preferred for their high bioavailability, but other oral antibiotics are needed due to concerns of resistance and adverse effects. As an effort to facilitate antibiotic stewardship, BL should be explored as an additional oral option for EB treatment.

Methods

This retrospective study compared clinical characteristics and outcomes in patients with EB treated with BL vs. FQ as definitive oral therapy between January 2013 and July 2017. Adult patients diagnosed with their first incidence of EB and transitioned from IV antibiotics to either study antibiotic class were included. Primary and secondary outcomes assessed recurrence, collateral damage, readmission, and all-cause mortality.

Results

A total of 173 patients were included (BL n = 59, FQ n = 114). Median age was 70 years, Pitt bacteremia score was 2 (range 0–7), and Charlson Comorbidity Index was 5 (0–12); all were comparable between groups. Urinary source of infection was most common (57%). The majority of oral BL courses used cefpodoxime (63%). More patients in FQ vs. BL had a prior transplant (9% vs. 0%, P = 0.05), presence of abscess (11% vs. 0%, P = 0.01), and Infectious Diseases consultation (63% vs. 34%, P = 0.0001). Onset of EB in an intensive care unit was more common in BL vs. FQ (24% vs. 10%, P = 0.01). Median duration of IV and oral therapy was 5 vs. 4 days, P = 0.22 and 11 vs. 12 days, P = 0.17 in BL and FQ, respectively. Recurrence within 90 days was 7% in BL and 4% in FQ, P = 0.49 (adjusted OR 1.44, 95% CI 0.31–6.66; P = 0.64). Multivariate analysis identified liver cirrhosis (OR 16.89, 95% CI 1.06–268.32; P = 0.05) as an independent predictor of recurrence within 90 days. All secondary outcomes were similar between BL vs. FQ: superinfection within 90 days (10% vs. 9%, P = 0.76), C. difficile infection within 90 days (3% vs. 1%, P = 0.27), 30-day readmission (15% vs. 20%, P = 0.43), all-cause 30-day mortality (0% vs. 3%, P = 0.55).

Conclusion

In our cohort of patients with EB, clinical outcomes were similar between those treated with oral BL compared with FQ. Oral BL may be considered for definitive treatment of EB, although further investigation in larger studies is needed.

Disclosures

All authors: No reported disclosures.
1075. A Retrospective Comparison of Native Valve Endocarditis and Prosthetic Valve Endocarditis in a Large Tertiary Care Teaching Hospital From 2007 to 2015
Authors: Annie Lo Hoi Yee , Mostaghim Anahita , Khardori Nancy
Published: November 2018

Background

Studies comparing native valve and prosthetic valve endocarditis (NVE and PVE) have mixed findings on the risk factors and outcomes between the two cohorts. This retrospective review of infective endocarditis (IE) at a teaching hospital in the United States aims to compare the clinical and microbiological features between NVE and PVE.

Methods

Patients were retrospectively identified from 2007 to 2015 using appropriate IE-related ICD-9 codes. Cases that met definite Modified Duke Criteria for IE were further classified as either PVE or NVE, and were reviewed for epidemiology, causative organism(s), affected valves and associations, risk factors, dental procedures in the past 6 months, and 30-day mortality.

Results

A total of 363 admissions met criteria for definite endocarditis, with 261 NVE cases and 59 PVE cases. Forty-three cases that were either associated with an infection involving both native and prosthetic valves or intracardiac devices were omitted from this study. Most risk factors, such as hemodialysis and intravenous drug use, did not show any significant difference amongst the two groups. IE involving the aortic valve as well as a previous history of IE were more likely to be seen in PVE (both P < 0.0001). Dental procedures done in the preceding 6 months before IE admission were more likely to be associated with PVE than NVE (P = 0.0043). PVE showed a higher likelihood of 30-day mortality compared with NVE (P = 0.067). The causative organisms of PVE were more likely to be caused by common gut pathogens such as Klebsiella and Enterobacter species.

Conclusion

PVE cases had a significantly higher chance of involving the aortic valve as well as having a history of IE. PVE cases were also significantly more likely to be associated with a dental procedure done in the preceding 6 months than with the NVE cases. This implies that patients with prosthetic valves, who are currently covered under the 2007 AHA guidelines to receive prophylaxis prior to dental procedures, are still at a high risk of developing PVE. It may be prudent to reconsider adding a post-procedure dose of antibiotics, instead of a single preprocedure dose, to extend the protection of this high-risk population with prosthetic valves. Furthermore, PVE cases showed higher rates of 30-day mortality compared with NVE with near significance, which is likely multifactorial.

