bluuebunny/crossref_metadata_2025_split huggingface dataset:
2141. Potential for Harm From Rapid Campylobacter Antigen Test: Quality Improvement Process Reveals 84% False-Positive STAT! Campy Stool Antigen Results
Authors: Farrell John J , Mathis Jessica , Knapp Sarah J 
Published: October 2019

Abstract

Background
The Immunocard STAT! Campy is known to have a poor correlation with Campylobacter culture, and bloody stools are thought to be the most common cause of false-positive tests. A CDC investigation of 11 cases of Campylobacter in premature infants with non-bloody stools between March and April, 2018 at the Children’s Hospital of Illinois identified a pseudo-outbreak secondary to false-positive stool antigen tests.

Methods
Beginning May 1, 2018, Immunocard STAT! Campy (Meridian BioScience) positive stools from 14-hospitals in the OSF network were sent to the OSF System lab for confirmation prior to resulting in the medical record (MR). Stool was placed into Cary Blair media and a STAT! Campy stool antigen test was repeated in the OSF System Lab. BioFire GI Panel (GIP) PCR was performed on STAT! Campy positive stools, and results reported in the MR.

Results
Between May 1, 2018 and April 30, 2019, 3,639 stools were submitted for culture. 372 tested positive by the STAT! Campy rapid antigen test and were referred for confirmation. Repeat rapid antigen tests were negative for 56% (208/372) of stools and were finalled in the MR as negative without GIP testing. GIP PCR was performed on 164 samples from 163 patients (mean age = 18). 43% (71/164) of GIP were completely negative; 16% (27/164) positive STAT! Campy antigens were confirmed by the GIP (84% were false positive). Pathogens detected by the GIP included: 30 viral infections (50% Norovirus), 27 cases of C. difficile, and 19 pathogenic E. coli (Table 1). Multiple pathogens were detected in 15% (25/163) patients (1 patient was positive for 4 pathogens). One case of Salmonella was not detected by GIP. One patient tested negative by the GIP but remained symptomatic and C. difficile was detected on repeat testing 10 days later.

Conclusion
C. difficile and Norovirus were the most common pathogens detected in stools that yielded false positive STAT! Campy results. These findings have important patient care and infection control implications. Currently neither FDA nor CDC requires Campylobacter culture (or other laboratory methods) of confirmation of positive Campylobacter stool antigen tests. Missed and incorrect diagnoses represent a significant risk of harm for patients (particularly C. difficile or Shiga toxin-infected patients, Table 1), and outbreaks in institutional settings.

Disclosures
All authors: No reported disclosures.
2148. Performance of the BioFire FilmArray Gastrointestinal Panel in a Clinical Setting of Infectious Diarrhea
Authors: Aguirre-García Gloria Mayela , Moraila-Baez Alejandra , Camacho-Ortiz Adrian 
Published: October 2019

Abstract

Background
Infectious diarrhea remains as one of the leading causes of morbidity and mortality worldwide among all age groups. Conventional methods for diagnosis are time consuming and expensive. The BioFire FilmArray gastrointestinal panel (FA-GIP) tests for 22 enteric pathogens, provides results in a few hours and improves healthcare costs. The impact on antibiotic stewardship is unknown.

Methods
We conducted a retrospective cohort, multi-center study to evaluate FA-GIP clinical performance in hospitalized patients with acute diarrhea. Patients from 3 hospitals from the Christus Muguerza health group were included between January 2017 and August 2018. The FA-GIP was ordered by the treating physician and was not influenced by the study. Duration of antibiotic therapy, length of hospital stay, and therapy modification were assessed. The comparison group consisted of patients with acute diarrhea in which no FA-GIP was ordered.

Results
Data from 130 patients with FA-GIP and 107 patients with conventional methods were collected. Pathogens were detected by FA-GIP in 72.3% of the cases. The median of duration of antibiotic therapy in FA-GIP group was 5 days (IQR 0–8) vs. 3 days (IQR 0–6) in conventional methods group, (P < 0.05). The mean length of stay was 3.3(SD ± 2.4) in FA-GIP group vs. 1.9 (SD ± 1.0) in the control group (P < 0.05). Patients in FA-GIP group had more days with diarrhea, lower hemoglobin levels, and higher creatinine levels at admission (Table 1). The most frequent pathogens detected were enteropathogenic Escherichia coli in 24.4%, norovirus in 19.1%, Clostridium difficile in 17.0% and Campylobacter jejuni in 15.9% (Table 2). Therapy modification after FA-GIP results was made in 51.1% of the patients with a detected pathogen, and in 42.8% of patients with no pathogen detected in FA-GIP the antibiotic was stopped.

