bluuebunny/crossref_metadata_2025_split huggingface dataset:
A-280 Impact of 2022 CLSI Revised Piperacillin/Tazobactam Clinical Breakpoints on Enterobacterales Isolates Identified at a Tertiary Medical Center in Southern Taiwan
Authors: Kuo S 
Published: September 2023

Abstract

Background
Piperacillin-tazobactam (TZP) is one of the most common antibiotics administered to hospitalized patients. Its broad activity against gram-negative, gram-positive, and anaerobic pathogens. The Clinical and Laboratory Standards Institute (CLSI) publishes revised TZP breakpoints in 2022. The purpose of this study was to evaluate the impact of changing the TZP breakpoint in a regional teaching hospital in southern Taiwan.

Methods
We retrospectively evaluated TZP for 1347 Enterobacterales isolates identified by MALDI-TOF (Bruker Daltonik, Bremen, Germany) between September 1, 2022, through December 31, 2022, at Chang Gung Memorial Hospital in Chiayi. Blood antimicrobial susceptibility testing was performed using an NMIC-411 panel on the BD Phoenix™ M50. The antibiotic susceptibility test of Enterobacterales from other sources of infection used the Disk diffusion method (Kirby-Bauer Method). Susceptibilities were assessed based on historic CLSI breakpoints in 2021 as well as the current CLSI breakpoints from the most recent CLSI MIC breakpoints, the 32th edition of document M100, published in 2022.

Results
We evaluated 1347 Enterobacterales isolates. Most isolates identified were Escherichia coli [n = 768 (57%)] and Klebsiella pneumoniae [n = 286(21.2%)]. The new TZP breakpoints reduced the percentage of strains that were previously judged to be susceptible by CLSI M100-S31 from 80.9%(1090/1347) to 50%(674/1347). The majority of isolates 674(50%) were susceptible; 416 (30.9%) isolates were susceptible-dose dependent and 257 (19.1%) were resistant to piperacillin/tazobactam using the new CLSI breakpoints. The results of the analysis of the source of infection found that the bacteria that had the greatest impact on the respiratory tract decreased from 43.6% to 12.7%, followed by the genitourinary tract infection decreased from 80.4% to 27%, bodily fluid infection decreased from 69.8% to 24.5%, and abscesses,wounds,pus decreased from 72.7% to 28.1%; The most insignificant are blood infection strains, from 83.1% to 81.3%.

Conclusion
Our results indicate an increase in resistance to Enterobacterales isolates tested. Non- susceptible to piperacillin/tazobactam from 19.1% to 50% using the revised CLSI breakpoints. The decreased susceptibilities make it clear that microbiology laboratories should accept new MIC breakpoints. Although our study has demonstrated decreased susceptibilities, there is no correlation with clinical outcomes. In conclusion, changes in breakpoints had a significant impact on the susceptibility of TZP for Enterobacterales isolates in our study. Understanding and evaluating the impact of the breakpoint changes is of paramount importance. Institutions should ensure that their breakpoints are up to date to allow for the most optimized treatment.
A-281 Analysis of Concurrent HBV Surface Antigen and HBV DNA Test Results
Authors: Pratt G W , Rao L V 
Published: September 2023

Abstract

Background
HBV surface antigen (HBsAg) is the serological hallmark of both acute and chronic infection. HBV DNA levels are monitored clinically in chronic HBV patients to evaluate HBV replication, candidacy for antiviral therapy and monitor patients on therapy. Although HBsAg has an intrinsic association with HBV DNA, it does not necessarily correlate with HBV DNA, especially in the natural course of infection. This study evaluates concurrent HBsAg and HBV DNA testing with a focus on natural infection serological markers such as detection of HBV core antibody (HBcAb), HBV e antigen (HBeAg), and HBV e antibody (HBeAb).

Methods
Clinical laboratory results from 1604 specimens tested over one year for both HBsAg and HBV DNA were analyzed. The HBsAg test is a qualitative assay, but concurrent quantitative HBV DNA results were available. HBV DNA results spanned the measurable range of the assay (lower limit-of-detection: 3.5 IU/mL, lower limit-of-quantitation: 10 IU/mL). HBsAg-positive/HBV DNA-negative results were further investigated to clarify under what circumstances such discordant results are more likely to be observed.