Disclosures

All authors: No reported disclosures.
1082. Meta-Analysis of Survival Outcomes in People Who Inject Drugs After Cardiac Surgery for Infective Endocarditis
Authors: Goodman-Meza David , Weiss Robert E , Gamboa Sebastián , Gallegos Abel , Landovitz Raphael J , Bui Alex A T , Goetz Matthew B , Shoptaw Steven
Published: November 2018

Background

The United States’ opioid epidemic has led to an increase in people who inject drugs (PWID) and opioid-associated infections, including infectious endocarditis (IE). Cardiac surgery is often indicated in IE to improve outcomes but is controversial in PWID due to the concerns about continued injection drug use leading to risk for reinfection and decreased survival. In response, we assessed the long-term survival after cardiac valve surgery in PWID compared with people who do not inject drugs (non-PWID) in the published literature.

Methods

We performed a systematic review and meta-analysis (MA) of studies that reported survival data after surgery for IE in PWID. We searched PUBMED up to April 2018. We extracted Kaplan–Meier (KM) curves from included studies. From the KM curves, we used an algorithm to estimate individual participant data (eIPD). In a one-step approach, we ran a Cox proportional hazards (CPH) model analysis of the eIPD with study random effects. In a two-step approach, we fitted CPH models by individual study; then, we ran a mixed-effects MA model of the log hazard ratios (HR) and standard errors.

Results

We identified 11 retrospective studies. Of these, six reported comparisons of PWID vs. non-PWID, and five reported results for PWID only. Based on eIPD, we included 407 PWID and 1,877 non-PWID. Mean age for PWID was 36.7 years (95% CI 34.4–39.1) and for non-PWID was 52.0 years (95% CI 45.3–59.4). There were 144 deaths (35.3%) in PWID and 559 (29.8%) deaths in non-PWID. We present by study and by group KM curves of eIPD (Figures 1 and 2). In one-step MA (included all 11 studies), the HR for PWID was 1.13 (95% CI 0.92–1.39). In two-step MA (included six comparison studies), heterogeneity was high (I2 = 72%); and there was no significant between-group difference (HR 1.29, 95% CI 0.80–2.07) (Figure 3).

Conclusion

Survival time post-surgery of PWID was similar to that of non-PWID. These estimates are concerning, as PWID on average are much younger than non-PWID with IE. Future studies should explore interventions to improve outcomes in PWID after surgery, including treatment of addiction during and after the index hospitalization and provision of naloxone at the time of discharge.

Disclosures

All authors: No reported disclosures.
1086. Impact of Systematic Thoraco-Abdomino-Pelvic CT Scan on the Diagnosis of Infective Endocarditis
Authors: Lecomte Raphaël , Issa Nahema , Turnier Paul Le , Gaborit Benjamin , Deschanvres Colin , Asseray Nathalie , Camou Fabrice , Boutoille David
Published: November 2018

Background

The incidence of embolic events (EE) is high in patients with infective endocarditis (IE). EE influence patient management in different settings because they are minor criteria in the Duke classification and may lead to changes medical therapy or surgical strategy. If current guidelines suggest that systematic thoraco-abdominopelvic CT scan (TAP-CT) may be helpful, reliable data are lacking. The main objective of this study was to describe how systematic TAP-CT affects the diagnosis of patients with IE. Secondary objectives were to assess the impact of the TAP-CT on the management of patients with IE and the incidence of contrast-induced acute kidney injury (CI-AKI).

Methods

In this multicenter cohort study between January 2013 and July 2016, we included consecutive patients who had definite or possible acute IE according to the Duke-modified criteria, and after validation by the endocarditis teams. The main exclusion criterion was the absence of TAP-CT scan. We compared the Duke classification diagnosis data and treatment data (medical and/or surgical) regarding the presence or the absence of EE on the CT and investigated the tolerance of this examination as well.

Results

Of the 522 patients included in this study, 217 (41.6%) had one or more EE on the TAP-CT. The two major Duke modified criteria were found in 397 patients (76,1%) and 457 patients (87,6%) had a definite endocarditis. On the basis of TAP-CT results in asymptomatic patients, diagnostic classification was upgraded from possible endocarditis to definite endocarditis for only four cases which represent 0.8% of the population. The presence of EE on CT did not modify the duration of antibiotic treatment (P = 0.55) and the decision of surgical treatment (P = 0.39). Specific treatment of the EE was necessary in 42 patients (8.0%) but only nine of these EE (1.9%) were asymptomatic. CI-AKI was observed in 78 patients (14.9%).

Conclusion

The CT-scan findings slightly affected diagnosis of IE. The impact on the therapeutic management is low and the incidence of CI-AKI should not be underestimated. Additional studies are needed to assess whether CT-scan improves patient outcomes, leads to unnecessary procedures and increased costs.

