bluuebunny/crossref_metadata_2025_split huggingface dataset:
2130. Detection of Carbapenemase-Producing Organisms and Impact on Antimicrobial Utilization for Carbapenem-Resistant Enterobacteriaceae (CRE) Infections
Authors: Minor Sarah Brooks , Alexander Jose 
Published: October 2019

Abstract

Background
CREs are feared pathogens with resistance occurring through the production of carbapenemases. Identification of carbapenemase-producing (CP) organisms assists with proper antimicrobial selection of commonly used agents, such as ceftazidime/avibactam (CA), meropenem/vaborbactam (MV), and tigecycline (TG). AdventHealth Orlando implemented a CRE screening method based on meropenem (MER) and a confirmatory CRE PCR testing in March 2018. Prior to implementing this test, patients were deemed to have CRE infections (CREI) if the organism demonstrated resistance to any carbapenem. The objective of this study was to evaluate the impact of this testing on the utilization of anti-CRE antibiotics.

Methods
This was a retrospective pre (March 2017–February 2018)- and post (March 2018–February 2019)-implementation study examining the impact of CRE PCR testing. Outcomes included the number of antibiotic days saved, average duration of therapy (DOT), median length of stay (LOS), and change in CP-CRE prevalence. The intervention consisted of the implementation of CRE PCR testing and included inpatients > 18 years old who received either CA, MV, or TG for the treatment of a CREI.

Results
Post-implementation, 30 unique patients were identified as having a positive K. pneumoniae carbapenemase gene by PCR, indicating a CP-CRE and received CA, MV, or TG; whereas, 42 patients in the pre-implementation group had a CREI and received CA, MV, or TG. Testing to identify CP-CREs led to a 50% reduction in the number of antibiotic days for CA, MV, and TG (575 vs. 287 days, P < 0.0001). Additionally, the average DOT decreased by 2.5 days in the post-implementation group (10.5 days vs. 8 days, P = 0.18) along with a 3.5-day shorter median LOS (15 days vs. 11.5 days, P = 0.48). The CRE prevalence based on resistance only to MER is 0.27%, compared with the previously reported rate of 2.5% that included resistance to ertapenem or MER.

Conclusion
Implementing CRE PCR testing to identify CP-CRE organisms resulted in a significant reduction in utilization of anti-CRE agents for CREIs. Additionally, the testing algorithm allowed for accurate reporting of our local CRE prevalence. By avoiding CA, MV, or TG in patients without CP-CREs, this has the potential to optimize therapy while reducing collateral damage associated with broad-spectrum agents.

Disclosures
All authors: No reported disclosures.
2132. Multicenter Evaluation of Eravacycline MIC Results for Enterobacteriaceae Using MicroScan Dried Gram-Negative MIC Panels
Authors: Traczewski Maria M , Beasley Denise , Harrington Amanda , DesJarlais Sharon , Garner Omai , Hastey Christine , Brookman Regina , Lockett Zabrina , Chau Jennifer , Zimmer Barbara 
Published: October 2019

Abstract

Background
A multicenter study was performed to evaluate the accuracy of eravacycline on a MicroScan Dried Gram-negative MIC (MSDGN) Panel when compared with a frozen CLSI broth microdilution reference panel.

Methods
For efficacy, an evaluation was conducted at three sites by comparing MIC values obtained using the MSDGN to MICs using a CLSI broth microdilution reference panel. A total of 414 Enterobacteriaceae clinical isolates were tested using the turbidity and Prompt®* methods of inoculation. For challenge, 79 Enterobacteriaceae isolates were tested on MSDGN panels at one site. For reproducibility, a subset of 11 organisms was tested on MSDGN panels at each site. MSDGN panels were incubated at 35 ± 2°C and read on the WalkAway System, the autoSCAN-4 instrument, and read visually. Read times for the MSDGN panels were at 16–20 hours. Frozen reference panels, prepared according to CLSI/ISO methodology, were inoculated using the turbidity inoculation method. All frozen reference panels were incubated at 35 ± 2°C and read visually. Frozen reference panels were read at 16–20 hours. FDA breakpoints (µg/mL) used for interpretation of MIC results were: Enterobacteriaceae ≤ 0.5 S. Potential major and very major errors were calculated using the NS result in place of resistant (R).