Results
HBsAg-positive and HBV DNA-negative results, which accounted for approximately 18% of the data set (284 out of 1604 samples), are more likely to occur when the specimen is HBeAg-negative (Table). A limitation of this study is a lack of information regarding treatment status of the study population. Additionally, HBsAg can persist during HBV treatment. This discordance between HBsAg and HBV DNA test results could also be due to increased integration of HBV into the host genome that produces HBsAg in the absence of measurable viral load in treatment-naïve individuals.

Conclusion
HBsAg-positive and HBV-DNA negative discordance is most often seen when HBeAg is negative.
A-297 Usefulness of Non-Skin Samples in the PCR Diagnosis of Monkeypox
Authors: Algarate S , Bueno J , Crusells M J , Ara M , Dehesa-García B , García-Manrique B , Alonso H , Alvarado E , Ducons M , Arnal S , Riesgo M , Benito R 
Published: September 2023

Abstract

Background
During 2022, human mpox cases were reported in several European countries. Until November 2022, in Spain, 7404 cases were detected, most of them linked to sexual intercourse. In that context, fast identification of cases and sources of infection were essential for an optimal management. Polymerase chain reaction (PCR) was the preferred laboratory test. Our objective was to evaluate the usefulness of sera and nasopharyngeal samples for MPXV detection, and its application in contact studies without skin or mucosal injuries.

Methods
In the Hospital Clínico Universitario of Zaragoza (Spain), 106 samples from 50 patients, 38 male and 12 female, aged between 11 to 62 years, with skin lesions suspected MPXV infection were analysed. Samples were collected between May and September 2022 in inactivating universal viral transport medium (Biocomma). Samples were obtained between 1 and 19 days of evolution. To perform the real-time PCR, the VIASURE Monkeypox Virus Real Time PCR Detection Kit and the VIASURE 48—Real Time PCR System were used. Nucleic acid extraction was performed with the automated nucleic acid extraction system MagLEAD12gC using the MagDEA®Dx SV reagents.

Results
Table 1 shows the results expressed in Ct values. Skin, anogenital and serum samples were the most efficient for MPXV diagnosis. Nevertheless, these data are influenced by the sample collection date.

Conclusion
Real-time PCR was positive in samples from all locations in 71,4% of the infected patients. Respiratory samples (pharyngeal and nasopharyngeal) were the ones that showed the highest number of false negative results, whereas there was only one skin sample and one serum sample with a negative result. This study shows that sera samples can be used in the diagnosis of MPXV infection because of ease of collection, applicability to contacts without lesions and the option of serology testing for other STI agents (HBV, HCV, HIV, Treponema pallidum…).
A-323 Pre-analytic Interference in PT and PTT Measurement using Mechanical vs Optical Clot Detection
Authors: Maciak D A , Dietzen D J 
Published: September 2023

Abstract

Background
Mechanical clot-detection is commonly thought to be less susceptible to optical pre-analytic interference. Pediatric specimens are particularly prone to be hemolyzed and/or icteric. Our hospital laboratory approached an impending change in coagulation instrumentation from mechanical (STAGO) to optical (IL) with some trepidation. We, therefore, performed a detailed comparison of plasma samples containing a broad range of hemoglobin, bilirubin, and triglyceride using IL reagents (RecombiPlasTin2G, SynthASil) on the TOPS 550 and a manual method on the STart 4.

Methods
7 independent pools (5 normal, 2 prolonged) of residual citrated plasma were supplemented with hemoglobin, bilirubin, or triglyceride up to 1000 mg/dL, 150 mg/dL, or 750 mg/dL, respectively, or with equal volumes of vehicle as control. Supplementation was confirmed and quantified by measuring HIL indices on a Roche Cobas 6000. PT and PTT were performed in duplicate on each experimental and control sample on the TOPS and STart systems. Imprecision of the two systems was monitored at two levels throughout the study.

Results
Imprecision (n = 20) of the TOPS PT and PTT assays ranged from 1.4–3.1% (CV). Imprecision (n = 20) of the STart PT and PTT assays ranged from 1.9–18.3% (CV). PT and PTT on both platforms were not impacted by hemolysis or lipemia up to an H index of 1000 and an L index of 500, respectively. As shown in the Figure, PT and PTT in normal pools on both platforms were significantly prolonged by the presence of bilirubin above an I-index of 30. Results were similar in the prolonged pools. Data points are the means (± SD) of 10 determinations across the 5 normal plasma pools for experimental (●) and control specimens (○).