Disclosures

All authors: No reported disclosures.
1091. Algorithmic Release of Clostridium difficile PCR Results From a Multiplex Gastrointestinal (GI) Panel in Children <3 Years Old
Authors: Hecht Shaina , Wang Huanyu , Everhart Kathy , Ardura Monica I , Leber Amy
Published: November 2018

Background

Infants have a high rate of asymptomatic Clostridium difficile (CD) colonization, up to 37%. Given this, our laboratory does not release CD+ results from the BioFire FilmArray Gastrointestinal Panel (FGP) in patients <3 years, unless requested by a physician. We sought to validate this model by comparing results from FGP to semi-quantitative CD PCRs for toxin B and glutamate dehydrogenase (GDH), enzyme immunoassay (EIA) for toxin A/B/GDH, and physician requests for CD results.

Methods

Retrospective analysis of children <3 years with GI illness and FGP CD+ results between September 2016 and April 2018. CD PCRs for toxin B and GDH, CD EIA for toxin A/B/GDH were performed on convenience samples of frozen aliquots in Cary Blair. Physician request for release of CD results was used as a surrogate of possible role of CD on GI illness.

Results

Of 5,990 FGP, 2,267 (38%) were in children <3 years: 619 (27%) were CD+. Of these 619, 602 (97%) were not reported per algorithm. 62% (386/619) of CD+ samples had copathogens detected; enteropathogenic Escherichia coli and norovirus most frequently. For CD PCRs and EIA performed in subset of 49 CD+, mean cycle threshold values (Cts) for toxin B were evaluated (Table 1). Of 48 samples with detectable CD by toxin B PCR, 14 (29%) had both GDH and toxin B detected, 24 (51%) had only GDH detected, and 9 (19%) had neither GDH nor toxin B detected.

Conclusion

Only 3% of FGP CD results in children <3 years were released per physician request, suggesting limited clinical significance. A copathogen was detected in 62% of CD+ samples that may explain illness. Among evaluable samples, only 28.6% of CD+ had both GDH and toxin detected by EIA, possibly indicating low specificity of CD PCR. Ongoing testing and prospective studies are warranted to determine the validity of our algorithm and if semi-quantitative PCR or EIA can be useful to identify when CD detection by FGP in children <3 years is clinically significant.

Disclosures

A. Leber, Nationwide Children’s Hospital: Research Contractor, Research support.
1094. Performance of Toxin Enzyme Immunoassays and PCR Cycle Threshold for Differentiating Clostridium difficile Infection From Colonization in Children With Diarrhea
Authors: Balaji Aakash , Espinosa Robyn , Todd Kathleen , Steed Kerry , Kociolek Larry
Published: November 2018

Background

Clostridium difficile colonization is common in children. PCR does not distinguish infection (CDI) from colonization. Toxin enzyme immunoassay (EIA) and PCR cycle threshold (Ct) may predict CDI in PCR+ adults, but assay performance in children is poorly understood.

Methods

Stools from children aged 2–21 years with laboratory-identified (labID) CDI (tcdB PCR+; GeneXpert) underwent: toxin EIA (QUIK CHEK Complete [QCC] and Immunocard [IC]); cell culture cytotoxicity neutralization assay (CCCNA); and C. difficile stool culture (Cx). Children were determined to have clinical CDI (cCDI) by chart review and/or parent communication if all were noted: at least three unformed stools (Bristol type 5–7) in 24 hours; response to CDI treatment within 5 days; and no other likely diarrheal etiology. EIA and PCR Ct performance were measured for various reference standards (RefStd) based on stool assay results and/or cCDI classification.

Results

A total of 253 PCR+ stools were included. All stools underwent QCC; 218 (86%) were quantity sufficient for IC. Discordant EIA results occurred in 19/218 (8.7%) stools. Table 1 lists EIA sensitivity (Sn), EIA specificity (Sp), and median PCR Ct for each RefStd. Figure 1 shows the receiver operating characteristic (ROC) curve for PCR Ct to identify PCR+/CCCNA+/cCDI+ children (area under curve = 0.76). The difference between sensitivity (71%) and specificity (72%) was minimized at Ct < 23.5.

Conclusion

Only a minority of PCR+ children meets strict clinical and laboratory CDI criteria. More stringent CDI definitions are associated with increasing toxin EIA Sn and lower PCR Ct (i.e., greater stool C. difficile inoculum). However, both toxin EIA and PCR Ct perform suboptimally as stand-alone tests to distinguish CDI from colonization in PCR+ children.

