bluuebunny/crossref_metadata_2025_split huggingface dataset:
185. Clinical Characterization of Staphylococcus aureus Bacteremia in Children at an Inner-City Community Hospital
Authors: Oommen Jomi K , Cani Eris , Park Tae E , Manwani Savita , Purswani Murli 
Published: October 2019

Abstract

Background
Staphylococcus aureus bacteremia (SAB) is associated with high morbidity and mortality rates. Data on epidemiology and outcomes of SAB in children is not as well described as in adults. The primary objective of this study was to describe clinical and microbiological cure rates of SAB in hospitalized children. Secondary objectives included time to clinical and microbiological cure, mortality, proportions of methicillin-sensitive and resistant SA (MSSA, MRSA) bacteremia, and antibiotic usage pattern.

Methods
This was an electronic chart abstraction conducted at a community hospital in the South Bronx, NY, of all pediatric cases of SAB (<21 years of age) from January 1, 2010 to March 30, 2017. Demographic, clinical and microbiological data along with risk factors for bacteremia were collected. Clinical cure was defined as resolution of acute symptoms and signs of SAB and microbiological cure was defined as documentation of first negative blood culture after initiation of treatment. Standard definitions were used for hospital-acquired (HA) and community-acquired (CA) isolates of SA.

Results
Of 41 patients, neonates comprised 12%, 1- to 23-month-old infants 56% and 2- to 17-year-olds 31%. Overall, 76% of patients had bacteremia due to MSSA, and 24% MRSA. MRSA was isolated in 37% of HA SAB compared with 14% of CA SAB (P = 0.15). The two highest risk factors identified for SAB were peripherally inserted central catheters lines (PICC, 29%) and skin and soft-tissue infections (22%). SAB in the neonatal period was associated with PICC lines when compared with children outside the neonatal period (80% vs. 22%, P = 0.02). Using available data, clinical and microbiological cure rates were similar at 73%. The median time to clinical cure was 5 days (interquartile range [IQR] 2–10) and to microbiological cure, 2 days (IQR 1–4). A 2-month-old infant died (mortality 2.4%). Initial antibiotic selection was vancomycin (39%), clindamycin (39%), and nafcillin (7%). The proportion of SA resistant to clindamycin was 22%.

Conclusion
Pediatric SAB was uncommon in this community hospital experience over 7 years and is associated with PICC lines in neonates. MSSA was more prevalent than MRSA. Initial antibiotic selection had anti-staphylococcal coverage in 85% of cases, while clindamycin resistance occurred in 22% of SA isolates.

Disclosures
All authors: No reported disclosures.
186. Risk Factors for Extended Spectrum β-Lactamase Bacteremia and External Application of a Clinical Prediction Tool
Authors: Burnell Jacqueline , Fallis Rebecca , Axelrod Peter , Mueller Daniel 
Published: October 2019

Abstract

Background
Extended spectrum β-lactamase (ESBL) bacteria are resistant to many antibiotics, which increases the risk of inadequate early antibiotic therapy. A previous single-center study had created a prediction tool to assist clinicians in identifying patients at risk for ESBL bloodstream infections. The purpose of our research project was to assess validity of this tool while also identifying risk factors for ESBL bacteremia within our own institution, which would allow for assessment of alternative prediction tools.

Methods
We performed a retrospective chart review of adult patients admitted to an urban university hospital who were found to have bacteremia with Escherichia coli, Klebsiella pneumoniae, and/or Klebsiella oxytoca between October 2016 and April 2018. Demographics and comorbidities were assessed, along with other potential risk factors including exposure to antibiotics and hospitalizations within the past 6 months.

Results
A total of 214 instances of bacteremia were identified and 14% were due to ESBL organisms. Risk factors for ESBL bacteremia in our cohort included history of positive culture for ESBL (RR = 5.9) or MRSA (RR = 3.5) and antibiotic usage in the past 6 months (RR = 2.3). Patients with ESBL bacteremia were hospitalized longer (mean 16 days vs. 6 days for non-ESBL), received longer durations of antibiotic therapy (11.7 days vs. 5.3 days), and were exposed to greater numbers of different antibiotics (1.9 vs. 0.7) in the previous 6 months. Multivariate logistic regression showed that history of prior ESBL infection (OR 14.7, CI 1.8–120) and increasing number of different antibiotic classes administered in the prior 6 months (OR 4.3, CI 1.7–11.2) were significant risk factors for ESBL bacteremia. The previously created prediction tool did not sufficiently differentiate higher and lower risk for ESBL bacteremia in our cohort.