Conclusion
Mechanical clot detection did not show superior resistance to pre-analytic interference vs an optical clot detection method.
A-339 Utomated Flow of a Non-invasive Fetal Gender Determination Lab-developed Molecular Test
Authors: Xavier Dias T S , da Silva V G , Santos M C , Batistutti V P , Osorio P S , Moratori D , Levi J E 
Published: September 2023

Abstract

Background
The discovery of cell-free fetal DNA in maternal circulation during pregnancy fostered the introduction of non-invasive tests. Fetal gender determination may be determined at early pregnancy by real-time PCR, identifying the presence or absence of Y chromosome markers in maternal plasma. Dasa has been offering this test for more than 10 years. In 2022, the assay was adapted to an automated flow.

Methods
The Flow Solution platform, powered by Roche®, was adapted to the in-house test, allowing the processing of 94 samples. Whole blood is obtained from pregnant women from the 8th week of pregnancy onwards. Each maternal plasma sample is extracted once and the DNA eluate submitted to real-time amplification targeting the DYS14 gene from the Y chromosome, in triplicate. The human RNAseP gene is co-amplified as an internal control. Full process takes 5 hours, with the possibility of overlapping a new routine every 2 hours, with a daily capacity of 12 routines (1128 samples/day).

Results
In 2022, 129 849 fetal gender determination results were released. Of these, 49% of the results indicated male and 51% female fetuses.A few samples displayed indeterminate results, showing amplification curves but with cycle threshold values that are above the cutoff. Other samples do not reach internal quality metrics and the analysis is repeated from the plasma or a new collection is requested. Results that, after the second collection, remain indeterminate, are forwarded with the patient's clinical history to the medical board. In contact with the patient, possible causes for inconclusive results are explained. In 2022, for every 10 000 tests there were 8 were medical contacts.The automated methodology developed and implemented, allowed a high processing volume, with 129 849 tests released in 2022, an increase of 33% compared to 2021 when the method had manual steps. The Total Service Time (TST) from collection to results release in 2022 was approximately 5 days, a 20% reduction compared to 2021, and the repetition rate of 2.43% in 2022 was 0.9% lower than 2021. Recollections also diminished from 1% in 2021 falling to 0.8% in 2022.

Conclusion
A new automated flow was successfully implemented in 2022 improving the productivity and quality of the service, achieving a high accuracy and leading to a significant reduction in errors and repetitions while reducing the turnaround time and recollections.
A-350 Myth Debunked: Same UrineAliquot is not Suitable for hCG Test AfterMicroscopic Analysis
Authors: Li X 
Published: September 2023

Abstract

Background
It has been imparted in the laboratories that the suspending fluid, Lamina, from Iris IQ 200 Analyzer system is prone to interfere with urine human chorionic gonadotropin (hCG) test, especially on a small volume urine specimen. The myth is that the sample is diluted or contaminated by Lamina, which gives falsely negative result for hCG test. An add-on urine pregnancy test was ordered for a specimen, which was completed urinalysis and microscopic analysis. This is the only urine aliquot available, and it is approximately 2mL. This order raised many concerns among laboratory technicians regarding the accuracy of the result. However, no documents or articles were found to support the suspicions. In this study, A serial of experiments was completed to address this concern.

Methods
Known pregnant patients were confirmed their pregnancies with serum hCG tests prior to collecting the urine specimens. The experiment was conducted with 4 positive patient urines. A series of samples ran on DXI 800 system and the point-of-care (POC) Alere hCG combo cassettes. Then the same specimen performed urinalysis and microscopic analysis on Iris IQ 200 Analyzer. To evaluate the Lamina impact, the sample concentrations were verified with point-of-care (POC) Alere hCG combo cassettes and later DXI 800 system. Meantime, the significance of sample size was also evaluated in the study.

Results
The final concentrations of the samples were at &lt;5, 5, 10, 15, 20, 25, 30, 40, 50, and 60 mIU/mL. The cutoff for Alere hCG combo cassettes was verified at 20 mIU/mL for urine, the assay gives the accurate result at and above that value. The results are consistent between immunoassay and POCT prior to and after microscopic analysis. Therefore, no significant interferences were identified with the desired sample volume, 3 mL, or short sample volume, 2mL. The volume usage by iQ 200 Analyzer was less than 500 uL.