Disclosures

L. Kociolek, Alere/Techlab: Investigator, Research support.
1095. The Value of Hardwiring Diagnostic Stewardship in the Electronic Health Record: Electronic Ordering Restrictions for PCR-Based Rapid Diagnostic Testing of Diarrheal Illnesses
Authors: Marcelin Jasmine R , Brewer Charlotte , Beachy Micah , Lyden Elizabeth , Winterboer Tammy , Hood Lauren , Fey Paul D , Van Schooneveld Trevor
Published: November 2018

Background

In 2015, the microbiology laboratory introduced a multiplex PCR test (FilmArray™ Gastrointestinal Panel (GIP)), replacing traditional stool culture. The GIP is faster and more sensitive than traditional stool culture, detecting 22 common viral, bacterial, and parasitic pathogens; but is significantly more expensive. The antimicrobial stewardship program (ASP) developed guidelines on test use and interpretation, recommending inpatient use only once per admission and not after hospital day 5. C. difficile test results from the GIP were not reported at any time.

Methods

Inpatient GIP use was reviewed over one year and considered inappropriate if performed >3 days after admission or repeated. Noncompliance with ASP recommendations was common; no meaningful pathogens were detected upon review of all inappropriate GIP use. An inpatient GIP electronic order restriction was implemented in April 2017 eliminating the ability to order tests inappropriately. GIP testing outside the restriction could be approved by the microbiology lab director. We captured separate C. difficile testing rates as a counterbalance measure. We used Poisson regression models to compare the rate of GIP and C. difficile tests per month between Period 1 (July 2015–March 2017) and Period 2 (April 2017–March 2018) per 1,000 patient-days (PD).

Results

The restriction resulted in a 26% reduction in GIP ordering rates between the two periods (Table 1, Figure 1). Direct cost savings was approximately $63,000. Table 1 shows changes in C. difficile test ordering rates during Periods 1 and 2. When including GIP tests that were ordered but not completed, potential GIP testing was reduced by 46% for a savings of $131,000 (Figure 2). Only 42 test overrides were approved by the microbiology director since the intervention; of those only two were positive (Cryptosporidium and Norovirus).

Conclusion

Diagnostic stewardship of GIP using guidelines and electronic ordering restrictions can lead to meaningful improvements in test appropriateness and reduction in cost and waste, demonstrating the value of ASP interacting with the microbiology laboratory.

Disclosures

All authors: No reported disclosures.
1098. Clinical Features and Outcomes of United States Marine Corps Recruits Hospitalized With Shiga Toxin-Producing Escherichia coli Infection and Hemolytic–Uremic Syndrome
Authors: Sanders Terrel , Ellis Graham , Castrovinci Philip , Deiss Robert , Maves Ryan
Published: November 2018

Background

Shiga toxin-producing Escherichia coli (STEC) is associated with potentially life-threatening dysentery, along with its most feared complication, the hemolytic–uremic syndrome (HUS), occurring in up to 20% of STEC-infected patients. 10–30% of patients may experience chronic renovascular and neurologic sequelae after acute resolution. We describe clinical features and outcomes of a young, male military recruit population hospitalized for STEC infection and HUS in 2017.

Methods

Between October and November 2017, an STEC outbreak occurred at Marine Corps Recruit Depot San Diego (MCRD-SD) affecting 244 recruits, including 30 who required hospitalization. Polymerase chain reaction and pulsed-field gel electrophoresis of stool culture isolates demonstrated stx2-positive E. coli O157:H7. Thirty recruits required hospitalization; the remaining 214 underwent daily clinical evaluation and laboratory testing at MCRD with daily crystalloid volume expansion until the resolution of dysentery.

Results

50% (15/30) of hospitalized recruits developed HUS and were initially managed with volume expansion until the onset of oliguria. Five recruits with severe HUS required hemodialysis; six required intensive critical care unit (ICU) admission; and three suffered from respiratory failure requiring mechanical ventilation. Average length of hospitalization was 10 days. Patients requiring hemodialysis received an average 7.4 days of renal replacement. Three patients experienced encephalopathy with seizures and were managed with levetiracetam and corticosteroids for Stx-induced cerebral edema. One patient received eculizumab, a terminal complement inhibitor approved for atypical HUS, with resolution of seizures and return to his neurocognitive baseline but with persistent electroencephalographic abnormalities. There were no deaths, and all recruits had recovery of renal function.

Conclusion

This case series represents the largest STEC-HUS outbreak affecting a military population. Rates of HUS and mortality were lower than seen in prior outbreaks, in part due to a high level of baseline health and early detection and management of suspect cases. Early volume expansion and close monitoring of cases may have reduced the risk for HUS progression and long-term renal sequelae.