Conclusion
Patients in the FA-GIP group had a more complex clinical scenario upon admission, they also had a longer duration of antibiotic therapies and longer length of stay. Although antibiotic therapy was positively influenced by the FA-GIP result, and no pathogen detection leads to withdrawal of unnecessary antibiotics.

Disclosures
All authors: No reported disclosures.
2161. Organism-Specific Turn Around Time Improvement in Urinary Specimens as a Result of Microbiological Laboratory Automation
Authors: Farooq Nouman , Emrick Alanna , Gonzalez-Ortiz Carolyn , Sellers David , Tabak Ying P , Vankeepuram Latha , Kurtz Stephen , Levent Fatma 
Published: October 2019

Abstract

Background
University Medical Center in Lubbock, TX is one of few medical centers using Becton Dickinson (BD) Kiestra Total Laboratory Automation (TLA) system since May 2015. The impact on organism-specific turn around time (TAT) in urinary specimens after implementation of TLA was evaluated.

Methods
After approval from the Quality Improvement Review Board, a retrospective analysis of microbiological data from urinary specimens in BD research database was performed. Before vs. after implementation (2013 vs. 2016) TAT was compared. Ten clinically relevant organisms were analyzed. Statistical analysis was performed with SAS software version 9.2. Data were analyzed using Chi-squared test. A P-value of < 0.05 was considered statistically significant.

Results
Overall, 2282 specimens from 2013 and 2306 specimens from 2016 were analyzed. Compared with before vs. after implementation of TLA, an overall improvement in TAT was observed (expressed as mean hours for each organism): Enterococcus faecalis (55.2 vs. 38.8), Enterococcus faecium (68.4 vs. 43.8), Escherichia coli (44.2 vs. 41.0), Klebsiella pneumoniae (45.0 vs. 44.0), Proteus mirabilis (44.8 vs. 38.6), Pseudomonas aeruginosa (58.9 vs. 37.7), Staphylococcus aureus (49.2 vs. 36.0), Streptococcus agalactiae (49.2 vs. 31.4), Streptococcus pneumoniae (51.7 vs. 61.8), Streptococcus pyogenes (62.6 vs. 26.6). It was also observed that improvement in TAT was more pronounced for Gram-positive organisms than Gram-negative organisms. P-value was < 0.01 for all organisms except Streptococcus pneumoniae (0.7985) and Streptococcus pyogenes (0.2562). The number of specimens with these two organisms was too small to be considered significant.

Conclusion
Automation of microbiology laboratory leads to significant TAT improvement in urinary specimens, making early data availability to clinicians. This improves efficiency as well as supporting earlier antibiotic switch, antimicrobial stewardship and optimal patient care in treating urinary tract infections.

Disclosures
All authors: No reported disclosures.
2162. Comparison of Plazomicin Disk Diffusion vs. Gradient Diffusion Susceptibility Testing Results Against Drug-Resistant Clinical Enterobacteriaceae Isolates
Authors: Lepak Alexander , Lepak Alexander , Grajcevci Luriane , Banach Joyce , Meyer Katherine , Chen Derrick 
Published: October 2019

Abstract

Background
Plazomicin, a novel aminoglycoside, is active against carbapenem-resistant Enterobacteriaceae (EB) and is not inhibited by most aminoglycoside modifying enzymes that affect gentamicin and tobramycin. We investigated the activity of plazomicin against resistant EB clinical isolates and compared disk diffusion (DD) vs. gradient diffusion (GD) results.

Methods
EB isolates that were carbapenem resistant and/or resistant to both gentamicin and tobramycin were retrieved from the UW Health clinical isolate repository. Each isolate was tested against plazomicin using both DD (MAST Group Ltd. Plazomicin disk 30 µg) and GD (Liofilchem Plazomicin MIC Test Strip 0.16–256 µg/mL) methods according to manufacturer instructions and using FDA clinical breakpoints for interpretation.

Results
51 isolates were tested: 21 E. coli, 9 P. mirabilis, 7 E. cloacae, 6 K. pneumoniae, 3 K. oxytoca, 3 S. marcescens, 1 K. aerogenes, and 1 C. freundii. Specimen sites included: 29 blood, 8 urine, 8 soft tissue or bone, 5 intra-abdominal, and 1 sputum. Previous phenotypic AST results demonstrated 19 (37%) were CRE, of which 5 were also gentamicin and tobramycin resistant, and 32 (63%) were tobramycin and gentamicin resistant but carbapenem susceptible. Plazomicin zone diameters and minimal inhibitory concentrations (MIC) for all isolates are shown in the figure (data jittered to show frequency). There was a significant correlation between increased MIC and smaller zone diameters (Pearson coefficient −0.443, P = 0.001). However, while all 51 isolates were susceptible by DD breakpoints, only 46 (92%) were susceptible by GD breakpoints. All 5 discordant results were P. mirabilis which had an MIC of 4 µg/mL (intermediate) but zone diameters of 20–21 mm (susceptible).