Results
When compared with frozen reference panel results, essential and categorical agreements for isolates tested in the Efficacy and Challenge are as follows (see table). Reproducibility among the three sites were greater than 95% for all read methods for both the turbidity and Prompt inoculation methods.

Conclusion
This multicenter study showed that eravacycline MIC results for Enterobacteriaceae obtained with the MSDGN panel correlate well with MICs obtained using frozen reference panels using FDA interpretive criteria. * PROMPT® is a registered trademark of 3M Company, St. Paul, MN USA. Beckman Coulter, the stylized logo and the Beckman Coulter product and service marks mentioned herein are trademarks or registered trademarks of Beckman Coulter, Inc. in the United States and other countries. Xerava™ (Eravacycline) is a registered trademark of Tetraphase Pharmaceuticals, Inc.

Disclosures
All authors: No reported disclosures.
2149. Performance of a Gradient Diffusion Method (Etest®) on Mueller–Hinton Agar with Sheep Blood for Aerococcus urinae Antimicrobial Susceptibility Testing
Authors: Berteau Tammy , Emilie Roy France , Bestman-Smith Julie , Grandjean-Lapierre Simon , Longtin Jean , Dufresne Simon-Frédéric , Domingo Marc-Christian , Leduc Jean-Michel 
Published: October 2019

Abstract

Background
Aerococcus urinae is frequently identified by MALDI-TOF in urinary specimens. It is generally susceptible to β-lactams, but its susceptibility pattern to fluoroquinolones (FQ) remains unpredictable. The goal of this study was to evaluate the performance of the gradient diffusion method (Etest®) to determine FQ susceptibility compared with broth microdilution (BMD) and agar dilution (AD).

Methods
Prospectively collected isolates of A. urinae from urinary tract specimens originating from 5 hospitals in Quebec city and Montreal were identified by MALDI-TOF (Vitek-MS). All isolates were tested using BMD according to CLSI guidelines, and also with Etest® strips on MH agar w/ 5% sheep blood. Isolates showing trailing, insufficient growth or discordance between both methods were further tested by agar dilution (MH agar w/5% horse blood + β-NAD) according to EUCAST guidelines. Breakpoints were interpreted using CLSI M45-A3. Combined results of BMD and AD were then compared with Etest.

Results
Of the 207 isolates of A. urinae tested, 37 showed trailing (17,8%) and 19 (9,2%) insufficient growth with the BMD method and were retested using AD. Moreover, 38 isolates (ciprofloxacin) and 13 isolates (levofloxacin) showed either lack of categorical or essential agreement between Etest and BMD and were also retested using AD to arbitrate discrepancies. Susceptibility profiles combining BMD and AD are presented in Table 1. As suggested in EUCAST guidelines, readings were much clearer and growth was better with AD compared with BMD. The categorical agreement of the Etest® with BMD+AD was 95% for ciprofloxacin and 97% for levofloxacin. Essential agreement was 95% for ciprofloxacin and 97% for levofloxacin. No very major errors were identified. Two major errors were identified for levofloxacin (1,2%) and one for ciprofloxacin (0.6%).

Conclusion
Gradient diffusion method using Etest® strips on MH agar w/ sheep blood is a valid method to determine susceptibility to FQ for urinary tract isolates. As a reference method, AD provides clearer endpoints and better growth than BMD for FQ susceptibility testing.