Disclosures

All authors: No reported disclosures.
1117. Avascular Necrosis of the Femoral Head as a Sequela of Shiga Toxin-producing Escherichia coli (STEC) Infection
Authors: Stone-Garza Kristi , Barlow Brian , Maves Ryan
Published: November 2018

Background

Shiga toxin-producing Escherichia coli (STEC) infection may be complicated by the hemolytic-uremic syndrome (HUS). Long-term sequelae of HUS are most often related to renovascular disease. Osteoarticular complications are rare. Avascular necrosis (AVN) has not been previously reported as a complication of STEC infection.

Methods

We report two cases of United States Marine Corps (USMC) recruits who developed AVN of the femoral head following STEC infection during a large outbreak.

Results

Between October and November 2017, an STEC outbreak occurred at Marine Corps Recruit Depot San Diego (MCRD-SD) affecting over 250 USMC recruits. Case 1: A 19-year-old recruit developed nine days of non-bloody diarrhea. Stool culture, Shiga toxin enzyme immunoassay (EIA), and polymerase chain reaction (PCR) demonstrated E. coli O157. Complete blood count (CBC) was normal 5 days after symptom resolution. One month after resolution of his infection, he developed right hip pain. Magnetic resonance imaging (MRI) revealed right femoral head AVN (Image 1). He was treated conservatively with nonsteroidal anti-inflammatory drug (NSAID) and physical therapy. Case 2: A 19-year-old recruit developed seven days of dysentery. Stool culture, Shiga toxin EIA and PCR demonstrated E. coli O157. He had a hemoglobin nadir of 8.0 g/dL and platelet nadir of 109 × 103/microL. Renal function was normal except for mild proteinuria and microscopic hematuria. One month after resolution of his infection, he developed non-traumatic left hip pain. MRI revealed left femoral head AVN with subchondral collapse (Image 2). He completed three months of bisphosphonate therapy prior to his left hip core decompression and sub-chondroplasty.

Conclusion

AVN of the hip is rare among healthy young adults and is not commonly observed in military recruits. We hypothesize that STEC-associated subclinical intravascular coagulopathy may cause microscopic occlusive disease. AVN should be considered in patients with new non-traumatic hip pain after known or suspected STEC infection.

Disclosures

All authors: No reported disclosures.
1122. Evaluation of Fecal Microbiota Transplant (FMT) in Elderly Patients With recurrent Clostridium difficile Infection (CDI)
Authors: Hassoun Ali , Edwards Jonathan
Published: November 2018

Background

CDI is a bacterial infection that typically occurs after the use of broad-spectrum antibiotics. Older adults are particularly susceptible to this potentially deadly disease and at higher risk of recurrence.

Methods

The study was approved by the hospital’s IRB. Patients 65 years of age and older with refractory or recurrent CDI who received FMT administered via colonoscopy or oral capsules were included. Patients with severe-complicated infection were excluded and ineligible to receive FMT. Each patient was evaluated 8 weeks post-transplant to assess for sustained clinical response and adverse events. Data collection included patient demographics, number of recurrent CDI episodes, CDI severity, previous antibiotic treatment regimens, clinical cure, adverse events, and donor information.

Results

Thirty-five patients were enrolled (23 colonoscopy FMT vs. 13 oral capsule FMT). One patient received FMT via colonoscopy twice. Mean age was 77 years [65–93], female 60%, median recurrent episode was 3, and median CDI severity score was 2. Total success rate was 69.4% (25/36), 60.9% (14/23) via colonoscopy vs. 84.6% (11/13) via capsule. Total success rate for female 67% vs. 73% male and age group of 65–75 was 60% vs. 76% in age group 75+. For capsules only, cure rate was 80% in female vs. 100% in male and 75% in 65–75 age group vs. 89% in patients older than 75 while in colonoscopy only group, success rate was 55% in female vs. 67% in males and 46% in 65–75 age group vs. 67% in age group 75+. There did not seem to be a correlation between FMT donor and success rate. No serious adverse events were reported in the study population.

Conclusion

FMT may be considered a potentially useful therapy for the treatment of refractory or recurrent CDI cases in patients 65 years of age and older. Further studies are needed to confirm the above findings.

Older adults are particularly susceptible to this potentially deadly disease

Disclosures

All authors: No reported disclosures.
1128. Utility of Anaerobic and Fungal Blood Cultures in the Pediatric Oncologic Population
Authors: Kumar Madan , Hanisch Benjamin
Published: November 2018

Background

In our institution, a febrile or ill appearing oncology patient will often be evaluated with aerobic, anaerobic, and fungal cultures. This is especially true in patients with persistent fevers without a clear etiology on empiric antimicrobial therapy. It is common for all three cultures to be repeated multiple times per admission.