Conclusion
In this study, Lamina doesn't cause any interference with hCG values using Alere hCG combo cassettes despite the short sample volume. However, variations between POC urinary hCG devices may contribute to different outcomes. Therefore, a separate validation is highly recommended if a different POC urinary hCG device is involved.
A-386 Performance assessment of Point of care testing for blood glucose: a 5 year review of EQA data
Authors: Thomas M A , Davies G , Blount N 
Published: September 2023

Abstract

Introduction
WEQAS is the largest External Quality Assessment (EQA) provider for the Point of Care Testing (POCT) market within the UK supplying samples and assessment to over 30 000 sites per month with over 20 Programmes across the entire Health care sector. All the Programmes are accredited to ISO 17043.The aim of the programme is to provide support to POCT co-ordinators, to identify non compliant sites and improve the analytical performance of users. Most of the programmes are designed to allow the full assessment of all the devices within the organisation at either monthly, bimonthly or quarterly intervals. A Co-ordinator in each organisation is given a Group Administrator function for the EQA website and maintains the database for its own organisation. The role of performance surveillance is therefore devolved to each individual Co-ordinator at a local level and monitored nationally by the EQA organiser. The powerful database gives POCT Co-ordinators a wealth of information on method and analyser performance both within their own organisation and between organisations. Organisation performance summary reports, distribution letters, non-compliance reports, poor performance reports and cumulative reports are generated from one system. The POCT Users are also provided with a simple traffic light system with clear action limits. For the POCT glucose programme one sample is distributed each month with samples covering a range of 2 to 28 mmol/l annually.

Methods
A review of performance was undertaken between January 2018 and January 2023 for the POCT glucose Programmes for a selection of devices. Devices that were no longer available were excluded as were devices with &lt;50 users in the group. This represented data from 10 360 devices per month in 2018 and 12 277 in 2023. Performance was assessed as the coefficient of variation (CV%) for the device group after outlier exclusion and calculated for a wide range of glucose concentrations.

Results
For devices with CV less than 5% in 2018 there was generally no further improvement in performance, however at a glucose of 2 mmol/L an improvement in performance of 0.5to 3.5% was observed for the other devices. In 2018 CVs ranged from 3.7 to 12% and 3.1 to 8.3%% at 2.5 and 26 mmol/L respectively compared with 4 to 10.3% and 3.3 to 7.2% in 2022.

Conclusion
Although there were numerous examples where EQA identified poor performance at an individual user level, there was little evidence to suggest that the performance of POCT glucose devices had improved significantly over the last 5 years.
A-390 Implementation of the New GEM Hemochron 100 Point-of-care Coagulation System for Heparin Monitoring During Cardiopulmonary Bypass Procedures
Authors: Sheffield A , Oldendorp G , Jordan M , Mast D , Losos M , Siddiqui I , Stieglitz H 
Published: September 2023

Abstract

Background
The Ohio State University Wexner Medical Center has monitored the administration of unfractionated heparin (UFH) during cardiopulmonary bypass (CPB) procedures with the activated coagulation time test, using the Hemochron Signature Elite (Elite) instrument (Werfen) with the ACT+ cartridge. An assessment was conducted to evaluate the performance of the newest Hemochron model, the GEM Hemochron 100 (Werfen), to upgrade current instruments.

Methods
Precision and Methods Comparison studies were conducted with nine GEM Hemochron 100 systems. Each GEM Hemochron 100 instrument was analyzed with two levels of directCHECK liquid quality control, five replicates, over four days. The Method Comparison study compared the results from one Elite system's result, against the average result reported from one to three GEM Hemochron 100 systems. This methodology was repeated in multiple groups, using different Elite and GEM Hemochron 100 systems. All tests were performed with the ACT+ assay, which is sensitive to UFH from 1–6 IU/mL.

Results
Precision: All nine GEM Hemochron 100 instruments yielded: Level 1 CV ≤ 9.5%, and Level 2 CV ≤ 2.5%. Method Comparison: Total datasets 66; range 94–902 seconds; estimated bias at the 300, 420, and 480 second ACT+ clinical decision points were 1.6, 3.2, 4.1 seconds respectively; correlation (r) 0.97; slope 1.01; average CV across GEM Hemochron 100 systems 6.0%.