Conclusion
Concordance between plazomicin DD and GD susceptibility was only 92%. All 5 discordant results were P. mirabilis. Surveillance studies demonstrate >80% of P. mirabilis have MIC of 2–4 mg/L. Given the DD breakpoint is 16 mm, our data suggest DD was overly active in our sample set. Comparison of DD and GD to reference broth microdilution against a larger set of isolates is warranted to determine which method is optimal; however, our data suggest DD may result in categorical errors for P. mirabilis.

Disclosures
Alexander Lepak, MD, Paratek Pharmaceuticals: Research Grant; Tetraphase Pharmaceuticals: Research Grant.
2167. Evaluation of Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy for Rapid and Reagent-Free Identification of Burkholderia spp.
Authors: Lam Lisa M T , Ismail Ashraf , Sedman Jacqueline , Vallières Émilie 
Published: October 2019

Abstract

Background
Burkholderia cepacia complex including B. gladioli are opportunistic pathogenic bacteria affecting the immunocompromised population. For prognosis and appropriate treatment, rapid and accurate species identification is particularly important for those diagnosed with cystic fibrosis (CF). Conventional biochemical identification techniques are insensitive and problematic for identifying Burkholderia spp., leading to common misidentification or inconclusive results. Recent studies have successfully employed attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy for rapid, reagent-free and cost-effective microbial identification. In the present study, identification of Burkholderia spp. by this technique is investigated.

Methods
A total of 59 isolates belonging to 7 species of Burkholderia were included in this study; all these isolates had been well-characterized by VITEK 2, 16S rRNA sequencing, random amplification of polymorphic DNA (recA typing) and/or matrix-assisted laser desorption/ionization time of flight mass spectrometry. ATR-FTIR spectra were acquired directly from colonies on 5% blood agar plates.

Results
A spectral database containing ATR-FTIR spectra of over 4300 bacterial isolates, encompassing over 70 genera and 190 species, was updated to include spectra of 39 isolates collected in this study and employed in the identification of the other isolates (n = 20). All isolates were correctly identified as Burkholderia by a multitier search approach. For Burkholderia species identification, spectra belonging to 39 isolates representative of all 7 species were used to construct a spectral database employed to identify the other 20 isolates [B. anthina (n = 2), B. gladioli (n = 8), B. multivorans (n = 7), and B. vietnamiensis (n = 3)]. Compared with VITEK 2 (30% correct species identification), ATR-FTIR spectroscopy correctly identified all but one isolate, resulting in overall correct species identification of 95%. Prospectively (10 months), 5 of 1100 isolates collected were identified as Burkholderia spp. by ATR-FTIR spectroscopy in concordance with VITEK 2.

Conclusion
ATR-FTIR spectroscopy can provide the means of rapid Burkholderia spp. identification for appropriate treatment of those diagnosed with CF.

Disclosures
All authors: No reported disclosures.
2181. Yield and Impact of Molecular Diagnostics for Pathogen Detection in Pediatric Patients: 16/18S rRNA PCR and Noninvasive Assays
Authors: Chun Angela , Heald-Sargent Taylor , Malczynski Michael , Muller William J , Qi Chao , Seed Patrick C , Mithal Leena B , Mithal Leena B 
Published: October 2019

Abstract

Background
Molecular diagnostic tests can identify bacterial and fungal pathogens from clinical samples. Nucleic acid detection tests include 16S and 18S rRNA gene PCR (16/18S PCR) and plasma next-generation sequencing (NGS). Other assays (fungal galactomannan and 1,3-β-d-glucan) detect structural factors. Our objective was to assess the utilization, yield, and impact of molecular diagnostics in pediatric patients who had samples sent for 16/18S PCR.

Methods
Sterile site fluid or tissue specimens were collected as part of standard care at Lurie Children’s Hospital, cultured, and sent to Northwestern Memorial Hospital for 16/18S PCR as clinically indicated. Medical records were reviewed for diagnostics, antibiotics, and clinical course.