Conclusion
Although risk factors were similar, the previously derived stepwise prediction tool did not predict ESBL bacteremia in our external cohort. Point-based prediction modeling might better assess risk across institutions. Additionally, the number of different antibiotics received was associated with risk for ESBL bacteremia and should be investigated further.

Disclosures
All authors: No reported disclosures.
193. Comparison of Survival for MSSA and MRSA Endocarditis
Authors: Kanyo Emese , Shrestha Nabin K , Gordon Steven M 
Published: October 2019

Abstract

Background
Prior studies have yielded conflicting findings regarding outcomes for MRSA vs. MSSA infective endocarditis (IE). Our experience suggests that MSSA IE is not any less severe than MRSA IE. The purpose of this study was to compare survival in MSSA and MRSA IE.

Methods
Episodes of IE caused by Staphylococcus aureus were identified from the Cleveland Clinic Infective Endocarditis Registry. Only the first episode was included for each patient. Acceptance for surgery was considered surgical treatment. Survival from the surgical decision date was compared for MSSA vs. MRSA endocarditis using multivariable Cox proportional hazards regression. Selection of variables for the model was done by stepwise backward elimination from a collection of clinically important baseline variables.

Results
Between January 1, 2008 and January 1, 2010, 76 episodes of IE caused by S. aureus were identified. The mean (SD) patient age was 58 (15) years, 46 (61%) were males, 14 (18%) had a prior history of IE, 33 (43%) had diabetes mellitus, 22 (29%) had end-stage renal disease (ESRD), 27 (36%) had prosthetic valve endocarditis (PVE), 70 (92%) had left side involvement, 27 (36%) had invasive disease, 59 (78%) were referred patients, and 39 (51%) were treated surgically. The mean (SD) time to decision on surgery was 6 (7) days. Of these episodes 40 (53%) had MSSA IE and 36 (47%) had MRSA IE. There was no difference in hazard of death between MSSA and MRSA IE (HR 0.98, 95% C.I. 0.54–1.78, P-value 0.96), after adjusting for age, ESRD, prior history of IE, PVE, invasive disease, calendar year, and surgical treatment, which were the significant explanatory variables in the multivariable analysis. Survivals predicted by the model for a reference patient with MSSA IE and MRSA IE are shown in the figure.

Conclusion
Preliminary findings suggest that survival in MSSA IE may be similar to that in MRSA IE. The study is limited by its small sample size. The study finding will need confirmation with a larger sample.

Disclosures
All authors: No reported disclosures.
195. Descriptive Study of the Use of External Cooling Blankets in Hyperthermia
Authors: Chen Thomas , Malhotra Prashant , Khameraj Aradhana , Vyas Pooja , Ong-Bello Nelda , Rasul Rehana , Schwartz Rebecca , Farber Bruce 
Published: October 2019

Abstract

Background
Fever is a beneficial physiologic response to infection and is protective in gram-negative bacteremia and invasive candidiasis. Cooling blankets (CBs) are used in fevers due to a perception of providing symptomatic relief. However, external cooling of septic patients has been shown to be an independent risk factor for adverse effects. Here, we present a retrospective analysis of CB use in our institution and the associations of infections with CB duration.

Methods
We reviewed electronic medical records of patients aged ≥18 years admitted to a tertiary care hospital between 2015–2017 and in whom a CB was used. Study variables included demographics and clinical characteristics such as infection and fever duration (time of CB start to first defervescence). Correlations between continuous variables were assessed using the Spearman's rank correlation test and differences in the distribution of continuous variables by groups were assessed using Mann–Whitney U and Kruskal–Wallis tests.