Disclosures
All authors: No reported disclosures.
2152. Detection of Uropathogens Using BD Kiestra™ Total Laboratory Automation with Urine Culture Application
Authors: Patel Parul , Droske Lauren E , Patel Jignesh , Barza Ruby , Lindgren Rebecca , McElvania Erin 
Published: October 2019

Abstract

Background
Urine is the most frequently cultured specimen type for the majority of clinical microbiology laboratories. Typically, around 30% of cultures are positive for uropathogens with 70% yielding insignificant or mixed growth. BD is developing a software Urine Culture Application (UCA) for the BD Kiestra Total Laboratory Automation (TLA) system to screen images of urine culture plates, sort them based on growth vs. insignificant growth and also allow for presumptive pathogen identification.

Methods
De-identified urine specimens were inoculated onto BD BBL™ CHROMagar™ Orientation Media (CHROM; BD, Sparks, MD), CHROM/Trypticase™ Soy Agar II with 5% Sheep Blood (TSA) biplate, BD BBL MacConkey II agar, and TSA using the BD Kiestra TLA system. Plates were imaged at 24 hours using the BD Kiestra™ ReadA Compact imaging acquisition software and an algorithm was applied to the images using the UCA (Version 2.0). Semi-quantitative measurements of <100, 100–1,000, 1,000–10,000, 10,000–100,000, and >100,000 cfu/mL growth were determined by UCA for all media types and presumptive ID was determined using CHROM. Manual reading of the images by two technologists was the gold standard for comparison. For discrepant results, a third manual reader was used as an arbitrator.

Results
Testing between 877 and 934 urine specimens on each of five media types using UCA resulted in an exact semi-quantitative agreement with manual reading for 85.5–95.0% of specimens (Table 1). If semi-quantitative values ± one category of agreement are included, the number rises to 98.2–99.4% agreement. Using CHROM for presumptive identification of pure or predominant organisms, UCA was in agreement with manual identification in 251 of 272 cultures (92.3%). Of the 21 discrepant organisms, 19 were classified as “other” by manual reading but were identified as specific organisms by UCA. Definitive organism identification was not performed.

Conclusion
UCA was able to accurately categorize bacterial growth into five semi-quantitative categories using five media types. Pure and predominant uropathogens were accurately identified from CHROM using UCA. The use of UCA software application may enable laboratories to save time screening urine cultures by allowing more efficient use of technologist time.

Disclosures
All authors: No reported disclosures.
2155. Accelerated Confirmation of Porin Loss in Carbapenem-Resistant Enterobacterales: A MALDI-TOF Mass Spectrometry-Based Approach
Authors: Correa-Martinez Carlos , Idelevich Evgeny A , Becker Karsten 
Published: October 2019

Abstract

Background
The accurate identification of carbapenem resistance mechanisms is decisive for the appropriate selection of antibiotic regimens. Numerous methods can detect carbapenemase-producing carbapenem-resistant bacteria (CPCR). However, non-CPCR (NCPCR) are routinely assumed to display porin loss as a diagnosis of exclusion. No further confirmatory tests are performed since the gold standard (sodium dodecylsulfate polyacrylamide gel electrophoresis, SDS–PAGE) is laborious and time consuming. We propose a test for rapid and easy detection of porin loss by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

Methods
Clinical meropenem-resistant Enterobacterales strains (10 CPCR, 10 NCPCR) and control strains recommended by EUCAST (5 carbapenemase-producing, one with porin loss, one-negative control) were analyzed. Membrane proteins were extracted by successive centrifugation of bacterial suspensions (McFarland 0.5) and addition of ethanol, formic acid and acetonitrile. MALDI-TOF MS of the protein extracts was performed on a 96-spot target (Bruker Daltonics, Germany). Peaks between 35 and 40 kDa were analyzed for the presence of porins and compared with the bands observed in the SDS–PAGE of the protein extracts.