Results
From 1/2016–8/2018, 236 samples were sent for 16 and/or 18S PCR from 183 patients. 83% had a concurrent ID consult. 16S PCR was done on 215 samples, 42 (20%) were positive, and 36 yielded species identification (Table 1). Antibacterial agents were administered prior to specimen collection in 73% and did not affect likelihood of positive 16S PCR. 18S PCR was sent on 163 samples; 12 (7.4%) were positive (Table 2) of which 10 were from immunocompromised hosts. 40% of patients were on antifungals prior to sample acquisition. 16/18S PCR impacted antimicrobial decision-making in 70 cases (30%). A pathogenic fungus was detected by PCR but not culture in 2 cases. Time to positivity of fungal culture was 1–15 days. Fungal culture was positive in 5 cases with-negative 18S PCR. Seventeen patients had positive serum 1,3-ß-D-glucan and/or galactomannan: 3 of which had positive 18S PCR, 5 with fungal growth, 5 presumed infection based on imaging, 1 Nocardia, and 3 noninfectious etiology. Plasma NGS was sent on 45 cases, was positive in 34, and affected clinical management in 10.

Conclusion
16S PCR can identify bacterial pathogens in the setting of negative culture and impact clinical care. Abscess, bronchial/pleural fluid, and brain/organ tissue were high yield specimens. 18S PCR can provide expeditious fungal identification in cases of suspected invasive disease, but fungal culture and serum molecular testing increase diagnostic yield. No single fungal test is comprehensive. Plasma NGS had relatively high yield and clinical impact in selected patients.

Disclosures
All authors: No reported disclosures.
2182. Harnessing Direct-from-Blood MALDI-TOF (DBM) and Local Blood Stream Infection (BSI) Antibiogram Data to Direct Optimal Therapy for Gram-Negative Rod (GNR) Bacteremia
Authors: Tischendorf Jessica , Lepak Alexander , Lepak Alexander 
Published: October 2019

Abstract

Background
GNR bacteremia is common in the hospital environment. Drug-resistance challenges thoughtful use of, and timely de-escalation to, regimens that limit carbapenem use. DBM accurately provides rapid identification of bacteremia pathogens, but lacks antibiotic susceptibility testing (AST) results to aid clinicians in refining therapy. We investigated whether integrating DBM identification and local BSI antibiogram data could be used to identify carbapenem-sparing regimens with predicted efficacy of ≥ 95% prior to traditional AST results.

Methods
We identified GNR blood culture results in adults from January 1, 2018 to December 31, 2018. The first isolate per bacteremia episode per patient was analyzed. AST was performed by MicroScan. We categorized isolates into 1 of 3 groups based on the most common resistance mechanisms in our population (i.e. CTX-M ESBL, AmpC): 1] Escherichia spp. and Klebsiella spp. (EK), 2] S. marscecens, P. mirabilis, E. (Klebsiella) aerogenes, C. freundii, M. morganii, E. cloacae complex, and C. non-freundii (SPEC-MEC), and 3] P. aeruginosa (PA). We compiled susceptibility rates to common antibiotics for GNR sepsis and compared results using Chi-square.

Results
381 GNR isolates were recovered in blood cultures from adult patients in 2018: EK 264 (69%), SPEC-MEC 66 (17%), PA 36 (9%), other 15 (4%). Susceptibility results in common GNR sepsis agents are shown in Figure 1 (*P < 0.05 between groups). Within each organism group, susceptibility was highest in the following scenarios: 1] EK: PTZ and MEM (P < 0.05 vs. FEP, TOB, CIP, and ATM), 2] SPEC-MEC: FEP, TOB, and MEM (P < 0.05 vs. PTZ and ATM), and 3] PA: comparably similar (> 90%) for PTZ, FEP, TOB, and MEM.

Conclusion
Integration of DBM and antibiogram data identified species-specific carbapenem-sparing regimens that would predict ≥ 95% of patients with GNR bacteremia are on effective therapy prior to traditional AST results. In appropriate patients, this could lead to a significant reduction in carbapenem duration and avoid broad-scale carbapenem use while also optimizing time to effective therapy. This is a readily adaptable process for other centers to improve care of patients with GNR bacteremia. Our data suggest using β-lactam alternatives for GNR bacteremia, especially EK, should be done with caution.

Disclosures
Alexander Lepak, MD, Paratek Pharmaceuticals: Research Grant; Tetraphase Pharmaceuticals: Research Grant.
2188. Provider Education and Rapid Antigen Detection Test Use in Private and Academic Pediatric Clinics
Authors: Dahl Steven , Hurley Emily A , Lee Brian R , Newland Jason , Bradley-Ewing Andrea , Donis De Miranda Evelyn , Pina Kimberly A , Mackenzie Alexander , Goggin Kathy , Myers Angela , Myers Angela 
Published: October 2019

Abstract

Background
Rapid antigen detection testing (RADT) is needed to differentiate Group A Streptococcal (GAS) pharyngitis from viral pharyngitis. Guidelines do not recommend RADT in patients with viral symptoms or in children <3 years old without GAS exposure. Reduction in unnecessary RADT use may impact inappropriate antibiotic use by decreasing prescriptions in children likely colonized with GAS. We examined the impact of guideline concordant education of appropriate RADT and antibiotic use in pharyngitis on providers’ (physician and APRN) use of RADT in an academic and private pediatric primary care clinic.