Although this practice may seem sensible, there is to our knowledge little evidence to confirm its necessity in this population.

Methods

A record of all positive blood cultures originating from our institutions oncology ward was obtained from January 2010 to April 2017. Duplicate cultures (obtained on consecutive days with repeat organisms) were excluded. Each anaerobic and fungal culture was then evaluated for corollary positive aerobic cultures from the same time frame.

Results

A total of 10,950 blood cultures were evaluated for this study, including 2,391 anaerobic cultures and 1,980 fungal cultures. Forty-two unique anaerobic cultures (1.7%) were identified. The viridans group of Streptococcus was a large contributor with nine unique cultures. Only seven cultures of obligate anaerobes were observed: four cultures of Clostridial species, two Propionobacterium acnes, and one Peptostreptococcus species. Twenty-three unique fungal cultures (1.2%) were identified. Notably most of these isolates (14) were identified as having one colony present and regarded as probable contaminants. Penicillium, Cladosporium, and unidentified dermatiaceous molds were present in greatest frequency.

Conclusion

Over a 7-year period of routinely obtaining anaerobic and fungal cultures for febrile oncology patients only 42 unique anaerobic and 23 unique fungal cultures were identified. Given the predominance of facultative anaerobes, this may simply reflect the findings of increased blood sampling rather than added utility of the growth medium. Similarly, even among the limited unique fungal cultures the majority were of suspect validity given the presence of a single colony. These findings suggest judicious use of selective growth media in cases with higher clinical suspicion may be more useful than empiric evaluation.

Disclosures

All authors: No reported disclosures.
1138. Retrospective Cohort Analysis of Amphotericin B Nephrotoxicity in Kidney Transplant Recipients
Authors: Assi Mariam , Engracia Dominic , Yakubu Idris , Gupta Gaurav , Kurbanova Nargiza , Cruz Oveimar De La
Published: November 2018

Background

Treatment of invasive fungal infections with amphotericin B is a concern in kidney transplant patients due to fear of allograft loss. Reluctance to use amphotericin B may lead to suboptimal therapy and poor treatment outcomes. The risk of amphotericin B-related nephrotoxicity and allograft dysfunction has not been studied in kidney transplant patients. Our aim was to study the association between amphotericin B and acute kidney injury (AKI) as defined by the Acute Kidney Injury Network classification, allograft loss and patient mortality in kidney transplant recipients.

Methods

We used SPSS to conduct a descriptive analysis of a retrospective cohort of 30 adult kidney transplant recipients who were admitted to Virginia Commonwealth University Medical Center and received treatment with amphotericin B from 2005 to 2015.

Results

The median age in our cohort was 57. 40% were female, 60% were male. 60% had received a kidney transplant from a deceased donor; 13.3% from a living related donor; 13.3% from a living unrelated donor; and 13.3% had received a combined kidney–pancreas transplant. 63.3% of patients had received liposomal amphotericin B; 33.3% had received lipid-complex amphotericin B; 3.3% had received conventional amphotericin B. We found an association between cumulative amphotericin B doses above 5,000 mg and AKI, whereby 64.7% of patients exposed to less than 5,000 mg of amphotericin B developed AKI and 100% of patients exposed to more than 5,000 mg of amphotericin B developed AKI (P = 0.017). We did not find an association between cumulative amphotericin B doses above 5,000 mg and return to dialysis at 3 months and 12 months post-exposure (P = 0.436 and 0.288, respectively). We also did not find an association between such doses of amphotericin B and mortality at 30 and 90 days (P = 0.869 and 0.193, respectively).

Conclusion

In the first descriptive analysis of a retrospective cohort of kidney transplant patients exposed to amphotericin B, our results suggest that the risk of nephrotoxicity may be significantly increased when a cumulative dose of 5,000 milligrams is exceeded. Our results also suggest that amphotericin B doses associated with nephrotoxicity in kidney transplant patients may not have an effect on allograft survival and patient mortality.

Disclosures

All authors: No reported disclosures.
1143. Epidemiologic Characteristics of Outbreaks Associated With the Healthcare Environment
Authors: Kanamori Hajime , Weber David , Rutala William , Kaku Mitsuo
Published: November 2018

Background

The healthcare environment serves as a reservoir or a source for outbreaks. Single outbreaks via an environmental reservoir have often been described in healthcare settings, while the trend of these multiple outbreaks has not been understood well. Here, we investigated the epidemiologic features of outbreaks associated with the healthcare environment.

Methods

Structured data on environmental sources from Outbreak Database based on information from articles published worldwide were extracted. A total of 317 articles of outbreaks associated with the healthcare environment (e.g., environmental surfaces, patent care items, water and water-related appliances, and air and ventilation systems) in 48 countries during 1965–2016 were analyzed.