Results
Within the molecular weight range of 35–40 kDa, the MALDI-TOF MS-based method revealed peaks in all CPCR isolates corresponding to those observed in the carbapenemase-producing control strains. In contrast, the control strain with porin loss as well as all CNCR isolates showed a lower quantity of peaks in this range. All peaks observed correlated with the bands observed in the SDS–PAGE of the protein extracts at the corresponding molecular weight (Figure 1).

Conclusion
Yielding results that reliably correspond to the current gold standard, we propose a method for accelerated detection of porin loss as an alternative to the diagnosis of exclusion usually made in routine settings. With a processing time of approximately 20 minutes, the method can be easily implemented in the clinical setting. Applying this MALDI-TOF MS-based approach, valuable information will be provided about a resistance mechanism that otherwise remains unexplained.

Disclosures
All authors: No reported disclosures.
2169. An Algorithm-Based Approach Reduces Overuse of Meningitis/Encephalitis Multiplex PCR Panel
Authors: Gitman Melissa R , Nowak Michael D , Navis Allison , Mia. Sordillo Emilia 
Published: October 2019

Abstract

Background
Syndromic molecular panels enable rapid diagnosis and optimized management of infections with significant morbidity and mortality, but may be overused without clear guidelines. A recent report indicated there was little clinical suspicion of infection in up to 1/3 of cases for which a FILMARRAY® Meningitis/Encephalitis Panel (ME Panel, bioMérieux) was ordered. We recently implemented the ME Panel in our multicenter health system. We assessed ME Panel use for the 6-month period following test implementation.

Methods
A testing algorithm was developed, vetted with our system-wide Infectious Diseases (ID) and Neuro-ID Services, and used as the basis for the education of the Emergency Medicine, Internal Medicine, Hospitalist, Pediatric, and Critical Care Medicine Services. Algorithm elements were embedded in the electronic medical record (EMR). Lab records and EMRs were reviewed for all patients tested by ME Panel or cerebrospinal (CSF) culture. Lab results, baseline demographic and underlying medical history, and results of singleplex viral PCR CSF tests and the multiplex NY State Encephalitis PCR Panel (NYS Panel, Wadsworth Laboratory, Albany, NY) were recorded. ME Panel results were compared with other findings.

Results
115 ME Panels were performed, with 5 (4%) positives [1 N.meningitidis, 1 H.influenzae, 1 cytomegalovirus (CMV), 1 Herpes simplex virus type 1 (HSV1), and 1 varicella zoster virus (VZV)]. Other findings were consistent with true infection for the N. meningitis, HSV and VZV; the CMV was likely reactivation. Significance of the H. influenzae was unclear. There were 830 CSF cultures, with 38 (4%) positive; 5 of the 38 were ME Panel targets. 29 NYS Panels were sent [1 positive each for Human Herpesvirus 6 (HHV6) and Epstein Barr Virus (EBV)]. Finally, 7 singleplex PCRs were positive [5 HSV, 1 CMV and 1 HHV6], including one negative by ME Panel.

Conclusion
We did not find ME Panel overuse; rather, we found several cases for which the ME Panel could have given a more rapid diagnosis. We did identify areas for improvement in test ordering, such as minimizing duplicate testing (e.g., singleplex PCR) A multi-disciplinary approach engaging stakeholders in the lab, ID and Neuro-ID can assist appropriate test utilization and diagnostic stewardship.

Disclosures
All authors: No reported disclosures.
2174. Comparison of the Verigene® and the ePlex® Blood Culture Identification Panels for Gram-Positive and Gram-Negative Bloodstream Infections
Authors: Johnson J Kristie , Kpadeh-Rogers Zegbeh , Paszkiewicz Gwen , Claeys Kimberly C 
Published: October 2019

Abstract

Background
Rapid diagnostic testing for the management of bloodstream infections has become paramount to improving patient outcomes. The primary objective of this study was to assess the differences between 2 FDA approved instruments.