Results
This analysis included 548 patients who used a total of 575 CBs during their stay (27 patients used ≥1 CB). The median age was 61.9 years and 56.9% were male. The most frequent comorbidities were immunocompromised state (40.3%), diabetes mellitus (33.6%) and coronary artery disease (32.3%). Pneumonia was the most common infection within 5 days of CB start (31.9%). Only 174 CBs had a documented discontinuation during hospitalization; for the remaining CBs, such documentation was absent. The median CB duration for these patients was 33.8 hrs (IQR: 18.0–80.9) while median fever duration was only 21.8 hours (IQR: 6.6–52.2). CB duration was highly correlated with fever duration (rho=.773, p

Conclusion
Clinician documentation of CB use was poor, only 30.2% recorded a stop time. Documented CB duration exceeded fever duration by more than 1.5 times and led to shivering responses in over 2/3 of patients. These findings suggest that CB use is arbitrary, not in keeping with established protocol or rationale, and its adverse effects may outweigh potential benefits. Their role should be re-evaluated and appropriate institutional protocols formulated.

Disclosures
All authors: No reported disclosures.
224. Epidemiology of Bloodstream infections in a Cohort of Allogeneic Hematopoietic Stem Cell Transplant Patients from 2009 to 2018
Authors: Classen Annika , Jakob Carolin , Stecher Melanie , Tobys David , Piepenbrock Ellen , Holtick Udo , Scheid Christof , Cornely Oliver , Janne Vehreschild Jörg 
Published: October 2019

Abstract

Background
Due to severe immunosuppression, patients undergoing allogeneic hematopoietic stem cell transplantation (aSCT) are at increased risk of infection and especially bloodstream infections (BSI) remain a major cause of death. Knowledge of the specific epidemiology of pathogens and resistances is of utmost importance to optimize antimicrobial treatment strategies.

Methods
Based on the Cologne Cohort of Neutropenic Patients (CoCoNut) database, we conducted a retrospective analysis of blood cultures collected within 100 days following transplantation of patients undergoing aSCT between January 2009 and December 2018 at the University Hospital of Cologne, Germany. Contamination of coagulase-negative Staphylococci (CoNS) isolates (single positive isolate within 5 days) was considered within the analysis.

Results
In total, 843 aSCT patients were available for analysis (484/843 [57%] male). The median age was 53 (interquartile range [IQR] 43–62) years, predominant underlying diseases were acute myeloid leukemia (47%, 397/843), lymphoma (14%, 117/843), and acute lymphoblastic leukemia (11%, 89/843). Median inpatient stay was 39 (IQR 34–50) days, while 67/843 (8%) patients died. Antibacterial prophylaxis was administered in 289/843 (34%) and antifungal prophylaxis in 738/843 (88%) patients. BSI was diagnosed in 233/843 (28%) patients. In total, 5,489 pairs of blood cultures were taken (median 4 per patient, IQR 2–8), while a pathogen could only be detected in 922/5,489 (17%). Most frequent pathogens were CoNS (259/922, 28%), Enterococcus spp. (219/922, 24%), E. coli (132/922, 14%), Klebsiella spp. (44/922, 5%), P. aeruginosa (39/922, 4%), S. aureus (37/922, 4%), and Candida spp. (42/922, 5%). Polymicrobial infection was detected in 58/922 (6%) cases. Within Enterococci isolates, 24/219 (11%) were VRE. None of the Klebsiella, but 9/132 (7%) of E. coli isolates were ESBL positive. In 4/37 (11%) cases S. aureus isolates were MRSA.

Conclusion
Patients in the early phase after aSCT are at high risk of BSI with a predominantly gram-positive spectrum. Empirical antimicrobial treatment must consider pathogen epidemiology and resistance patterns while waiting for blood culture results.

Disclosures
All authors: No reported disclosures.
235. Next-Generation Sequencing for Investigation of Hospital Outbreak of Carbapenem--Resistant Klebsiella pneumoniae
Authors: Kholy Amani , Soliman May Mohamed Sherif , Ramadan Arwa , El-Kholy Jehan 
Published: October 2019

Abstract

Background
Carbapenem--resistant Enterobacteriaceae constitute an urgent public health problem worldwide. In 2018, carbapenem--resistant Klebsiella pneumoniae (CR-KP) caused outbreaks of infection in 4 intensive-care units (ICUs)in a tertiary-care hospital in Egypt. We aimed to identify the clonal relatedness of isolates by whole genome (WGS).

Methods
Identification and antibiotic susceptibility testing was done by VITEK-2. Eleven isolates showed identical resistance pattern (resistant to Amikacin, gentamicin, Imipenem, meropenem, levofloxacin, and Piperacillin/Tazobactam) and were susceptible only to colistin. Caba-NP test was positive for carbapenemase production. The 11 isolates were studied by WGS by Illumina Miseq in a reference lab in Cairo University Hospital.