Results

Of the 317 outbreaks reviewed, 295 (93%) were monophasic. One hundred sixty-one outbreaks (51%) occurred in an ICU setting. The 6,317 infected patients and 338 healthcare personnel were involved in 317 healthcare-associated outbreaks via the environment. Two hundred fifty-one patients (4%) died of an infection. Two hundred sixty-five outbreaks (84%) caused at least one infection among patients involved, including 112 pneumonias (35%) and 104 bloodstream infections (33%) (Figure 1). Bacteria (N = 244, 77%) were the most frequent pathogen, followed by fungi (N = 49, 15%) and mycobacteria (N = 15, 5%) (Figure 2). Of the bacteria, nonfermenting Gram-negative bacilli (N = 100, 41%) was the most common, followed by Legionella (N = 56, 23%), Enterobacteriaceae (N = 35, 14%), and multidrug-resistant organisms (N = 31, 13%). One hundred thirty-six outbreaks (43%) were obviously transmitted by contact, followed by inhalation and invasive technique. Genotyping was performed in 66% of outbreaks (N = 209). Key control measures included modification of care/equipment (N = 181, 57%) and improved disinfection/sterilization (N = 170, 54%). Forty-seven (15%) and 5 (2%) outbreaks led to closure of the affected location and restriction of workload, respectively (Figure 3).

Conclusion

This study characterized epidemiologically outbreaks associated with healthcare environment, demonstrating the environmental role in healthcare-associated outbreaks. Analysis of structured data on multiple outbreaks can help develop infection prevention strategies in healthcare facilities.

Disclosures

D. Weber, PDI: Consultant, Consulting fee. W. Rutala, PDI: Consultant and Speaker’s Bureau, Consulting fee and Speaker honorarium.
1144. Modern Problem, Medieval Cure-Resistant Aeromonas in Medicinal Leeches
Authors: Parkes Leighanne Olivia , Barker Kevin , Poutanen Susan M , Grant Jennifer M , Libman Michael , Leis Jerome , Stapleton Patrick , Silverman Michael , Hota Susy
Published: November 2018

Background

Medicinal leeches are used primarily in plastic and reconstructive surgery when venous congestion threatens tissue viability. The associated infection risk ranges from 4.1 to 20%. Prophylactic antimicrobials such as fluoroquinolones (FQ) or trimethoprim-sulfamethoxazole (SXT) are recommended and target commonly isolated pathogen and gut symbiont, Aeromonas. However, resistance to these agents has been reported and detected in leeches, including at hospital systems across Canada that acquire their stock from the same supplier. Our objective was to describe the local epidemiology of leech-related Aeromonas resistant to one or more commonly used prophylactic agents, and determine if such resistance originates from the common supplier.

Methods

Six hospital systems across Canada using leech therapy, purchased from the same supplier, were surveyed. A 5-year retrospective review of all antimicrobial resistant leech-related Aeromonas, derived from clinical, leech, and tank fluid specimens was performed. All Aeromonas resistant to either FQ or SXT were included, and retained frozen isolates from each system were analysed by pulse-field gel electrophoresis (PFGE) using a published Aeromonas protocol.

Results

All six hospital systems reported leech-related Aeromonas resistant to one or more antimicrobials, totalling 15 isolates. Three systems only reported data from the last year. Four systems used FQ and two used SXT as prophylaxis. Fifteen of 15 were either FQ resistant or intermediate, and four of 15 were SXT resistant. Three of 10 isolates tested for ceftriaxone (CRO) susceptibility were resistant. Five of 15 of the isolates were resistant to two or more agents. Of the two leech quality control isolates, 2/2 were FQ resistant and 1/2 was FQ, SXT and CRO resistant. Only three isolates, each from a different, geographically distinct hospital system, had been retained. PFGE analysis indicated 2/3 are closely related (Figure 1).

Conclusion

Our preliminary investigation suggests that the presence of FQ and SXT resistance in leech-related Aeromonas might be more common than previously suspected, and that such resistance might originate from a common source. A broader study of the molecular epidemiology of leech-related Aeromonas is warranted.

Disclosures

All authors: No reported disclosures.
1147. Pseudo-Outbreak of Clostridium paraputrificum Related to Anaerobic Tent Contamination
Authors: Mitchell Kaitlin , Rece Luann , Duster Megan , Shirley Daniel , Safdar Nasia , Chen Derrick
Published: November 2018

Background

Over a 2-month period, eight patient cultures in our clinical microbiology laboratory were positive for Clostridium paraputrificum, an uncommon spore-forming microbe. The possibility of a pseudo-outbreak related to contamination in the laboratory’s anaerobic tent was considered.