Methods
Retrospective study from August 2018 to April 2019 at the University of Maryland Medical Center. One positive blood culture from each patient was tested using the Verigene® blood culture Gram-positive (BC-GP) or Gram-negative (BC-GN) panels based on the Gram stain and then analyzed using the ePlex® Blood Culture Identification (BCID) Gram-positive (BCID-GP) or Gram-negative (BCID-GN) research-use-only panels and compared with culture results.

Results
The study consisted of 140 positive blood culture bottles. 14 bottles were excluded for a total of 55 GN and 71 GP bottles. Of the 55 GN bottles, 3 had 2 GN rods for a total of 58 GNRs. BCID-GN missed 1 P. aeruginosa, 2 S. maltophilia, and 1 E. coli for a 93% (53/57) positive agreement. The BCID-GN does not detect A. junii and therefore it was excluded. BC-GN did not identify 1 K. pneumoniae with a 98% (47/48) positive agreement. BC-GN does not include the detection of S. maltophilia (4), Serratia (4), Morganella (1), and B. fragilis (1)and these were excluded in the BC-GN analysis. CTX-M was the only resistant marker detected and both panels identified it correctly. 5 samples using the BCID-GN also detected Pan Gram-Positive; 3 grew GP organisms, the other 2 only grew E. coli. Of the 71 GP bottles, 3 had two GP bacteria totaling 74 GPs. BCID-GP missed 1 S. aureus, 1 invalid, and called an E. faecalis that was not identified by the reference method for a 99% (72/73) positive agreement. BC-GP does not detect Micrococcus (6) or E. gallinarum (1) and missed 1 S. mitis/oralis for a 99% (66/67) positive agreement. 18 samples were positive for mecA detected by both panels. 4 samples were vanA/B positive; 1 by BCID-GP was sensitive to vancomycin and not detected by BC-GP. BCID-GP detected 1 sample as Pan Gram-negative although a GNR was not detected.

Conclusion
BothVerigene® and ePlex® GP and GN panels have a high percent positive agreement. Laboratories should take into consideration the epidemiology of their bloodstream infections when deciding on panels for the rapid detection of bloodstream infections.

Disclosures
All authors: No reported disclosures.
2176. A New Rapid Test for Detection of The Cefazolin Inoculum Effect (CIE) in Methicillin-Susceptible Staphylococcus aureus (MSSA)
Authors: Carvajal Lina P , Ordonez Diaz Karen M , Cristancho Quintero Edilberto , Echeverri Aura M , Vargas Sandra , Porras Jessica , Rincon Sandra , Seas Carlos , Luna Carlos , Arias Cesar A , Reyes Jinnethe 
Published: October 2019

Abstract

Background
Most MSSA harbor one of the four different variants of β-lactamase (BlaZ) (A, B, C and D). The CIE is defined as an MIC >16 μg/mL when a high inoculum (107 CFU/mL) is used and depends on the presence of BlaZ. The presence of the CIE has been associated with therapeutic failure in invasive MSSA infections. In some countries of South America, the prevalence of CIE is high, ranging from 36% to 51% (Colombia and Argentina, respectively). Type A BlaZ is most often associated with the CIE due to its high affinity for cefazolin. Here, we developed a rapid test based on the premise that the extracellular form of BlaZ is responsible for the CIE. We aimed to identify invasive MSSA that exhibit the CIE and validate the test in two cohorts of isolates from patients in Colombia and Argentina

Methods
152 MSSA clinical isolates were collected from Colombia (n = 71) and Argentina (n = 81). We determined MIC at standard and high inoculum. We developed a test using induction of BlaZ with ampicillin (150 μg/mL) for 20 minutes and, using the supernatant for incubation with nitrocefin for 30 min. A change in color from yellow to red was considered positive. MSSA TX0117 (BlaZ +, with the CIE), ATCC 29213 (BlaZ-negative) and ATCC 25923 (BlaZ + lacking the CIE) were used as controls. BlaZ typing of all Argentinian isolates was available by sequencing

Results
A high proportion (43%) of MSSA exhibited the CIE (34% and 52% of Colombian and Argentinian isolates, respectively) by MIC. The rapid test identified 76% of isolates exhibiting the CIE and correctly ruled out all isolates lacking the CIE (sensitivity 80%, specificity 100%). Furthermore, the rapid test detected all isolates with the CIE that harbored Type A BlaZ from Argentina. Conversely, the test failed to identify the CIE in Argentinian isolates that produce type B and C BlaZ. The sensitivity and specificity of the rapid test for the Colombian isolates whose BlaZ type was unknown were 89% and 100%, respectively.