Methods
Retrospective chart review of 1,085 healthy children, age 1–5 years old, seen in clinics between September 2015 and March 2019 (355 pre- and 730 post-education; 211 academic and 874 private). Education occurred in 3/2017. Cases selected had either complaint of sore throat, RADT, or diagnosis of GAS pharyngitis or pharyngitis. Data collected included the presence of viral symptoms (e.g., cough, rhinorrhea), RADT/GAS culture results, diagnosis, and prescribed antibiotics. RADT was deemed unnecessary for all children < 3 years old without GAS exposure, in patients with ≥ 2 viral symptoms, or in patients ≥ 3 years old without pharyngitis.

Results
Overall, RADT use decreased from pre to post intervention (72.1% vs. 23.4% of patients, P ≤ 0.0001). Unnecessary RADT use decreased overall (50.4% vs. 16.2%, P ≤ 0.0001), in all clinics (private: 56.2% vs. 16.0%, P ≤ 0.0001; academic: 38.1% vs. 17.4%, P = 0.0012), and with all providers (physician: 41.6% vs. 18.3%, P ≤ 0.0001; APRN: 58.8% vs. 14.1%, P ≤ 0.0001). Unnecessary RADT use decreased for children <3 years old (28.1% vs. 7.4%, P ≤ 0.0001) and ≥2 viral symptoms (65.7% vs. 16.5%, P ≤ 0.0001).

Conclusion
Unnecessary RADT use decreased in the post-education period overall (34%), in children <3 years old (21%), and in patients with ≥ 2 viral symptoms (49%). Reductions were also seen in both academic (21%) and private (40%) clinics as well as with both physicians (23%) and ARPNs (45%). Limitations include lack of a control group and sample size variance by the clinic. We observed positive trends in RADT reduction following provider education in private and academic settings; however, further research including control and optimal sample size is needed to confirm any direct impact.

Disclosures
All authors: No reported disclosures.
2208. Development and Evaluation of Predictive Models for Estimating Infection Susceptibility to Empiric Treatment Regimens Among Patients with Pneumonia in Intensive Care Units
Authors: Dewart Courtney M , Hade Erinn , Gao Yuan , Rahman Protiva , Lustberg Mark , Pancholi Preeti , Stevenson Kurt , Hebert Courtney 
Published: October 2019

Abstract

Background
Predictive models for empiric antibiotic prescribing often estimate the probability of infection with multidrug-resistant organisms. In this work, we developed models to predict coverage of specific treatment regimens to better target antibiotics to high- and low-risk patients.

Methods
We established a retrospective cohort of adults admitted to the ICU in a 1,300-bed teaching hospital from November 1, 2011 to June 30, 2016. We included patients with a diagnosis of pneumonia and positive respiratory culture collected during their ICU stay. We collected demographics, comorbidities, and medical history from the electronic health record. We evaluated three penalized regression methods for predicting infection susceptibility to 11 treatment regimens: least absolute selection and shrinkage operator (LASSO), minimax concave penalty (MCP), and smoothly clipped absolute deviation (SCAD). We developed models for susceptibility prediction at two stages of the diagnostic process: for all pathogenic bacteria and for infections with Gram-negative organisms only. We selected final models based on higher area under the receiver operating characteristic (AUROC), acceptable goodness of fit, lower variability of the AUROCs in the cross-validation run, and fewer predictors.

Results
Among 1,917 cases of pneumonia, 54 different pathogens were identified. The most frequently isolated organisms were: Pseudomonas aeruginosa (16.6%), methicillin-resistant Staphylococcus aureus (16.1%), and Staphylococcus aureus (13.5%). Frequently selected variables included age, Elixhauser score, tracheostomy status, recent antimicrobial use, and prior infection with a carbapenem-resistant organism. All final models used MCP or SCAD methods. Point estimates for the AUROCs in the training set ranged from 0.70 to 0.80, and estimates in the internal validation set ranged from 0.64 to 0.77.

Conclusion
MCP and SCAD outperformed LASSO. For some regimens, models predicted infection susceptibility with fair accuracy. These models have potential to help antibiotic stewardship efforts to better target appropriate antibiotic use.

Disclosures
All authors: No reported disclosures.