Results
In only one ICU, WGS identified 4 outbreak isolates of CR-KP that group together as a tight clonal cluster, suggestive of intra-ward transmission event. The outbreak isolates belonged to MLST 147. All isolates carried blaCTXM-15, blaoxa-48, and blaNDM1 encoding ESBL and carbapenemase activity. Other identified resistance genes were Str, AadA, MsrE, Tet, and DfrA, encoding resistance to aminoglycosides, macrolide–lincosamide–streptogramin, tetracycline and trimethoprim/sulphonamides. Virulence genes included Yersiniabactin, aerobactin, rmpA, rmpA2 and wzi64, which has been associated with pathogenicity and hypervirulent K. pneumoniae lineages. No clonal relationships were identified between the isolates from other ICUs.

Conclusion
WGS is a powerful tool that goes beyond high-resolution tracking of transmission events into identifying the genetic basis of drug-resistance and virulence.

Disclosures
All authors: No reported disclosures.
238. Direct identification of Bacterial Species with MinION Nanopore Sequencer In Clinical Specimens Suspected of Polybacterial Infection
Authors: Il Jun Kang , Moon Jangsup , Soo Kim Taek , Kyung Kang Chang , Mi Moon Song , Song Kyoung-Ho , Gyun Choe Pyoeng , Hwan Bang Ji , Won Park Sang , Suk Kim Eu , Kim Nam-Joong , Oh Myoung-don , Chu Kon , Beom Park Wan 
Published: October 2019

Abstract

Background
Conventional culture tests usually identify only a few bacterial species, which can grow well in the culture system, in the cases of polybacterial infection. 16S rRNA gene nanopore sequencing enables semi-quantitative identification of bacterial genetic materials. We aimed to evaluate usefulness of 16s rRNA gene nanopore sequencing in the cases suspected of polybacterial infection.

Methods
The research was conducted in a single university hospital for one year. Conventional bacterial culture identification and nanopore sequencing of 16s rRNA gene were carried out simultaneously for cases where polybacterial infection is strongly suspected. Blood agar plate was used for conventional culture, and Microscan (Beckman Coulter, United States) and Vitek 2 (Biomerieux, FR) automated systems were used for identification. For nanopore sequencing, 16S rRNA gene PCR was performed from the clinical specimens, and sequencing libraries were generated from the PCR products using the rapid barcoding sequencing kit (Oxford nanopore technologies, UK). MinION sequencing was performed for 1–3 hours and the generated reads were analyzed using the EPI2ME 16S BLAST workflow.

Results
Specimens were obtained from 15 patients; 6 liver abscess, 2 psoas abscess, 2 thigh abcess, 1 paraspinal abscess, 1 mycotic aneurysm, 1 necrotizing fasciitis, 1 fingertip gangrene and 1 abscess in coccyx area. 16s rRNA gene nanopore sequencing showed monobacterial organism in 8 (53.3%) specimens and polybacterial organisms in 7 (46.6%) specimens. In three (37.5%) cases of 8 cases with monobacterial infections identified by 16s rRNA gene sequencing, no organism was grown in conventional culture, possibly due to previous antibiotic administration. Notably, among 8 cases with polybacterial infection by 16s rRNA gene nanopore sequencing test, traditional culture test showed polybacterial infection in only two (25%) cases and single bacterial organism was identified in the other 6 (75%) cases.

Conclusion
Nanopore sequencing of 16s rRNA gene using the MinION sequencer may be useful for identification of causing microorganism and differentiation between monobacterial and polybacterial infection when polybacterial infection is suspected.

Disclosures
All authors: No reported disclosures.
245. Plasma and Respiratory Specimen Metagenomic Sequencing for the Diagnosis of Severe Pneumonia in Mechanically-Ventilated Patients
Authors: Kitsios Georgios , Yang Libing , Nettles Rachel , Haris Zia , Dunlap Daniel , Rapport Sarah , Haidar Ghady , Ho Carine , Hollemon Desiree D , Ahmed Asim A , Hong David K , Morris Alison , McVerry Bryan 
Published: October 2019

Abstract

Background
Metagenomic sequencing of respiratory microbial communities may overcome the limitations of culture-based pneumonia diagnostics. Nonetheless, respiratory metagenomics requires high-quality specimens, may miss deep-seated infections and cannot distinguish colonization from infection. Plasma microbial cell-free DNA (mcfDNA) sequencing may offer a noninvasive alternative for culture-independent diagnosis and help refine interpretations of respiratory metagenomics.