Methods

This study occurred at a 505-bed tertiary care university-affiliated teaching hospital. Patient samples were cultured and evaluated following standard protocols, and isolates of C. paraputrificum were identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). To identify additional cases, MALDI-TOF MS testing reports were manually reviewed and matched to patient records. Concurrently, the laboratory’s anaerobic tent was sampled after cleaning with isopropyl alcohol (and later with bleach or sporicidal disinfectant) following standard procedures and protocols recommended by the tent manufacturer (Coy). Pulsed-field gel electrophoresis (PFGE) was performed on isolates from patients (n = 8) and the anaerobic tent (n = 6).

Results

Despite cleaning with isopropyl alcohol or bleach, surface samples from the anaerobic tent grew C. paraputrificum. PFGE analysis revealed all patient and anaerobic tent isolates to be indistinguishable, suggesting that they originated from a common source. Growth of the organism from patient samples was therefore regarded as potential contamination. Prior to this, six of the eight patients received antibiotics related to this positive culture and had Infectious Disease consultations. Providers of the patients were contacted regarding the contamination issue. The anaerobic tent manufacturer was consulted and ultimately recommended using Peridox Sporicidal Disinfectant. Six months later, the tent was re-sampled and did not yield positive cultures.

Conclusion

A pseudo-outbreak of the uncommon organism C. paraputrificum was related to insufficient disinfection practices of an anaerobic culture tent. This had negative effects on our institution and patient care in terms of cost, time, and unnecessary treatment. The use of sporicidal disinfectant has since proven effective to prevent contamination from spore-producing microbes.

Disclosures

All authors: No reported disclosures.
1163. Impact of Difficult-to-Treat Resistance on Survival in Gram-Negative Bacteremia: A Risk-Adjusted Analysis Using Electronic Health Record-based Clinical Data From 140 US Hospitals
Authors: Kadri Sameer S , Lai Yi Ling , Ricotta Emily E , Strich Jeffrey , Babiker Ahmed , Rhee Chanu , Klompas Michael , Dekker John P , Powers III John H , Danner Robert L , Adjemian Jennifer ,   NIH Antimicrobial Resistance Outcomes Research Initiative (ARORI)
Published: November 2018

Background

In Gram-negative bacteremia (GNB), administrative data suggest that “difficult-to-treat resistance” (DTR; i.e., co-resistance to all first-line antibiotics) increases mortality. However, adequate risk-adjustment for severity of illness (SOI) may require granular laboratory and physiologic data.

Methods

Adult inpatients with GNB were identified from electronic health records (EHRs) of 140 hospitals in the Cerner Healthfacts database between 2009 and 2015. Mortality from DTR (intermediate/resistant in vitro to β-lactams including carbapenems and fluoroquinolones) was compared with GNB phenotypes susceptible to at least one first-line agent, but otherwise resistant to carbapenems (CR), extended-spectrum cephalosporins (ECR), or fluoroquinolones (FQR) per US Centers for Disease Control and Prevention surveillance definitions. Relative risk of mortality was adjusted (aRR) for age, sex, baseline Sequential Organ Failure Assessment (SOFA) score, Elixhauser comorbidity index, GNB source, taxon, hospital vs. community onset, year, and hospital region, bed capacity, and urban and teaching status using Poisson regression.

Results

Of 25,448 unique GNB encounters, 207 (1%) met DTR criteria. DTR patients were 2-fold more likely to receive intravenous colistin and 5-fold more likely to receive tigecycline compared with CR cases susceptible to ≥1 first-line agent. Crude mortality varied considerably by taxon and resistance phenotype, but resistance per se was associated with only a minority of overall deaths (DTR = 3% of deaths; any of the four resistance phenotypes = 28% of deaths; Figure 1). Inclusion of EHR-derived, baseline SOFA scores in SOI adjustments decreased aRR effect estimates; nonetheless, all resistance phenotypes still significantly increased mortality (Figure 2A). Among resistance phenotypes, aRR of mortality was similar for DTR vs. CR (aRR = 1.18; 95% CI, 0.91–1.54; P = 0.2), but higher for DTR vs. ECR (aRR = 1.26 [1.01–1.58]; P = 0.04), and DTR vs. FQR (aRR = 1.36 [1.08–1.70]; P = 0.008), respectively (Figure 2B).

Conclusion

DTR is associated with nonsurvival and greater use of reserve antibiotics in GNB, but adds little to the risk of death associated with CR. The impact of resistance on survival is attenuated but still present even after risk adjustment using granular clinical data.

Disclosures

All authors: No reported disclosures.