Conclusion
A rapid test of less than 2 h can readily identify MSSA isolates exhibiting the CIE. For isolates carrying type A BlaZ, which is highly associated with the CIE, the test had a sensitivity and specificity of 100%. Rapid identification of MSSA with the CIE may have important therapeutic consequences in deep-seated infections

Disclosures
All authors: No reported disclosures.
2186. Differentiation of Severe Fever with Thrombocytopenia Syndrome from Scrub Typhus
Authors: Sul Hyoung , Ra Yun Na , Kim Dong-Min , Kim Jieun , Hur Jian , In Jung Sook , Ryu Seong-yeol , Yeon Lee Ji , Huh Kyungmin , Gyung Kwak Yee , Keun Kim Young , Won Jeong Hye , Yeon Heo Jung , Sik Jung Dong , Bae In-Gyu , Lee Su-Jin , Hee Lee Sun , Hee Park Sun , Yeom Joon-Sup , Lee Hyungdon 
Published: October 2019

Abstract

Background
SFTS and scrub typhus have similar clinical features and difficult to differentiate. Thus, a study to develop a scoring system to differentiate between two diseases in a clinical setting before the confirmation of laboratory results was reported by Kim et al. However, the statistical power could be low because of low numbers of cases (21 SFTS, 91 scrub typhus), our study analyzed by increasing the number of cases to overcome these limitations.

Methods
We retrospectively collected data from 183 SFTS and 178 scrub typhus patients who visited the 21 hospitals in South Korea between October, 2013 and November, 2017. The study protocol was approved by the IRB of each institution. SFTS was diagnosed through detection of SFTS viral RNA using RT–PCR. Scrub typhus was diagnosed either detection of 56-kDa antigen of O. tsutsugamushi using nested PCR or ≥ 4 fold rise in IgM or IgG titer using indirect IFA. Statistical analyses were performed by using SPSS and Medcalc.

Results
To differentiate SFTS from scrub typhus, we applied the scoring system proposed by Kim et al. After multivariable logistic regression, altered mental status, leukopenia, prolonged aPTT, and normal CRP(≤ 1.0 mg/dL) were significantly associated with SFTS compared with scrub typhus. Each variable was scored by 1 point, with a total score of 0–4 points, the optimal cutoff value was > 1 for the ROC curve. A score > 1 had 92% sensitivity, 96% specificity for diagnosis of SFTS, with a ROC AUC of 0.974. Because the sensitivity was less than 95%, we changed the normal CRP criteria to ≤ 3.0 mg/dL. The modified scoring system had 97% sensitivity, 96% specificity for diagnosis of SFTS, with an AUC of 0.983, and it showed a statistically higher accuracy than original scoring system (P = 0.0487). In this study, four factors for predicting SFTS were newly developed: leukopenia, prolonged aPTT, normal CRP (≤3.0 mg/dL), and elevated CK (>1,000 IU/L). Our study scoring system had 97% sensitivity, 98% specificity for diagnosis of SFTS, with an AUC of 0.992, and it showed a statistically higher accuracy than original scoring system (P = 0.0308).

Conclusion
In conclusion, we can easily differentiate SFTS from scrub typhus by using our scoring system of leukopenia, prolonged aPTT, normal CRP, and elevated CK in the endemic area.

Disclosures
All authors: No reported disclosures.