Conclusion
The performance of the new GEM Hemochron 100 system demonstrated acceptable agreement compared to the Elite system during CPB, maintaining existing ACT+ procedural target times. Results of system performance were consistent with the manufacturer's package insert, as well as previously published data. Based on the clinical performance, GEM Hemochron 100 systems have been implemented into our surgical suites.
B-026 Evaluation of Colorimetric and Electrolyte Test Assays on the Fuji Dri-Chem NX700I Clinical Chemistry Analyzer
Authors: Theologou P , Wichert R , Zacchini F , Moennikes R , Wahl H 
Published: September 2023

Abstract

Background
The FUJI DRI-CHEM NX700i holds 28 colorimetric and 3 electrolyte test assays and analyzes up to 190 tests/hour (colorimetry + electrolytes). A STAT testing position is available. The colorimetric method slide is a multilayered slide composed of dry chemical ingredients needed for the reaction quantifying enzymes and substrates by colorimetric methods. The potentiometric method slide contains ion selective film electrodes. Calibration is done with QC cards except for CRP working with a calibrator. Each test needs 10μL of sample except for CRP (5 μL) and ISE (50μL for all 3 tests).

Methods
In this study the Fuji Dri-Chem NX700i was evaluated using serum samples. The parameters investigated were albumin (ALB), blood urea nitrogen (BUN), creatinine (CRE), total bilirubin (TBIL), aspartate aminotransferase (AST/GOT), Alanine Aminotransferase (ALT/GPT), γ-glutamyltransferase (GGT), C-reactive protein (CRP), lipase (LIP), triglycerides (TG) and ammonia (NH3). Interferences from hemolytic, lipemic, icteric or highly elevated total protein samples were excluded according to the manufacturers method specific declarations and studied separately. Method comparison was done by measuring 50 samples for each analyte at the same time on the NX700i and the Siemens Atellica CH analyzer. For each parameter inter- (controls, n = 10) and intra-assay (patient samples, n = 10) coefficients of variation (CV) were calculated for low, medium and high concentrations.

Results
Inter-assay CVs (n = 10) were 1.1 to 7.7% (Low), 0.7 to 3.9% (Medium) and 0.8 to 5.5% (High). Intra-assay CVs (n = 10) were &lt;0.01 to 9.5% (Low), &lt;0.01 to 3.7% (Medium) and 0.7 to 3.3% (High). Method comparison (Passing-Bablok Regression) of routine samples from hospital patients revealed good agreement of the two methods with correlation coefficients of r = 0.98 and higher except for LIP (0.83), NH3 (0.87) and Alb (0.93).

Conclusion
The FUJI DRI-CHEM NX700i shows good intra- and inter-assay precision with low CVs and excellent correlation with the Siemens Atellica CH analyzer.
B-028 Clinical Performance of a Fully-Automated Fecal Calprotectin Chemiluminescence Immunoassay (CLIA)
Authors: Petzke J A , McDermott B , Thienes C , Veenstra K , Wisherd C 
Published: September 2023

Abstract

Background
Fecal calprotectin is a noninvasive marker for inflammatory bowel disease (IBD). Traditionally, calprotectin is measured by the well-established enzyme linked immunosorbent assay (ELISA) method. More recently, advances in fully automated platforms allow for comparable performance and diagnostic accuracy whilst improving laboratory efficiency. In this study, we assessed the diagnostic performance of the fully automated ALPCO calprotectin chemiluminescence immunoassay (CLIA), and compared it to the predicate, ALPCO’s 510(k) cleared manual calprotectin chemiluminescence ELISA.

Methods
Fecal calprotectin levels were measured with the ALPCO Calprotectin Chemiluminescence ELISA and the recently developed ALPCO Calprotectin CLIA, utilizing glow and flash chemiluminescence, respectively. An IRB approved study included over 400 individuals with clinical suspicion of IBD. The estimates of clinical sensitivity, and clinical specificity of the ALPCO Calprotectin Chemiluminescence ELISA and the ALPCO Calprotectin CLIA were determined by comparing analytical test results of the prospectively collected stool specimens against the clinical diagnosis made by the clinical investigator/gastroenterologist with ileocolonoscopic and histopathological sampling (reference standard).

Results
When distinguishing IBD from irritable bowel syndrome (IBS) and healthy persons, the sensitivity (70/76) and specificity (322/348), at a fecal calprotectin cut-off level of 50 µg/g, were 92.1% and 92.5%, respectively for the ALPCO Calprotectin Chemiluminescence ELISA. Sensitivity (73/78) and specificity (319/342), at a fecal calprotectin cut-off level of 50 µg/g, were 93.6% and 93.3%, respectively for the ALPCO Calprotectin CLIA.

Conclusion
The ALPCO Calprotectin CLIA showed comparable clinical performance for detection of IBD compared to the predicate 510(k) cleared ALPCO Calprotectin Chemiluminescence ELISA. The automation of the ALPCO calprotectin immunoassay allows for increased laboratory efficiency without sacrificing diagnostic accuracy.