Methods
We obtained concurrent plasma and endo-tracheal aspirate (ETA) samples from 29 mechanically-ventilated patients (15 culture-positive, 11 culture-negative pneumonia, 3 uninfected control patients). We performed plasma mcfDNA sequencing (Karius®Test, Redwood City, CA) and ETA metagenomics (MiNION, Oxford Nanopore Technologies). We compared sequencing results with clinical microbiologic cultures for identified DNA pathogens.

Results
Uninfected control patients had a negative signal for mcfDNA in plasma and oral bacteria in ETA specimens. In culture-positive pneumonia samples, Karius testing identified a median of 2 pathogens per sample (range 0–10), which were concordant with clinical isolates in 11/15 (73%) cases (figure). In 5/11 (45%) of concordant cases, Karius and MiNION suggested polymicrobial infections with additional pathogens not identified by cultures. In culture-negative cases, Karius detected potential pathogens in 8/11 (73% cases), which matched the species identified in ETA specimens by MiNION. In cases of clinical aspiration, Karius detected more organisms (median 8, range 0–14) per sample mainly consisting of oral origin bacteria compared with cases without history of aspiration (median 1, range 0–6, P = 0.04).

Conclusion
Metagenomic sequencing in plasma and ETA samples showed good concordance between the blood and lung compartments as well as with culture results in pneumonia patients. Metagenomics revealed potential pathogens missed by cultures in ~75% of culture-negative pneumonias and suggested polymicrobial infections especially in cases with aspiration. Further research is needed to evaluate the clinical utility of real-time metagenomics for pneumonia diagnosis in mechanically ventilated patients.

Disclosures
All authors: No reported disclosures.
248. Thirty-Day Mortality Among Patients with Candidemia Diagnosed by T2Candida Assay Alone: Influence of Risk Factors and Candida Species
Authors: White Cameron , McCarty Todd , Lee Rachael A , Leal Sixto M , Pappas Peter 
Published: October 2019

Abstract

Background
Candidemia is a common cause of healthcare-associated bloodstream infection with high mortality rates despite antifungal therapy. Risk factors include prolonged ICU stay, immunosuppression, and exposure to broad-spectrum antibiotics. Blood cultures (BC) remain the gold standard for diagnosis but lack sensitivity and can take days to result. T2Candida (T2C) is a rapid diagnostic test utilizing PCR and magnetic resonance technology to detect five Candida species in whole blood in less than 6 hours. In this study we examined characteristics of patients with positive T2C assays in the absence of positive BC including risk factors and 30-day mortality rates.

Methods
We conducted a retrospective analysis of positive T2C cases at UAB Medical Center from 2016 to 2018 with either negative or no BC. For each patient we determined if clinical signs (e.g., hypotension, leukocytosis) and risk factors for candidemia were present at the time of collection. Our primary outcome of interest was 30-day mortality. Data were compared by multivariate analysis.

Results
A total of 173 patients with T2C positivity alone were included in the analysis. The most common risk factor was the use of broad-spectrum antibiotics followed by CVC (Table 1). The mean number of risk factors per patient was 3.6 (Figure 1). Overall 30-day mortality was 41%. Patients with a T2C result of C. albicans/C. tropicalis were almost 2.5 times more likely to die at 30 days (aOR 2.401, CI 1.159–4.974) compared with those with other positive results. Increasing number of risk factors (aOR 1.457, CI 1.126–1.886) and increasing age (aOR 1.052, CI 1.026–1.079) were significantly associated with increased odds of death at 30 days (Table 2).

Conclusion
In this study we demonstrate a significant association between increasing number of risk factors, older age, and A/T result with higher odds of 30-day mortality among patients with T2C positivity alone. While concern for false-positives exists when using T2C, our data suggest that this is an acutely ill population which warrants early and aggressive antifungal therapy. The lower limit of detection of T2C (1 cfu/mL) as compared with BC may explain lack of paired positive cultures in these patients despite clinical signs of and risk factors for candidemia.

Disclosures
All authors: No reported disclosures.